👤 Xian-Jie Zhen

Chronic inflammation and T cell dysregulation persist in individuals infected with human immunodeficiency virus type 1 (HIV-1), even after successful antiretroviral treatment. The mechanism involved is not fully understood. Here, we used Olink proteomics to comprehensively analyze the aberrant inflammation-related proteins (IRPs) in chronic HIV-1-infected individuals, including in 24 treatment-naïve individuals, 33 immunological responders, and 38 immunological non-responders. T cell dysfunction was evaluated as T cell exhaustion, activation, and differentiation using flow cytometry. We identified a cluster of IRPs (cluster 7), including CXCL11, CXCL9, TNF, CXCL10, and IL18, which was closely associated with T cell dysregulation during chronic HIV-1 infection. Interestingly, IRPs in cluster 5, including ST1A1, CASP8, SIRT2, AXIN1, STAMBP, CD40, and IL7, were negatively correlated with the HIV-1 reservoir size. We also identified a combination of CDCP1, CXCL11, CST5, SLAMF1, TRANCE, and CD5, which may be useful for distinguishing immunological responders and immunological non-responders. In conclusion, the distinct inflammatory milieu is closely associated with immune restoration of T cells, and our results provide insight into immune dysregulation during chronic HIV-1 infection. Show less

The absence of prominent, actionable genetic alternations in osteosarcomas (OS) implies that transcriptional and epigenetic mechanisms significantly contribute to the progression of this life-threatening form of cancer. Therefore, the identification of potential transcriptional events that promote the survival of OS cells could be key in devising targeted therapeutic approaches for OS. We have previously shown that RUNX2 is a transcription factor (TF) essential for OS cell survival. Unfortunately, the transcriptional network or circuitry regulated by RUNX2 in OS cells is still largely unknown. The TFs that are in the RUNX2 transcriptional circuitry were identified by analyzing RNAseq and ChIPseq datasets of RUNX2. To evaluate the effect of SOX9 knockdown on the survival of osteosarcoma cells in vitro, we employed cleaved caspase-3 immunoblotting and propidium iodide staining techniques. The impact of SOX9 and JMJD1C depletion on OS tumor growth was examined in vivo using xenografts and immunohistochemistry. Downstream targets of SOX9 were identified and dissected using RNAseq, pathway analysis, and gene set enrichment analysis. Furthermore, the interactome of SOX9 was identified using BioID and validated by PLA. Our findings demonstrate that SOX9 is a critical TF that is induced by RUNX2. Both in vitro and in vivo experiments revealed that SOX9 plays a pivotal role in the survival of OS. RNAseq analysis revealed that SOX9 activates the transcription of MYC, a downstream target of RUNX2. Mechanistically, our results suggest a transcriptional network involving SOX9, RUNX2, and MYC, with SOX9 binding to RUNX2. Moreover, we discovered that JMJD1C, a chromatin factor, is a novel binding partner of SOX9, and depletion of JMJD1C impairs OS tumor growth. The findings of this study represent a significant advancement in our understanding of the transcriptional network present in OS cells, providing valuable insights that may contribute to the development of targeted therapies for OS. Show less

Triglycerides (TG) are required for fatty acid transport and storage and are essential for human health. Angiopoietin-like-protein 8 (ANGPTL8) has previously been shown to form a complex with ANGPTL3 that increases circulating TG by potently inhibiting LPL. We also recently showed that the TG-lowering apolipoprotein A5 (ApoA5) decreases TG levels by suppressing ANGPTL3/8-mediated LPL inhibition. To understand how LPL binds ANGPTL3/8 and ApoA5 blocks this interaction, we used hydrogen-deuterium exchange mass-spectrometry and molecular modeling to map binding sites of LPL and ApoA5 on ANGPTL3/8. Remarkably, we found that LPL and ApoA5 both bound a unique ANGPTL3/8 epitope consisting of N-terminal regions of ANGPTL3 and ANGPTL8 that are unmasked upon formation of the ANGPTL3/8 complex. We further used ANGPTL3/8 as an immunogen to develop an antibody targeting this same epitope. After refocusing on antibodies that bound ANGPTL3/8, as opposed to ANGPTL3 or ANGPTL8 alone, we utilized bio-layer interferometry to select an antibody exhibiting high-affinity binding to the desired epitope. We revealed an ANGPTL3/8 leucine zipper-like motif within the anti-ANGPTL3/8 epitope, the LPL-inhibitory region, and the ApoA5-interacting region, suggesting the mechanism by which ApoA5 lowers TG is via competition with LPL for the same ANGPTL3/8-binding site. Supporting this hypothesis, we demonstrate that the anti-ANGPTL3/8 antibody potently blocked ANGPTL3/8-mediated LPL inhibition in vitro and dramatically lowered TG levels in vivo. Together, these data show that an anti-ANGPTL3/8 antibody targeting the same leucine zipper-containing epitope recognized by LPL and ApoA5 markedly decreases TG by suppressing ANGPTL3/8-mediated LPL inhibition. Show less

Hereditary multiple exostosis (HME) is an autosomal dominant skeletal disorder characterized by the development of multiple cartilage-covered tumors on the external surfaces of bones (osteochondromas). Most of HME cases result from heterozygous loss-of-function mutations in EXT1 or EXT2 gene. Clinical examination was performed to diagnose the patients: Whole exome sequencing (WES) was used to identify pathogenic mutations in the proband, which is confirmed by Sanger sequencing and co-segregation analysis: qRT-PCR was performed to identify the mRNA expression level of EXT1 in patient peripheral blood samples: minigene splicing assay was performed to mimic the splicing process of EXT1 variants in vitro. We evaluated the pathogenicity of EXT1 c.1056 + 1G > T in a Chinese family with HME. The clinical, phenotypic, and genetic characterization of patients in this family were described. The variant was detected by whole-exome sequencing (WES) and confirmed by Sanger sequencing. Sequencing of the RT-PCR products from the patient's blood sample identified a large deletion (94 nucleotides), which is the whole exome 2 of the EXT1 cDNA. Splicing assay indicated that the mutated minigene produced alternatively spliced transcripts, which cause a frameshift resulting in an early termination of protein expression. Our study establishes the pathogenesis of the splicing mutation EXT1 c.1056 + 1G > T to HME and provides scientific foundation for accurate diagnosis and precise medical intervention for HME. Show less

IL-27 is an anti-inflammatory cytokine that triggers enhanced antitumor immunity, particularly cytotoxic T lymphocyte responses. In the present study, we sought to develop IL-27 into a therapeutic adjutant for adoptive T cell therapy using our well-established models. We have found that IL-27 directly improved the survival status and cytotoxicity of adoptive OT-1 CD8 Show less

Triglyceride (TG) molecules represent the major storage form of fatty acids, and TG metabolism is essential to human health. However, the mechanistic details surrounding TG metabolism are complex and incompletely elucidated. Although it is known that angiopoietin-like protein 8 (ANGPTL8) increases TGs through an ANGPTL3/8 complex that inhibits LPL, the mechanism governing ApoA5, which lowers TGs, has remained elusive. Current hypotheses for how ApoA5 acts include direct stimulation of LPL, facilitation of TG-containing particle uptake, and regulation of hepatic TG secretion. Using immunoprecipitation-MS and Western blotting, biolayer interferometry, functional LPL enzymatic assays, and kinetic analyses of LPL activity, we show that ApoA5 associates with ANGPTL3/8 in human serum and most likely decreases TG by suppressing ANGPTL3/8-mediated LPL inhibition. We also demonstrate that ApoA5 has no direct effect on LPL, nor does it suppress the LPL-inhibitory activities of ANGPTL3, ANGPTL4, or ANGPTL4/8. Importantly, ApoA5 suppression of ANGPTL3/8-mediated LPL inhibition occurred at a molar ratio consistent with the circulating concentrations of ApoA5 and ANGPTL3/8. Because liver X receptor (LXR) agonists decrease ApoA5 expression and cause hypertriglyceridemia, we investigated the effect of the prototypical LXR agonist T0901317 on human primary hepatocytes. We observed that T0901317 modestly stimulated hepatocyte ApoA5 release, but markedly stimulated ANGPTL3/8 secretion. Interestingly, the addition of insulin to T0901317 attenuated ApoA5 secretion, but further increased ANGPTL3/8 secretion. Together, these results reveal a novel intersection of ApoA5 and ANGPTL3/8 in the regulation of TG metabolism and provide a possible explanation for LXR agonist-induced hypertriglyceridemia. Show less

Psoriasis is a severe skin disease with significant physical and psychological health consequences. As a typical type of immune disease, both innate and adaptive immunity disorders play key roles in the development of psoriasis. Interleukin (IL)-30 was thought as a natural antagonist of gp130-mediated signaling that affects T helper type 1 and 17 cell polarization by inhibiting IL-6 and IL-27 signaling pathways. Here, we found that, in vitro, IL-30 reduced cytokine levels of HaCaT keratinocytes and dendritic cells (DCs), weakened the maturationS of DCs, inhibited DC-mediated T cell proliferation, and blocked the activation of nuclear factor-κB. In vivo, IL-30 inhibited the development of skin disease in two animal models: Krt14-Vegfa and imiquimod (IMQ)-induced psoriasis-like skin disease. Thus, IL-30 may be useful as a therapeutic agent for controlling psoriasis. Show less

Pulmonary fibrosis (PF) is a severe chronic disease. Although astragaloside IV (ASV) is known to have therapeutic effects on PF, the therapeutic targets of ASV require further study. This study was designed to elucidate the regulatory effect of ASV on PF via NLRP3. PF was triggered by transforming growth factor-β (TGF-β) Show less

Angiopoietin-like protein (ANGPTL)8 has been implicated in metabolic syndrome and reported to regulate adipose FA uptake through unknown mechanisms. Here, we studied how complex formation of ANGPTL8 with ANGPTL3 or ANGPTL4 varies with feeding to regulate LPL. In human serum, ANGPTL3/8 and ANGPTL4/8 complexes both increased postprandially, correlated negatively with HDL, and correlated positively with all other metabolic syndrome markers. ANGPTL3/8 also correlated positively with LDL-C and blocked LPL-facilitated hepatocyte VLDL-C uptake. LPL-inhibitory activity of ANGPTL3/8 was >100-fold more potent than that of ANGPTL3, and LPL-inhibitory activity of ANGPTL4/8 was >100-fold less potent than that of ANGPTL4. Quantitative analyses of inhibitory activities and competition experiments among the complexes suggested a model in which localized ANGPTL4/8 blocks the LPL-inhibitory activity of both circulating ANGPTL3/8 and localized ANGPTL4, allowing lipid sequestration into fat rather than muscle during the fed state. Supporting this model, insulin increased ANGPTL3/8 secretion from hepatocytes and ANGPTL4/8 secretion from adipocytes. These results suggest that low ANGPTL8 levels during fasting enable ANGPTL4-mediated LPL inhibition in fat tissue to minimize adipose FA uptake. During feeding, increased ANGPTL8 increases ANGPTL3 inhibition of LPL in muscle via circulating ANGPTL3/8, while decreasing ANGPTL4 inhibition of LPL in adipose tissue through localized ANGPTL4/8, thereby increasing FA uptake into adipose tissue. Excessive caloric intake may shift this system toward the latter conditions, possibly predisposing to metabolic syndrome. Show less

Cancer metastasis is the primary cause of death in patients diagnosed with colorectal cancer. Piperine, an active nontoxic ingredient in pepper, has potent anti-inflammatory and anti-cancer properties. However, little is known about the anti-migratory and anti-invasive effects of piperine on colorectal cancer. We demonstrated piperine inhibited the migration and invasion of colorectal cancer cells. Then, we found piperine reversed the biomarker expression of epithelial-to-mesenchymal transition (EMT), and suppressed the EMT regulator Snail. Furthermore, signal transducers and activators of transcription 3 (STAT3) was downregulated by piperine. Finally, STAT3 inhibitors were applied to observe the role of STAT3 in colorectal cancer migration, invasion and EMT. Collectively, piperine inhibits colorectal cancer migratory and invasive capacities through STAT3/Snail mediated EMT. Therefore, piperine could be applied as a possible therapeutic regimen for the prevention of colorectal cancer metastasis. Show less

Genetic studies based on single-nucleotide polymorphisms have provided valuable insights into the genetic architecture of complex diseases. However, a large fraction of heritability for most of these diseases remains unexplained, and the impact of small insertions and deletions (InDels) has been neglected. We performed a comprehensive screen on the exome sequence data of 1,326 genes using the SOAP-PopIndel method for InDels in 32,043 Chinese Han individuals and identified 29 unreported InDels within 25 susceptibility genes associated with psoriasis. Specifically, we identified 12 common, 9 low-frequency, and 8 rare InDels that explained approximately 1.29% of the heritability of psoriasis. Further analyses identified KIAA0319, RELN, NCAPG, ABO, AADACL2, LMAN1, FLG, HERC5, CCDC66, LEKR1, AFF3, ABCG2, ANXA7, SYTL2,GIPR, METTL1, and FYCO1 as unreported genes for psoriasis. In addition, identified InDels were associated with the following reported genes: IFIH1, ERAP1, ERAP2, LNPEP, UBLCP1, and STAT3; unreported independent associations for exonic InDels were found within GJB2 and ZNF816A. Our study enriched the genetic basis and pathogenesis of psoriasis and highlighted the non-negligible impact of InDels on complex human diseases. Show less

Objective To investigate the effect of Legionella pneumophila (LP) on the autophagy flux of RAW264.7 macrophages and explore the molecular mechanism of the expression changes of autophagy-related factors. Methods Live LP and inactivated LP (MOI=10, 50, 100) were separately used to affect RAW264.7 for 1, 2 and 3 hours so as to screen the optimum condition of LP infection. The optimal condition for LP infection was MOI=50 and the infection time was 2 hours. After affected by rapamycin (RAPA) for 12 hours, RAW264.7 cells were then treated by live and inactivated LP for another 2 hours. Normal control group, RAPA group, live LP group, inactivated LP group, RAPA-treated live LP group, RAPA-treated inactivated LP group were designed. The pmCherry-C1-EGFP-LC3B double fluorescent labeling protein method was used to monitor the changes of autophagy flux. The relevant factor CLN3, histone deacetylase 6 (HDAC6), regulator of G protein signaling 19 (RGS19), tumor necrosis factor (TNF), cathepsin B (CTSB), GABA type A receptor associated protein like 2 (GABARAPL2), P62, microtubule-related protein 1 light chain 3 (LC3) were screened by gene array analysis. In order to validate the results of gene array, real-time quantitative PCR (RT-qPCR) was used to detect the mRNA levels of nuclear factor erythroid derived 2 like 2 (Nrf2), beclin1 and kelch like ECH associated protein 1 (Keap1); Western blot analysis was performed to measure the protein levels of Nrf2, beclin1 and Keap1. Results Both the live LP group and the inactivated LP group inhibited the autophagy flux compared with the normal control group and the RAPA group. Gene array analysis showed that in the live LP and inactivated LP groups, LC3 expression was down-regulated and P62 expression was up-regulated. The results of RT-qPCR and Western blot analysis were consistent with the gene array. The mRNA and protein levels of Keap1, beclin1, and Nrf2 significantly decreased, while the mRNA and protein levels of Nrf2 significantly increased. Conclusion LP can inhibit the autophagy of macrophage via activating Nrf2-Keap1 signaling pathway. Show less

Chromobox (CBX) proteins are important components of epigenetic regulation complexes known to play key roles in hepatocellular carcinoma (HCC). Little is known about the function of distinct CBXs in HCC. To address this issue, the study investigated the roles of CBXs in the prognosis of HCC using ONCOMINE, UALCAN, Human Protein Atlas, Kaplan-Meier Plotter, Show less

MIP-T3 is a human protein found previously to associate with microtubules and the kinesin-interacting neuronal protein DISC1 (Disrupted-in-Schizophrenia 1), but whose cellular function(s) remains unknown. Here we demonstrate that the C. elegans MIP-T3 ortholog DYF-11 is an intraflagellar transport (IFT) protein that plays a critical role in assembling functional kinesin motor-IFT particle complexes. We have cloned a loss of function dyf-11 mutant in which several key components of the IFT machinery, including Kinesin-II, as well as IFT subcomplex A and B proteins, fail to enter ciliary axonemes and/or mislocalize, resulting in compromised ciliary structures and sensory functions, and abnormal lipid accumulation. Analyses in different mutant backgrounds further suggest that DYF-11 functions as a novel component of IFT subcomplex B. Consistent with an evolutionarily conserved cilia-associated role, mammalian MIP-T3 localizes to basal bodies and cilia, and zebrafish mipt3 functions synergistically with the Bardet-Biedl syndrome protein Bbs4 to ensure proper gastrulation, a key cilium- and basal body-dependent developmental process. Our findings therefore implicate MIP-T3 in a previously unknown but critical role in cilium biogenesis and further highlight the emerging role of this organelle in vertebrate development. Show less

Voltage-gated cation channels regulate neuronal excitability through selective ion flux. NALCN, a member of a protein family that is structurally related to the alpha1 subunits of voltage-gated sodium/calcium channels, was recently shown to regulate the resting membrane potentials by mediating sodium leak and the firing of mouse neurons. We identified a role for the Caenorhabditis elegans NALCN homologues NCA-1 and NCA-2 in the propagation of neuronal activity from cell bodies to synapses. Loss of NCA activities leads to reduced synaptic transmission at neuromuscular junctions and frequent halting in locomotion. In vivo calcium imaging experiments further indicate that while calcium influx in the cell bodies of egg-laying motorneurons is unaffected by altered NCA activity, synaptic calcium transients are significantly reduced in nca loss-of-function mutants and increased in nca gain-of-function mutants. NCA-1 localizes along axons and is enriched at nonsynaptic regions. Its localization and function depend on UNC-79, and UNC-80, a novel conserved protein that is also enriched at nonsynaptic regions. We propose that NCA-1 and UNC-80 regulate neuronal activity at least in part by transmitting depolarization signals to synapses in C. elegans neurons. Show less

There are more than 1 million patients with hypertrophic cardiomyopathy (HCM) in China, but the genetic basis is presently unknown. We investigated 100 independent patients with HCM (proband 51, sporadic 49) by sequencing the three most frequent HCM-causing genes (MYH7, MYBPC3, TNNT2). Thirty-four patients (34%) carried 25 types of mutations in the selected genes, most (14/25) were newly identified. MYH7 and MYBPC3 accounted for 41% and 18% of the familial HCM, respectively. TNNT2 mutations only caused 2% of the familial HCM. These results suggested that MYH7 and MYBPC3 were the predominant genes responsible for HCM, and TNNT2 mutation less proportionally contributed to Chinese HCM. MYH7 mutations caused HCM at younger age, more frequent syncope and ECG abnormalities compared with MYBPC3 mutations. The patients carrying R663C, Q734P, E930K in MYH7 and R130C in TNNT2 expressed malignant phenotype. R403Q in MYH7, the most common hot and malignant mutation in Caucasians, was not identified in Chinese. We confirmed the diversity of mutation profile in different populations and suggest that a global registry of HCM mutations and their phenotypes is necessary to correlate genotype with phenotype. Show less