ACY-241, a histone deacetylase 6 inhibitor, suppresses the epithelial-mesenchymal transition in lung cancer cells by downregulating hypoxia-inducible factor-1 alpha.

Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor activated under hypoxic conditions, and it plays a crucial role in cellular stress regulation. While HIF-1α activity is essential in normal tissues, its presence in the tumor microenvironment represents a significant risk factor as it can induce angiogenesis and confer resistance to anti-cancer drugs, thereby contributing to poor prognoses. Typically, HIF-1α undergoes rapid degradation in normoxic conditions via oxygen-dependent degradation mechanisms. However, certain cancer cells can express HIF-1α even under normoxia. In this study, we observed an inclination toward increased normoxic HIF-1α expression in cancer cell lines exhibiting increased HDAC6 expression, which prompted the hypothesis that HDAC6 may modulate HIF-1α stability in normoxic conditions. To prove this hypothesis, several cancer cells with relatively higher HIF-1α levels under normoxic conditions were treated with ACY-241, a selective HDAC6 inhibitor, and small interfering RNAs for HDAC6 knockdown. Our data revealed a significant reduction in HIF-1α expression upon HDAC6 inhibition. Moreover, the downregulation of HIF-1α under normoxic conditions decreased zinc finger E-box-binding homeobox 1 expression and increased E-cadherin levels in lung cancer H1975 cells, consequently suppressing cell invasion and migration. ACY-241 treatment also demonstrated an inhibitory effect on cell invasion and migration by reducing HIF-1α level. This study confirms that HDAC6 knockdown and ACY-241 treatment effectively decrease HIF-1α expression under normoxia, thereby suppressing the epithelial-mesenchymal transition. These findings highlight the potential of selective HDAC6 inhibition as an innovative therapeutic strategy for lung cancer.

Efficacy of bioactive compounds of Chaihu () on glaucomatous optic atrophy through interleukin-6/hypoxia inducible factor-1α signal pathway.

OBJECTIVE: To investigate the bioactive compounds of Chaihu (Radix Bupleuri Chinensis) (RB) on glaucomatous optic atrophy (GOA), and to study the pharmacological mechanism. METHODS: We collected information on the bioactive compounds of RB from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Targets related to bioactive compounds and GOA were also obtained. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and network analyses were performed to investigate the potential mechanism of RB against GOA. Subsequently, the main bioactive compounds of RB and targets of GOA were docked by Autodock software. Moreover, a GOA model of retinal ganglion cells (RGCs) induced by cobalt chloride was established to verify the effect of RB on GOA. RESULTS: There were 17 main bioactive compounds and 46 key targets were screened as potential players in GOA. The compound-target network mainly contained 17 compounds and 46 corresponding targets, and the key targets consisted of interleukin-6 (IL-6), hypoxia inducible factor-1α (HIF1A), Caspase-3, estrogen receptor alpha (ESR1), MYC proto-oncogene (MYC), and vascular endothelial growth factor A (VEGFA). Forty-nine significantly enriched GO terms, and 134 KEGG signaling pathways were identified (P < 0.05), including HIF-1, tumor necrosis factor, VEGF, prolaction, and other signaling pathways. Molecular docking results showed that the main bioactive compounds of RB exhibited the strongest binding activity with IL-6. Furthermore, experimental validation showed that the RB extract inhibited the activity and promoted apoptosis of RGCs in a dose-dependent manner. The RB extract also suppressed the expression of Bax, Caspase-3, and Caspase-9 and regulated malonaldehyde, superoxide dismutase, and glutathione peroxide by inhibiting the IL-6/HIF-1α signaling pathway. CONCLUSIONS: The present study provided insights into the mechanism of RB on GOA. RB mainly reverses GOA by inhibiting the IL-6/HIF-1α signaling pathway.

Low expression of HIF1AN accompanied by less immune infiltration is associated with poor prognosis in breast cancer.

Background: Hypoxia-inducible factor 1-alpha (HIF-1α) stability and transcriptional action are reduced by the hypoxia-inducible factor 1-alpha subunit suppressor (HIF1AN). Its inappropriate expression is associated with the development of cancer and immune control. It is yet unknown how HIF1AN, clinical outcomes, and immune involvement in breast cancer (BC) are related. Methods: Using the GEPIA, UALCAN, TIMER, Kaplan-Meier plotter, and TISIDB datasets, a thorough analysis of HIF1AN differential expression, medical prognosis, and the relationship between HIF1AN and tumor-infiltrating immune cells in BC was conducted. Quantitative real-time PCR (qRT-PCR) analysis of BC cells were used for external validation. Results: The findings revealed that, as compared to standard specimens, BC cells had significantly lower levels of HIF1AN expression. Good overall survival (OS) for BC was associated with higher HIF1AN expression. Additionally, in BC, the expression of HIF1AN was closely associated with the chemokines and immune cell infiltration, including neutrophils, macrophages, T helper cells, B cells, Tregs, monocytes, dendritic cells, and NK cells. A high correlation between HIF1AN expression and several immunological indicators of T-cell exhaustion was particularly revealed by the bioinformatic study. Conclusions: HIF1AN is a predictive indicator for breast tumors, and it is useful for predicting survival rates.

Expression and role of angiopoietin-like protein 4 signaling pathway in rats with adenine- induced chronic kidney disease / 中华肾脏病杂志

Objective:To observe the expression of angiopoietin-like protein 4 (ANGPTL4) signaling pathway in adenine-induced chronic kidney disease (CKD) rat model, and to explore the role of this pathway in renal fibrosis.Methods:Thirty-six male Sprague-Dawley rats were randomly divided into control group (saline, intragastric administration, n=15) and CKD group (250 mg·kg -1·d -1 2.5% adenine, intragastric administration, n=21). At the end of the 1st, 2nd and 4th week, 5 rats were randomly selected from each group. Renal function and 24-hour urinary protein quantity were measured. HE and Masson staining were used to observe the pathological changes of kidneys. Immunohistochemistry and real-time PCR were used to detect renal protein and mRNA expressions of hypoxia-inducible factor-1α (HIF-1α), ANGPTL4, bone morphogenetic protein 7 (BMP7), Smad1, α-smooth muscle actin (α-SMA) and type Ⅰ collagen (Col-Ⅰ). Pearson correlation analysis was used to analyze the correlation between the different indicators. Results:(1) Compared with the control group, the expression levels of serum creatinine and blood urea nitrogen in CKD group were higher at each time point, and the expression levels of 24-hour urinary protein quantity were higher at the end of the 2nd and 4th week (all P < 0.05). (2) HE and Masson staining showed that there were obvious renal structural disorders and collagen fiber deposition at each time point in CKD group compared with the control group, which got worse with time. (3) The results of immunohistochemistry and real-time PCR showed that compared with the control group, the protein and mRNA expression levels of ANGPTL4, α-SMA and Col-Ⅰ were higher, while the protein and mRNA expression levels of BMP7 and Smad1 were lower at the end of the 1st, 2nd and 4th week, and the protein and mRNA expression levels of HIF-1α were higher at the end of 2nd and 4th week in CKD group (all P < 0.05). (4) Correlation analysis results showed that HIF-1α and ANGPTL4 mRNA expression were positively correlated with α-SMA mRNA ( r=0.919, P < 0.001; r=0.757, P < 0.001), and also positively correlated with Col-Ⅰ mRNA ( r=0.925, P < 0.001; r=0.777, P < 0.001). HIF-1α mRNA expression was positively correlated with ANGPTL4 mRNA ( r=0.766, P < 0.001). There were significant negative correlations between HIF-1α, ANGPTL4 mRNA and BMP7 mRNA ( r=-0.652, P < 0.001; r=-0.741, P < 0.001). Conclusions:ANGPTL4 signaling pathway may be activated in adenine-induced CKD rat model, and involved in the renal fibrosis process of CKD.

Overexpression of HIF1α in Hunner Lesions of Interstitial Cystitis: Pathophysiological Implications.

PURPOSE: The aim of our study was to elucidate biological changes in Hunner lesions, which underlie the pathophysiology of Hunner-type interstitial cystitis, by characterizing their whole transcriptome and immunopathological profiles. MATERIALS AND METHODS: Paired bladder mucosal biopsies, 1 sample each from the Hunner lesion and nonlesion area, were obtained from 25 patients with Hunner-type interstitial cystitis. The samples were subjected to whole-transcriptome profiling; immunohistochemical quantification of CD3, CD4, CD8, CD20, CD138, mast cell tryptase, cytokeratin and HIF1α; and quantitative polymerase chain reaction for IFN-α, IFN-ß, IFN-γ, TNF, TGF-ß1, HIF1α, IL-2, IL-4, IL-6, IL-10 and IL-12A. The results were compared between the lesion and nonlesion areas. RESULTS: RNA sequencing identified 109 differentially expressed genes and 30 significantly enriched biological pathways in Hunner lesions. Up-regulated pathways (24) included HIF1α signaling pathway, PI3K-Akt signaling pathway, RAS signaling pathway and MAPK signaling pathway. By contrast, down-regulated pathways (6) included basal cell carcinoma and protein digestion and absorption. The mRNA levels of HIF1α, IFN-γ and IL-2, and the HIF1α protein level were significantly higher in lesion areas. Otherwise, there were no significant differences between the lesion and nonlesion samples in terms of mRNA levels of inflammatory cytokines or histological features such as lymphoplasmacytic and mast cell infiltration, epithelial denudation and CD4/CD8 T-lymphocyte ratio. CONCLUSIONS: Our findings demonstrate significant overexpression of HIF1α and up-regulation of its related biological pathways in Hunner lesions. The results indicate that ischemia, in conjunction with inflammation, plays a pathophysiological role in this subtype of interstitial cystitis/bladder pain syndrome, particularly in Hunner lesions.

Role of HIF-1α/BNIP3 signaling pathway in dexmedetomidine-induced reduction of myocardial ischemia-reperfusion-induced brain injury in mice / 中华麻醉学杂志

Objective:To evaluate the role of hypoxia-inducible factor-1α (HIF-1α)/Bcl-2/E1B 19-kDa interacting protein 3 (BNIP3) signaling pathway in dexmedetomidine-induced reduction of myocardial ischemia-reperfusion (I/R)-induced brain injury in mice.Methods:Sixty clean-grade healthy male C57BL/6 mice, aged 8-10 weeks, weighting 20-30 g, were divided into 5 groups ( n=12 each) using a random number table method: sham operation group (S group), myocardial I/R group (IR group), myocardial I/R plus dexmedetomidine group (IRD group), myocardial I/R plus HIF-1α inhibitor 2ME2 group (IR-M group), and myocardial I/R plus dexmedetomidine plus HIF-1α inhibitor 2ME2 group (IRD-M group). The myocardial I/R-induced brain injury was produced by ligating the left anterior descending coronary artery for 30 min followed by 2 h of reperfusion in anesthetized mice.Dexmedetomidine 50 μg/kg was intraperitoneally injected at 5 min before ischemia in IRD group and IRD-M group.In IR-M and IRD-M groups, 2ME2 15 mg/kg was intraperitoneally injected at 5 min before ischemia.Blood samples were collected from the thoracic aorta at 2 h of reperfusion to measure the serum S-100β protein and neuron-specific enolase (NSE) concentrations.The animals were then sacrificed, brains were removed and hippocampi were obtained for determination of the apoptosis index (by TUNEL method) and expression of HIF-1α, BNIP3, Beclin-1, microtubule-associated protein 1 light chain 3 (LC3) and phosphorylated Tau protein (p-Tau) (by Western blot) and for microscopic examination of the pathological changes in hippocampal CA1 region.LC3Ⅱ/Ⅰ ratio was calculated. Results:Compared with group S, the concentrations of serum S-100β protein and NSE and apoptosis index of hippocampal neurons were significantly increased, the expression of HIF-1α, BNIP3, Beclin-1 and p-Tau was up-regulated, LC3Ⅱ/Ⅰ ratio was increased ( P<0.05), and the pathological changes in hippocampal CA1 region were aggravated in group IR.Compared with group IR, the concentrations of serum S-100β protein and NSE and apoptosis index of hippocampal neurons were significantly decreased, the expression of HIF-1α, BNIP3 and Beclin-1 was up-regulated, the expression of p-Tau was down-regulated, and LC3Ⅱ/Ⅰ ratio was increased ( P<0.05), and the pathological changes in hippocampal CA1 region were significantly attenuated in group IRD.Compared with group IRD, the concentrations of serum S-100β protein and NSE and apoptosis index of hippocampal neurons were significantly increased, the expression of p-Tau was up-regulated, the expression of HIF-1α, BNIP3 and Beclin-1 was down-regulated, LC3Ⅱ/Ⅰ ratio was decreased ( P<0.05), and the pathological changes in hippocampal CA1 region were aggravated in IR-M and IRD-M groups. Conclusions:HIF-1α/BNIP3 signaling pathway is involved in dexmedetomidine-induced reduction of myocardial I/R-induced brain injury in mice.

Expressions and significances of silent information regulator 1, hypoxia-inducible factor-1α and mutant P53 proteins in colorectal adenocarcinoma / 肿瘤研究与临床

Objective:To investigate the expression levels of silent information regulator 1 (SIRT1), hypoxia-inducible factor-1α (HIF-1α) and mutant P53 proteins in colorectal adenocarcinoma tissues and their clinical significances.Methods:The data of 68 cases of colorectal adenocarcinoma confirmed by pathology in Shanxi Traditional Chinese Medical Hospital from March 2015 to October 2021 were collected. The expressions of SIRT1, HIF-1α and mutant P53 proteins in colorectal adenocarcinoma tissues and paracancerous tissues were determined by immunohistochemistry. The correlation among SIRT1, HIF-1α and mutant P53 proteins and their relationship with clinicopathological features of patients were analyzed.Results:Among 68 colorectal adenocarcinoma tissues and paracancerous tissues, SIRT1 protein was positive in 38 cases (55.88%) and 11 cases (16.18%) ( χ2 = 23.25, P < 0.001), HIF-1α protein was positive in 47 cases (69.12%) and 5 cases (7.35%) ( χ2 =54.92, P < 0.001), and mutant P53 protein was positive in 41 cases (60.29%) and 0 cases (0) ( P < 0.001). The positive expression rate of SIRT1 protein was high in patients with high clinical stage and lymph node metastasis (both P < 0.05); the positive expression rate of HIF-1α protein was high in patients with poor differentiation ( P < 0.05); the positive expression rate of mutant P53 protein was high in patients with poor differentiation and lymph node metastasis (both P < 0.05). There was a negative correlation between expressions of SIRT1 and mutant P53 proteins ( rs = -0.38, P = 0.001); there was a positive correlation between expressions of HIF-1α and mutant P53 proteins ( rs = 0.56, P < 0.001); there was a negative correlation between expressions of SIRT1 and HIF-1α proteins ( rs = -0.40, P = 0.001). Conclusions:SIRT1, HIF-1α and mutant P53 proteins are highly expressed in colorectal adenocarcinoma and are correlated with clinicopathological features suggesting poor prognosis. Combined detection of the three proteins may be used for the diagnosis and prognosis of colorectal adenocarcinoma and serve as a new target for treatment.

Hypoxia-inducible factor 1α affects the migration and invasion of hypoxia-inducible pancreatic cancer cells through regulating miRNA-296-5p / 肿瘤研究与临床

Objective:To investigate the effect of miRNA-296-5p (miR-296-5p) on the migration and invasion of hypoxia-induced pancreatic cancer cells and its related mechanisms.Methods:Human pancreatic cancer cell line PANC-1 was selected. Pancreatic cancer tissues from 55 pancreatic cancer patients who underwent the resection and adjacent carcinoma normal pancreatic tissues from 10 patients at Shanghai Fengxian District Central Hospital and Bengbu Medical College First Affiliated Hospital between January 2010 and December 2014 were collected. The expression levels of hypoxia-inducible factor 1α (HIF-1α) and miR-296-5p in tissue microarray of pancreatic cancer and adjacent carcinoma normal pancreatic tissues were detected by using immunohistochemistry and in situ hybridization. The relationship between miR-296-5p and HIF-1α as well as their correlation with clinicopathological characteristics of patients were analyzed. PANC-1 cells were divided into hypoxic group and normoxic group. Transwell assay was used to detect the cell migration and invasion ability of both groups. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to examine the expressions of HIF-1α and miR-296-5p under hypoxic environment of both groups. The expression of HIF-1α was interfered by transfecting small interfering RNA (siRNA). PANC-1 cells were divided into PANC-1 group (the empty control), PANC-1-NC group (the negative control) and PANC-1-siRNA group. The expression of miR-296-5p was measured. After co-transfecting miR-296-5p agonist and miR-296-5p inhibitor, the cells were divided into Agomir-miR-296-5p group (agonist group), Agomir-miR-296-5p-NC group (agonist negative control group), Antagomir-miR-296-5p group (inhibitor group) and Antagomir-miR-296-5p-NC group (inhibitor negative control group). Transwell assay was used to detect the cell migration and invasion ability of all groups. Luciferase reporter gene system was used to verify whether miR-296-5p promoter region had binding site of HIF-1α.Results:The high expression rate of HIF-1α in pancreatic cancer tissues was higher than that of adjacent carcinoma normal pancreatic tissues [81.8% (45/55) vs. 0 (0/10), P<0.01], and the high expression rate of miR-296-5p in pancreatic cancer tissues was lower than that of adjacent carcinoma normal pancreatic tissues [12.7% (7/55) vs. 90.0% (9/10), χ2 = 27.23, P<0.01]. The expression of HIF-1α was negatively correlated with that of miR-296-5p ( r = -0.53, P<0.01). The low expression of miR-296-5p was closely related with the tumor diameter, TNM staging, lymph node metastasis (all P<0.05). The number of PANC-1 invasion cell was 15.3±2.1 in normoxic group and 24.7±1.5 in hypoxic group, and the difference was statistically significant ( t = 0.26, P = 0.003). The number of PANC-1 migration cell was 20.7±3.8 in hypoxic group and 32.7±1.2 in normoxic group, and the difference was statistically significant ( t = 5.25, P = 0.006). The relative expression level of HIF-1α mRNA in PANC-1 cell of hypoxic group was higher than that of normoxic group [(1.00±0.01) vs. (0.30±0.02)], and the difference was statistically significant ( t = 56.45, P<0.01); the relative expression level of miR-296-5p in PANC-1 cell of hypoxic group was lower than that of normoxic group [(1.14±0.04) vs. (3.05±0.20)], and the difference was statistically significant ( t = 16.05, P<0.01). The number of invasion cells in PANC-1 group, PANC-1-NC group and PANC-1-siRNA group was 24.7±1.5, 25.7±1.5, 12.0±1.7, respectively, and the difference was statistically significant ( F = 68.13, P<0.01).The cell invasion ability in PANC-1-siRNA group was decreased compared with that in PANC-1 group ( t = 9.50, P = 0.001). The number of cell migration was 32.7±1.2, 37±1.0, 17.3±1.2, respectively in PANC-1 group, PANC-1-NC group and PANC-1-siRNA group, and the difference was statistically significant ( F = 262.09, P<0.01). The cell migration ability in PANC-1-siRNA group was decreased compared with that in PANC-1 group ( t = 16.26, P<0.01). The cell invasion and migration ability in Antagomir-miR-296-5p group was increased compared with that in PANC-1 group (all P<0.05); the cell invasion and migration ability in Agomir-miR-296-5p group was decreased compared with that in PANC-1 group (all P<0.05). The results of luciferase activity detected by luciferase reporter gene system showed that miR-296-5p had the target binding to HIF-1α. Conclusions:HIF-1α plays a key role in the invasion and migration of hypoxia-induced pancreatic cancer cells through negatively reducing miR-296-5p.

Effect of pomegranate peel polyphenols on mTOR/HIF-1α/IL-17 signaling pathway in a rat auriclular model of acne / 中华皮肤科杂志

Objective:To explore the anti-inflammatory effect of pomegranate peel polyphenols on a rat auriclular model of acne and its mechanism of action.Methods:Totally, 36 specific-pathogen-free SD rats were randomly divided into 6 groups: blank group, model group, low-, medium- and high-dose pomegranate peel polyphenol groups and positive control group. In all groups except the blank group, 0.5 ml of 100% oleic acid was applied to the openings of bilateral auricular ducts once a day for 3 consecutive weeks, followed by subcutaneous injections of 50 μl of Propionibacterium acnes suspension at the oleic acid-applied sites once a day for 3 consecutive days, so as to establish a rat auriclular model of acne. After the model was confirmed to be successfully established by naked eyes, the low-, medium-, high-dose pomegranate peel polyphenol groups were topically treated with 0.5 mg of 1.4%, 2.8%, 5.6% (mass fraction) pomegranate peel polyphenol ointment respectively, the positive control group was topically treated with 0.5 mg of clindamycin hydrochloride gel, and the blank group and model group were topically treated with the same amount of distilled water. All the topical treatments were performed twice a day for 2 consecutive weeks. Twenty-four hours after the last topical treatment, abdominal aortic blood samples were collected, and enzyme-linked immunosorbent assay (ELISA) was conducted to detect the serum level of interleukin 17 (IL-17) in rats; rat auricular tissues were resected, hematoxylin-eosin (HE) staining was performed to observe histopathological changes of the skin tissues in each group, and immunohistochemical study to determine the expression of mammalian target of rapamycin (mTOR) , hypoxia-inducible factor-1α (HIF-1α) , and retinoic acid-related orphan receptor-γt (RORγt) in local tissues. Data meeting the assumptions of homogeneity of variances were analyzed by using one-way analysis of variance, and those that did not meet the assumptions of homogeneity of variances were analyzed by using Kruskal-Wallis H test; multiple comparisons were performed by using least significant difference- t test. Results:Compared with the model group, the pomegranate peel polyphenol groups and positive control group showed marked improvement in cysts, desquamation, crusts and epidermal keratinization, and reduced infiltration with inflammatory factors in the dermis at the modeling site. The serum level of IL-17 was significantly lower in the low-, medium- and high-dose pomegranate peel polyphenol groups (61.03 ± 5.99 ng/L, 55.35 ± 2.24 ng/L, 54.35 ± 4.29 ng/L, respectively) , positive control group (48.11 ± 4.07 ng/L) and blank group (42.10 ± 5.62 ng/L) than in the model group (70.24 ± 3.30 ng/L; t = 3.12, 5.34, 5.70, 8.29, 10.54, respectively, all P<0.05) . Immunohistochemical study revealed that the HIF-1α expression level was significantly lower in the low-, medium- and high-dose pomegranate peel polyphenol groups (0.29 ± 0.05, 0.29 ± 0.03, 0.33 ± 0.02, respectively) and positive control group (0.30 ± 0.01) than in the model group (0.41 ± 0.04; t = 4.89, 5.50, 3.62, 5.21, respectively, all P<0.05) ; the RORγt expression level was significantly lower in the low- and high-dose pomegranate peel polyphenol groups (0.28 ± 0.02, 0.31 ± 0.04, respectively) than in the model group (0.35 ± 0.02, t = 3.68, 2.18, respectively, both P<0.05) ; there was no significant difference in the mTOR expression level among these groups ( P = 0.119) . Conclusion:Pomegranate peel polyphenols could improve inflammatory reactions in the rat auriclular model of acne, which may be related to the down-regulation of HIF-1α/RORγt signaling pathway.

Expression of silent information regulator 1 and 3 and hypoxia-inducible factor 1α in cutaneous squamous cell carcinoma tissues and cells / 中华皮肤科杂志

Objective:To determine the expression of silent information regulator 1 (Sirt1) , Sirt3 and hypoxia-inducible factor 1α (HIF-1α) in cutaneous squamous cell carcinoma (CSCC) tissues and cells, and to explore their role in the occurrence and development of CSCC.Methods:From January 2019 to December 2020, 30 lesional skin tissues were obtained from patients with histopathologically confirmed poorly-, moderately- or well-differentiated CSCC, and 30 normal skin tissues were obtained from patients with non-cancerous diseases in Department of Dermatology, General Hospital of Ningxia Medical University. A CSCC cell line A431 and a human keratinocyte cell line HaCaT were cultured. Immunohistochemical study, Western blot analysis and real-time quantitative PCR (RT-PCR) were performed to determine the protein and mRNA expression of Sirt1, Sirt3 and HIF-1α in CSCC tissues of different grades of differentiation and normal skin tissues, cytochemical and immunofluorescence staining and RT-PCR were conducted to determine the protein and mRNA expression of Sirt1, Sirt3 and HIF-1α in A431 and HaCaT cells, respectively. Comparisons of measurement data among multiple groups were performed by using one-way analysis of variance, and comparisons between two groups by using t test. Results:Immunohistochemical study showed that the expression level of Sirt3 (expressed as the average optical density) was 100 ± 12.12, 117.72 ± 26.23, 127.32 ± 24.45, 132.71 ± 31.61 in the normal skin tissues and well-, moderately- and poorly-differentiated CSCC tissues respectively, and there was a significant difference among these groups ( F = 20.14, P < 0.001) ; the expression of Sirt1 and HIF-1α increased in turn from the normal skin tissues to the well-, moderately- and poorly-differentiated CSCC tissues, and significantly differred in these groups ( F = 174.50, 225.00, respectively, both P < 0.001) . As Western blot analysis revealed, the expression level of Sirt3 significantly differed among the normal skin tissues, well-, moderately- and poorly-differentiated CSCC tissues (expressed as relative gray value: 1.000 ± 0.132, 1.403 ± 0.411, 1.387 ± 0.393, 1.677 ± 0.683, respectively; F = 34.97, P < 0.001) , and so did the expression levels of Sirt1 and HIF-1α ( F = 69.29, 199.90, respectively, both P < 0.00l) , with a gradually increasing trend in their expression levels from the the normal skin tissues to well-, moderately- and poorly-differentiated CSCC tissues. RT-PCR showed that the mRNA expression of Sirt3, Sirt1 and HIF-1α was sequentially increased from the normal skin tissues to well-, moderately- and poorly-differentiated CSCC tissues, and significant differences were observed among these groups ( F = 113.00, 174.50, 50.33, respectively, all P < 0.001) . The protein expression levels of Sirt3, Sirt1 and HIF-1α were significantly higher in the A431 cells than in the HaCaT cells ( t = 16.75, 18.34, 27.76, respectively, all P < 0.001) , and so were their mRNA expression levels ( t= 14.22, 9.62, 16.86, respectively, all P < 0.001) . Conclusion:Increased expression of Sirt3, Sirt1 and HIF-1α was observed in CSCC tissues and cells, which may promote the occurrence and development of CSCC.

[Early constant observation of the effect of deferoxamine mesylate on improvement of vascularized bone regeneration in SD rat skull critical size defect model].

OBJECTIVE: To investigate the effect of local administration of deferoxamine mesylate (DFO) on vascularization and osteogenesis and its ability to maintain the activity of hypoxia inducible factor-1α (HIF-1α), by constantly observing early changes of vessel-like structures and bone tissues during bone defects healing. METHODS: Skull critical bone defect models were constructed on a total of thirty male SD rats (6-8 weeks old). The rats were randomly divided into experimental group (DFO group) or control group (normal saline group). 300 µL 200 µmol/L DFO solution or normal saline was locally injected on the 4th day after the defect was made. On the 5th, 7th, 10th, 14th, and 28th days after surgery, three rats in each group were sacrificed respectively. HE staining and Masson staining were performed to observe new bone formation and mineralization. HIF-1α immunohistochemistry staining was performed to examine relative expression of protein. Qualitative analysis and comparation were performed by t-tests on relative expression of HIF-1α, numbers of blood vessels and percentages of mineralization tissues of new bone areas. RESULTS: On the 5th, 7th, 10th, 14th and 28th days after surgery, the average numbers of blood vessels were 30.40±12.15, 62.00±17.87, 73.43±15.63, 40.00±7.84, 48.71±11.64 in the DFO group, and 18.75±6.63, 19.13±2.80, 51.35±16.21, 27.18±7.32, 30.88±13.43 in the control group. The number of blood vessels in the DFO group was significantly higher than that of the control group at each time point (P < 0.05). The mass of new bone in the DFO group was higher than that in the control group on the 14th and 28th days after surgery. The percentage of mineralization tissues of new bone area on the 14th and 28th days after injection were (27.73±5.93)% and (46.53±3.66)% in the DFO group, and (11.99±2.02)% and (31.98±4.22)% in the control group. The percentage of mineralization tissues in the DFO group was significantly higher than that of the control group at each time point (P < 0.001). The relative expression of HIF-1α in the DFO group compared with the control group was 2.86±0.48, 1.32±0.26, 1.32±0.32, 1.28±0.38 and 1.05±0.34 on the 5th, 7th, 10th, 14th and 28th days, with significant expression difference on the 5th day (P < 0.01). CONCLUSION: Use of DFO in bone defects promotes vascularization and osteogenesis in the defect area, and maintains the protein activity of HIF-1α temporarily.

Efficacy of Shouzhangshen (Rhizoma Gymnadeniae Crassinervidis) extract against acute high altitude hypoxia-induced brain injury in mice.

OBJECTIVE: To evaluate the protective effect of Shouzhangshen (Rhizoma Gymnadeniae Crassinervidis) extract against acute high altitude hypoxia-induced brain injury in mice. METHODS: Sixty C57BL/6J mice were selected and assigned to six groups (n = 10): normal control group, low-pressure hypoxia group, positive control group (dexamethasone 500 mg/kg), and three groups treated with Shouzhangshen extract (250, 500, and 750 mg/kg, respectively). The Morris water maze test was performed to evaluate alterations in spatial learning and memory deficits. Nissl staining was performed to detect Nissl bodies and neuron damage. Hypoxia-inducible factor (HIF)-1α, interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), and malondialdehyde (MDA) expression in brain tissue and serum, as well as superoxide dismutase (SOD) and glutathione (GSH) activity in brain tissues were measured by enzyme-linked immunosorbent assays, quantitative real-time-polymerase chain reaction and western blots. RESULTS: The Morris water maze test results showed that Shouzhangshen extract can significantly reduce the latency and swimming distance to escape onto a visible platform, increase neuron density and hierarchy and the number of pyramidal neurons, and decrease the expression of HIF-1α, IL-1ß, TNF-α, and VEGF mRNAs and proteins in both brain tissue and serum (P < 0.05). Furthermore, significantly lower MDA expression and higher GSH activity were detected in the three groups treated with Shouzhangshen compared with the low-pressure hypoxia group (P < 0.05). However, no significant alteration was observed for SOD activity (P > 0.05). CONCLUSION: Our findings suggest that Shouzhangshen extract may have a significant effect on acute high altitude hypoxia-induced brain injury in mice.

Effects of moderate-intensity intermittent hypoxic training on health outcomes of patients recovered from COVID-19: the AEROBICOVID study protocol for a randomized controlled trial.

BACKGROUND: Recent studies point to a lower number and reduced severity of cases in higher altitude cities with decreased oxygen concentration. Specific literature has shown several benefits of physical training, so, in this sense, physical training with hypoxic stimulus appears as an alternative that supports the conventional treatments of the COVID-19 patient's recovery. Thus, this study's primary aim is to analyze the effects of moderate-intensity intermittent hypoxic training on health outcomes in COVID-19 recovered patients. METHODS: A clinical trial controlled double-blind study was designed. Participants (30-69 years old) will be recruited among those with moderate to severe COVID-19 symptoms, approximately 30 days after recovery. They will be included in groups according to the training (T) and recovery (R) association with hypoxia (H) or normoxia (N): (a) TH:RH, (b) TN:RH, (c) TN:RN, and last (d) the control group. The 8-week exercise bike intervention will be carried out with a gradual load increase according to the established periods, three times a week in sets of 5 min, 90 to 100% of the anaerobic threshold (AT), and a 2.5-min break. Blood will be collected for genotyping. First, after 4 weeks (partial), after 8 weeks, and later, 4 weeks after the end of the physical training intervention, participants will perform assessments. The primary outcome is the maximum oxygen consumption (VO2peak). The secondary outcomes include lung function, inflammatory mediators, hematological, autonomic parameters, AT, body composition analysis, quality of life, mental health, anthropometric measurements, and physical fitness. The statistical analysis will be executed using the linear regression model with mixed effects at a 5% significance level. DISCUSSION: This study is designed to provide evidence to support the clinical benefits of moderate-intensity intermittent hypoxic training as a part of the treatment of patients recovered from COVID-19. It may also provide evidence on the efficacy and safety of intermittent hypoxic training in different health conditions. Lastly, this study presents an innovative strategy enabling up to 16 participants in the same training session. TRIAL REGISTRATION: ClinicalTrials.gov RBR-5d7hkv. Registered after the start of inclusion on 3 November 2020 with the Brazilian Clinical Trials Registry.

Effect of hypoxia-inducible factor-1α on stemness and epirubicin sensitivity of HepG2 hepatoma cells / 临床肝胆病杂志

ObjectiveTo investigate the effect of hypoxia-inducible factor-1α (HIF-1α) on the stemness and epirubicin sensitivity of hepatoma cells. MethodsHepatoma cells were selected for experiment. HepG2 hepatoma cells transfected with HIF-1α overexpression plasmid were selected as experimental group, and those transfected with pcDNA3.1 empty plasmid were selected as control group; HepG2 cells alone were selected as HepG2 group. Quantitative real-time PCR was used to measure the mRNA expression of HIF-1α; Western blot was used to measure the protein expression of HIF-1α; flow cytometry was used to measure the expression of CD133 on the surface of hepatoma cells. The three groups of cells were treated with epirubicin at different concentrations (0, 6.25, 12.5, 25, and 50 μmol/L) for 24 hours; MTT assay was used to measure cell viability, and flow cytometry was used to measure apoptosis after treatment with epirubicin (50 μmol/L). A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the t-test was used for further comparison between two groups. ResultsCompared with the HepG2 group and the control group, the experimental group had a significant increase in the mRNA expression of HIF-1α (both P＜0.001), and Western blot showed high expression of HIF-1α in the experimental group. The percentage of CD133 cells was 0.040%±0.003% in the HepG2 group, 0.030%±0.010% in the control group, and 20.110%±0.600% in the experimental group, and the experimental group had a significantly higher positive rate of CD133+ than the HepG2 group and the control group (both P＜0.001). At an epirubicin concentration of 25 and 50 μmol/L, the HepG2 group and the control group had significantly inhibited cell viability and a significantly lower cell viability than the experimental group (both P＜005). After the treatment with 50 μmol/L epirubicin for 48 hours, the experimental group had a significantly lower cell apoptosis rate than the HepG2 group (67.9%±2.5% vs 93.6%±1.5%, P＜0.001) and the control group (67.9%±2.5% vs 93.0%±1.2%, P＜0001). ConclusionHepG2 cells are successfully transfected with HIF-1α overexpression plasmid, and HIF-1α can increase the percentage of liver cancer stem cells and improve their resistance to epirubicin.

Research status and progress of hypoxia-inducible factor on the regulation of diabetic retinopathy / 中华眼底病杂志

The intervention therapy targeting vascular endothelial growth factor (VEGF) has become a specific and effective method for the treatment of diabetic retinopathy (DR). However, some patients did not respond or responded poorly to anti-VEGF therapy, and its effects of eliminating edema and improving vision appear to be unstable in the same patient. Hypoxia-inducible factor-1α (HIF-1α), an important upstream transcriptional regulator of VEGF, is an oxygen concentration-sensitive protein expressed in tissues under hypoxia. It can simultaneously target many downstream target genes except VEGF, such as placental growth factor and angiopoietin-like protein 4, to cause blood-retinal barrier damage and neovascularization, and thus participate in various pathological changes of DR to promote the occurrence and development of DR. Therefore, direct intervention of HIF-1α or targeting one or more downstream target genes regulated by HIF-1α to treat DR may have better efficacy. In the future, the development of effective and safe HIF inhibitors or anti-VEGF with HIF-1α other target gene inhibitors may have broader clinical application prospects.

Expression and function of hypoxia-inducible factor 1 alpha signaling pathway in aortic calcification in rats with chronic kidney disease / 中华肾脏病杂志

Objective:To observe the expression of hypoxia-inducible factor 1 alpha (HIF-1α) signaling pathway in the aorta of chronic kidney disease (CKD) rats with vascular calcification and to explore the role of this pathway in aortic calcification of CKD.Methods:Forty 8-week-old male SD rats were randomly divided into control group (CON group, n=15) and CKD with aortic calcification group (CKD+AC group, n=25). The rats were sacrificed at the end of 4 th, 6 th and 8 th week respectively and urine, blood, aorta and kidney samples were collected. The level of serum HIF-1α was tested by ELISA. The pathology changes of kidney were observed by HE staining. The aortic calcification was evaluated by alizarin red staining and calcium content detection. Immunohistochemistry and real-time PCR were applied to detect the protein and mRNA expression of alpha-smooth muscle actin (α-SMA), Runt-related transcription factor 2 (Runx2), HIF-1α, vascular endothelial growth factor A (VEGFA) and Notch1 in the aorta. Results:Compared with CON group, serum urea, creatinine, cystatin C, phosphorus, calcium-phosphorus product and 24-h urine protein were significantly higher in CKD+AC group (all P<0.05). Serum HIF-1α levels were higher at 4 th and 8 th week in CKD+AC group than that in CON group (both P<0.05). There was no significant calcium deposit in the aorta of the CON group at all time points, and calcium deposits were seen in the aorta of the CKD+AC rats at each time point, which gradually increased with time. Compared with CON group, the expressions of aortic α-SMA protein and mRNA were significantly decreased in CKD+AC group at each time point, however the protein and mRNA expressions of Runx2, HIF-1α, VEGFA and Notch1 in the aorta of CKD+AC group rats were markedly increased at each time point (all P<0.05). Correlation analysis showed that the aortic calcium content was positively correlated with serum HIF-1α ( r=0.706, P<0.001) and the protein expressions of HIF-1α ( r=0.852, P<0.001), VEGFA ( r=0.747, P<0.001) and Notch1 ( r=0.813, P<0.001) in aorta. Conclusion:The HIF-1α-VEGFA-Notch1 signaling pathway is activated during aortic calcification in CKD rats, suggesting that this signaling pathway might be involved in the vascular calcification in CKD, and serum HIF-1α is expected to be one of serum markers for CKD vascular calcification.

Role of HIF-1α in renal injury induced by myocardial ischemia-reperfusion in diabetic rats: relationship with SLC7A11 / 中华麻醉学杂志

Objective:To evaluate the role of hypoxia-inducible factor-1α (HIF-1α) in the renal injury induced by myocardial ischemia-reperfusion (I/R) in diabetic rats and its relationship with solute carrier family7 member11 (SLC7A11).Methods:SPF-grade healthy male Sprague-Dawley rats, aged 4 weeks, weighing 100-130 g, were fed with high-fat and high-sucrose diet freely.The weight of the rats was measured once a week.After the weight of the animals reached 240 g, 1% streptozotocin (STZ)-citrate buffer 35 mg/kg was injected intraperitoneally to induce type 2 diabetes mellitus.After injection of STZ, the animals were fed with high-fat and high-sucrose diet continuously.Blood samples were collected from the tail vein for determination of blood glucose concentrations 1 week later.When random blood glucose was ≥16.7 mmol/L for 3 times, the model of type 2 diabetes mellitus was considered to be established successfully.After the model was established successfully, the animals were fed with high-fat and high-sucrose diet continuously for 6 weeks.Eighteen rats with type 2 diabetes mellitus were selected and divided into 3 groups ( n=6 each) using a random number table method: diabetic sham operation group (group DS), diabetic myocardial I/R group (group DIR) and diabetic myocardial I/R+ HIF-1α agonist DMOG group (DIR+ DMOG group). Twelve non-diabetic rats were divided into 2 groups ( n=6 each) using a random number table method: non-diabetic sham operation group (NS group) and non-diabetic myocardial I/R group (NIR group). The rat myocardial I/R injury model was established by ligating the anterior descending branch of the left coronary artery for 30 min followed by 120 min reperfusion in anesthetized rats.Blood samples were collected from the right internal carotid artery at 120 min of reperfusion for determination of the serum creatinine (Cr), urea nitrogen (BUN) and neutrophil gelatinase-associated lipocalin (NGAL) concentrations (by enzyme-linked immunosorbent assay). Renal tissues were obtained for examination of the pathological changes (by HE staining method) and for determination of the expression of HIF-1α and SLC7A11 (by Western blot). The damage to the renal tubules was scored. Results:Compared with group NS, the concentrations of serum Cr, BUN and NGAL and renal tubular damage score were significantly increased in group DS and group NIR, the expression of HIF-1α and SLC7A11 was down-regulated in group DS, and the expression of HIF-1α and SLC7A11 was up-regulated in group NIR ( P<0.05). Compared with group DS, the concentrations of serum Cr, BUN and NGAL and renal tubular damage score were significantly increased, and the expression of HIF-1α and SLC7A11 was up-regulated in group DIR ( P<0.05). Compared with group NIR, the concentrations of serum Cr, BUN and NGAL and renal tubular damage score were significantly increased, and the expression of HIF-1α and SLC7A11 was down-regulated in group DIR ( P<0.05). Compared with group DIR, the concentrations of serum Cr, BUN and NGAL and renal tubular damage score were significantly decreased, and the expression of HIF-1α and SLC7A11 was up-regulated in group DIR+ DMOG ( P<0.05). Conclusion:HIF-1α is involved in the renal injury induced by myocardial I/R, which is related to regulation of the expression of SLC7A11 in rats.

Prediction of adverse cardiovascular events in patients with acute ST-elevation myocardial infarction after percutaneous coronary intervention / 中国基层医药

Objective:To investigate the application value of combined detection of hypoxia-inducible factor-1α (HIF-1α), N-terminal proBNP (NT-proBNP) and thromboxane B 2 (TXB 2) in the prediction of major adverse cardiovascular events (MACE) after percutaneous coronary intervention (PCI) in patients with acute ST-elevation myocardial infarction. Methods:The clinical data of 136 patients with acute ST-elevation myocardial infarction who received treatment in Jinhua Municipal Central Hospital, China between February 2018 and September 2019 were retrospectively analyzed. These patients were assigned to MACE group ( n = 33) and no MACE group ( n = 103) according to whether MACE occurred. The basic data was compared between the two groups. Serum levels of HIF-1α, NT-proBNP and TXB 2 prior to PCI were analyzed. The receiver operating characteristic (ROC) curve was plotted to investigate the application value of combined detection of serum HIF-1α, NT-proBNP and TXB 2 levels in the prediction of acute ST-elevation myocardial infarction after PCI. Results:At 6 months after PCI, MACE occurred in 33 out of 136 patients with acute ST-elevation myocardial infarction, with the incidence of 24.26%. There were no significant differences in age, sex and accompanied diseases between MACE and no MACE groups (all P > 0.05). Serum HIF-1α level in the MACE group was significantly lower than that in the no MACE group [(31.54 ± 5.26) ng/L vs. (37.18 ± 6.94) ng/L, t = 4.286, P < 0.05]. Serum levels of NT-proBNP and TXB 2 in the MACE group were (1 246.83 ± 243.71) μg/L and (125.13 ± 20.16) ng/L, respectively, which were significantly higher than those in the no MACE group [(876.92 ± 173.04) μg/L, (95.73 ± 18.24) ng/L, t = 9.617, 7.835, both P < 0.05]. ROC curve analysis showed that the optimal cutoff values of serum HIF-1α, NT-proBNP and TXB 2 levels in the prediction of MACE occurrence in patients with acute ST-elevation myocardial infarction after PCI were 32.67 ng/L, 1 018.27 μg/L and 112.19 ng/L, respectively. The sensitivity and specificity of combined detection of serum HIF-1α, NT-proBNP and TXB 2 levels in the prediction of MACE occurrence in patients with acute ST-elevation myocardial infarction after PCI were 69.70% (23/33) and 98.06% (101/103), respectively. The specificity of the combined detection of serum HIF-1α, NT-proBNP and TXB 2 levels was higher than that of detection of serum HIF-1α, NT-proBNP or TXB 2 level alone. The area under the curve (AUC) plotted regarding the prediction of MACE occurrence in patients with acute ST-elevation myocardial infarction after PCI by combined detection of serum HIF-1α, NT-proBNP and TXB 2 levels was 0.901, which was significantly higher than the AUC obtained for detection of serum HIF-1α, NT-proBNP or TXB2 level alone ( Z = 2.007, 1.991 and 2.217, all P < 0.05). Conclusion:Combined detection of serum HIF-1α, NT-proBNP and TXB 2 levels exhibits a higher value in the prediction of MACE occurrence in patients with acute ST-elevation myocardial infarction after PCI than detection of serum HIF-1α, NT-proBNP or TXB 2 level alone.

The value of combined detection of serum neurogranin and hypoxia-inducible factor-1α on the prognosis in patients with severe craniocerebral trauma / 中国医师进修杂志

Objective:To investigate the value of combined detection of serum neurogranin (NG) and hypoxia-inducible factor-1α (HIF-1α) in patients with severe craniocerebral trauma.Methods:Ninety-seven patients with severe craniocerebral trauma from June 2018 to March 2020 in Jinshan Branch of Shanghai Sixth People′s Hospital were selected. According to the Glasgow outcome score (GOS), 97 patients were divided into good prognosis group (GOS>3 scores, 46 cases) and poor prognosis group (GOS ≤ 3 scores, 51 cases). The NG, HIF-1α, Glasgow coma score (GCS), acute physiology and chronic health status score Ⅱ (APACHE Ⅱ) were compared between 2 groups. The independent risk factors of prognosis in patients with severe craniocerebral trauma were analyzed by multivariate Logistic regression analysis. The diagnostic efficacy of NG and HIF-1α on poor prognosis in patients with severe craniocerebral trauma was analyzed by receiver operating characteristic (ROC) curve. The correlation between serum NG, HIF-1α and APACHE Ⅱ in patients with severe craniocerebral trauma was analyzed by Pearson analysis.Results:The GCS in good prognosis group was significantly higher than that in poor prognosis group: (6.50 ± 1.74) scores vs. (4.76 ± 0.78) scores, the NG, HIF-1α and APACHE Ⅱwere significantly lower than those in poor prognosis group: (696.98 ± 158.96) ng/L vs. (875.92 ± 188.52) ng/L, (34.72 ± 13.98) μg/L vs. (51.29 ± 14.17) μg/L and (15.69 ± 3.45) scores vs. (22.58 ± 6.45) scores, and there were statistical differences ( P<0.01). Multivariate Logistic regression analysis result showed that the NG, HIF-1α, APACHEⅡ, GCS and type of craniocerebral trauma were independent risk factors on the prognosis in patients with severe craniocerebral trauma ( P<0.05 or<0.01). ROC curve analysis result showed that the AUC of NG and HIF-1αNG and HIF-1α combined detection to assess the poor prognosis in patients with severe craniocerebral trauma was significantly higher than NG and HIF-1α alone detection (0.873 vs. 0.772 and 0.821, Z = 2.276 and 1.949, P<0.05). Pearson correlation analysis result showed that APACHE Ⅱ was positive correlation with serum NG and HIF-1α in severe craniocerebral trauma patients with poor or good prognosis ( r = 0.852 and 0.889, P<0.01; r = 0.717 and 0.851, P<0.01). Conclusions:The combined detection of serum NG and HIF-1α can be used as an evaluation index for the prognosis in patients with severe craniocerebral trauma, which helps to determine the severity of craniocerebral trauma and has great value for clinical diagnosis and treatment.

Mechanism and application of hypoxia affecting immunotherapy drug resistance / 国际肿瘤学杂志

Immunotherapy is a new anti-tumor method. The application of immune checkpoint inhibitor greatly improves the survival benefit for patients, but the drug resistance of immunotherapy affects the efficacy. Therefore, it is very important to explore the mechanism of drug resistance and solve the problem of drug resis-tance in tumor immunotherapy. Hypoxia in tumor microenvironment is the key factor of immune drug resistance. Hypoxia can inhibit the immune cells function and lead to immune escape through various mechanisms. It can be the breakthrough for overcoming the immunotherapy drug resistance that blocking pathway of hypoxia to promote immune resistance. By reviewing the mechanism of immunotherapy drug resistance induced by hypoxia, it is helpful to explore the development prospect of hypoxia-inducible factor-1α (HIF-1α) related targeted drugs in clinical application for immunotherapy.