👤 Jiaqi Yue

Post-transcriptional regulation of mRNA translation and stability is primarily achieved by RNA-binding proteins, which are of increasing importance for heart function. Furthermore, G-quadruplex (G4) and G4 resolvase activity are involved in a variety of biological processes. However, the role of G4 resolvase activity in heart function remains unknown. The present study aims to investigate the role of RNA helicase associated with adenylate- and uridylate-rich element (RHAU), an RNA-binding protein with G4 resolvase activity in postnatal heart function through deletion of Rhau in the cardiomyocytes of postnatal mice. RHAU-deficient mice displayed progressive pathological remodeling leading to heart failure and mortality and impaired neonatal heart regeneration. RHAU ablation reduced the protein levels but enhanced mRNA levels of Yap1 and Hexim1 that are important regulators for heart development and postnatal heart function. Furthermore, RHAU was found to associate with both the 5' and 3' UTRs of these genes to destabilize mRNA and enhance translation. Thus, we have demonstrated the important functions of RHAU in the dual regulation of mRNA translation and stability, which is vital for heart physiology. Show less

The complications caused by diabetes mellitus (DM) are the focus of clinical treatment. However, little is known about diabetic enteropathy (DE) and its potential underlying mechanism. Intestinal epithelial cells (IECs) and intestinal epithelial stem cells (IESCs) were harvested from BKS.Cg-Dock7 Abnormal differentiation of IECs was observed in the mice with DM. The expression of Rspo3 was upregulated in the IECs from the mice with DM. This phenomenon was associated with Rspo3 overexpression. Additionally, Rspo3 is a major determinant of Lgr5+ stem cell identity in the diabetic state. Microarray analysis, bioinformatics analysis, and luciferase reporter assays revealed that microRNA (miR)-380-5p directly targeted Rspo3. Moreover, miR-380-5p upregulation was observed to attenuate the abnormal differentiation of IECs by regulating Rspo3 expression. Together, our results provide definitive evidence of the essential role of Rspo3 in the differentiation of IECs in DM. Show less

Neutrophilic asthmatics (NA) have less response to inhaled corticosteroids. We aimed to find out the predictor of treatment response in NA. Asthmatics (n = 115) and healthy controls (n = 28) underwent clinical assessment during 6-month follow-up with standardized therapy. Asthmatics were categorized by sputum differential cell count. The mRNA expressions were measured by RT-qPCR for sputum cytokines (IFN-γ, IL-1β, IL-27, FOXP3, IL-17A, and IL-5). The protein of IL-1β in sputum supernatant was detected by ELISA. Reticular basement membranes (RBM) were measured in the biopsy samples. The role and signaling pathways of IL-1β mediating the epithelial-mesenchymal transition (EMT) process were explored through A549 cells. NA had increased baseline sputum cell IL-1β expression compared to eosinophilic asthmatics (EA). After follow-up, NA had less improvement in FEV IL-1β level in baseline sputum predicts the poor lung function improvement in NA. The potential mechanism may be related to IL-1β augmenting TGF-β1-induced steroid-resistant EMT through MAPK signaling pathways. This study was approved by the Ethics Committee of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (IRB ID: 20150406). Show less

This study intends to explore the role of Vaspin and cholesterol metabolism in the process of osteoarthritis (OA) and its mechanism in vitro and in vivo. In vitro, chondrocytes were treated with interleukin-1β (IL-1β, 20 ng/mL) in combination with Vaspin at different concentrations for 48 h. The expressions of Aggrecan (ACAN), Collagen 2a1 (Col2a1), A Disintegrin And Metalloproteinase with Thrombo Spondin type 1 motifs 5 (ADAMTS 5), and Matrix metalloproteinase 13 (MMP13) were detected. In vivo, the expression of liver X receptor (LXRα) and other Cholesterol efflux related genes were detected in the rat OA knee cartilage-induced by papain. In vitro, in a concentration-dependent manner, Vaspin reversed the decreased expression of ACAN and Col2a1, and the increased expression of ADAMTS 5 and MMP13 caused by IL-1β. Besides, Vaspin promoted the expression of LXRα and other Cholesterol efflux related genes in a concentration-dependent manner in chondrocytes. However, miR155 mimics reversed the Vaspin-induced expression changes of cholesterol efflux pathway in chondrocytes. In vivo, the expression of LXRα and other Cholesterol efflux related genes were decreased in the rat OA knee cartilage-induced by papain. Besides, the level of Vaspin was reduced and the miroRNA155 (miR155) expression was increased in OA knee cartilage of rats. In conclusion, the decreased expression of Vaspin inhibited the expression of Cholesterol efflux pathway via miR155/LXRα. Finally, the inhibited Cholesterol efflux pathway led to the cholesterol accumulation and OA in cartilage. Show less

NRBF2, a regulatory subunit of the ATG14-BECN1/Beclin 1-PIK3C3/VPS34 complex, positively regulates macroautophagy/autophagy. In this study, we report that NRBF2 is required for the clearance of apoptotic cells and alleviation of inflammation during colitis in mice. NRBF2-deficient mice displayed much more severe colitis symptoms after the administration of ulcerative colitis inducer, dextran sulfate sodium salt (DSS), accompanied by prominent intestinal inflammation and apoptotic cell accumulation. Interestingly, we found that Show less

Metastatic recurrence remains a major cause of colorectal cancer (CRC) mortality. In this study, we investigated the mechanistic role of nuclear factor of activated T cells 1 (NFATc1) in CRC metastasis. First, we explored the potential role of NFATc1 in CRC using bioinformatics and hypothesized that NFATc1 might play different roles at different stages of CRC development. Then, we examined the relative expression of NFATc1 in 25 CRC tissues and adjacent normal tissues, and further analyzed the correlation between NFATc1 expression levels and clinical stages in 120 CRC patients. The role of NFATc1 in CRC metastasis and the molecular mechanisms were investigated in both in vitro and in vivo models. Our results showed that the expression of NFATc1 was increased in metastatic CRC tissues and positively associated with clinical stages (stage I vs. stage II, III or IV) of CRC. Overexpression of NFATc1 promoted CRC cell migration, invasion, and epithelial-mesenchymal transition (EMT). Moreover, SNAI1 was verified as the direct transcriptional target of NFATc1 and interacted with SLUG to promote EMT. Remarkably, our lung and liver metastasis mouse model demonstrated that NFATc1 overexpression accelerated CRC metastasis, and treatment with FK506, a calcineurin-NFAT pathway inhibitor, could suppress CRC metastasis in vivo. Taken together, our findings suggest that NFATc1 could transcriptionally activate SNAI1, which in turn interacts with SLUG to mediate EMT to promote CRC metastasis. Thus, making NFATc1 a promising therapeutic target in the treatment of metastatic CRC. Show less

Metastasis and chemoresistance are major causes of poor prognosis in patients with esophageal squamous cell carcinoma (ESCC), manipulated by multiple factors including deubiquitinating enzyme (DUB). DUB PSMD14 is reported to be a promising therapeutic target in various cancers. Here, we explored the antitumor activity of Thiolutin (THL), the PSMD14 inhibitor, as a new therapy strategy in ESCC. Show less

Porphyromonas gingivalis (Pg) is one of the pathogenic bacteria that cause periodontal diseases, lipopolysaccharide (LPS) is the key factor that triggers alveolar bone absorption. This study explored the action of Axin 1 on Pg-LPS-induced osteoblasts injury, so as to search a possible treatment for periodontal diseases. Rat osteoblasts were dealt with Pg-LPS and Axin 1 knockdown alone or in combination. The effect of Pg-LPS and Axin 1 on osteoblast viability and apoptosis were detected by Cell Counting Kit-8 and flow cytometry. The expressions of alkaline phosphatase (ALP) and Axin 1 in processed osteoblasts were measured by western blot (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) assays. Furthermore, the role of Axin 1 knockdown in the levels of inflammatory cytokines and apoptosis-related proteins were also determined. Pg-LPS inhibited the viability of osteoblasts and promote apoptosis with concentration and time dependence. ALP expression in Pg-LPS-treated osteoblasts was reduced, while Axin 1 expression was increased. On the one hand, Axin 1 knockdown reversed the Pg-LPS-induced reduction of cell activity and pro-apoptosis effect. On the other hand, Axin 1 knockdown not only improved the ALP activity of Pg-LPS-treated cells, but also reduced the elevation of inflammatory cytokines (TNF-α, IL-1β and IL-6) caused by Pg-LPS. Moreover, Pg-LPS increased the expressions of cleaved Caspase-3 and Bax, and inhibited Bcl-2 expressed, which was rescued by Axin 1 knockdown. Axin 1 knockdown inhibited Pg-LPS-induced osteoblastic apoptosis by regulating the levels of inflammatory cytokines, which may be helpful for the treatment of periodontal diseases. Show less

Contraction stimulates skeletal muscle glucose uptake predominantly through activation of AMP-activated protein kinase (AMPK) and Rac1. However, the molecular details of how contraction activates these signaling proteins are not clear. Recently, Axin1 has been shown to form a complex with AMPK and liver kinase B1 during glucose starvation-dependent activation of AMPK. Here, we demonstrate that electrical pulse-stimulated (EPS) contraction of C2C12 myotubes or treadmill exercise of C57BL/6 mice enhanced reciprocal coimmunoprecipitation of Axin1 and AMPK from myotube lysates or gastrocnemius muscle tissue. Interestingly, EPS or exercise upregulated total cellular Axin1 levels in an AMPK-dependent manner in C2C12 myotubes and gastrocnemius mouse muscle, respectively. Also, direct activation of AMPK with 5-aminoimidazole-4-carboxamide ribonucleotide treatment of C2C12 myotubes or gastrocnemius muscle elevated Axin1 protein levels. On the other hand, siRNA-mediated Axin1 knockdown lessened activation of AMPK in contracted myotubes. Further, AMPK inhibition with compound C or siRNA-mediated knockdown of AMPK or Axin1 blocked contraction-induced GTP loading of Rac1, p21-activated kinase phosphorylation, and contraction-stimulated glucose uptake. In summary, our results suggest that an AMPK/Axin1-Rac1 signaling pathway mediates contraction-stimulated skeletal muscle glucose uptake. Show less

Protein-protein interactions drive self-assembly of biomacromolecules and thus enable important physiological functions at a cellular level. Supramolecular chemists have developed artificial host-guest interactions that are similar with, yet distinct from and orthogonal to, the natural protein-protein interactions. For instance, cucurbit[ Show less

Impaired function of gonadotropin-releasing hormone (GnRH) neurons can cause a phenotypic spectrum ranging from delayed puberty to isolated hypogonadotropic hypogonadism (IHH). We sought to identify a new genetic etiology for these conditions. Exome sequencing was performed in an extended family with autosomal dominant, markedly delayed puberty. The effects of the variant were studied in a GnRH neuronal cell line. Variants in the same gene were sought in a large cohort of individuals with IHH. We identified a rare missense variant (F900V) in DLG2 (which encodes PSD-93) that cosegregated with the delayed puberty. The variant decreased GnRH expression in vitro. PSD-93 is an anchoring protein of NMDA receptors, a type of glutamate receptor that has been implicated in the control of puberty in laboratory animals. The F900V variant impaired the interaction between PSD-93 and a known binding partner, Fyn, which phosphorylates NMDA receptors. Variants in DLG2 that also decreased GnRH expression were identified in three unrelated families with IHH. The findings indicate that variants in DLG2/PSD-93 cause autosomal dominant delayed puberty and may also contribute to IHH. The findings also suggest that the pathogenesis involves impaired NMDA receptor signaling and consequently decreased GnRH secretion. Show less

IL-27 attenuates allergic inflammation and improves lung function in mouse models of allergic asthma. However, plasma IL-27 levels of asthma patients and the association with clinical features remain poorly understood. This study examined plasma IL-27 protein expression in untreated asthma patients and controls, analyzed its correlation with Th2 inflammation and lung function, and evaluated the effect of corticosteroids on IL-27 expression. Plasma IL-27 levels were lower in untreated asthma patients compared to controls. Plasma IL-27 levels were inversely correlated with sputum IL-5 mRNA expression in Th2 The results indicate that low levels of IL-27 in peripheral blood are closely related to Th2 inflammation and lung function of asthma patients. Low IL-27 levels in combination with high Th2 inflammation identify an asthma phenotype with high AHR and substantial response to corticosteroids. Understanding of this interaction could help to elucidate the inherent inflammation heterogeneity of asthma. Show less

Developing effective treatments for obesity and related metabolic disease remains a challenge. One logical strategy targets the appetite-regulating actions of gut hormones such as incretins. One of these incretins, glucose-dependent insulinotropic polypeptide (GIP), has garnered much attention as a potential target: however, whether it is beneficial to boost or block the action of GIP to promote weight loss remains an unresolved question. In this issue of the JCI, Kaneko and colleagues show that antagonizing GIP signaling in the CNS enhances the weight-reducing effects of leptin in rodents with diet-induced obesity. The authors posit that an increase in circulating intestinally derived GIP, as a consequence of overnutrition, acts in the brain to impair hypothalamic leptin action, resulting in increased food intake and body weight gain. This research advances the idea that multiple GIP signaling pathways and mechanisms exist in the obese state and offers intriguing new insights into the antiobesogenic consequences of antagonizing brain GIP action. Show less

Antipsychotic-induced metabolic disturbance (AIMD) is a common adverse effect of antipsychotics with genetics partly underpinning variation in susceptibility among schizophrenia patients. Melanocortin4 receptor (MC4R) gene, one of the candidate genes for AIMD, has been under-studied in the Chinese patients. We conducted a pharmacogenetic study in a large cohort of Chinese patients with schizophrenia. In this study, we investigated the genetic variation of MC4R in Chinese population by genotyping two SNPs (rs489693 and rs17782313) in 1,991 Chinese patients and examined association of these variants with the metabolic effects that were often observed to be related to AIMD. Metabolic measures, including body mass index (BMI), waist circumference (WC), glucose, triglyceride, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels were assessed at baseline and after 6-week antipsychotic treatment. We found that interaction of SNP×medication status (drug-naïve/medicated) was significantly associated with BMI, WC, and HDL change %, respectively. Both SNPs were significantly associated with baseline BMI and WC in the medicated group. Moderate association of rs489693 with WC, Triglyceride, and HDL change % were observed in the whole sample. In the drug-naïve group, we found recessive effects of rs489693 on BMI gain more than 7%, WC and Triglyceride change %, with AA incurring more metabolic adverse effects. In conclusion, the association between rs489693 and the metabolic measures is ubiquitous but moderate. Rs17782313 is less involved in AIMD. Two SNPs confer risk of AIMD to patients treated with different antipsychotics in a similar way. Show less

Danshen (Salvia miltiorrhiza) and prednisone are extensively applied in the treatment of kidney disease. Salvianolic acid A (SAA), the major biologically active component of Danshen, which has various biological effects. Our previous findings have demonstrated the renoprotective effect of SAA in various kidney disease rodent models. Here, we explore the therapeutic potential and possible mechanisms of SAA in combination with low-dose prednisone in adriamycin (ADR)-induced minimal change disease (MCD) rat model and mouse podocyte injury cell model. SAA was injected via tail vein at 10 mg/kg/day and prednisone at 5 mg/kg/day via gavage. Each drug was administered daily alone or in combination for 3 weeks. Combination therapy showed significant therapeutic efficacy as manifested by relieved urinary proteins, improved blood biochemical indicators including serum total protein, albumin, triglyceride, cholesterol, the indices of renal function i.e. blood urea nitrogen and serum creatinine levels, and ameliorated pathological lesions. Particularly, co-administration showed a significant anti-proteinuria effect in MCD rats. Further studies suggested that co-administration effectively ameliorated the podocyte injury as indicated by the reduction of podocyte foot processes fusion, up-regulation of synaptopodin and down-regulation of desmin. These beneficial effects are accompanied by activation of the Nrf2/HO-1 and PPARγ/Angptl4 pathways in vivo, and the effect of SAA on PPARγ/Angptl4 is also demonstrated in vitro. These findings suggested that SAA exerted podocyte-protection against MCD injury through PPARγ/Angptl4 and Nrf2/HO-1 pathways, and combined with low-dose prednisone possessed a significant anti-proteinuria and therapeutic effects in MCD rats. Show less

Increased circulating branched-chain amino acids (BCAAs) have been involved in the pathogenesis of obesity and insulin resistance (IR). However, evidence relating berberine (BBR), gut microbiota, BCAAs, and IR is limited. Here, we showed that BBR could effectively rectify steatohepatitis and glucose intolerance in high-fat diet (HFD)-fed mice. BBR reorganized gut microbiota populations under both the normal chow diet (NCD) and HFD. Particularly, BBR noticeably decreased the relative abundance of BCAA-producing bacteria, including order Clostridiales; families Streptococcaceae, Clostridiaceae, and Prevotellaceae; and genera Streptococcus and Prevotella. Compared with the HFD group, predictive metagenomics indicated a reduction in the proportion of gut microbiota genes involved in BCAA biosynthesis but the enrichment genes for BCAA degradation and transport by BBR treatment. Accordingly, the elevated serum BCAAs of HFD group were significantly decreased by BBR. Furthermore, the Western blotting results implied that BBR could promote the BCAA catabolism in the liver and epididymal white adipose tissues of HFD-fed mice by activation of the multienzyme branched-chain α-ketoacid dehydrogenase complex (BCKDC), whereas by inhibition of the phosphorylation state of BCKDHA (E1α subunit) and branched-chain α-ketoacid dehydrogenase kinase (BCKDK). The ex vivo assay further confirmed that BBR could increase BCAA catabolism in both AML12 hepatocytes and 3T3-L1 adipocytes. Finally, data from healthy subjects and diabetics confirmed that BBR could improve glycemic control and modulate circulating BCAAs. Together, our findings clarified BBR improving IR associated not only with gut microbiota alteration in BCAA biosynthesis but also with BCAA catabolism in liver and adipose tissues. Show less

Dysfunctional autophagy is implicated in Alzheimer's Disease (AD) pathogenesis. The alterations in the expression of many autophagy related genes (ATGs) have been reported in AD brains; however, the disparity of the changes confounds the role of autophagy in AD. To further understand the autophagy alteration in AD brains, we analyzed transcriptomic (RNAseq) datasets of several brain regions (BA10, BA22, BA36 and BA44 in 223 patients compared to 59 healthy controls) and measured the expression of 130 ATGs. We used autophagy-deficient mouse models to assess the impact of the identified ATGs depletion on memory, autophagic activity and amyloid-β (Aβ) production. We observed significant downregulation of multiple components of two autophagy kinase complexes BECN1-PIK3C3 and ULK1/2-FIP200 specifically in the parahippocampal gyrus (BA36). Most importantly, we demonstrated that deletion of NRBF2, a component of the BECN1-PIK3C3 complex, which also associates with ULK1/2-FIP200 complex, impairs memory in mice, alters long-term potentiation (LTP), reduces autophagy in mouse hippocampus, and promotes Aβ accumulation. Furthermore, AAV-mediated NRBF2 overexpression in the hippocampus not only rescues the impaired autophagy and memory deficits in NRBF2-depleted mice, but also reduces β-amyloid levels and improves memory in an AD mouse model. Our data not only implicates NRBF2 deficiency as a risk factor for cognitive impairment associated with AD, but also support the idea of NRBF2 as a potential therapeutic target for AD. Show less

Recently single-cell whole-exome sequencing (scWES) has deeply expanded and sharpened our knowledge of cancer evolution and subclonality. Herein, with scWES and matched bulk whole-exome sequencing (bulk WES) on two colorectal cancer (CRC) patients with normal or adenomatous polyps, we found that both the adenoma and cancer were of monoclonal origin, and both shared partial mutations in the same signaling pathways, but each showed a specific spectrum of heterogeneous somatic mutations. In addition, the adenoma and cancer further developed intratumor heterogeneity with the accumulation of nonrandom somatic mutations specifically in GPCR, PI3K-Akt and FGFR signaling pathways. We identified novel driver mutations that developed during adenoma and cancer evolution, particularly in OR1B1 (GPCR signaling pathway) for adenoma evolution, and LAMA1 (PI3K-Akt signaling pathway) and ADCY3 (FGFR signaling pathway) for CRC evolution. In summary, we demonstrated that both colorectal adenoma and CRC are monoclonal in origin, and the CRCs further diversified into different subclones with heterogeneous mutation profiles accumulating in GPCR, PI3K-Akt and FGFR signaling pathways. ScWES provides evidence for the importance of mutations in certain pathways that would not be as apparent from bulk sequencing of tumors, and can potentially establish whether specific mutations are mutually exclusive or occur sequentially in the same subclone of cells. Show less

The present study is aimed to evaluate difference of lipid metabolism related gene single nucleotide polymorphisms (SNPs) with ischemic stroke (IS) in Han and Uighur population of Xinjiang, China. Four hundred eight patients with ischemic stroke and 347 unrelated healthy individuals of age and sex matched were genotyped for Apolipoprotein A5 (ApoA5), lipoprotein lipase (LPL), Cholesteryl ester transfer protein (CETP) and low-density lipoprotein receptor (LDL-R) genes. Their mutation difference was analyzed by SNaP shot techniques. GeneMapper4.1 SPSS20.0 software was used for data management and analysis. Using a single locus analysis, the distribution difference of genotype loci in ischemic stroke cases and controls were detected to assess the genetic risk factors of ischemic stroke. Significance differences of genotype distribution in ischemic stroke cases and controls were observed in LDLR rs688 in Han and Uighur population in recessive model from analysis of single gene locus. It also was found that dramatic difference of triglyceride (TG) of LPL rs328 and systolic blood pressure in CETP rs708277 of total population. In binary logistic regression analysis of total studied population, ischemic stroke was observed significantly associated with LDLR rs688 both addictive model (TT/CC, adjusted OR = 1.47, 95% CI = 1.04-2.07) and recessive model (TT/CT + CC, adjusted Odds ratio (OR) = 2.66, 95% Confidence Interval (CI) = 1.37-5.14). In Han population, ischemic stroke was observed significantly associated with rs688 both in addictive model (TT/CC, adjusted OR = 3.27, 95% CI = 1.06-10.05). In Uighur population, no significant association was found between gene polymorphisms and the risk of ischemic stroke. Combined analysis of multiple gene and loci, interaction effects of LDLR rs688 C/T, ApoA5 rs662799 A/G and CETP rs708272 C/T denoted a significant influence on IS susceptibility. Single nucleotide polymorphisms of lipid metabolism relative gene were significantly associated with the morbidity of ischemic stroke in Han population. The interaction effects of rs688 C/T with ApoA5 rs662799 A/G and CETP rs708272 C/T promoted the occurrence of IS. Show less

This study was aimed to investigate the correlation of lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1 expressions in plasma by qPCR with rheumatoid arthritis (RA) risk and disease activity. 30 RA patients and 30 health controls (HC) were enrolled in this study. Plasma sample were collected from RA patients before any treatment carried out and HCs. Top 3 RA related long non-coding RNAs (lncRNAs) (lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1) were selected by a computational framework prediction. The expression of lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1 were determined by qPCR method. Age (P=0.350) and gender (P=0.542) were similar between RA patients and HCs. lnc-ITSN1-2 level was extremely increased in RA patients compared with HCs (P<0.001), while both lnc-APOC3-2 and lnc-AL355149.1 expressions were numerically higher in RA patients but with no statistical significance (P=0.152 and P=0.139 respectively). Receiver Operating Characteristic (ROC) curves were performed and we found lnc-ITSN1-2 disclosed a great diagnostic value for RA with area under curve (AUC) 0.898, 95% CI 0.813-0.983, and sensitivity was 90.0% and specificity was 80.0% respectively at the best cut-off point. In addition, plasma lnc-ITSN1-2 level was illuminated to be positively associated with erythrocyte sedimentation rate (ESR) (P=0.049), C-reactive protein (CRP) (P<0.001) and disease activity score in 28 joints (DAS28) (P=0.007). Circulating lnc-ITSN1-2 expression was observed to be a novel and convincing biomarker for RA diagnosis as well as disease management. Show less

In the intestinal epithelium, the aberrant regulation of cell/cell junctions leads to intestinal barrier defects, which may promote the onset and enhance the severity of inflammatory bowel disease (IBD). However, it remains unclear how the coordinated behaviour of cytoskeletal network may contribute to cell junctional dynamics. In this report, we identified ACF7, a crosslinker of microtubules and F-actin, as an essential player in this process. Loss of ACF7 leads to aberrant microtubule organization, tight junction stabilization and impaired wound closure in vitro. With the mouse genetics approach, we show that ablation of ACF7 inhibits intestinal wound healing and greatly increases susceptibility to experimental colitis in mice. ACF7 level is also correlated with development and progression of ulcerative colitis (UC) in human patients. Together, our results reveal an important molecular mechanism whereby coordinated cytoskeletal dynamics contributes to cell adhesion regulation during intestinal wound repair and the development of IBD. Show less

Alzheimer disease (AD) is the most common neurodegenerative disease characterized by the deposition of amyloid plaque in the brain. The autophagy-associated PIK3C3-containing phosphatidylinositol 3-kinase (PtdIns3K) complex has been shown to interfere with APP metabolism and amyloid beta peptide (Aβ) homeostasis via poorly understood mechanisms. Here we report that NRBF2 (nuclear receptor binding factor 2), a key component and regulator of the PtdIns3K, is involved in APP-CTFs homeostasis in AD cell models. We found that NRBF2 interacts with APP in vivo and its expression levels are reduced in hippocampus of 5XFAD AD mice; we further demonstrated that NRBF2 overexpression promotes degradation of APP C-terminal fragments (APP-CTFs), and reduces Aβ Show less

NRBF2/Atg38 has been identified as the fifth subunit of the macroautophagic/autophagic class III phosphatidylinositol 3-kinase (PtdIns3K) complex, along with ATG14/Barkor, BECN1/Vps30, PIK3R4/p150/Vps15 and PIK3C3/Vps34. However, its functional mechanism and regulation are not fully understood. Here, we report that NRBF2 is a fine tuning regulator of PtdIns3K controlled by phosphorylation. Human NRBF2 is phosphorylated by MTORC1 at S113 and S120. Upon nutrient starvation or MTORC1 inhibition, NRBF2 phosphorylation is diminished. Phosphorylated NRBF2 preferentially interacts with PIK3C3/PIK3R4. Suppression of NRBF2 phosphorylation by MTORC1 inhibition alters its binding preference from PIK3C3/PIK3R4 to ATG14/BECN1, leading to increased autophagic PtdIns3K complex assembly, as well as enhancement of ULK1 protein complex association. Consequently, NRBF2 in its unphosphorylated form promotes PtdIns3K lipid kinase activity and autophagy flux, whereas its phosphorylated form blocks them. This study reveals NRBF2 as a critical molecular switch of PtdIns3K and autophagy activation, and its on/off state is precisely controlled by MTORC1 through phosphorylation. Show less

The aim of the present study is to investigate whether the single nucleotide polymorphism (SNP) in lipid metabolism related genes would affect the effectiveness of atorvastatin in both Han and Uighur populations. 200 ischemic stroke patients were treated with atorvastatin. The differences of blood lipid level and their ratios were measured. Six lipid related genes, HMGCR, APOA5, LPL, CETP, LDLR and PCSK9 were selected as candidate genes. And nine SNP loci in these six genes were genotyped by SNaPshot technique. In all patients treated with atorvastatin, the SNP rs662799 significantly affected the ratio of x0394;LDL and x0394;LDL/LDL (p < 0.05); the SNP rs320 significantly affected the ratio of x0394;LDL/LDL and x0394;(LDL/HDL)/(LDL/HDL) (p < 0.01) and the SNP rs708272 significantly affected the ratio of x0394;LDL (p < 0.05). In Han population treated with atorvastatin, the SNP rs662799 significantly affected the ratio of x0394;TG (p < 0.05); the SNP rs320 significantly affected the ratio of x0394;LDL/LDL and x0394;(LDL/HDL)/(LDL/HDL) (p < 0.01). In Uighur population treated with atorvastatin, the SNP rs2266788 significantly affected the ratio of x0394;HDL (p < 0.05); the SNP rs662799 significantly affected the ratio of x0394;LDL/LDL (p < 0.05) and the SNP rs708272 significantly affected the ratio of x0394;LDL (p < 0.05). Polymorphisms of rs662799 and rs2266788 in APOA5 gene, rs320 in LPL gene and rs708272 in CETP gene had significant association with the effect of the lipid-lowering therapy via atorvastatin calcium on ischemic stroke patients. Show less

Pulmonary arterial hypertension (PAH) is associated with sustained vasoconstriction, inflammation and suppressed apoptosis of smooth muscle cells. Our previous studies have found that rat bone marrow-derived mesenchymal stem cells (rBMSCs) transduced with a mutant caveolin-1(F92A-Cav1) could enhance endothelial nitric oxide synthase (eNOS) activity and improve pulmonary vascular remodeling, but the potential mechanism is not yet fully explored. The present study was to investigate the gene expression profile upon rBMSCs/F92A-Cav1delivered to PAH rat to evaluate the role of F92A-Cav1 in its regulation. PAH was induced with monocrotaline (MCT, 60mg/kg) prior to delivery of lentiviral vector transduced rBMSCs expressing Cav1 or F92A-Cav1. Gene expression profiling was performed using Rat Signal Transduction PathwayFinder array. The expression changes of 84 key genes representing 10 signal transduction pathways in rat following rBMSCs/F92A-Cav1 treatment was examined. Screening with the Rat Signal Transduction PathwayFinder R rBMSCs/F92A-Cav1 inhibits inflammation and cell proliferation by regulating signaling pathways that related to inflammation, proliferation, cell cycle and oxidative stress. Show less

Turnover of focal adhesions allows cell retraction, which is essential for cell migration. The mammalian spectraplakin protein, ACF7 (Actin-Crosslinking Factor 7), promotes focal adhesion dynamics by targeting of microtubule plus ends towards focal adhesions. However, it remains unclear how the activity of ACF7 is regulated spatiotemporally to achieve focal adhesion-specific guidance of microtubule. To explore the potential mechanisms, we resolve the crystal structure of ACF7's NT (amino-terminal) domain, which mediates F-actin interactions. Structural analysis leads to identification of a key tyrosine residue at the calponin homology (CH) domain of ACF7, whose phosphorylation by Src/FAK (focal adhesion kinase) complex is essential for F-actin binding of ACF7. Using skin epidermis as a model system, we further demonstrate that the phosphorylation of ACF7 plays an indispensable role in focal adhesion dynamics and epidermal migration in vitro and in vivo. Together, our findings provide critical insights into the molecular mechanisms underlying coordinated cytoskeletal dynamics during cell movement. Show less

Reactive oxygen species (ROS) have been commonly accepted as inducers of autophagy, and autophagy in turn is activated to relieve oxidative stress. Yet, whether and how oxidative stress, generated in various human pathologies, regulates autophagy remains unknown. Here, we mechanistically studied the role of TRPM2 (transient receptor potential cation channel subfamily M member 2)-mediated Ca(2+) influx in oxidative stress-mediated autophagy regulation. On the one hand, we demonstrated that oxidative stress triggered TRPM2-dependent Ca(2+) influx to inhibit the induction of early autophagy, which renders cells more susceptible to death. On the other hand, oxidative stress induced autophagy (and not cell death) in the absence of the TRPM2-mediated Ca(2+) influx. Moreover, in response to oxidative stress, TRPM2-mediated Ca(2+) influx activated CAMK2 (calcium/calmodulin dependent protein kinase II) at levels of both phosphorylation and oxidation, and the activated CAMK2 subsequently phosphorylated BECN1/Beclin 1 on Ser295. Ser295 phosphorylation of BECN1 in turn decreased the association between BECN1 and PIK3C3/VPS34, but induced binding between BECN1 and BCL2. Clinically, acetaminophen (APAP) overdose is the most common cause of acute liver failure worldwide. We demonstrated that APAP overdose also activated ROS-TRPM2-CAMK2-BECN1 signaling to suppress autophagy, thereby causing primary hepatocytes to be more vulnerable to death. Inhibiting the TRPM2-Ca(2+)-CAMK2 cascade significantly mitigated APAP-induced liver injury. In summary, our data clearly demonstrate that oxidative stress activates the TRPM2-Ca(2+)-CAMK2 cascade to phosphorylate BECN1 resulting in autophagy inhibition. Show less