Wogonin ameliorates ER stress-associated inflammatory response, apoptotic death and renal fibrosis in a unilateral ureteral obstruction mouse model.

Wogonin, a vital bioactive compound extracted from the medicinal plant, Scutellaria baicalensis, has been wildly used for its potential in mitigating the progression of chronic diseases. Chronic kidney disease (CKD) represents a significant global health challenge due to its high prevalence, morbidity and mortality rates, and associated complications. This study aimed to assess the potential of wogonin in attenuating renal fibrosis and to elucidate the underlying molecular mechanisms using a unilateral ureteral obstruction (UUO) mouse model as a CKD mimic. Male mice, 8 weeks old, underwent orally administrated of either 50 mg/kg/day of wogonin or positive control of 5 mg/kg/day candesartan following UUO surgery. NRK52E cells were exposed to tumor growth factors-beta (TGF-ß) to evaluate the anti-fibrotic effects of wogonin. The results demonstrated that wogonin treatment effectively attenuated TGF-ß-induced fibrosis markers in NRK-52E cells. Additionally, administration of wogonin significantly improved histopathological alterations and downregulated the expression of pro-fibrotic factors (Fibronectin, α-smooth muscle actin, Collagen IV, E-cadherin, and TGF-ß), oxidative stress markers (Catalase, superoxide dismutase 2, NADPH oxidase 4, and thioredoxin reductase 1), inflammatory molecules (Cyclooxygenase-2 and TNF-α), and the infiltration of neutrophils and macrophages in UUO mice. Furthermore, wogonin treatment mitigated endoplasmic reticulum (ER) stress-associated molecular markers (GRP78, GRP94, ATF4, CHOP, and the caspase cascade) and suppressed apoptosis. The findings indicate that wogonin treatment ameliorates key fibrotic aspects of CKD by attenuating ER stress-related apoptosis, inflammation, and oxidative stress, suggesting its potential as a future therapeutic target.

Therapeutic Effect of Icaritin on Cerebral Ischemia-Reperfusion-Induced Senescence and Apoptosis in an Acute Ischemic Stroke Mouse Model.

An ischemic stroke is brain damage caused by interruption of blood supply to the brain that can cause death and long-term disability. New medical strategies or therapies are urgently needed for ischemic stroke. Icaritin (ICT) is a metabolite of icariin (ICA), which are two active flavonoid components extracted from Herba epimedii and considered neuroprotective agents in animal models of Alzheimer's disease and ischemic stroke. The therapeutic effect of ICT on ischemic still remains to be clarified. The aim of this study was to investigate the therapeutic effect of ICT on cerebral ischemia-reperfusion-associated senescence and apoptosis in a middle cerebral artery occlusion (MCAO) mouse model (ischemia for 50 min and reperfusion for 24 h). Administration of ICT after ischemia significantly reduced MCAO-induced neurological damage, infarct volume, and histopathological changes in the brain of acute ischemic stroke mice. ICT treatment could also reduce neuronal apoptosis and senescence and reversed the expression of apoptosis- and senescence-related signaling proteins. These findings suggest that ICT may have therapeutic potential to ameliorate acute ischemic stroke.

Nobiletin Alleviates Ferroptosis-Associated Renal Injury, Inflammation, and Fibrosis in a Unilateral Ureteral Obstruction Mouse Model.

Nobiletin (Nob), a critical active flavonoid of citrus fruits, has received attention for its superior physical functions, which have shown to improve the progression of diseases. Chronic kidney disease (CKD) is recognized as a global health problem, and its mortality and morbidity rates are worsened with an increased risk of accompanying disorders. In this study, we aimed to elucidate whether Nob treatment ameliorates kidney fibrosis and also to identify the potential signaling networks in a unilateral ureteral obstructive (UUO) mouse model, which was used to mimic the progression of CKD. Six-week-old C57BL/6J mice were orally treated with 50 mg/kg of Nob for 14 constitutive days after UUO surgery. We found that the administration of Nob diminished kidney fibrosis and the expression of EMT markers, ameliorated oxidative stress and ferroptosis-associated injury, and mitigated the inflammatory response in the kidneys of UUO mice. Our results suggested that Nob treatment has antiferroptosis, anti-inflammatory, and antifibrotic effects, improving the progression of CKD in UUO mice. Nob may serve as a potential therapeutic candidate for the improvement of progressive CKD in further studies.

Protective Effects of Nootkatone on Renal Inflammation, Apoptosis, and Fibrosis in a Unilateral Ureteral Obstructive Mouse Model.

Nootkatone is one of the major active ingredients of Alpiniae oxyphyllae, which has been used as both food and medicinal plants for the treatment of diarrhea, ulceration, and enuresis. In this study, we aimed to investigate whether nootkatone treatment ameliorated the progression of chronic kidney diseases (CKD) and clarified its underlying mechanisms in an obstructive nephropathy (unilateral ureteral obstructive; UUO) mouse model. Our results revealed that nootkatone treatment preventively decreased the pathological changes and significantly mitigated the collagen deposition as well as the protein expression of fibrotic markers. Nootkatone could also alleviate oxidative stress-induced injury, inflammatory cell infiltration, and renal cell apoptotic death in the kidneys of UUO mice. These results demonstrated for the first time that nootkatone protected against the progression of CKD in a UUO mouse model. It may serve as a potential therapeutic candidate for CKD intervention.

Bioactive Flavonoids Icaritin and Icariin Protect against Cerebral Ischemia-Reperfusion-Associated Apoptosis and Extracellular Matrix Accumulation in an Ischemic Stroke Mouse Model.

Stroke, which is the second leading cause of mortality in the world, is urgently needed to explore the medical strategies for ischemic stroke treatment. Both icariin (ICA) and icaritin (ICT) are the major active flavonoids extracted from Herba epimedii that have been regarded as the neuroprotective agents in disease models. In this study, we aimed to investigate and compare the neuroprotective effects of ICA and ICT in a middle cerebral artery occlusion (MCAO) mouse model. Male ICR mice were pretreated with both ICA and ICT, which ameliorated body weight loss, neurological injury, infarct volume, and pathological change in acute ischemic stroke mice. Furthermore, administration of both ICA and ICT could also protect against neuronal cell apoptotic death, oxidative and nitrosative stress, lipid peroxidation, and extracellular matrix (ECM) accumulation in the brains. The neuroprotective effects of ICT are slightly better than that of ICA in acute cerebral ischemic stroke mice. These results suggest that pretreatment with both ICA and ICT improves the neuronal cell apoptosis and responses of oxidative/nitrosative stress and counteracts the ECM accumulation in the brains of acute cerebral ischemic stroke mice. Both ICA and ICT treatment may serve as a useful therapeutic strategy for acute ischemic stroke.

A novel 111indium-labeled dual carbonic anhydrase 9-targeted probe as a potential SPECT imaging radiotracer for detection of hypoxic colorectal cancer cells.

Tumor hypoxia is a common feature in colorectal cancer (CRC), and is associated with resistance to radiotherapy and chemotherapy. Thus, a specifically targeted probe for the detection of hypoxic CRC cells is urgently needed. Carbonic anhydrase 9 (CA9) is considered to be a specific marker for hypoxic CRC diagnosis. Here, a nuclear imaging Indium-111 (111In)-labeled dual CA9-targeted probe was synthesized and evaluated for CA9 detection in in vitro, in vivo, and in human samples. The CA9-targeted peptide (CA9tp) and CA9 inhibitor acetazolamide (AAZ) were combined to form a dual CA9-targeted probe (AAZ-CA9tp) using an automatic microwave peptide synthesizer, which then was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for radioisotope (111In) labeling (111In-DOTA-AAZ-CA9tp). The assays for cell binding, stability, and toxicity were conducted in hypoxic CRC HCT15 cells. The analyses for imaging and biodistribution were performed in an HCT15 xenograft mouse model. The binding and distribution of 111In-DOTA-AAZ-CA9tp were detected in human CRC samples using microautoradiography. AAZ-CA9tp possessed good CA9-targeting ability in hypoxic HCT15 cells. The dual CA9-targeted radiotracer showed high serum stability, high surface binding, and high affinity in vitro. After exposure of 111In-DOTA-AAZ-CA9tp to the HCT15-bearing xenograft mice, the levels of 111In-DOTA-AAZ-CA9tp were markedly and specifically increased in the hypoxic tumor tissues compared to control mice. 111In-DOTA-AAZ-CA9tp also targeted the areas of CA9 overexpression in human colorectal tumor tissue sections. The results of this study suggest that the novel 111In-DOTA-AAZ-CA9tp nuclear imaging agent may be a useful tool for the detection of hypoxic CRC cells in clinical practice.

Withaferin A protects against endoplasmic reticulum stress-associated apoptosis, inflammation, and fibrosis in the kidney of a mouse model of unilateral ureteral obstruction.

BACKGROUND: Withaferin A is a functional ingredient of a traditional medicinal plant, Withania somnifera, which has been broadly used in India for protecting against chronic diseases. This bioactive steroidal lactone possesses multiple functions such as anti-oxidation, anti-inflammation, and immunomodulation. Chronic kidney disease (CKD) is one of the major health problems worldwide with the high complication, morbidity, and mortality rates. The detailed effects and underlying mechanisms of withaferin A on CKD progression still remain to be clarified. PURPOSE: We aimed to investigate whether withaferin A treatment ameliorates the development of renal fibrosis and its related mechanisms in a CKD mouse model. METHODS: A mouse model of unilateral ureteral obstruction (UUO) was used to mimic the progression of CKD. Male adult C57BL/6J mice were orally administered with 3 mg/kg/day withaferin A for 14 consecutive days after UUO surgery. Candesartan (5 mg/kg/day) was used as a positive control. RESULTS: Both Withaferin A and candesartan treatments significantly ameliorated the histopathological changes and collagen deposition in the UUO kidneys. Withaferin A could significantly reverse the increases in the protein levels of pro-fibrotic factors (fibronectin, transforming growth factor-ß, and α-smooth muscle actin), inflammatory signaling molecules (phosphorylated nuclear factor-κB-p65, interleukin-1ß, and cyclooxygenase-2), and cleaved caspase-3, apoptosis, and infiltration of neutrophils in the UUO kidneys. The protein levels of endoplasmic reticulum (ER) stress-associated molecules (GRP78, GRP94, ATF4, CHOP, phosphorylated eIF2α, and cleaved caspase 12) were increased in the kidneys of UUO mice, which could be significantly reversed by withaferin A treatment. CONCLUSION: Withaferin A protects against the CKD progression that is, at least in part, associated with the moderation of ER stress-related apoptosis, inflammation, and fibrosis in the kidneys of CKD. Withaferin A may serve as a potential therapeutic agent for the development of CKD.

Prevention of acute kidney injury by low intensity pulsed ultrasound via anti-inflammation and anti-apoptosis.

The therapeutic effects of low intensity pulsed ultrasound (LIPUS) on renal ischemia/reperfusion injury (IRI) with acute kidney injury (AKI) are still unclear. A renal tubule cell model under H2O2 or hypoxia/reoxygenation (H/R) conditions with or without LIPUS pre-treatment (1 MHz, 30 and 100 mW/cm2, 15 min) was used to test the in vitro effects of LIPUS. An AKI mouse model of unilateral IRI with nephrectomy of the contralateral kidney for 48 h with or without LIPUS treatment (3 MHz, 100 mW/cm2, 20 min/day) 5 day before IRI were used to investigate the in vivo effects of LIPUS. LIPUS significantly protected the renal tubule cell viability and prevented inflammatory signals against H2O2 challenge. LIPUS could inhibit the apoptosis-related molecular signals and increase the protein levels of endogenous antioxidant enzymes, α-Klotho, and Sirt1 in renal tubule cells after H/R challenge. LIPUS alleviated the increases in the serum levels of blood urea nitrogen, creatinine, and cystatin C, renal pathological changes and apoptosis-related molecular signals, and impaired antioxidant enzymes in AKI mice. The IRI-induced inflammatory responses in the kidneys and spleens could be reversed by LIPUS. These findings suggest that LIPUS treatment displays the benefits for renal protection in IRI-induced AKI mice.

Indium-111-labeled CD166-targeted peptide as a potential nuclear imaging agent for detecting colorectal cancer stem-like cells in a xenograft mouse model.

BACKGROUND: Cancer stem cells (CSCs) are involved in drug resistance, metastasis, and relapse of cancers, which can significantly affect tumor therapy. Hence, to develop specifically therapeutic target probe at CSCs for improvement of survival and quality of life of cancer patients is urgently needed. The CD166 protein has been suggested to be involved in colorectal cancer (CRC) tumorigenesis and to be considered a marker for colorectal CSCs (CRCSCs) detection. In this study, therefore, we attend to apply a nuclear imaging agent probe, Glycine18-Cystine-linked CD166-targeted peptides (CD166tp-G18C), to detect the changes of CD166 level in a CRC xenograft mouse model. RESULTS: We isolated the CD166-positive cells from the HCT15 CRC cell line (CD166+HCT15) and evaluated their morphology and ability of clone formation, migration, protein expression, and drug resistance. The CD166-positive HCT15 cells display the CSCs characteristics. We discovered and designed a CD166-targeted peptide (CD166tp-G18C) as a targeted probe of CRC stem-like cell for cell binding assay. The CD166tp-G18C confirmed the CD166 protein targeting ability in CD166+HCT15 cells. The diethylenetriaminopentaacetic acid (DTPA)-conjugated CD166tp-G18C further was labeled with indium-111 (111In-DTPA-CD166tp-G18C) as nuclear imaging agent for imaging and bio-distribution analysis in vivo. Finally, we observed that the 111In-DTPA-CD166tp-G18C was significantly enhanced in tumor tissues of CD166+HCT15 xenograft mice as compared to the non-CD166tp-G18C control. CONCLUSIONS: Our results indicated that the indium-111-labeled CD166tp-G18C may be served as a powerful tool for colorectal CSCs nuclear imaging in the CRC patients.

Low Intensity Pulsed Ultrasound Prevents Recurrent Ischemic Stroke in a Cerebral Ischemia/Reperfusion Injury Mouse Model via Brain-derived Neurotrophic Factor Induction.

The incidence of stroke recurrence is still higher despite the advanced progression of therapeutic treatment and medical technology. Low intensity pulsed ultrasound (LIPUS) has been demonstrated to possess therapeutic effects on neuronal diseases and stroke via brain-derived neurotrophic factor (BDNF) induction. In this study, we hypothesized that LIPUS treatment possessed therapeutic benefits for the improvement of stroke recurrence. Adult male C57BL/6J mice were subjected to a middle cerebral artery occlusion (MCAO) surgery and then followed to secondary MCAO surgery as a stroke recurrence occurred after nine days from the first MCAO. LIPUS was administered continuously for nine days before secondary MCAO. LIPUS treatment not only decreased the mortality but also significantly moderated neuronal function injury including neurological score, motor activity, and brain pathological score in the recurrent stroke mice. Furthermore, the administration of LIPUS attenuated the apoptotic neuronal cells and increased Bax/Bcl-2 protein expression ratio and accelerated the expression of BDNF in the brain of the recurrent stroke mice. Taken together, these results demonstrate for the first time that LIPUS treatment arouses the expression of BDNF and possesses a therapeutic benefit for the improvement of stroke recurrence in a mouse model. The neuroprotective potential of LIPUS may provide a useful strategy for the prevention of a recurrent stroke.

Role of Calbindin-D28k in Diabetes-Associated Advanced Glycation End-Products-Induced Renal Proximal Tubule Cell Injury.

Diabetes-associated advanced glycation end-products (AGEs) can increase extracellular matrix (ECM) expression and induce renal fibrosis. Calbindin-D28k, which plays a role in calcium reabsorption in renal distal convoluted tubules, is increased in a diabetic kidney. The role of calbindin-D28k in diabetic nephropathy still remains unclear. Here, calbindin-D28k protein expression was unexpectedly induced in the renal tubules of db/db diabetic mice. AGEs induced the calbindin-D28k expression in human renal proximal tubule cells (HK2), but not in mesangial cells. AGEs induced the expression of fibrotic molecules, ECM proteins, epithelial-mesenchymal transition (EMT) markers, and endoplasmic reticulum (ER) stress-related molecules in HK2 cells, which could be inhibited by a receptor for AGE (RAGE) neutralizing antibody. Calbindin-D28k knockdown by siRNA transfection reduced the cell viability and obviously enhanced the protein expressions of fibrotic factors, EMT markers, and ER stress-related molecules in AGEs-treated HK2 cells. Chemical chaperone 4-Phenylbutyric acid counteracted the AGEs-induced ER stress and ECM and EMT markers expressions. Calbindin-D28k siRNA in vivo delivery could enhance renal fibrosis in db/db diabetic mice. These findings suggest that inducible calbindin-D28k protects against AGEs/RAGE axis-induced ER stress-activated ECM induction and cell injury in renal proximal tubule cells.

The antifibrotic and anti-inflammatory effects of icariin on the kidney in a unilateral ureteral obstruction mouse model.

BACKGROUND: The pathology change of renal tubulointerstitial fibrosis is a critical feature of chronic kidney disease (CKD), regardless of the primary insults. The infiltration of inflammatory cells and the consecutive secretion of profibrotic factors are frequently and conspicuously observed during the development of renal fibrosis. Icariin, an active polyphenol of the Epimedium genus, has been found to alleviate the symptoms of chronic diseases like diabetes, neurodegeneration, and heart and renal diseases. The effect and mechanism of icariin on the prevention of CKD-associated renal fibrosis still needed clarification. PURPOSE: The aims of this study were to investigate whether icariin treatment improves the development of CKD-associated renal fibrosis and its possible mechanism. METHODS: An experimental unilateral ureteral obstruction (UUO)-induced chronic renal fibrosis mouse model was used. Mice were orally administered with icariin (20 mg/kg/day) for 3 consecutive days before and 14 consecutive days after UUO surgery. RESULTS: The pathological changes, collagen deposition, and protein expressions of profibrotic factors (transforming growth factor-ß and connective tissue growth factor) and fibrotic markers (α-smooth muscle actin and fibronectin), which were significantly elevated in the kidneys of UUO mice, could be significantly reversed by icariin treatment. Icariin treatment also significantly inhibited the increased Smad2/3 and decreased E-cadherin protein expressions in the kidneys of UUO mice. Icariin treatment prominently mitigated the protein expression of proinflammatory factors like nuclear factor-κB, cyclooxygenase-2, interleukin 1-ß and prooxidative enzyme (NADPH oxidase-4), and it increased the protein expression of antioxidative enzymes (superoxide dismutase and catalase). CONCLUSION: Icariin treatment protects against CKD-associated renal fibrosis via its antifibrotic and anti-inflammatory properties. Icariin may serve as a therapeutic agent in the prevention of CKD-associated renal fibrosis.

Gender difference of CCAAT/enhancer binding protein homologous protein deficiency in susceptibility to osteopenia.

Expression of CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP) is induced during endoplasmic reticulum (ER) stress, which is related to apoptosis in several cell types. CHOP null mice have been exhibited to decrease bone formation. However, a study of transgenic mice overexpressing CHOP in the bone microenvironment showed that CHOP overexpression impairs the osteoblastic function leading to osteopenia. The regulatory role of CHOP in bone formation is controversial and still remains to be clarified. Here, we investigated the alterations in bone microstructure of CHOP knockout (Chop-/- ) mice and tested the gender difference of CHOP deficiency in susceptibility to osteopenia. Adult female and male mice (WT) and Chop-/- mice were used. The microcomputed tomography (µCT) analysis in trabecular bone and cortical bone of tibia was determined. Trabecular bone volume fraction (BV/TV), trabecular number, and bone mineral density (BMD) in tibia are markedly decreased in both male and female Chop-/- mice compared to the control WT mice. Unexpectedly, the BMD and BV/TV in trabecular bone of tibia in female Chop-/- mice were significantly lower than in male Chop-/- mice. The similar results could also be observed in the cortical bone of tibia in Chop-/- mice. This gender difference was also observed in the decreased capacity of osteoblast differentiation of bone marrow cells isolated from Chop-/- mice. These results indicated that ER stress-related CHOP signaling might play an important role in the bone formation in a mouse model, especially in females. There is the gender difference of CHOP deficiency in susceptibility to osteopenia. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Polyethylene glycol-conjugated HER2-targeted peptides as a nuclear imaging probe for HER2-overexpressed gastric cancer detection in vivo.

BACKGROUND: The human epidermal growth factor receptor 2 (HER2) involved proliferation, angiogenesis, and reduced apoptosis in gastric cancer (GC), which is a common target for tumor therapy. HER2 is usually overexpressed in more than 15% GC patients, developing a reliable diagnostic tool for tumor HER2 detection is important. In this study, we attend to use polyethylene glycol (PEG) linked anti-HER2/neu peptide (AHNP-PEG) as a nuclear imaging agent probe for HER2 detection in GC xenograft animal model. METHODS: The HER2 expression of human sera and tissues were detected in GC patients and normal subjects. GC cell lines NCI-N87 (high HER2 levels) and MKN45 (low HER2 levels) were treated with AHNP-PEG to assess the cell viability and HER2 binding ability. The NCI-N87 was treated with AHNP-PEG to observe the level and phosphorylation of HER2. The MKN45 and NCI-N87-induced xenograft mice were intravenous injection with fluorescence labeled AHNP-PEG for detecting in vivo fluorescence imaging properties and biodistribution. The AHNP-PEG was conjugated with diethylenetriaminopentaacetic acid (DTPA) for indium-111 labeling (111In-DTPA-AHNP-PEG). The stability of was assessed in vitro. The imaging properties and biodistribution of 111In-DTPA-AHNP-PEG were observed in NCI-N87-induced xenograft mice. RESULTS: The serum HER2 (sHER2) levels in GC patients were significantly higher than the normal subjects. The sHER2 levels were correlated with the tumor HER2 levels in different stages of GC patients. The AHNP-PEG inhibited the cell growth and down-regulated HER2 phosphorylation in HER2-overexpressed human GC cells (NCI-N87) via specific HER2 interaction of cell surface. In addition, the GC tumor tissues from HER2-postive xenograft mice presented higher HER2 fluorescence imaging as compared to HER2-negative group. The HER2 levels in the tumor tissues were also higher than other organs in NCI-N87-induced xenograft mice. Finally, we further observed that the 111In-DTPA-AHNP-PEG was significantly enhanced in tumor tissues of NCI-N87-induced xenograft mice compared to control. CONCLUSIONS: These findings suggest that the sHER2 measurement may be as a potential tool for detecting HER2 expressions in GC patients. The radioisotope-labeled AHNP-PEG may be useful to apply in GC patients for HER2 nuclear medicine imaging.

The pathological role of advanced glycation end products-downregulated heat shock protein 60 in islet ß-cell hypertrophy and dysfunction.

Heat shock protein 60 (HSP60) is a mitochondrial chaperone. Advanced glycation end products (AGEs) have been shown to interfere with the ß-cell function. We hypothesized that AGEs induced ß-cell hypertrophy and dysfunction through a HSP60 dysregulation pathway during the stage of islet/ß-cell hypertrophy of type-2-diabetes. We investigated the role of HSP60 in AGEs-induced ß-cell hypertrophy and dysfunction using the models of diabetic mice and cultured ß-cells. Hypertrophy, increased levels of p27Kip1, AGEs, and receptor for AGEs (RAGE), and decreased levels of HSP60, insulin, and ATP content were obviously observed in pancreatic islets of 12-week-old db/db diabetic mice. Low-concentration AGEs significantly induced the cell hypertrophy, increased the p27Kip1 expression, and decreased the HSP60 expression, insulin secretion, and ATP content in cultured ß-cells, which could be reversed by RAGE neutralizing antibody. HSP60 overexpression significantly reversed AGEs-induced hypertrophy, dysfunction, and ATP reduction in ß-cells. Oxidative stress was also involved in the AGEs-decreased HSP60 expression in ß-cells. Pancreatic sections from diabetic patient showed islet hypertrophy, increased AGEs level, and decreased HSP60 level as compared with normal subject. These findings highlight a novel mechanism by which a HSP60-correlated signaling pathway contributes to the AGEs-RAGE axis-induced ß-cell hypertrophy and dysfunction under diabetic hyperglycemia.

C/EBP homologous protein (CHOP) deficiency ameliorates renal fibrosis in unilateral ureteral obstructive kidney disease.

Renal tubulointerstitial fibrosis is an important pathogenic feature in chronic kidney disease and end-stage renal disease, regardless of the initiating insults. A recent study has shown that CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP) is involved in acute ischemia/reperfusion-related acute kidney injury through oxidative stress induction. However, the influence of CHOP on chronic kidney disease-correlated renal fibrosis remains unclear. Here, we investigated the role of CHOP in unilateral ureteral obstruction (UUO)-induced experimental chronic tubulointerstital fibrosis. The CHOP knockout and wild type mice with or without UUO were used. The results showed that the increased expressions of renal fibrosis markers collagen I, fibronectin, α-smooth muscle actin, and plasminogen activator inhibitor-1 in the kidneys of UUO-treated wild type mice were dramatically attenuated in the kidneys of UUO-treated CHOP knockout mice. CHOP deficiency could also ameliorate lipid peroxidation and endogenous antioxidant enzymes depletion, tubular apoptosis, and inflammatory cells infiltration in the UUO kidneys. These results suggest that CHOP deficiency not only attenuates apoptotic death and oxidative stress in experimental renal fibrosis, but also reduces local inflammation, leading to diminish UUO-induced renal fibrosis. Our findings support that CHOP may be an important signaling molecule in the progression of chronic kidney disease.

Blocking heme oxygenase-1 by zinc protoporphyrin reduces tumor hypoxia-mediated VEGF release and inhibits tumor angiogenesis as a potential therapeutic agent against colorectal cancer.

BACKGROUND: Hypoxia in tumor niche is one of important factors to start regeneration of blood vessels, leading to increase survival, proliferation, and invasion in cancer cells. Under hypoxia microenvironment, furthermore, steadily increased hypoxia-inducible factor -1α (HIF-1α) is observed, and can increase vascular endothelial growth factor (VEGF) expression and promote angiogenesis. Zinc protoporphyrin (ZnPP), a heme oxygenase-1 (HO-1) inhibitor, is potential to inhibit tumor proliferation and progression. However, the mechanism of ZnPP in inhibition of tumor is not completely clear. We hypothesize that ZnPP may modulate HIF-1α through inhibiting HO-1, and then inhibit angiogenesis and tumor progression. This study aimed to dissect the mechanism of ZnPP in tumor suppression. RESULTS: We observed the amount of VEGF was increased in the sera of the colorectal cancer (CRC) patients (n = 34, p < 0.05). Furthermore, increased VEGF expression was also measured in colorectal cancer cells, HCT-15, culturing under mimicking hypoxic condition. It suggested that hypoxia induced VEGF production from cancer cells. VEGF production was significantly reduced from HCT-15 cells after exposure to HIF-1α inhibitor KC7F2, suggesting that HIF-1α regulated VEGF production. Moreover, we observed that the HO-1 inhibitor ZnPP inhibited the expressions of HIF-1α and VEGF coupled with cell proliferations of HCT-15 cells, suggesting that ZnPP blocked HIF-1α expression, and then inhibited the consequent VEGF production. In the xenograft model, we also observed that the animals exposed to ZnPP displayed much smaller tumor nodules and less degree of angiogenesis with decreased expression of the angiogenesis marker, αvß3 integrin, compared to that in normal control. CONCLUSIONS: This study demonstrated that VEGF level in serum was elevated in the patients with CRC. The HO-1 inhibitor, ZnPP, possessed the properties of anti-tumor agent by decreasing HIF-1α levels, blocking VEGF production, impairing tumor angiogenesis, and inhibiting tumor growth.

Sulfonamide derivative targeting carbonic anhydrase IX as a nuclear imaging probe for colorectal cancer detection in vivo.

Hypoxic microenvironment is a common situation in solid tumors. Carbonic anhydrase IX (CA9) is one of the reliable cellular biomarkers of hypoxia. The role of CA9 in colorectal cancer (CRC) remains to be clarified. CA9 inhibitor such as sulfonamides is known to block CA9 activation and reduce tumor growth consequently. Here, we aimed to investigate the CA9 expression in serum and tumor from different stages of CRC patients and utilize sulfonamide derivative with indium-111 labeling as a probe for CRC nuclear imaging detection in vivo. The serum CA9 was correlated with the tumor CA9 levels in different stages of CRC patients. Hypoxia increased cell viability and CA9 expression in colorectal cancer HCT-15 cells. Sulfonamide derivative 5-(2-aminoethyl)thiophene-2-sulfonamide (ATS) could bind with CA9 in vitro under hypoxia. Moreover, tumor tissues in HCT-15-induced xenograft mice possessed higher hypoxic fluorescence signal as compared with other organs. We also found that the radioisotope signal of indium-111 labeled ATS, which was utilized for CRC detection in HCT-15-induced xenograft mice, was markedly enhanced in tumors as compared with non-ATS control. Taken together, these findings suggest that CA9 is a potential hypoxic CRC biomarker and measurement of serum CA9 can be as a potential tool for diagnosing CA9 expressions in CRC clinical practice. The radioisotope-labeled sulfonamide derivative (ATS) may be useful to apply in CRC patients for nuclear medicine imaging.

ATP synthase subunit-ß down-regulation aggravates diabetic nephropathy.

In this study, we investigated the role of ATP synthase subunit-ß (ATP5b) in diabetic nephropathy. Histopathological changes, fibrosis, and protein expressions of α-smooth muscle actin (α-SMA), advanced glycation end-products (AGEs), and ATP5b were obviously observed in the kidneys of db/db diabetic mice as compared with the control db/m(+) mice. The increased ATP5b expression was majorly observed in diabetic renal tubules and was notably observed to locate in cytoplasm of tubule cells, but no significant increase of ATP5b in diabetic glomeruli. AGEs significantly increased protein expression of ATP5b and fibrotic factors and decreased ATP content in cultured renal tubular cells via an AGEs-receptor for AGEs (RAGE) axis pathway. Oxidative stress was also induced in diabetic kidneys and AGEs-treated renal tubular cells. The increase of ATP5b and CTGF protein expression in AGEs-treated renal tubular cells was reversed by antioxidant N-acetylcysteine. ATP5b-siRNA transfection augmented the increased protein expression of α-SMA and CTGF and CTGF promoter activity in AGEs-treated renal tubular cells. The in vivo ATP5b-siRNA delivery significantly enhanced renal fibrosis and serum creatinine in db/db mice with ATP5b down-regulation. These findings suggest that increased ATP5b plays an important adaptive or protective role in decreasing the rate of AGEs-induced renal fibrosis during diabetic condition.

CCAAT-Enhancer-Binding Protein Homologous Protein Deficiency Attenuates Oxidative Stress and Renal Ischemia-Reperfusion Injury.

AIMS: Renal ischemia-reperfusion (I/R) is a major cause of acute renal failure. The mechanisms of I/R injury include endoplasmic reticulum (ER) stress, inflammatory responses, hypoxia, and generation of reactive oxygen species (ROS). CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP) is involved in the ER stress signaling pathways. CHOP is a transcription factor and a major mediator of ER stress-induced apoptosis. However, the role of CHOP in renal I/R injury is still undefined. Here, we investigated whether CHOP could regulate I/R-induced renal injury using CHOP-knockout mice and cultured renal tubular cells as models. RESULTS: In CHOP-knockout mice, loss of renal function induced by I/R was prevented. Renal proximal tubule damage was induced by I/R in wild-type mice; however, the degree of alteration was significantly less in CHOP-knockout mice. CHOP deficiency also decreased the I/R-induced activation of caspase-3 and -8, apoptosis, and lipid peroxidation, whereas the activity of endogenous antioxidants increased. In an in vitro I/R model, small interfering RNA targeting CHOP significantly reversed increases in H2O2 formation, inflammatory signals, and apoptotic signals, while enhancing the activity of endogenous antioxidants in renal tubular cells. INNOVATION: To the best of our knowledge, this is the first study which demonstrates that CHOP deficiency attenuates oxidative stress and I/R-induced acute renal injury both in vitro and in vivo. CONCLUSION: These findings suggest that CHOP regulates not only apoptosis-related signaling but also ROS formation and inflammation in renal tubular cells during I/R. CHOP may play an important role in the pathophysiology of I/R-induced renal injury.