👤 Jiayi Xian

Angiopoietin-like protein 3 (Angptl3), a factor secreted by the liver, inhibits lipoprotein lipase and other lipases by forming a complex with Angptl4 and 8. However, whether inhibition of Angptl3 can alleviate hepatic lipid accumulation and atherosclerosis remains unclear. Therefore, this study explored the effect of small interfering RNA (siRNA)-based inactivation of Angptl3 on metabolic dysfunction-associated fatty liver disease (MAFLD) and atherosclerosis in male LDLR-deficient hamsters. Recombinant adeno-associated virus serotype 9 (AAV9) encoding Angptl3-siRNA or empty AAV (AAV9-null) were injected into male 4-month-old LDLR On HFD, Angptl3-siRNA-treated hamsters displayed significantly decreased plasma triglyceride (TG), total cholesterol, high-density lipoprotein-cholesterol, and glucose levels, compared with the AAV9-null hamsters. FPLC analysis further revealed a marked reduction of TG and cholesterol contents in VLDL/LDL fractions. Plasma apolipoprotein analysis showed relatively lower ApoB/ApoE levels and higher ApoA1 levels. Moreover, Angptl3-siRNA markedly accelerated the clearance of triglyceride-rich lipoproteins in LDLR These findings demonstrated that siRNA-based inactivation of Angptl3 alleviated MAFLD and atherosclerosis induced by HFD in LDLR The online version contains supplementary material available at 10.1186/s12944-026-02916-3. Show less

Ischemic heart failure (IHF) is one of the leading causes of death in the world. Plasma apolipoprotein C3 (ApoC3) levels are significantly elevated in patients with heart failure and positively associated with the incidence of ischemic heart disease (IHD). However, the causal association between ApoC3 and IHD development is unclear. ApoC3 expression changes were assessed in plasma from IHF patients/healthy donors and cardiac tissue from rodent models. 10-week-old male human ApoC3 transgenic (ApoC3 Overexpression of human ApoC3 in ApoC3 ApoC3 overexpression could activate cardiac TLR2/NF-κB to trigger the inflammation, oxidation, and apoptosis pathways, finally aggravating IHF in mice. Inactivation of ApoC3 could significantly alleviate IHF in hamsters. Show less

Vascular calcification (VC) is prevalent in patients with chronic renal failure (CRF), and it is closely related to the morbidity and mortality of cardiovascular diseases; however, no medical treatments are available for this condition. Recent clinical studies have shown that plasma apolipoprotein C3 (ApoC3) levels are positively correlated with VC. However, whether ApoC3 is involved in VC remains unclear. Sections of calcified renal arteries from CRF patients were immunostained to measure calcium deposition and ApoC3 expression. VC was induced in ApoC3 transgenic (Tg) and knockout (KO) mice by both 5/6 nephrectomy and vitamin D ApoC3 expression levels were increased in calcified arteries from mice and patients with CRF. ApoC3 overexpression exacerbated calcium deposition in the calcified aortas from Tg mice in vivo, and in calcified aortic rings of Tg mice ex vivo and VSMCs infected by adenovirus of ApoC3 in vitro. Consistently with these findings, ApoC3 deficiency alleviated these effects. Furthermore, ApoC3 overexpression increased ferroptosis in calcified aortas and VSMCs, whereas ApoC3 deficiency suppressed ferroptosis. Further investigation revealed that ApoC3 inhibited the AMPK/NRF2 signaling pathway through toll-like receptor 2 (TLR2) in calcified VSMCs, downregulated the expression of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4), subsequently increased lipid peroxidation and promoted ferroptosis, ultimately exacerbating calcification in the VSMCs. Furthermore, we found that knockdown of ApoC3 by siRNA remarkably attenuated calcification of renal arterial rings in humans. We demonstrated that ApoC3 exacerbated VC and increased the osteogenic transdifferentiation in VSMCs by increasing ferroptosis. ApoC3 might be a potential target for VC treatment. Show less

To investigate the role of adipokines in primary open angle glaucoma (POAG) by comparing the levels of these molecules in the aqueous humor among POAG patients and cataract patients with or without metabolic disorders. In this cross-sectional study, aqueous humor samples of 22 eyes of POAG patients (POAG group), 24 eyes of cataract patients without metabolic disorders (cataract group), and 24 eyes of cataract patients with metabolic disorders (cataract+metabolic disorders group) were assessed for 15 adipokines by Luminex bead-based multiplex array. The correlation between aqueous humor adipokines and clinical indicators of POAG was analyzed and compared across the groups. The analysis revealed that the levels of adiponectin, leptin, adipsin, retinol-binding protein 4 (RBP4), angiopoietin-2, angiopoietin-like protein 4 (ANGPTL4), chemokine (C-C motif) ligand 2 (CCL2), interleukin-8 (IL-8), and interleukin-18 (IL-18) in the aqueous humor of the POAG group were significantly higher than those in the cataract group. Additionally, the level of angiopoietin-2 in the POAG group was higher than in the cataract+metabolic disorders group. However, no significant correlation was found between the levels of adipokines in the POAG group and intraocular pressure (IOP), severity of POAG, or the use of glaucoma medications. This study demonstrates significant differences in aqueous humor adipokine levels between POAG and cataract patients. The findings suggest that the levels of aqueous humor adipokines may reflect the inflammatory states in POAG and systemic metabolic abnormalities. Show less

Tumorigenesis is typically accompanied by cellular dedifferentiation and the acquisition of stem cell-like attributes. However, few studies have comprehensively evaluated the putative relationships between these characteristics and various cancers. Here, we integrated gene expression and DNA methylation quantitative trait loci (cis-eQTL and cis-mQTL) data from the blood to perform multi-omics Mendelian randomization analysis. Our analyses revealed 967 stem cell-associated genes (P < 0.05) and 11,262 methylation sites (P < 0.01) significantly related to 12 cancers. SMAD7 (cg14321542) in colon cancer, IGF2 (cg13508136) in prostate cancer, and FADS1 (cg07005513) in rectal cancer were prioritized as candidate causal genes and regulatory elements. Notably, using cis-eQTL data from the corresponding tissue sites, we detected 16 stem cell-associated genes dramatically causally associated with six cancers (FDR<0.2). The gene THBS3 was particularly common in both blood and stomach tissues and exhibited prognostic significance. Furthermore, it was markedly associated with one microbial metabolic pathway and four immunophenotypes. Functional validation using the ECC12 gastric cancer cell line revealed that the inhibition of its expression could accelerate oxidative phosphorylation and reactive oxygen species production, reduce clonal proliferation ability, and promote the apoptosis of stomach tumor cells. Additionally, based on spatial transcriptomic data from gastrointestinal cancers, the results demonstrated the clusters enriched with the most stem cell-associated genes exhibited significantly enhanced tumor-promoting potency, and the THBS3-expressing cells displayed suppressed oxidative phosphorylation. Overall, this study enhances our understanding of tumorigenic mechanisms and aids in the identification of therapeutic targets. Show less

GATA family transcription factors are somatically variable (SV) in esophageal adenocarcinomas (EAC) and inducible by simulated reflux. Our study examines the mechanisms whereby GATA family members (GATA4, GATA6, and the atypical TRPS-1) influence oncogenesis during the Barrett's esophagus (BE) metaplasia-dysplasia transition preceding EAC. RNAseq analyses of esophageal cell lines and lesion-derived adult stem cells (ASCs) in conjunction shRNA- or CRISPR-facilitated gene silencing, together with reanalysis of The Cancer Genome Atlas data, spatial transcriptomics, and organ-on-a-chip studies were used. Although a gastroesophageal reflux disease history positively correlated with GATA4/6 somatically variable and a columnar-associated gene signature (ANPEP/GATA4) in The Cancer Genome Atlas EAC cases, it negatively associated with a squamous lineage-linked signature (TP63/SOX15) containing TRPS1. In experimental data, opposing effects on regulators of squamous and columnar lineage identity were uncovered between TRPS1 and classical GATA factors (GATA4/6). Interrogation of this GATA "fulcrum" defined further genes (CGN, IL6R, and GPRC5B) targeted for TRPS1-mediated suppression or GATA4/6 activation. A novel spatial transcriptomic signature of BE-associated high-grade dysplasia (HGD) captured GATA fulcrum action, through GPRC5B expression. Functionally, GPRC5B was found to be low-pH-responsive, to increase proliferative and colony formation rates, and when overexpressed facilitate a hyperproliferative HGD-like transformation of BE-ASCs. Using an organ-on-a-chip platform, cellular overgrowth, reduced luminal villus structures, lower goblet cell numbers, and loss of intestine-associated marker gene expression (TFF3/MUC2) were observed following GPRC5B overexpression in BE-ASCs, mirroring HGD. This study identifies critical GATA factor-mediated processes underlying cellular phenotype in the BE-HGD-EAC transition and identifies GATA-inducible GPRC5B as a functional marker and possible driver of progression through HGD to EAC. Show less

Signal-induced proliferation-associated 1 like 3 (SIPA1L3) is a member of the protein family. Very limited data are currently available regarding the role of SIPA1L3 in human carcinoma. Therefore, in this study, we investigated the expression pattern and function of SIPA1L3 in non-small cell lung cancer (NSCLC). We analyzed the distribution of SIPA1L3 in NSCLC specimens by immunohistochemistry, the relationship between SIPA1L3 expression and patient clinicopathological features, and investigated the effect of SIPA1L3 on cell growth and invasion in vivo and in vitro using small interfering RNA. Western blotting and immunoprecipitation were performed to demonstrate the interaction between SIPA1L3 and tight junction-associated angiomotin (AMOT) and Pals1-associtated tight junction protein. We found that SIPA1L3 was overexpressed in NSCLC clinical tissue samples and was associated with several clinicopathological factors. SIPA1L3 affects the proliferation and invasion of cancer cells both in vivo and in vitro. Using a SIPA1L3 mutant, we found that SIPA1L3 interacts with AMOT through its PDZ domain, which inhibits the binding of AMOT to Pals1-associtated tight junction protein and further decreases AMOT anchoring to tight junctions. Our findings suggested that SIPA1L3 promotes tumorigenesis in lung cancer cells through its PDZ domain-mediated interaction with AMOT, suggesting that SIPA1L3 is a novel candidate gene that contributes to the malignant phenotype of lung cancer. Show less

Ischemic stroke (IS) is a severe disease. The altered activation states of microglia play important roles in IS. In present study, a total of 125 C57BL/6 mice was used (N = 6 per group). Middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation (OGD) were performed for in vivo and in vitro model construction. The infarct size was detected using TTC staining. The nerve injury was evaluated by a neurological deficit score. OGD-treated brain microvascular endothelial cells (BMECs) were co-cultured with BV2 cells. Cell viability was determined by CCK-8 assay, and the apoptosis rate was identified by flow cytometry analysis. Transendothelial electronic resistance (TEER) of the cells was measured by TEER measurement. Molecular interactions were analyzed using dual-luciferase reporter gene, ChIP, and Co-IP assays. All in vitro experiments were conducted with three replicates, and each experiment was performed in triplicate. We found that Src Homology 2B Adaptor Protein 3 (SH2B3) was overexpressed in the cerebral cortex tissues of MCAO treated mice (P < 0.01), and BMECs co-cultured with BV-2 cells under OGD conditions (P < 0.01). SH2B3 knockdown or Myocyte Enhancer Factor 2 A (MEF2A) overexpression reduced infarct size and improved neurological function in MCAO mice. SH2B3 knockdown enhanced OGD-treated cell viability (P < 0.05), inhibited cell apoptosis (P < 0.05) in BMECs, and ameliorated BBB (P < 0.01). Moreover, SH2B3 knockdown changed the activation status of microglia. MEF2A promoted the transcriptional activation of WW Domain Containing E3 Ubiquitin Protein Ligase 2 (WWP2) and WWP2 promoted the ubiquitination and degradation of SH2B3. SH2B3 overexpression reversed the effects of MEF2A overexpression on microglia states, BMECs injury and BBB function. In summary, MEF2A promoted the ubiquitination-mediated degradation of SH2B3 via transcription up-regulating WWP2, then changed the activation status of microglia, thus ameliorating BMEC injury, and finally ameliorating IS injury. Show less

Previous studies have demonstrated that naringenin possesses lipid-lowering effects; however, the underlying mechanisms, particularly its specific molecular targets, remain uncertain. Using bioinformatics, three traditional Chinese medicine databases and one human disease database were integrated to establish two naringenin-target-hyperlipidemia modules: naringenin-oxidative stress (OS) and naringenin-lipid metabolism (LM). Data on 1,850 proteins from 1,871 genetic instruments were sourced from seven previous studies. Using Mendelian randomization based on data from the Integrative Epidemiology Unit genome-wide association study (case, n = 5,153; control, n = 344,069), we identified potential drug targets that were subsequently validated in the UK Biobank (396,565 individuals) and FinnGen (412,181 individuals) cohorts. Using molecular docking and molecular dynamics simulation to verify the binding ability of naringenin and causal protein. In plasma, every standard deviation increase in apolipoprotein B (APOB) was associated with an increased risk of hyperlipidemia (odds ratio [OR] = 9.37, 95% confidence interval [CI], 5.12-17.12; This Mendelian randomization-based combined analysis offers a robust framework for elucidating the pharmacological effects of naringenin and identifying candidate proteins for further investigation in the context of hyperlipidemia treatment. Show less

Within the context of residual cardiovascular risk in post-statin era, emerging evidence from epidemiologic and human genetic studies have demonstrated that triglyceride (TG)-rich lipoproteins and their remnants are causally related to cardiovascular risk. While, carriers of loss-of-function mutations of ApoC3 have low TG levels and are protected from cardiovascular disease (CVD). Of translational significance, siRNAs/antisense oligonucleotide (ASO) targeting ApoC3 is beneficial for patients with atherosclerotic CVD. Therefore, animal models of atherosclerosis with both hypercholesterolemia and hypertriglyceridemia are important for the discovery of novel therapeutic strategies targeting TG-lowering on top of traditional cholesterol-lowering. In this study, we constructed a novel mouse model of familial combined hyperlipidemia through inserting a human ApoC3 transgene (hApoC3-Tg) into C57BL/6 J mice and injecting a gain-of-function variant of adeno-associated virus-proprotein convertase subtilisin/kexin type 9 (AAV-PCSK9)-D377Y concurrently with high cholesterol diet (HCD) feeding for 16 weeks. In the last 10 weeks, hApoC3-Tg mice were orally treated with a combination of atorvastatin (10 mg·kg Show less

GPIHBP1 plays an important role in the hydrolysis of triglyceride (TG) lipoproteins by lipoprotein lipases (LPLs). However, Gpihbp1 knockout mice did not develop hypertriglyceridemia (HTG) during the suckling period but developed severe HTG after weaning on a chow diet. It has been postulated that LPL expression in the liver of suckling mice may be involved. To determine whether hepatic LPL expression could correct severe HTG in Gpihbp1 deficiency, liver-targeted LPL expression was achieved via intravenous administration of the adeno-associated virus (AAV)-human LPL gene, and the effects of AAV-LPL on HTG and HTG-related acute pancreatitis (HTG-AP) were observed. Suckling Gpihbp1 Show less

ApoC3 plays a central role in the hydrolysis process of triglyceride (TG)-rich lipoproteins mediated by lipoprotein lipase (LPL), which levels are positively associated with the incidence of cardiovascular disease (CVD). Although targeting ApoC3 by antisense oligonucleotide (ASO), Volanesorsen markedly reduces plasma TG level and increase high-density lipoprotein cholesterol (HDL-C) in patients with hypertriglyceridemia (HTG), the cholesterol-lowering effect of ApoC3 inhibition and then the consequential outcome of atherosclerotic cardiovascular disease (ASCVD) have not been reported in patients of familial hypercholesterolemia (FH) with severe refractory hypercholesterolemia yet. To investigate the precise effects of depleting ApoC3 on refractory hypercholesterolemia and atherosclerosis, we crossed ApoC3-deficient hamsters with a background of LDLR deficiency to generate a double knockout (DKO) hamster model (LDLR On the standard laboratory diet, DKO hamsters had reduced levels of plasma TG and total cholesterol (TC) relative to LDLR In this study, our novel findings provide new insight into the application of ApoC3 inhibition for severe refractory hypercholesterolemia and ASCVD. Show less

Differentiation blockade is a hallmark of acute myeloid leukemia (AML). A strategy to overcome such a blockade is a promising approach against the disease. The lack of understanding of the underlying mechanisms hampers development of such strategies. Dysregulated ribonucleotide reductase (RNR) is considered a druggable target in proliferative cancers susceptible to deoxynucleoside triphosphate (dNTP) depletion. Herein, we report an unanticipated discovery that hyperactivating RNR enables differentiation and decreases leukemia cell growth. We integrate pharmacogenomics and metabolomics analyses to identify that pharmacologically (eg, nelarabine) or genetically upregulating RNR subunit M2 (RRM2) creates a dNTP pool imbalance and overcomes differentiation arrest. Moreover, R-loop-mediated DNA replication stress signaling is responsible for RRM2 activation by nelarabine treatment. Further aggravating dNTP imbalance by depleting the dNTP hydrolase SAM domain and HD domain-containing protein 1 (SAMHD1) enhances ablation of leukemia stem cells by RRM2 hyperactivation. Mechanistically, excessive activation of extracellular signal-regulated kinase (ERK) signaling downstream of the imbalance contributes to cellular outcomes of RNR hyperactivation. A CRISPR screen identifies a synthetic lethal interaction between loss of DUSP6, an ERK-negative regulator, and nelarabine treatment. These data demonstrate that dNTP homeostasis governs leukemia maintenance, and a combination of DUSP inhibition and nelarabine represents a therapeutic strategy. Show less

Apolipoprotein C3 (ApoC3) is a regulator of triglyceride metabolism and inflammation, and its plasma levels are positively correlated with the progression of diabetic nephropathy (DN) in patients. However, the role and underlying mechanism of ApoC3 in DN remain unclear. Diabetes was induced in ApoC3 transgenic (Tg) and knockout (KO) mice by injection of streptozotocin. We studied the effect of ApoC3 on type 1 DN after 4 months of diabetes. Plasma glucose and lipid levels, renal function parameters and inflammation- and fibrogenesis-related gene and protein expression levels were studied. In vitro, human mesangial cells (HMCs) were incubated with high levels of glucose or/and triglyceride-rich lipoproteins (TRLs) with a high or low ApoC3 content isolated from Tg or wild-type (WT) mice, respectively, to explore the mechanisms of ApoC3 on development of DN. We found that compared to WT mice, Tg mice exhibited hypertriglyceridemia (HTG), aggravated early renal function injury and inflammation, enlarged glomerular and mesangial surface areas, renal lipid deposition and elevated fibrogenesis-related gene expression levels after 4 months of diabetes. ApoC3 overexpression activated the renal Toll-like receptor 2 (TLR2) and nuclear factor-κB (NF-κB) signaling pathways and increased the renal gene and protein expression levels of the downstream inflammatory factors TNF-α, VCAM-1 and MCP-1. Unfortunately, we did not find that ApoC3 deficiency had an obvious protective effect against DN. In vitro, we found that TRLs with a high ApoC3 content increased the gene and protein expression levels of inflammation- and fibrogenesis-related factors in HMCs compared to those following administration of the same concentration of TRLs with a low ApoC3 content. These effects of ApoC3 were inhibited by blockade of TLR2 or NF-κB. These findings suggest that ApoC3 aggravates early-stage DN by activating the renal TLR2/NF-κB pathway which is partially independent of HTG. Show less

Hereditary multiple exostoses (HME) is a rare skeletal disorder characterized by the formation of multiple benign cartilage-capped tumors, usually in the metaphyseal region of the long bones. Over 70% of HME cases arise from monoallelic mutations in either of the two genes encoding the heparan sulfate (HS) synthesis enzymes, ext1 and ext2. To identify more HME-associated mutations, genomic DNA from members of five independent consanguineous families with HME was sequenced with whole exome sequencing (WES). A novel heterozygous splice site mutation (c.1173+2T>A) in ext2 was detected in all three affected members of family V. Further study showed that the novel mutation caused exon 7 of ext2 mRNA to be skipped during splicing and caused a frameshift after the codon for Arg360, which results in the appearance of new 43 codons, followed by a termination codon. Although the resulting truncated protein was still localized to the Golgi, similar to the full-length EXT2, its HS synthesis activity decreased by 40%. In this study, a novel splice site mutation in ext2 was identified and suggested to be a pathogenic mutation of HME, which may expand the genetic etiology spectrum of HME and may be helpful for clinical genetic counseling and prenatal diagnosis. Show less

To examine the serum levels of interleukin (IL)-30 in patients with psoriasis and evaluate the correlations with the Psoriasis Area and Severity Index (PASI). Serum was collected from 26 patients with psoriasis and 26 healthy controls in a case-control setting, and the level of IL-30 was determined using an enzyme-linked immunosorbent assay. Statistical analysis of the IL-30 levels among groups and further correlation analyses of IL-30 levels with PASI scores were performed. A significant increase in the level of IL-30 in patients with psoriasis compared with healthy controls was observed. In addition, a positive correlation between the IL-30 concentration and PASI scores was found in patients with psoriasis. IL-30 is presumably involved in the proliferation of epidermal cells during the development of psoriasis. Further studies with a larger number of participants are required to comprehensively elucidate the biological roles of IL-30 in the pathogenesis of psoriasis. Show less

Colorectal cancer (CRC) is the third most common type of cancer worldwide. Metastasis and chemoresistance are regarded as the two leading causes of treatment failure and high mortality in CRC. Forkhead Box M1 (FOXM1) has been involved in malignant behaviors of cancer. However, the role and mechanism of FOXM1 in simultaneously regulating metastasis and chemoresistance of CRC remain poorly understood. Here, we found that FOXM1 was overexpressed in oxaliplatin- and vincristine-resistant CRC cells (HCT-8/L-OHP and HCT-8/VCR) with enhanced metastatic potential, compared with HCT-8 cells. FOXM1 overexpression increased migration, invasion and drug-resistance to oxaliplatin and vincristine in HCT-8 cells, while FOXM1 knockdown using shFOXM1 impaired metastasis and drug-resistance in HCT-8/L-OHP and HCT-8/VCR cells. Moreover, FOXM1 up-regulated Snail to trigger epithelial-mesenchymal transition-like molecular changes and multidrug-resistance protein P-gp expression, while silencing Snail inhibited FOXM1-induced metastasis and drug-resistance. We further identified that disheveled-2 (DVL2) was crucial for FOXM1-induced Snail expression, metastasis and chemoresistance. Furthermore, FOXM1 bound to DVL2, and enhanced nuclear translocation of DVL2 and DVL2-mediated transcriptional activity of Wnt/β-catenin known to induce Snail expression. In conclusion, FOXM1/DVL2/Snail axis triggered aggressiveness of CRC. Blocking FOXM1/DVL2/Snail pathway simultaneously inhibited metastasis and chemoresistance in CRC cells, providing a new strategy for successful CRC treatment. Show less

Hypertriglyceridemia severity is linked to acute pancreatitis prognosis, but it remains unknown why a portion of severe hypertriglyceridemia patients do not develop severe acute pancreatitis. To investigate whether hypertriglyceridemia subtypes affect acute pancreatitis progression, we analyzed two genetically modified hypertriglyceridemia mouse models-namely, glycosylphosphatidylinositol high-density lipoprotein binding protein 1 knockout (Gpihbp1-/-) and apolipoprotein C3 transgenic (ApoC3-tg) mice. Acute pancreatitis was induced by 10 intraperitoneal caerulein injections. Biochemical assays and pathological analysis were performed for the severity evaluation of acute pancreatitis. Plasma triglyceride-rich lipoproteins (TRLs), including chylomicrons and very low-density lipoprotein (VLDL), were collected via ultracentrifugation to evaluate their cytotoxic effects on primary pancreatic acinar cells (PACs). We found that the particle sizes of Gpihbp1-/- TRLs were larger than ApoC3-tg TRLs. Severe pancreatic injury with large areas of pancreatic necrosis in the entire lobule was induced in Gpihbp1-/- mice when plasma triglyceride levels were greater than 2000 mg/dL. However, ApoC3-tg mice with the same triglyceride levels did not develop large areas of pancreatic necrosis, even upon the administration of poloxamer 407 to further increase triglyceride levels. Meanwhile, in the acute pancreatitis model, free fatty acids (FFAs) in the pancreas of Gpihbp1-/- mice were greater than in ApoC3-tg mice. TRLs from Gpihbp1-/- mice released more FFAs and were more toxic to PACs than those from ApoC3-tg mice. Chylomicrons from patients showed the same effects on PACs as TRLs from Gpihbp1-/- mice. Gpihbp1-/- mice with triglyceride levels below 2000 mg/dL had milder pancreatic injury and less incidence of pancreatic necrosis than those with triglyceride levels above 2000 mg/dL, similar to Gpihbp1-/-mice with triglyceride levels above 2000 mg/dL but with fenofibrate administration. These findings demonstrated that hypertriglyceridemia subtypes with large TRL particles could affect acute pancreatitis progression and that chylomicrons showed more cytotoxicity than VLDL by releasing more FFAs. Show less

Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a key role in cholesterol homeostasis and atherogenesis. However, there are only limited rodent models, with a functional low-density lipoprotein receptor (LDLR) pathway and cholesteryl ester transfer protein (CETP) to evaluate the drug candidates targeting the PCSK9/LDLR pathway, that are translatable to humans. Here, by using our recently generated LDLR heterozygote ( Show less

Lecithin cholesterol acyltransferase (LCAT) plays a pivotal role in HDL metabolism but its influence on atherosclerosis remains controversial for decades both in animal and clinical studies. Because lack of cholesteryl ester transfer protein (CETP) is a major difference between murine and humans in lipoprotein metabolism, we aimed to create a novel Syrian Golden hamster model deficient in LCAT activity, which expresses endogenous CETP, to explore its metabolic features and particularly the influence of LCAT on the development of atherosclerosis. CRISPR/CAS9 gene editing system was employed to generate mutant LCAT hamsters. The characteristics of lipid metabolism and the development of atherosclerosis in the mutant hamsters were investigated using various conventional methods in comparison with wild type control animals. Hamsters lacking LCAT activity exhibited pro-atherogenic dyslipidemia as diminished high density lipoprotein (HDL) and ApoAI, hypertriglyceridemia, Chylomicron/VLDL accumulation and significantly increased ApoB100/48. Mechanistic study for hypertriglyceridemia revealed impaired LPL-mediated lipolysis and increased very low density lipoprotein (VLDL) secretion, with upregulation of hepatic genes involved in lipid synthesis and transport. The pro-atherogenic dyslipidemia in mutant hamsters was exacerbated after high fat diet feeding, ultimately leading to near a 3- and 5-fold increase in atherosclerotic lesions by aortic en face and sinus lesion quantitation, respectively. Our findings demonstrate that LCAT deficiency in hamsters develops pro-atherogenic dyslipidemia and promotes atherosclerotic lesion formation. Show less

Microtubule actin crosslinking factor 1 (MACF1) is a large spectraplakin protein known to have crucial roles in regulating cytoskeletal dynamics, cell migration, growth, and differentiation. However, its role and action mechanism in bone remain unclear. The present study investigated optimal conditions for effective transfection of the large plasmid PEGFP-C1A-ACF7 (∼21 kbp) containing full-length human MACF1 cDNA, as well as the potential role of MACF1 in bone formation. To enhance MACF1 expression, the plasmid was transfected into osteogenic cells by electroporation in vitro and into mouse calvaria with nanoparticles. Then, transfection efficiency, osteogenic marker expression, calvarial thickness, and bone formation were analyzed. Notably, MACF1 overexpression triggered a drastic increase in osteogenic gene expression, alkaline phosphatase activity, and matrix mineralization in vitro. Mouse calvarial thickness, mineral apposition rate, and osteogenic marker protein expression were significantly enhanced by local transfection. In addition, MACF1 overexpression promoted β-catenin expression and signaling. In conclusion, MACF1 overexpression by transfecting the large plasmid containing full-length MACF1 cDNA promotes osteoblast differentiation and bone formation via β-catenin signaling. Current data will provide useful experimental parameters for the transfection of large plasmids and a novel strategy based on promoting bone formation for prevention and therapy of bone disorders. Show less

Mechanical unloading was considered a major threat to bone homeostasis, and has been shown to decrease osteoblast proliferation although the underlying mechanism is unclear. Microtubule actin crosslinking factor 1 (MACF1) is a cytoskeletal protein that regulates cellular processes and Wnt/β-catenin pathway, an essential signaling pathway for osteoblasts. However, the relationship between MACF1 expression and mechanical unloading, and the function and the associated mechanisms of MACF1 in regulating osteoblast proliferation are unclear. This study investigated effects of mechanical unloading on MACF1 expression levels in cultured MC3T3-E1 osteoblastic cells and in femurs of mice with hind limb unloading; and it also examined the role and potential action mechanisms of MACF1 in osteoblast proliferation in MACF1-knockdown, overexpressed or control MC3T3-E1 cells treated with or without the mechanical unloading condition. Results showed that the mechanical unloading condition inhibited osteoblast proliferation and MACF1 expression in MC3T3-E1 osteoblastic cells and mouse femurs. MACF1 knockdown decreased osteoblast proliferation, while MACF1 overexpression increased it. The inhibitory effect of mechanical unloading on osteoblast proliferation also changed with MACF1 expression levels. Furthermore, MACF1 was found to enhance β-catenin expression and activity, and mechanical unloading decreased β-catenin expression through MACF1. Moreover, β-catenin was found an important regulator of osteoblast proliferation, as its preservation by treatment with its agonist lithium attenuated the inhibitory effects of MACF1-knockdown or mechanical unloading on osteoblast proliferation. Taken together, mechanical unloading decreases MACF1 expression, and MACF1 up-regulates osteoblast proliferation through enhancing β-catenin signaling. This study has thus provided a mechanism for mechanical unloading-induced inhibited osteoblast proliferation. Show less

Osteoblast differentiation is a multistep process delicately regulated by many factors, including cytoskeletal dynamics and signaling pathways. Microtubule actin crosslinking factor 1 (MACF1), a key cytoskeletal linker, has been shown to play key roles in signal transduction and in diverse cellular processes; however, its role in regulating osteoblast differentiation is still needed to be elucidated. To further uncover the functions and mechanisms of action of MACF1 in osteoblast differentiation, we examined effects of MACF1 knockdown (MACF1-KD) in MC3T3-E1 osteoblastic cells on their osteoblast differentiation and associated molecular mechanisms. The results showed that knockdown of MACF1 significantly suppressed mineralization of MC3T3-E1 cells, down-regulated the expression of key osteogenic genes alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and type I collagen α1 (Col Iα1). Knockdown of MACF1 dramatically reduced the nuclear translocation of β-catenin, decreased the transcriptional activation of T cell factor 1 (TCF1), and down-regulated the expression of TCF1, lymphoid enhancer-binding factor 1 (LEF1), and Runx2, a target gene of β-catenin/TCF1. In addition, MACF1-KD increased the active level of glycogen synthase kinase-3β (GSK-3β), which is a key regulator for β-catenin signal transduction. Moreover, the reduction of nuclear β-catenin amount and decreased expression of TCF1 and Runx2 were significantly reversed in MACF1-KD cells when treated with lithium chloride, an agonist for β-catenin by inhibiting GSK-3β activity. Taken together, these findings suggest that knockdown of MACF1 in osteoblastic cells inhibits osteoblast differentiation through suppressing the β-catenin/TCF1-Runx2 axis. Thus, a novel role of MACF1 in and a new mechanistic insight of osteoblast differentiation are uncovered. Show less

Activation of MEK5 in many cancers is associated with carcinogenesis through aberrant cell proliferation. In this study, we determined the level of phosphorylated MEK5 (pMEK5) expression in human colorectal cancer (CRC) tissues and correlated it with clinicopathologic data. pMEK5 expression was examined by immunohistochemistry in a tissue microarray (TMA) containing 335 clinicopathologic characterized CRC cases and 80 cases of nontumor colorectal tissues. pMEK5 expression of 19 cases of primary CRC lesions and paired with normal mucosa was examined by Western blotting. The relationship between pMEK5 expression in CRC and clinicopathologic parameters, and the association of pMEK5 expression with CRC survival were analyzed respectively. pMEK5 expression was significantly higher in CRC tissues (185 out of 335, 55.2%) than in normal tissues (6 out of 80, 7.5%; P < 0.001). Western blotting demonstrated that pMEK5 expression was upregulated in 12 of 19 CRC tissues (62.1%) compared to the corresponding adjacent nontumor colorectal tissues. Overexpression of pMEK5 in CRC tissues was significantly correlated to the depth of invasion (P = 0.001), lymph node metastasis (P < 0.001), distant metastasis (P < 0.001) and high preoperative CEA level (P < 0.001). Consistently, the pMEK5 level in CRC tissues was increased following stage progression of the disease (P < 0.001). Analysis of the survival curves showed a significantly worse 5-year disease-free (P = 0.002) and 5-year overall survival rate (P < 0.001) for patients whose tumors overexpressed pMEK5. However, in multivariate analysis, pMEK5 was not an independent prognostic factor for CRC (DFS: P = 0.139; OS: P = 0.071). pMEK5 expression is correlated with the staging of CRC and its expression might be helpful to the TNM staging system of CRC. Show less