👤 Zezhong Xiong

Early diagnosis is crucial to improve outcomes for pancreatic cancer patients (PC). The present study is designed to identify differently expressed peptides involved in PC as potential biomarkers. The serum proteome of 22 PC patients, 12 pancreatitis patients (PP), and 45 healthy controls (HC) are analyzed using magnetic bead-based weak cation exchange (MB-WCX) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Next, a supervised neural network (SNN) algorithm model is established by ClinProTools and the candidate biomarker identified using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Finally, the candidate biomarker is validated in tissue samples. The SNN algorithm model discriminates PC from HC with 92.97% sensitivity and 94.55% specificity. Seventy-six differentially expressed peptides are identified, seven of which are significantly different among PC, PP, and HC (p < 0.05). Only one peak (m/z: 1466.99) tends to be upregulated in samples from HC, PP, and PC, which is identified as region of RNA-binding motif protein 6 (RBM6). In subsequent tissue analysis, it is verified that RBM6 expression is significantly higher in PC tissues than paracancerous tissue. The results indicate that RBM6 might serve as a candidate diagnostic biomarker for PC. Methods used in this study could generate serum peptidome profiles of PC, PP, and HC, and present an approach to identify potential biomarkers for diagnosis of this malignancy. Show less

Epidemiological studies have identified that high levels of low-density lipoprotein-cholesterol (LDL-C) and low levels of high-density lipoprotein-cholesterol (HDL-C) are two independent causes of cardiovascular disease (CVD). Statins, niacin and fibrate are used for the treatment of CVD. However, some defects are shown in the treatment process. Thus, there is a demand for better treatment strategies that confer preferable efficacy with fewer side effects. Cholesteryl ester transfer protein (CETP) promotes the movement of CEs from HDL to LDL and VLDL in exchange for triglycerides (TGs). In this review, we reviewed the development and therapeutic applications of CETP inhibitors. A comprehensive review of the patents and pharmaceutical applications between 2009 and 2017 has been highlighted. Recently, CETP inhibitors have attracted considerable interest in atherosclerosis-related disease. There are four drugs (torcetrapib, anacetrapib, evacetrapib and dalcetrapib) that have been clinically evaluated in phase III clinical trials and showed promising results in raising HDL-C levels, but there were suboptimal performances in reducing the risk of cardiovascular events with all the compounds. The correlation between plasma HDL-C levels and CVD incidence needs further verification. The timeline is still long for CETP inhibitors to emerge from the treatment of CVD. Show less

Alzheimer's disease (AD) is a devastating neurodegenerative disease with limited treatment options and no cure. Beta-amyloid (Aβ) is a hallmark of AD that has potent neurotoxicity in neural stem cells (NSCs). Dual specificity phosphatase 6 (DUSP6) is a member of the mitogen-activated protein kinases (MAPKs), which is involved in regulating various physiological and pathological processes. Whether DUSP6 has a protective effect on Aβ-induced NSC injury remains to be explored. C17.2 neural stem cells were transfected with DUSP6-overexpressed plasmid. NSCs with or without DUSP6 overexpression were administrated with Aβ25⁻35 at various concentrations (i.e., 0, 2.5, 5 μM). DUSP6 expression after Aβ treatment was detected by Real-Time Polymerase Chain Reaction (RT-PCR) and Western blot and cell vitality was examined by the CCK8 assay. The oxidative stress (intracellular reactive oxygen species (ROS) and malondialdehyde (MDA)), endoplasmic reticulum stress (ER calcium level) and mitochondrial dysfunction (cytochrome c homeostasis) were tested. The expression of Show less

Restless Legs syndrome (RLS) is a common sleep disorder for which the genetic contribution remains poorly explained. In 2007, the first large scale genome wide association study (GWAS) identified three genomic regions associated with RLS. MEIS1, BTBD9 and MAP2K5/SKOR1 are the only known genes located within these loci and their association with RLS was subsequently confirmed in a number of follow up GWAS. Following this finding, our group reported the MEIS1 risk haplotype to be associated with its decreased expression at the mRNA and protein levels. Here we report the effect of the risk variants of the three other genes strongly associated with RLS. While these variants had no effect on the mRNA levels of the genes harboring them, we find that the homeobox transcription factor MEIS1 positively regulates the expression of the transcription co-repressor SKOR1. This regulation appears mediated through the binding of MEIS1 at two specific sites located in the SKOR1 promoter region and is modified by an RLS associated SNP in the promoter region of the gene. Our findings directly link MEIS1 and SKOR1, two significantly associated genes with RLS and also prioritize SKOR1 over MAP2K5 in the RLS associated intergenic region of MAP2K5/SKOR1 found by GWAS. Show less

The efficiency of in vitro embryo production remains low compared with that observed in vivo. Recent studies have independently shown that cyclic adenosine monophosphate (cAMP) modulation prior to in vitro maturation (IVM) supplementation improves oocyte developmental competence. In this context, special cAMP modulators have been applied during IVM as promising alternatives to improve this biotechnology. Accordingly, this study was conducted to evaluate the effects of treatment with cilostazol, a PDE3 inhibitor, during pre-IVM culture on oocyte meiotic maturation in yak. Immature yak cumulus-oocyte complexes (COCs) were treated in vitro without (control) or with 5μM cilostazol for 0, 2, or 4h prior to IVM. Results showed that the presence of cilostazol in pre-IVM medium significantly increased the percentages of oocytes at metaphase II stage compared with that in the control groups (P<0.05). Moreover, pre-IVM with cilostazol significantly enhanced intraoocyte cAMP and glutathione (GSH) levels at the pre-IVM or IVM phase relative to the no pre-IVM groups (P<0.05). After in vitro fertilization (IVF) and parthenogenetic activation (PA), the developmental competences of oocytes and embryo quality were improved significantly after pre-IVM with cilostazol compared with the control groups (P<0.05), given that the cleavage and blastocyst formation rates and the total number of blastocyst cells were increased. The presence of cilostazol also increased the levels of mRNA expression for adenylate cyclase 3 (ADCY3) and protein kinase 1 (PKA1), as well as decreased the abundance of phosphodiesterase 3A (PDE3A) in COCs and IVF blastocysts, compared with their control counterparts (P<0.05). The results demonstrated that the meiotic progression of immature yak oocytes could be reversibly affected by cAMP modulators. By contrast, treatment with cilostazol during pre-IVM positively affected the developmental competence of yak oocytes, probably by improving intraoocyte cAMP and GSH levels and regulating mRNA expression patterns. We concluded that appropriate treatment with cilostazol during pre-IVM would be beneficial for oocyte maturation in vitro. Show less

To develop a cost-effective molecular regulator to improve growth metabolism and immunity of animals, a recombinant plasmid co-expressing fatty acid desaturase (mFat-1) and pig insulin growth like factor 1 (IGF-1) genes was constructed by the 2 A self-cleavage technique. After entrapment within modified chitosan nanoparticles (chitosan modified with polyethyleneglycol-polyethylenimine, CPP), the recombinant plasmid was injected intramuscularly into mice. Compared with controls, co-expression of mFat-1 and IGF-1 significantly raised the level of serum IGF-1, and increased the liver and muscle docosa hexaenoic acid (DHA) content. Th and Tc cell levels were also elevated, as were expression levels of serum IL-4 and IL-6 genes. These results demonstrate that the immunity and metabolism of an animal can be effectively improved by co-expression of mFat-1 and IGF-1 genes in vivo, which may contribute to further development of novel immunomodulators with beneficial effects on growth metabolism and immunity. Show less

17β-Hydroxysteroid dehydrogenase type 3 (17β-HSD3) converts the inactive Δ4-androstenedione (A) to testosterone (T). Its deficiency is the most common testosterone biosynthesis defect that results in 46,XY Disorders Of Sex Development (DSD). However, the disease is difficult to distinguish from other 46,XY DSD for similar clinical phenotypes. Therefore, genetic testing provides good criteria for the diagnosis of the disease. In this study, HSD17B3 gene was examined in 3 unrelated Chinese patients with 46,XY DSD. Direct sequencing and quantitative PCR of HSD17B3 gene revealed the presence of a compound heterozygous mutation (p.I60T/exon1 deletion) in Patient 1, a homozygous (p.I60T) mutation in Patient 2 and a frameshift mutation (p.V25Efs∗54) and an exon1 deletion in Patient 3. All of the mutations have not been reported previously. These novel mutations may expand the mutation database of HSD17B3 gene and provide us new insights into the molecular mechanism of 17β-HSD3 deficiency. It is noteworthy that when direct sequence analysis showed a rare homozygous mutation in patients with non-consanguineous parents, "apparent homozygosity" should be taken into an account and the intragenic deletion should be screened. In addition, when single mutation was found in patients with disease in recessive heredity mode, the intragenic deletion should also be screened. Show less

Spectraplakins are a family of evolutionarily conserved gigantic proteins and play critical roles in many cytoskeleton-related processes. Microtubule actin crosslinking factor 1 (MACF1) is one of the most versatile spectraplakin with multiple isoforms. As a broadly expressed mammalian spectraplakin, MACF1 is important in maintaining normal functions of many tissues. The loss-of-function studies using knockout mouse models reveal the pivotal roles of MACF1 in embryo development, skin integrity maintenance, neural development, bone formation, and colonic paracellular permeability. Mutation in the human MACF1 gene causes a novel myopathy genetic disease. In addition, abnormal expression of MACF1 is associated with schizophrenia, Parkinson's disease, cancer and osteoporosis. This demonstrates the crucial roles of MACF1 in physiology and pathology. Here, we review the research advances of MACF1's roles in specific tissue and in human diseases, providing the perspectives of MACF1 for future studies. Show less

The cytoskeleton not only provides structure, it is an active component of cell function, and in several neurodegenerative disorders, there is evidence of cytoskeletal collapse. Cytoskeletal proteins have been specifically implicated in the pathogenesis of Parkinson's disease (PD), where degeneration of dopaminergic (DA) neurons is the hallmark, but in which many factors may determine the resilience of DA neurons during aging and stress. Here we report that the human Microtubule Actin Cross-linking Factor 1 gene (MACF1), a downstream target of PD biochemical pathways, was significantly associated with PD in 713 nuclear families. A significant allelic association between PD and rs12118033, with P = 0.0098, was observed, and a P < 0.03 was observed in the association analysis by both a trend test and an allelic test. We further observed that it is the MACF1b isoform, not the MACF1a isoform, which is expressed in DA neurons from six human postmortem brains. In a Caenorhabditis elegans system, used to explore the effect of altered MACF1b on neurons, knockdown or knockout of the MACF1b orthologue vab-10 resulted in the selective loss of DA neurons, which validated MACF1's risk candidacy in PD. These findings strongly suggest that MACF1b may contribute to the genetic etiology and mechanistic causation of PD. Show less

Inflammatory factors regulated by NF-κB play a significant role in PAH and myocardial hypertrophy. LXR activation may inhibit myocardial hypertrophy via suppressing inflammatory pathways; it is unknown whether LXR is also involved in PAH-induced myocardial hypertrophy or remodeling. To further explore the protective effect of LXR in PAH-induced cardiac hypertrophy and remodeling, a PAH model was developed, and T0901317, an agonist of LXR, was used to examine the effect of LXR activation. PAH rats demonstrated obvious cardiac hypertrophy and remodeling in the right ventricle, but significant improvement of cardiac hypertrophy and remodeling was observed in PAH rats treated with T0901317. Through RT-PCR, Western blot and ELISA examination, NF-κB, IL-6, TNF-α, and iNOS were found to be significantly reduced in PAH rats treated with T0901317 compared to PAH rats treated with DMSO. Apoptosis was also significantly reduced in PAH rats treated with T0901317. Thus, LXR activation may inhibit PAH-induced cardiac hypertrophy and remodeling by inhibiting NF-κB-mediated inflammatory pathways. Show less

Jasmonates (JAs) and abscisic acid (ABA) are phytohormones known play important roles in plant response and adaptation to various abiotic stresses including salinity, drought, wounding, and cold. JAZ (JASMONATE ZIM-domain) proteins have been reported to play negative roles in JA signaling. However, direct evidence is still lacking that JAZ proteins regulate drought resistance. In this study, OsJAZ1 was investigated for its role in drought resistance in rice. Expression of Show less

The fatality rate for cardiovascular disease (CVD) has increased in recent years and higher levels of triglyceride have been shown to be an independent risk factor for atherosclerotic CVD. Dysfunction of endothelial cells (ECs) is also a key factor of CVD. APOC3 is an important molecule in lipid metabolism that is closely associated with hyperlipidemia and an increased risk of developing CVD. But the direct effects of APOC3 on ECs were still unknown. This study was aimed at determining the effects of APOC3 on inflammation, chemotaxis and exudation in ECs. ELISA, qRT-PCR, immunofluorescence, flow cytometry and transwell assays were used to investigate the effects of APOC3 on human umbilical vein endothelial cells (HUVECs). SiRNA-induced TNF-α and JAM-1 silencing were used to observe how APOC3 influenced the inflammatory process in the ECs. Our results showed that APOC3 was closely associated with the inflammatory process in ECs, and that this process was characterized by the increased expression of TNF-α. Inflammatory processes further disrupted the tight junctions (TJs) between HUVECs by causing increased expression of JAM-1. JAM-1 was involved in maintaining the integrity of TJs, and it promoted the assembly of platelets and the exudation of leukocytes. Changes in its expression promoted chemotaxis and the exudation of ECs, which contributed to atherosclerosis. While the integrity of the TJs was disrupted, the adhesion of THP-1 cells to HUVECs was also increased by APOC3. In this study, we describe the mechanism by which APOC3 causes inflammation, chemotaxis and the exudation of ECs, and we suggest that controlling the inflammatory reactions that are caused by APOC3 may be a new method to treat CVD. Show less

Ehrlichia chaffeensis is an obligatory intracellular bacterium that causes a potentially fatal emerging zoonosis, human monocytic ehrlichiosis. E. chaffeensis has a limited capacity for biosynthesis and metabolism and thus depends mostly on host-synthesized nutrients for growth. Although the host cell cytoplasm is rich with these nutrients, as E. chaffeensis is confined within the early endosome-like membrane-bound compartment, only host nutrients that enter the compartment can be used by this bacterium. How this occurs is unknown. We found that ehrlichial replication depended on autophagy induction involving class III phosphatidylinositol 3-kinase (PtdIns3K) activity, BECN1 (Beclin 1), and ATG5 (autophagy-related 5). Ehrlichia acquired host cell preincorporated amino acids in a class III PtdIns3K-dependent manner and ehrlichial growth was enhanced by treatment with rapamycin, an autophagy inducer. Moreover, ATG5 and RAB5A/B/C were routed to ehrlichial inclusions. RAB5A/B/C siRNA knockdown, or overexpression of a RAB5-specific GTPase-activating protein or dominant-negative RAB5A inhibited ehrlichial infection, indicating the critical role of GTP-bound RAB5 during infection. Both native and ectopically expressed ehrlichial type IV secretion effector protein, Etf-1, bound RAB5 and the autophagy-initiating class III PtdIns3K complex, PIK3C3/VPS34, and BECN1, and homed to ehrlichial inclusions. Ectopically expressed Etf-1 activated class III PtdIns3K as in E. chaffeensis infection and induced autophagosome formation, cleared an aggregation-prone mutant huntingtin protein in a class III PtdIns3K-dependent manner, and enhanced ehrlichial proliferation. These data support the notion that E. chaffeensis secretes Etf-1 to induce autophagy to repurpose the host cytoplasm and capture nutrients for its growth through RAB5 and class III PtdIns3K, while avoiding autolysosomal killing. Show less

Non-obstructive azoospermia (NOA), a severe form of male infertility, is often suspected to be linked to currently undefined genetic abnormalities. To explore the genetic basis of this condition, we successfully sequenced ~650 infertility-related genes in 757 NOA patients and 709 fertile males. We evaluated the contributions of rare variants to the etiology of NOA by identifying individual genes showing nominal associations and testing the genetic burden of a given biological process as a whole. We found a significant excess of rare, non-silent variants in genes that are key epigenetic regulators of spermatogenesis, such as BRWD1, DNMT1, DNMT3B, RNF17, UBR2, USP1 and USP26, in NOA patients (P = 5.5 × 10(-7)), corresponding to a carrier frequency of 22.5% of patients and 13.7% of controls (P = 1.4 × 10(-5)). An accumulation of low-frequency variants was also identified in additional epigenetic genes (BRDT and MTHFR). Our study suggested the potential associations of genetic defects in genes that are epigenetic regulators with spermatogenic failure in human. Show less

The remarkable regenerative capacity of the zebrafish has made it an important model organism for studying heart regeneration. However, current loss-of-function studies are limited by a lack of conditional-knockout and effective gene-knockdown methods for the adult heart. Here, we report a novel siRNA knockdown method facilitated by poly(ethylene glycol)-b-poly(D,L-lactide) (PEG-PLA) nanoparticles. The siRNA-encapsulated nanoparticles successfully entered cells and resulted in remarkable gene-specific knockdown in the adult heart. This effect was demonstrated by down-regulation of the Aldh1a2 and Dusp6 proteins after intrapleural delivery of nanoparticle-encapsulated siRNAs. Furthermore, siRNA-mediated knockdown of Aldh1a2 was sufficient to inhibit myocardial proliferation and decrease the numbers of Gata4-positive cardiomyocytes after ventricular resection. Therefore, the results of this work demonstrate that nanoparticle-facilitated siRNA delivery provides an alternative tool for loss-of-function studies of genes in the adult heart in particular and other organs in general in the adult zebrafish. Show less

Cytogenetic analyses have revealed that complex karyotypes with numerous and highly variable genomic aberrations including single-nucleotide polymorphisms (SNPs) and copy number variants (CNVs), are observed in most of the conventional osteosarcomas (OSs). Several genome-wide studies have reported that the dysregulated expression of many genes is correlated with genomic aberrations in OS. We first compared OS gene expression in Gene Expression Omnibus (GEO) data sets and genomic aberrations in International Cancer Genome Consortium (ICGC) database to identify differentially expressed genes (DEGs) associated with SNPs or CNVs in OS. Then the function annotation of SNP- or CNV-associated DEGs was performed in terms of gene ontology analysis, pathway analysis and protein-protein interactions (PPIs). Finally, the expression of genes correlated with both SNPs and CNVs were confirmed by quantitative reverse-transcription PCR. Eight publicly available GEO data sets were obtained, and a set of 979 DEGs were identified (472 upregulated and 507 downregulated DEGs). Moreover, we obtained 1039 SNPs mapped in 938 genes, and 583 CNV sites mapped in 2915 genes. Comparing genomic aberrations and DGEs, we found 41 SNP-associated DEGs and 124 CNV-associated DEGs, in which 7 DGEs were associated with both SNPs and CNVs, including WWP1, EXT1, LDHB, C8orf59, PLEKHA5, CCT3 and VWF. The result of function annotation showed that ossification, bone development and skeletal system development were the significantly enriched terms of biological processes for DEGs. PPI network analysis showed that CCT3, COPS3 and WWP1 were the significant hub proteins. We conclude that these genes, including CCT3, COPS3 and WWP1 are candidate driver genes of importance in OS tumorigenesis. Show less

Restless legs syndrome (RLS) is a common disorder, with several known genetic risk factors, yet the actual genetic causes are unclear. Whole-exome sequencing (WES) was performed in seven RLS families, focusing on six known genetic loci: MEIS1, BTBD9, PTPRD, MAP2K5/SKOR1, TOX3, and rs6747972. Genotyping using specific TaqMan assays was performed in two case-control cohorts (627 patients and 410 controls), and in a familial cohort (n = 718). WES identified two candidate GLO1 variants (within the BTBD9 locus), p.E111A and the promoter variant c.-7C>T, both co-segregated with the disease in four families. The GLO1 p.E111A variant was associated with RLS in the French-Canadian cohort (odds ratio, OR = 1.38, p = 0.02), and demonstrated a similar trend in the US cohort (OR = 1.26, p = 0.09, combined analysis OR = 1.28, p = 0.009). However, the original genome-wide association study (GWAS) marker, BTBD9 rs9357271, had stronger association with RLS (OR = 1.84, p = 0.0003). Conditional haplotype analysis, controlling for the effect of the BTBD9 variant rs9357271, demonstrated that the association of GLO1 p.E111A turned insignificant (p = 0.54). In the familial cohort, the two GLO1 variants were not associated with RLS. Other variants in the SKOR1 (p.W200R and p.A672V) and PTPRD (p.R995C, p.Q447E, p.T781A, p.Q447E, and c.551-4C > G) genes, did not co-segregate with the disease. The GLO1 variations studied here are not the source of association of the BTBD9 locus with RLS. It is likely that the genetic variants affecting RLS susceptibility are located in regulatory regions. Show less

Several studies proposed that Restless Legs Syndrome (RLS) and Parkinson disease (PD) may be clinically and/or etiologically related. To examine this hypothesis, we aimed to determine whether the known RLS genetic markers may be associated with PD risk, as well as with PD subtype. Two case-control cohorts from Tel-Aviv and New-York, including 1133 PD patients and 867 controls were genotyped for four RLS-related SNPs in the genes MEIS1, BTBD9, PTPRD and MAP2K5/SKOR1. The association between genotype, PD risk and phenotype was tested using multivariate regression models. None of the tested SNPs was significantly associated with PD risk, neither in any individual cohort nor in the combined analysis after correction for multiple comparisons. The MAP2K5/SKOR1 marker rs12593813 was associated with higher frequency of tremor in the Tel-Aviv cohort (61.0% vs. 46.5%, p = 0.001, dominant model). However, the risk allele for tremor in this gene has been associated with reduced RLS risk. Moreover, this association did not replicate in Tremor-dominant PD patients from New-York. RLS genetic risk markers are not associated with increased PD risk or subtype in the current study. Together with previous genetic, neuropathological and epidemiologic studies, our results further strengthen the notion that RLS and PD are likely to be distinct entities. Show less

Both genetic predisposition and lifestyle factors are associated with the risk for obesity. Multiple obesity loci have been identified using genome-wide association studies mainly in European populations. The aims of this study were to examine the associations of these loci with obesity and gene×dietary behavior interactions among Chinese children and adolescents. Nineteen candidate SNPs were genotyped using Sequenom technology in the Chinese children (N=2977, 853 obese and 2124 controls, aged 7-17). Dietary behaviors were assessed using self-administered questionnaires. After adjusting for age, sex and multiple testing, MC4R rs17782313, SEC16B rs543874, MAP2K5 rs2241423 and KCTD15 rs11084753 were associated with obesity and obesity-related traits (all P<0.005), with odd ratios ranging from 1.22 to 2.15. Dose-response association was significant between genetic risk score, which was calculated by summing the risk alleles, and the risk of obesity (P<0.001). Multiplicative interaction was found between rs543874 and salt preference on obesity with an OR of 4.40 (95% CI, 1.12-17.30). Additive interactions with salt preference were found in rs17782313 and rs11084753. Our findings indicated that rs17782313, rs543874, rs2241423 and rs11084753 were associated with the risk for children obesity in China, and interaction of genetic variants with diet behaviors on obesity. Show less

Macrophage foam cell formation is the most prominent characteristic of the early stages of atherosclerosis. Ubiquitin Fold Modifier 1 (UFM1) is a new member of the ubiquitin-like protein family, and its underlying mechanism of action in macrophage foam cell formation is poorly understood. Our current study focuses on UFM1 and investigates its role in macrophage foam cell formation. Using real-time quantitative PCR (qRT-PCR) and western blot analysis, we first analyzed the UFM1 expression in mouse peritoneal macrophages (MPMs) from ApoE－/－ mice in vivo and in human macrophages treated with oxLDL in vitro. Subsequently, the effects of UFM1 on macrophages foam cell formation were determined by Nile Red staining and direct lipid analysis. We then examined whether UFM1 affects the process of lipid metabolism in macrophages. Lastly, with the method of small interfering RNA (siRNA), we delineated the mechanism of UFM1 to attenuate lipid accumulation in THP-1 macrophages. UFM1 is dramatically upregulated under atherosclerosis conditions both in vivo and in vitro. Moreover, UFM1 markedly decreased macrophage foam cell formation. Mechanistic studies revealed that UFM1 increased the macrophage cholesterol efflux, which was due to the increased expression of ATP-binding cassette transporters A1 (ABCA1) and G1 (ABCG1). Furthermore, the upregulation of ABCA1 and ABCG1 by UFM1 resulted from liver X receptor α (LXRα) activation, which was confirmed by the observation that LXRα siRNA prevented the expression of ABCA1 and ABCG1. Consistent with this, the UFM1-mediated attenuation of lipid accumulation was abolished by such inhibition. Taken together, our results showed that UFM1 could suppress foam cell formation via the LXRα-dependent pathway. Show less

Type 2 diabetes mellitus is affecting more than 382 million people worldwide. Although much progress has been made, a comprehensive understanding of the underlying disease mechanism is still lacking. Here we report a role for the β-cell primary cilium in type 2 diabetes susceptibility. We find impaired glucose handling in young Bbs4(-/-) mice before the onset of obesity. Basal body/ciliary perturbation in murine pancreatic islets leads to impaired first phase insulin release ex and in vivo. Insulin receptor is recruited to the cilium of stimulated β-cells and ciliary/basal body integrity is required for activation of downstream targets of insulin signalling. We also observe a reduction in the number of ciliated β-cells along with misregulated ciliary/basal body gene expression in pancreatic islets in a diabetic rat model. We suggest that ciliary function is implicated in insulin secretion and insulin signalling in the β-cell and that ciliary dysfunction could contribute to type 2 diabetes susceptibility. Show less

Juvenile Neuronal Ceroid Lipofuscinosis (JNCL) is a lysosomal storage disease caused by an autosomal recessive mutation in CLN3 that leads to vision loss, progressive cognitive and motor decline, and premature death. Morphological evidence of astrocyte activation occurs early in the disease process and coincides with regions where neuronal loss eventually ensues. However, the consequences of CLN3 mutation on astrocyte function remain relatively ill-defined. Astrocytes play a critical role in CNS homeostasis, in part, by their ability to regulate the extracellular milieu via the formation of extensive syncytial networks coupled by gap junction (GJ) channels. In contrast, unopposed hemichannels (HCs) have been implicated in CNS pathology by allowing the non-discriminant passage of molecules between the intracellular and extracellular milieus. Here we examined acute brain slices from CLN3 mutant mice (CLN3Δex7/8) to determine whether CLN3 loss alters the balance of GJ and HC activity. CLN3Δex7/8 mice displayed transient increases in astrocyte HC opening at postnatal day 30 in numerous brain regions, compared to wild type (WT) animals; however, HC activity steadily decreased at postnatal days 60 and 90 in CLN3Δex7/8 astrocytes to reach levels lower than WT cells. This suggested a progressive decline in astrocyte function, which was supported by significant reductions in glutamine synthetase, GLAST, and connexin expression in CLN3Δex7/8 mice compared to WT animals. Based on the early increase in astrocyte HC activity, CLN3Δex7/8 mice were treated with the novel carbenoxolone derivative INI-0602 to inhibit HCs. Administration of INI-0602 for a one month period significantly reduced lysosomal ceroid inclusions in the brains of CLN3Δex7/8 mice compared to WT animals, which coincided with significant increases in astrocyte GJ communication and normalization of astrocyte resting membrane potential to WT levels. Collectively, these findings suggest that alterations in astrocyte communication may impact the progression of JNCL and could offer a potential therapeutic target. Show less

While the adult human heart has very limited regenerative potential, the adult zebrafish heart can fully regenerate after 20% ventricular resection. Although previous reports suggest that developmental signaling pathways such as FGF and PDGF are reused in adult heart regeneration, the underlying intracellular mechanisms remain largely unknown. Here we show that H2O2 acts as a novel epicardial and myocardial signal to prime the heart for regeneration in adult zebrafish. Live imaging of intact hearts revealed highly localized H2O2 (~30 μM) production in the epicardium and adjacent compact myocardium at the resection site. Decreasing H2O2 formation with the Duox inhibitors diphenyleneiodonium (DPI) or apocynin, or scavenging H2O2 by catalase overexpression markedly impaired cardiac regeneration while exogenous H2O2 rescued the inhibitory effects of DPI on cardiac regeneration, indicating that H2O2 is an essential and sufficient signal in this process. Mechanistically, elevated H2O2 destabilized the redox-sensitive phosphatase Dusp6 and hence increased the phosphorylation of Erk1/2. The Dusp6 inhibitor BCI achieved similar pro-regenerative effects while transgenic overexpression of dusp6 impaired cardiac regeneration. H2O2 plays a dual role in recruiting immune cells and promoting heart regeneration through two relatively independent pathways. We conclude that H2O2 potentially generated from Duox/Nox2 promotes heart regeneration in zebrafish by unleashing MAP kinase signaling through a derepression mechanism involving Dusp6. Show less

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults with median survival time of 14.6 months. A small fraction of cancer stem cells (CSC) initiate and maintain tumors thus driving glioma tumorigenesis and being responsible for resistance to classical chemo- and radio-therapies. It is desirable to identify signaling pathways related to CSC to develop novel therapies to selectively target them. Transient receptor potential cation channel, subfamily M, member 7, also known as TRPM7 is a ubiquitous, Ca(2+) and Mg(2+) permeable ion channels that are special in being both an ion channel and a serine/threonine kinase. In studies of glioma cells silenced for TRPM7, we demonstrated that Notch (Notch1, JAG1, Hey2, and Survivin) and STAT3 pathways are down regulated in glioma cells grown in monolayer. Furthermore, phospho-STAT3, Notch target genes and CSC markers (ALDH1 and CD133) were significantly higher in spheroid glioma CSCs when compared with monolayer cultures. The results further show that tyrosine-phosphorylated STAT3 binds and activates the ALDH1 promoters in glioma cells. We found that TRMP7-induced upregulation of ALDH1 expression is associated with increases in ALDH1 activity and is detectable in stem-like cells when expanded as spheroid CSCs. Finally, TRPM7 promotes proliferation, migration and invasion of glioma cells. These demonstrate that TRPM7 activates JAK2/STAT3 and/or Notch signaling pathways and leads to increased cell proliferation and migration. These findings for the first time demonstrates that TRPM7 (1) activates a previously unrecognized STAT3→ALDH1 pathway, and (2) promotes the induction of ALDH1 activity in glioma cells. Show less

Ezetimibe is a potent inhibitor of Niemann-Pick type C1-Like 1 and has been approved for the treatment of hypercholesterolemia. Our preliminary study showed that ezetimibe promotes cholesterol efflux from vascular smooth muscle cells (VSMCs). Our aim was to investigate the cellular mechanisms underlying the ezetimibe actions. Rat VSMCs were converted to foam cells by incubation with cholesterol:methyl-β-cyclodextrin. The intracellular free cholesterol, total cholesterol, and the ratio of cholesteryl ester to total cholesterol were decreased after the incubation of VSMCs with different concentrations of ezetimibe (3, 10, 30, and 30 μmol/l) or treated with 30 μmol/l of ezetimibe for different time periods (6, 12, 24, and 48 h). Our results also showed that the expression of caveolin-1, liver X receptor α, and ATP-binding cassette transporter ABCA1 was enhanced, but the expression of nSREBP-1c was decreased in a concentration- and time-dependent manner. RNA interference was used to determine the roles of caveolin-1 and SREBP-1 in the lipid-lowering effect of ezetimibe. The results showed that caveolin-1 was involved in the regulation of intracellular cholesterol content, and the expression of caveolin-1 was repressed by SREBP-1. The present study indicates that ezetimibe protects VSMCs from cholesterol accumulation by regulating the expression of lipid metabolism-related genes. Show less

MYB-type transcription factors (TFs) play essential roles in plant growth, development and respond to environmental stresses. Role of MYB-related TFs of rice in drought stress tolerance is not well documented. Here, we report the isolation and characterization of a novel MYB-related TF, OsMYB48-1, of rice. Expression of OsMYB48-1 was strongly induced by polyethylene glycol (PEG), abscisic acid (ABA), H2O2, and dehydration, while being slightly induced by high salinity and cold treatment. The OsMYB48-1 protein was localized in the nucleus with transactivation activity at the C terminus. Overexpression of OsMYB48-1 in rice significantly improved tolerance to simulated drought and salinity stresses caused by mannitol, PEG, and NaCl, respectively, and drought stress was caused by drying the soil. In contrast to wild type plants, the overexpression lines exhibited reduced rate of water loss, lower malondialdehyde (MDA) content and higher proline content under stress conditions. Moreover, overexpression plants were hypersensitive to ABA at both germination and post-germination stages and accumulated more endogenous ABA under drought stress conditions. Further studies demonstrated that overexpression of OsMYB48-1 could regulate the expression of some ABA biosynthesis genes (OsNCED4, OsNCED5), early signaling genes (OsPP2C68, OSRK1) and late responsive genes (RAB21, OsLEA3, RAB16C and RAB16D) under drought stress conditions. Collectively, these results suggested that OsMYB48-1 functions as a novel MYB-related TF which plays a positive role in drought and salinity tolerance by regulating stress-induced ABA synthesis. Show less

Juvenile neuronal ceroid lipofuscinosis (JNCL) is a lysosomal storage disease caused by an autosomal recessive mutation in CLN3. Regions of microglial activation precede and predict areas of neuronal loss in JNCL; however, the functional role of activated microglia remains to be defined. The inflammasome is a key molecular pathway for activating pro-IL-1β in microglia, and IL-1β is elevated in the brains of JNCL patients and can induce neuronal cell death. Here, we utilized primary microglia isolated from CLN3(Δex7/8) mutant and wild-type (WT) mice to examine the impact of CLN3 mutation on microglial activation and inflammasome function. Treatment with neuronal lysates and ceramide, a lipid intermediate elevated in the JNCL brain, led to inflammasome activation and IL-1β release in CLN3(Δex7/8) microglia but not WT cells, as well as increased expression of additional pro-inflammatory mediators. Similar effects were observed following either TNF-α or IL-1β treatment, suggesting that CLN3(Δex7/8) microglia exist in primed state and hyper-respond to several inflammatory stimuli compared to WT cells. CLN3(Δex7/8) microglia displayed constitutive caspase-1 activity that when blocked led to increased glutamate release that coincided with hemichannel opening. Conditioned medium from activated CLN3(Δex7/8) or WT microglia induced significant cell death in CLN3(Δex7/8) but not WT neurons, demonstrating that intrinsically diseased CLN3(Δex7/8) neurons are less equipped to withstand cytotoxic insults generated by activated microglia. Collectively, aberrant microglial activation may contribute to the pathological chain of events leading to neurodegeneration during later stages of JNCL. Show less

Zinc ions highly concentrate in hippocampus and play a key role in modulating spatial learning and memory. At a time when dietary fortification and supplementation of zinc have increased the zinc consuming level especially in the youth, the toxicity of zinc overdose on brain function was underestimated. In the present study, weaning ICR mice were given water supplemented with 15 ppm Zn (low dose), 60 ppm Zn (high dose) or normal lab water for 3 months, the behavior and brain zinc homeostasis were tested. Mice fed high dose of zinc showed hippocampus-dependent memory impairment. Unexpectedly, zinc deficiency, but not zinc overload was observed in hippocampus, especially in the mossy fiber-CA3 pyramid synapse. The expression levels of learning and memory related receptors and synaptic proteins such as NMDA-NR2A, NR2B, AMPA-GluR1, PSD-93 and PSD-95 were significantly decreased in hippocampus, with significant loss of dendritic spines. In keeping with these findings, high dose intake of zinc resulted in decreased hippocampal BDNF level and TrkB neurotrophic signaling. At last, increasing the brain zinc level directly by brain zinc injection induced BDNF expression, which was reversed by zinc chelating in vivo. These results indicate that zinc plays an important role in hippocampus-dependent learning and memory and BDNF expression, high dose supplementation of zinc induces specific zinc deficiency in hippocampus, which further impair learning and memory due to decreased availability of synaptic zinc and BDNF deficit. Show less

The dried succulent stem of Cistanche tubulosa (Schenk) R. Wight is one component of traditional Chinese medicine prescriptions for diabetes. However, there have been no modern scientific reports to confirm this traditional claim for the Cistanche species until now. Thus, we investigated the effects of Cistanche tubulosa on glucose homeostasis and serum lipids in male BKS.Cg-Dock7(m) +/+ Lepr(db)/J (db/db) mice, a model of type 2 diabetes. The verbascoside and echinacoside contents of Cistanche tubulosa powder were evaluated using HPLC. The total phenolic content, polysaccharide content and antioxidant activity of Cistanche tubulosa powder were also evaluated. Then, different doses of Cistanche tubulosa (equivalent to 120.9, 72.6 or 24.2mg verbascoside/kg) were administered orally once daily for 45 days to male db/db mice. Age matched db/+ mice were used as normal controls. Body weight, fasting blood glucose, postprandial blood glucose and insulin tolerance test were measured during the experiment. At the time of sacrifice, blood was collected for measurement of insulin level, the homeostatic model assessment of insulin resistance (HOMA-IR), and total cholesterol, triglyceride, HDL-c, LDL-c and VLDL-c levels; liver and muscle were harvested for measurement of glycogen levels. Cistanche tubulosa significantly suppressed the elevated fasting blood glucose and postprandial blood glucose levels, improved insulin resistance and dyslipidemia, and suppressed body weight loss in db/db mice. However, Cistanche tubulosa did not significantly affect serum insulin levels or hepatic and muscle glycogen levels. This study provides scientific evidence for the traditional use of Cistanche tubulosa to treat diabetes, suggesting that Cistanche tubulosa has the potential for development into a functional food ingredient or drug to prevent hyperglycemia and treat hyperlipidemia. Show less