Effects of Lactobacillus Rhamnosus GG on Activated Microglia and Tau Phosphorylation in the Hippocampus of Aged Mice Induced by Anesthesia and Surgery / 中山大学学报(医学科学版)

ObjectiveTo investigate the effects of Lactobacillus rhamnosus GG （LGG）on microglia and Tau phosphorylation in the hippocampus of aged mice induced by anesthesia and surgery. MethodsA total of thirty 18-month-old C57BL/6J mice were randomly divided into three groups： control group， anesthesia surgery group， and anesthesia surgery + LGG group （10 mice/group）. The aged mice were oral administered by NS or LGG 109 CFU 150 μL once a day for 20 days. Then anesthesia surgery group and anesthesia surgery +LGG group received anesthesia with isoflurane and exploratory laparotomy. The activation status of microglia in the hippocampus was detected by immunofluorescence staining 12 hours after surgery. IL-6 concentration changes was detected by ELISA. The expression changes of Tau protein phosphorylation site （Tau-pS202/pT205） and total Tau protein was detected by western blot. ResultsThe microglia in the hippocampus of the control group were in a resting state， and the concentration of inflammatory factor IL-6 was （82.08 ± 12.07） pg/mL in control group. Compared to the control group， the anesthesia surgery group showed microglial cell Microglia were activated， the concentration of inflammatory factors IL-6 increased significantly to （123.7±5.72） pg/mL （P=0.000）， and the expression of phosphorylated Tau-pS202/pT205 increased the hippocampus （P=0.002）. Compared to the anesthesia surgery group， the activated microglia were inhibited， the concentration of IL-6 decreased to （96.68±9.59） pg/mL （P=0.008）， and the expression of phosphorylated Tau-pS202/pT205 reduced significantly in the AS+LGG group （P=0.002）. While there were no significant changes in total Tau protein among 3 groups. ConclusionPreoperative administration of probiotic LGG can alleviate the activation of microglia， increased secretion of inflammatory factors， and increased Tau protein phosphorylation levels in the hippocampus of elderly mice caused by anesthesia surgery.

Role of post-translational modification of basic leucine zipper transcription factors in response to abiotic stresses in plants / 生物工程学报

Abiotic stresses substantially affect the growth and development of plants. Plants have evolved multiple strategies to cope with the environmental stresses, among which transcription factors play an important role in regulating the tolerance to abiotic stresses. Basic leucine zipper transcription factors (bZIP) are one of the largest gene families. The stability and activity of bZIP transcription factors could be regulated by different post-translational modifications (PTMs) in response to various intracellular or extracellular stresses. This paper introduces the structural feature and classification of bZIP transcription factors, followed by summarizing the PTMs of bZIP transcription factors, such as phosphorylation, ubiquitination and small ubiquitin-like modifier (SUMO) modification, in response to abiotic stresses. In addition, future perspectives were prospected, which may facilitate cultivating excellent stress-resistant crop varieties by regulating the PTMs of bZIP transcription factors.

The mechanism of action of mitochondrial dysfunction in the development of non-alcoholic fatty liver disease / 临床肝胆病杂志

Nonalcoholic fatty liver disease （NAFLD） has gradually become the main reason affecting human liver health， and many factors are involved in the development and progression of NAFLD. Mitochondria， as the “energy factory” of cells， plays an important role in maintaining normal physiological functions. Studies have shown that hepatic mitochondrial dysfunction promotes the development and progression of NAFLD. This article briefly introduces the latest research advances in the basic characteristics and physiological function of liver mitochondria and reviews new research findings in the association of mitochondrial dysfunction with obesity， simple fatty liver disease， and nonalcoholic steatohepatitis， in order to provide new ideas for the research on targeted mitochondrial therapy for NAFLD.

Alterations of serum biochemical parameters and tyrosine phosphorylation in kidney and liver of chronic stress-induced rats

Abstract Chronic stress (CS) can contribute to dysfunction in several organs including liver and kidney. This study was performed to investigate the changes in serum biochemistry, histological structure, as well as in localization of tyrosine phosphorylated proteins (TyrPho) and Heat shock protein 70 (Hsp-70) in liver and kidney tissues of CS rats induced by two stressors (restrained and force swimming) for 60 consecutive days. Samples of blood, liver, and kidney were collected from adult male SpragueDawley rats in each group. Our results showed that serum biochemical parameters including corticosterone, blood sugar, urea nitrogen, creatinine, cholesterol, triglyceride, HDL-C, LDL-C, ALT, AST, alkaline phosphatase in CS group were significantly different from that in normal group in both liver and kidney tissues. Although histological structure was not changed. TyrPho expression was significantly increased in liver lysate but significantly decreased in kidney. Hsp-70 expression in liver increased whereas in kidney decreased. In conclusion, CS can induce changes in liver and kidney functions.

Resumo O estresse crônico (SC) pode contribuir para a disfunção em vários órgãos, incluindo fígado e rim. Este estudo foi realizado para investigar as alterações na bioquímica sérica, estrutura histológica, bem como na localização de proteínas tirosina fosforiladas (TyrPho) e proteína de choque térmico 70 (Hsp-70) em tecidos hepáticos e renais de ratos CS induzidas por dois estressores (restrito e natação forçada) por 60 dias consecutivos. Amostras de sangue, fígado e rim foram coletadas de ratos Sprague-Dawley machos adultos em cada grupo. Nossos resultados mostraram que os parâmetros bioquímicos séricos, incluindo corticosterona, glicemia, nitrogênio ureico, creatinina, colesterol, triglicerídeos, HDL-C, LDL-C, ALT, AST, fosfatase alcalina no grupo CS foram significativamente diferentes do grupo normal em ambos os fígados e tecidos renais. Embora a estrutura histológica não tenha sido alterada, a expressão de TyrPho aumentou significativamente no lisado hepático, mas diminuiu significativamente no rim. A expressão de Hsp-70 no fígado aumentou, enquanto que no rim diminuiu. Em conclusão, a CS pode induzir alterações nas funções hepáticas e renais.

Alterations of serum biochemical parameters and tyrosine phosphorylation in kidney and liver of chronic stress-induced rats / Alterações dos parâmetros bioquímicos séricos e fosforilação da tirosina em rim e fígado de ratos induzidos por estresse crônico

Chronic stress (CS) can contribute to dysfunction in several organs including liver and kidney. This study was performed to investigate the changes in serum biochemistry, histological structure, as well as in localization of tyrosine phosphorylated proteins (TyrPho) and Heat shock protein 70 (Hsp-70) in liver and kidney tissues of CS rats induced by two stressors (restrained and force swimming) for 60 consecutive days. Samples of blood, liver, and kidney were collected from adult male Sprague-Dawley rats in each group. Our results showed that serum biochemical parameters including corticosterone, blood sugar, urea nitrogen, creatinine, cholesterol, triglyceride, HDL-C, LDL-C, ALT, AST, alkaline phosphatase in CS group were significantly different from that in normal group in both liver and kidney tissues. Although histological structure was not changed. TyrPho expression was significantly increased in liver lysate but significantly decreased in kidney. Hsp-70 expression in liver increased whereas in kidney decreased. In conclusion, CS can induce changes in liver and kidney functions.

O estresse crônico (SC) pode contribuir para a disfunção em vários órgãos, incluindo fígado e rim. Este estudo foi realizado para investigar as alterações na bioquímica sérica, estrutura histológica, bem como na localização de proteínas tirosina fosforiladas (TyrPho) e proteína de choque térmico 70 (Hsp-70) em tecidos hepáticos e renais de ratos CS induzidas por dois estressores (restrito e natação forçada) por 60 dias consecutivos. Amostras de sangue, fígado e rim foram coletadas de ratos Sprague-Dawley machos adultos em cada grupo. Nossos resultados mostraram que os parâmetros bioquímicos séricos, incluindo corticosterona, glicemia, nitrogênio ureico, creatinina, colesterol, triglicerídeos, HDL-C, LDL-C, ALT, AST, fosfatase alcalina no grupo CS foram significativamente diferentes do grupo normal em ambos os fígados e tecidos renais. Embora a estrutura histológica não tenha sido alterada, a expressão de TyrPho aumentou significativamente no lisado hepático, mas diminuiu significativamente no rim. A expressão de Hsp-70 no fígado aumentou, enquanto que no rim diminuiu. Em conclusão, a CS pode induzir alterações nas funções hepáticas e renais.

Embryo development is impaired by sperm mitochondrial-derived ROS

BACKGROUND: Basal energetic metabolism in sperm, particularly oxidative phosphorylation, is known to condition not only their oocyte fertilising ability, but also the subsequent embryo development. While the molecular pathways underlying these events still need to be elucidated, reactive oxygen species (ROS) could have a relevant role. We, therefore, aimed to describe the mechanisms through which mitochondrial activity can influence the first stages of embryo development. RESULTS: We first show that embryo development is tightly influenced by both intracellular ROS and mitochondrial activity. In addition, we depict that the inhibition of mitochondrial activity dramatically decreases intracellular ROS levels. Finally, we also demonstrate that the inhibition of mitochondrial respiration positively influences sperm DNA integrity, most likely because of the depletion of intracellular ROS formation. CONCLUSION: Collectively, the data presented in this work reveals that impairment of early embryo development may result from the accumulation of sperm DNA damage caused by mitochondrial-derived ROS.

The mechanism of "Trichosanthis Fructus-Allii Macrostemonis Bulbus" on phlegm and blood stasis syndrome-related cardiovascular diseases based on network pharmacology and experimental verification / 药学学报

This study aimed to investigate the mechanism of "Trichosanthis Fructus-Allii Macrostemonis Bulbus" (GX) on phlegm and blood stasis syndrome (PBSS) rats combining the methods of network pharmacology and experimental verification. Animal experiment ethical requirements were approved by the Ethical Committee Experimental Animal Center of Anhui University of Chinese Medicine (grant number: AHUCM-rats-2021070). Based on the HPLC-Q-TOF-MS analysis and database, 69 chemical constituents of GX and 163 targets of GX for the treatment of phlegm and blood stasis-related cardiovascular diseases were obtained. Then, key targets such as serine/threonine kinase 1 (Akt1), tumor necrosis factor (TNF), interleukin 6 (IL6), vascular endothelial growth factor A (VEGFA), cellular tumor antigen p53 (Tp53) were screened. Pathway analysis showed that the targets of GX in the treatment of phlegm and blood stasis-relate cardiovascular diseases were mainly involved in PI3K/Akt signaling pathway, sphingolipid metabolism, platelet activation, hypoxia inducible factor-1 (HIF-1), ras-proximate-1 (rap1) and other signaling pathways. In addition, molecular docking analysis showed that apigenin, cucurbitacin D, linolenic acid and kaempferol and other key components had potential binding ability with Akt1, TNF, IL6, VEGFA and Tp53. In the animal experiments, compared to the phlegm and blood stasis syndrome group, GX could significantly improve the traditional Chinese medicine syndrome score, blood lipid, vascular endothelial structure disorders and reduce serum endothelin-1 (ET-1) level, increase serum nitric oxide (NO) and endothelial nitric oxide synthase (eNOS) levels, which could restore aortic endothelial function. In addition, the expression of intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in aorta could be significantly reduced, which could improve the vascular endothelial injury of aorta. Western blot revealed that GX could significantly decrease the phosphorylation levels of phosphoinositide 3-kinase (PI3K) and Akt in aorta. This study revealed the mechanism of GX in treatment of phlegm and blood stasis-relate cardiovascular diseases is consistent with the characteristics of multiple ingredients, multiple targets and multiple pathways. In addition, this study also clarified that the reversal of pathological of phlegm and blood stasis syndrome rats may be related to GX inhibiting PI3K/Akt signaling pathway, which could improve vascular inflammation and vascular endothelial function injury.

Advances of SHP2 modulators in the cancer immunotherapy / 药学学报

Src homology phosphotyrosyl phosphatase 2 (SHP2) is a protein tyrosine phosphatase encoded by PTPN11, which catalyzes the dephosphorylation of protein tyrosine. As a convergence node, SHP2 mediates multiple signaling pathways such as rat sarcoma (RAS)-rapidly accelerated fibrosarcoma (RAF)-mitogen-activated extracellular signal-regulated kinase (MEK)-extracellular regulated protein kinases (ERK), phosphatidylinositol 3-kinase (PI3K)-serine/threonine kinase (AKT), janus kinase (JAK)-signal transducer and activator of transcription (STAT) and programmed death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1). It can not only regulate the growth and proliferation of tumor cells, but also mediate the immune escape of tumor cells by influencing the tumor microenvironment. Given its dual biological functions in tumor immune regulation, SHP2 is a promising target for cancer immunotherapy. To date, several SHP2 allosteric inhibitors have been advanced into clinical trials for tumor immunotherapy with single or combination therapeutic strategies. Additionally, SHP2 activators also showed therapeutic potential in the field of tumor immune modulation. In this paper, we reviewed the dual function of SHP2 in both tumor and immune cells. Besides, the challenges and prospects of SHP2 modulators in cancer immunotherapy were also briefly discussed, aiming to explore new horizon of SHP2 modulators for tumor immunotherapy.

Isoliquiritigenin alleviates energy metabolism imbalance in type 2 diabetic mice / 药学学报

Isoliquiritigenin (ISL) is a flavonoid compound isolated from licorice. It possesses excellent antioxidant and anti-diabetic activities. This study aims to investigate the molecular mechanism underlying the alleviatory effect of ISL on energy metabolism imbalance caused by type 2 diabetes mellitus (T2DM). 8-week-old male C57BL/6J mice were used in in vivo experiments. The high-fat-high-glucose diet combined with intraperitoneal injection of streptozotocin was applied to establish T2DM animal model. All animal experiments were performed in accordance with the Institutional Guidelines of Laboratory Animal Administration issued by the Committee of Ethics at Beijing University of Chinese Medicine. HepG2 cells were used in in vitro experiments. Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (RT-qPCR) were used to examine the protein and mRNA levels of mitochondrial function-related targets. The levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) in HepG2 cells were measured by the flow cytometry. Additionally, the molecular docking of ISL and key target proteins was analyzed. It was found that ISL significantly inhibited the activity of mitochondrial respiratory chain complex I and increased the protein levels of uncoupling protein 2 (UCP2) in the livers of mice and HepG2 cells. It also obviously decreased the ROS levels and increased the MMP levels in cultured HepG2 cells. In addition, ISL promoted mitochondrial biogenesis by activating proliferator-activated receptor gamma co-activator 1α (PGC-1α) and enhanced mitophagy by upregulating Parkin. It also improved mitochondrial fusion by increasing the mRNA and protein levels of mitofusin 2 (MFN2). In conclusion, ISL alleviates energy metabolism imbalance caused by T2DM through suppression of excessive mitochondrial oxidative phosphorylation and promotion of mitochondrial biogenesis, mitophagy, and fusion.

Combined oxidative phosphorylation deficiency type 4: clinical features and TUFM gene mutation analysis / 中华神经科杂志

Objective:To investigate the clinical characteristics of patients with combined oxidative phosphorylation deficiency type 4 (COXPD4) related to TUFM gene variation, in order to improve clinicians′ understanding of the disease. Methods:A case of COXPD4 with cystic leukodystrophy admitted to the Children′s Hospital of Zhengzhou University in June 2021 was taken as the study subject, and her clinical characteristics and genetic testing results were retrospectively analyzed. The "combined oxidative phosphorylation deficiency type 4" " TUFM gene" "cystic leukodystrophy" "combined oxidative phosphorylation deficiency 4" "COXPD 4" " TUFM" and "cystic leukodystrophy" were used as keywords, and the documents on COXPD4 related to TUFM gene mutations were reviewed from Wanfang Data Knowledge Service Platform, CNKI, PubMed Document Database, and National Center for Biotechnology Information (NCBI) until August 2021. The COXPD4 patients that have been reported internationally were analyzed for clinical features and variant types. Results:The patient was a 2-month-old girl with clinical manifestations of delayed development and progressive aggravation, elevated lactic acid in serum and cerebrospinal fluid, and diffuse white matter dysplasia with multiple cystic lesions in cerebral magnetic resonance imaging (MRI). Whole exome sequencing showed TUFM gene complex heterozygous variants c.684_684+4delGGTGA and c.1105C>T, which had not been reported in the past. A total of 5 cases of COXPD4 were reported in 4 English literatures. Together with 1 case in this study, there were 4 cases with detailed clinical history data, including 1 male and 3 females. The clinical manifestations were severe early-onset lactic acidosis and developmental lag, and 3 cases were accompanied by progressive infantile encephalopathy. Among them, 3 cases underwent head MRI examination, all of which showed diffuse white matter signal with multiple cystic lesions, 2 cases with basal ganglia involvement and multiple cerebellar gyri deformity. Genetic test indicated different types of TUFM gene variation. Conclusions:COXPD4 is a rare hereditary mitochondrial disease. For cases with COXPD4 clinical and imaging features, TUFM gene mutations can be screened first.

Research on BHLHE40 targets HMGA2 to reduce the sensitivity of thyroid cancer cells to cisplatin through activating the oxidative phosphorylation pathway / 国际肿瘤学杂志

Objective:To explore whether BHLHE40 can affect the sensitivity of thyroid cancer (TC) cells to cisplatin by activating oxidative phosphorylation (OXPHOS) pathway by targeting high mobility group A2 (HMGA2) .Methods:The mRNA expression of HMGA2 and its upstream transcription factor BHLHE40 in TC tissues was analyzed by TCGA-THCA and hTFtarget online databases. The si-HMGA2, oe-HMGA2, oe-BHLHE40, negative control si-NC and oe-NC were transfected into TC cells (K1 and SW579) by liposome transfection method. The mRNA expression levels of BHLHE40 and HMGA2 in TC cells (SW579, FTC-133, and K1) and normal thyroid cells (Nthy ori3-1) were detected by real-time quantitative PCR (qRT-PCR). The cell viability was detected by MTT assay, the half inhibitory concentration (IC 50) value of cisplatin was calculated by CCK-8 assay, the apoptosis level was detected by flow cytometry, and the expression of OXPHOS complex was detected by Western blotting. Seahorse XFe 96 was used to analyze the oxygen consumption rate of the TC cells. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) assay were used to analyze the binding relationship between BHLHE40 and HMGA2. Results:TCGA database results showed that the mRNA expression levels of HMGA2 and BHLHE40 in TC tissues (10.57±2.58, 13.89±1.13) were higher than those in normal thyroid tissues (4.82±1.69, 12.28±1.01), with statistically significant differences ( t=16.69, P<0.001; t=10.43, P<0.001). The results of qRT-PCR showed that the relative mRNA expression levels of HMGA2 in normal thyroid cells (Nthy ori3-1) and TC cells (SW579, FTC-133, and K1) were 1.00±0.13, 2.94±0.23, 4.71±0.41 and 6.29±0.49, while those of BHLHE40 were 1.00±0.12, 2.60±0.23, 3.39±0.35 and 6.18±0.51 respectively, both with statistically significant differences ( F=130.50, P<0.001; F=125.20, P<0.001). Further pairwise comparison showed that mRNA expression levels of HMGA2 and BHLHE40 in TC cells were significantly higher than those in normal thyroid cells (all P<0.001). According to MTT experimental results, si-HMGA2 treatment significantly reduced the cell viability of K1 cells compared to the si-NC group (all P<0.05). In addition, compared to the oe-NC group, oe-HMGA2 treatment significantly increased the cell viability of SW579 cells (all P<0.05). Compared to the oe-NC+DMSO group, the oe-HMGA2+DMSO group showed enhanced cell viability of SW579 cells, while the OXPHOS pathway inhibitor Gboxin was able to reverse the effect of overexpressing HMGA2 on cell viability (all P<0.05). The results of flow cytometry and CCK-8 experiments showed that compared to the si-NC group (apoptosis level: 6.19%±0.28%; cisplatin IC 50 value: 17.47 μmol/L), knocking down HMGA2 could increase the apoptosis level (11.96%±0.32%; t=19.17, P<0.001) and cisplatin sensitivity (IC 50 value: 1.49 μmol/L) of K1 cells. In addition, compared to the oe-NC group (apoptosis level: 9.98%±0.32%; cisplatin IC 50 value: 8.17 μmol/L), overexpressing HMGA2 significantly decreased the apoptosis level (4.32%±0.25%; t=19.65, P<0.001) and cisplatin sensitivity (IC 50 value: 34.95 μmol/L) of SW579 cells. The results of dual-luciferase assay showed that compared with the si-NC group, knocking down the expression of BHLHE40 in human kidney epithelial 293T cells significantly reduced the luciferase activity of wild-type HMGA2 (0.31±0.02 vs. 1.00±0.11; t=10.69, P=0.004). However, there was no significant effect on the luciferase activity of mutant-type HMGA2 (1.06±0.11 vs. 1.00±0.07; t=0.80, P=0.470). ChIP results showed that the mRNA expression level of HMGA2 in K1 cells was significantly increased in the anti-BHLHE40 group (6.57±0.62) compared with the IgG group (1.00±0.10; t=15.36, P<0.001). Compared to the oe-NC+DMSO group, the oe-HMGA2+DMSO group showed decreased apoptosis level ( P<0.05) and cisplatin sensitivity of SW579 cells, with a significant increase in the expression of OXPHOS complexes Ⅰ-Ⅴ and cellular oxygen consumption rates (all P<0.05). The effect of overexpressing HMGA2 was reversed by treatment with oe-HMGA2+Gboxin (all P<0.05). The recovery experiment showed that compared to the oe-NC+si-NC group, overexpression of BHLHE40 in SW579 cells increased cell viability and the expression of OXPHOS complexes Ⅰ-Ⅴ, while decreasing apoptosis levels and increasing cellular oxygen consumption rates and cisplatin IC 50 values (all P<0.05). However, simultaneous knockdown of HMGA2 reversed the effect of overexpressing BHLHE40 (all P<0.05) . Conclusion:BHLHE40 can activate the OXPHOS pathway by targeting and regulating the expression of HMGA2, thereby affecting the sensitivity of TC cells to cisplatin.

The Role of Post-Translational Modifications of Cav3. 2 in Neuropathic Pain / 中国生物化学与分子生物学报

Neuropathic pain is a common chronic pain that affects human health worldwide. As an important mediator of excitatory conduction in neurons, ion channels are important targets for mechanism research and drug research in this field. T-type calcium channel(Cav3) can be activated transiently when neurons are close to the resting potential of -70 mV, resulting in a transient Ca

Regulation mechanism of post-translational modification of farnesoid X receptor / 中国临床药理学与治疗学

Farnesoid X receptor (FXR) is a nuclear receptor activated by bile acid that is involved in regulating gene expression related to bile acid, fat, glucose, and amino acid metabolism. The activity of FXR is regulated by a variety of post-translational modifications. Common post-translational modifications of FXR include O-GlcNAcylation, phosphorylation, acetylation, sumoylation, methylation, etc. These post-translational modifications may affect FXR binding of DNA and ligand, heterodimerization, and subcellular localization, and may specifically regulate downstream gene transcription and expression. Different post-translational modifications can lead to changes in FXR stability and biological function, which are closely related to the occurrence of diseases. This paper aims to review the post-translational modification of FXR in the past five years and the mechanisms involved in disease regulation, to explore the effects of post-translational modification on the physiological function of FXR and to provide a theoretical basis for mechanism research targeting FXR.

Protein phosphorylation involved in psychedelic-induced head-twitch response in rats / 中国药理学通报

Aim To investigate the potential protein post-translational modifications of psychedelic-induced Head-twith response and underling mechanism. Methods Psychedelics LSD, DOM, or Psilocin was administered to rats by intraperitoneal injection to induce head-twitch response, then the most effective dosage was identified to create animal models of head-twitch behavior. Western blot was performed in detecting the protein phosphorylation, acetylation, and ubiquitination in prefrontal cortex of SD rats after 10 min or 30 min injection. Results LSD (0.025 mg • kg~, i. p.), DOM (3 mg•kg

HBXIP blocks myosin-IIA assembly by phosphorylating and interacting with NMHC-IIA in breast cancer metastasis

Tumor metastasis depends on the dynamic balance of the actomyosin cytoskeleton. As a key component of actomyosin filaments, non-muscle myosin-IIA disassembly contributes to tumor cell spreading and migration. However, its regulatory mechanism in tumor migration and invasion is poorly understood. Here, we found that oncoprotein hepatitis B X-interacting protein (HBXIP) blocked the myosin-IIA assemble state promoting breast cancer cell migration. Mechanistically, mass spectrometry analysis, co-immunoprecipitation assay and GST-pull down assay proved that HBXIP directly interacted with the assembly-competent domain (ACD) of non-muscle heavy chain myosin-IIA (NMHC-IIA). The interaction was enhanced by NMHC-IIA S1916 phosphorylation via HBXIP-recruited protein kinase PKCβII. Moreover, HBXIP induced the transcription of PRKCB, encoding PKCβII, by coactivating Sp1, and triggered PKCβII kinase activity. Interestingly, RNA sequencing and mouse metastasis model indicated that the anti-hyperlipidemic drug bezafibrate (BZF) suppressed breast cancer metastasis via inhibiting PKCβII-mediated NMHC-IIA phosphorylation in vitro and in vivo. We reveal a novel mechanism by which HBXIP promotes myosin-IIA disassembly via interacting and phosphorylating NMHC-IIA, and BZF can serve as an effective anti-metastatic drug in breast cancer.

Targeting metabolic vulnerability in mitochondria conquers MEK inhibitor resistance in KRAS-mutant lung cancer

MEK is a canonical effector of mutant KRAS; however, MEK inhibitors fail to yield satisfactory clinical outcomes in KRAS-mutant cancers. Here, we identified mitochondrial oxidative phosphorylation (OXPHOS) induction as a profound metabolic alteration to confer KRAS-mutant non-small cell lung cancer (NSCLC) resistance to the clinical MEK inhibitor trametinib. Metabolic flux analysis demonstrated that pyruvate metabolism and fatty acid oxidation were markedly enhanced and coordinately powered the OXPHOS system in resistant cells after trametinib treatment, satisfying their energy demand and protecting them from apoptosis. As molecular events in this process, the pyruvate dehydrogenase complex (PDHc) and carnitine palmitoyl transferase IA (CPTIA), two rate-limiting enzymes that control the metabolic flux of pyruvate and palmitic acid to mitochondrial respiration were activated through phosphorylation and transcriptional regulation. Importantly, the co-administration of trametinib and IACS-010759, a clinical mitochondrial complex I inhibitor that blocks OXPHOS, significantly impeded tumor growth and prolonged mouse survival. Overall, our findings reveal that MEK inhibitor therapy creates a metabolic vulnerability in the mitochondria and further develop an effective combinatorial strategy to circumvent MEK inhibitors resistance in KRAS-driven NSCLC.

SIRT1 activation synergizes with FXR agonism in hepatoprotection via governing nucleocytoplasmic shuttling and degradation of FXR

Farnesoid X receptor (FXR) is widely accepted as a promising target for various liver diseases; however, panels of ligands in drug development show limited clinical benefits, without a clear mechanism. Here, we reveal that acetylation initiates and orchestrates FXR nucleocytoplasmic shuttling and then enhances degradation by the cytosolic E3 ligase CHIP under conditions of liver injury, which represents the major culprit that limits the clinical benefits of FXR agonists against liver diseases. Upon inflammatory and apoptotic stimulation, enhanced FXR acetylation at K217, closed to the nuclear location signal, blocks its recognition by importin KPNA3, thereby preventing its nuclear import. Concomitantly, reduced phosphorylation at T442 within the nuclear export signals promotes its recognition by exportin CRM1, and thereby facilitating FXR export to the cytosol. Acetylation governs nucleocytoplasmic shuttling of FXR, resulting in enhanced cytosolic retention of FXR that is amenable to degradation by CHIP. SIRT1 activators reduce FXR acetylation and prevent its cytosolic degradation. More importantly, SIRT1 activators synergize with FXR agonists in combating acute and chronic liver injuries. In conclusion, these findings innovate a promising strategy to develop therapeutics against liver diseases by combining SIRT1 activators and FXR agonists.

Berberine targets the electron transport chain complex I and reveals the landscape of OXPHOS dependency in acute myeloid leukemia with IDH1 mutation / 中国天然药物

Metabolic reprogramming, a newly recognized trait of tumor biology, is an intensively studied prospect for oncology medicines. For numerous tumors and cancer cell subpopulations, oxidative phosphorylation (OXPHOS) is essential for their biosynthetic and bioenergetic functions. Cancer cells with mutations in isocitrate dehydrogenase 1 (IDH1) exhibit differentiation arrest, epigenetic and transcriptional reprogramming, and sensitivity to mitochondrial OXPHOS inhibitors. In this study, we report that berberine, which is widely used in China to treat intestinal infections, acted solely at the mitochondrial electron transport chain (ETC) complex I, and that its association with IDH1 mutant inhibitor (IDH1mi) AG-120 decreased mitochondrial activity and enhanced antileukemic effect in vitro andin vivo. Our study gives a scientific rationale for the therapy of IDH1 mutant acute myeloid leukemia (AML) patients using combinatory mitochondrial targeted medicines, particularly those who are resistant to or relapsing from IDH1mi.

Mechanisms of PiT2-loop7 Missense Mutations Induced Pi Dyshomeostasis / 神经科学通报·英文版

PiT2 is an inorganic phosphate (Pi) transporter whose mutations are linked to primary familial brain calcification (PFBC). PiT2 mainly consists of two ProDom (PD) domains and a large intracellular loop region (loop7). The PD domains are crucial for the Pi transport, but the role of PiT2-loop7 remains unclear. In PFBC patients, mutations in PiT2-loop7 are mainly nonsense or frameshift mutations that probably cause PFBC due to C-PD1131 deletion. To date, six missense mutations have been identified in PiT2-loop7; however, the mechanisms by which these mutations cause PFBC are poorly understood. Here, we found that the p.T390A and p.S434W mutations in PiT2-loop7 decreased the Pi transport activity and cell surface levels of PiT2. Furthermore, we showed that these two mutations attenuated its membrane localization by affecting adenosine monophosphate-activated protein kinase (AMPK)- or protein kinase B (AKT)-mediated PiT2 phosphorylation. In contrast, the p.S121C and p.S601W mutations in the PD domains did not affect PiT2 phosphorylation but rather impaired its substrate-binding abilities. These results suggested that missense mutations in PiT2-loop7 can cause Pi dyshomeostasis by affecting the phosphorylation-regulated cell-surface localization of PiT2. This study helps understand the pathogenesis of PFBC caused by PiT2-loop7 missense mutations and indicates that increasing the phosphorylation levels of PiT2-loop7 could be a promising strategy for developing PFBC therapies.

Phosphoproteomic analysis of human umbilical venous endothelial cells with DENV-2 infection / 南方医科大学学报

OBJECTIVE@#To analyze the differentially phosphorylated proteins in DENV-2-infected human umbilical venous endothelial cells (HUVECs) and explore the possible pathogenic mechanism of DENV-2 infection.@*METHODS@#The total proteins were extracted from DENV-2-infected HUVECs and blank control HUVEC using SDT lysis method. The phosphorylated proteins were qualitatively and quantitatively analyzed using tandem mass spectrometry (TMT). The identified differentially phosphorylated proteins were analyzed by bioinformatics analyses such as subcellular localization analysis, GO enrichment analysis, KEGG pathway analysis and protein-protein interaction (PPI) analysis. Western blotting was used to detect the expressions of phosphorylated Jun, map2k2 and AKT1 proteins in DENV-2-infected HUVECs.@*RESULTS@#A total of 2918 modified peptides on 1385 different proteins were detected, and among them 1346 were significantly upregulated (FC > 1.2, P < 0.05) and 1572 were significantly downregulated (FC < 0.83, P < 0.05). A total of 49 phosphorylated conserved motifs were obtained by amino acid conservative motif analysis. The most abundant differentially phosphorylated peptides in protein domain analysis included RNA recognition motif, protein kinase domain and PH domain. Subcellular localization analysis showed that the differentially modified peptides were mainly localized in the nucleus and cytoplasm. GO enrichment and KEGG pathway analysis showed that the differential peptides were mainly enriched in the regulation of stimulation response, biosynthesis of small molecules containing nuclear bases, and migration of phagosomes and leukocytes across the endothelium. PPI and KEGG joint analysis showed that the up-regulated and down-regulated differentially phosphorylated proteins were enriched in 15 pathways. In DENV-2-infected HUVECs, Western blotting detected differential expressions of phosphorylated proteins related with the autophagy pathway, namely JUN, MAP2K2 and AKT1, and among them p-JUN was significantly down-regulated and p-AKT1 and p-MAP2K2 were significantly upregulated (P < 0.01).@*CONCLUSION@#DENV-2 infected HUVECs show numerous differentially expressed proteins. The downregulation of p-JUN and upregulation of p-MAP2K2 and p-AKT1 suggest their potential roles in regulating autophagy, which is probably involved in the mechanism of DENV-2 infection.