Evaluating new biomarkers for diabetic nephropathy:Role ofα2-macroglobulin,podocalyxin,α-L-fucosidase,retinol-binding protein-4,and cystatin C

BACKGROUND The intricate relationship between type 2 diabetes mellitus(T2DM)and diabetic nephropathy(DN)presents a challenge in understanding the significance of various biomarkers in diagnosis.AIM To elucidate the roles and diagnostic values ofα2-macroglobulin(α2-MG),podocalyxin(PCX),α-L-fucosidase(AFU),retinol-binding protein-4(RBP-4),and cystatin C(CysC)in DN.METHODS From December 2018 to December 2020,203 T2DM patients were enrolled in the study.Of these,115 were diagnosed with DN(115 patients),while the remaining 88 patients were classified as non-DN.The urinary levels ofα2-MG,PCX,and AFU and the serum concentrations RBP-4 and CysC were measured in conjunction with other relevant clinical indicators to evaluate their potential correlations and diagnostic utility.RESULTS After adjustments for age and gender,significant positive correlations were observed between the biomarkers CysC,RBP-4,α2-MG/urinary creatinine(UCr),PCX/UCr,and AFU/UCr,and clinical indicators such as urinary albumin-to-creatinine ratio(UACR),serum creatinine,urea,24-h total urine protein,and neutrophil-to-lymphocyte ratio(NLR).Conversely,these biomarkers exhibited negative correlations with the estimated glomerular filtration rate(P<0.05).Receiver operating characteristic(ROC)curve analysis further demonstrated the diagnostic performance of these biomarkers,with UACR showcasing the highest area under the ROC curve(AUC^(ROC))at 0.97.CONCLUSION This study underscores the diagnostic significance ofα2-MG,PCX,and AFU in the development of DN.The biomarkers RBP-4,CysC,PCX,AFU,andα2-MG provide promising diagnostic insights,while UACR is the most potent diagnostic biomarker in assessing DN.

A peptide containing the receptor binding site of insulin-like growth factor binding protein-2 enhances bone mass in ovariectomized rats

Male Igfbp2-/-mice have a significant reduction in bone mass and administration of a peptide that contains the insulin-like growth factor binding protein-2(IGFBP-2) receptor-binding domain stimulates bone formation in these animals. Female Igfbp2-/-mice do not have this phenotype but following ovariectomy(OVX) lose more bone than OVX wild-type mice. This suggests that in the absence of estrogen, IGFBP-2 is required to maintain bone mass. Therefore these studies were undertaken to determine if this peptide could stimulate bone acquisition in OVX rats. OVX rats were divided into seven treatment groups: sham animals, OVX animals, OVX animals receiving a control scrambled peptide, or one of three doses of the active peptide termed PEG-HBD-1(0.7, 2,and 6 mg·kg^(-1)) and an OVX group receiving parathyroid hormone(PTH)(50 μg·kg-1 per day). The peptides were administered for8 weeks. DXA revealed a significant reduction in femoral and tibial areal bone mineral density(aBMD) after OVX, whereas treatment with the high-dose peptide increased aBMD by 6.2% ± 2.4%(P < 0.01) compared to control peptide; similar to the increase noted with PTH(5.6% ± 3.0%, P < 0.01). Similar increases were noted with two lower doses of the peptide(3.8% ± 1.5%, P < 0.05 for low dose; 3.1% ± 1.6%, P = 0.07 for middle dose). Micro CT showed that the OVX control peptide animals had reductions of 41% and64% in femoral trabecular BV/TV and trabecular number, respectively. All three doses of the peptide increased bone volume/total volume(BV/TV) significantly, while the low and middle doses increased trabecular number. Cortical BV/TV and thickness at the midshaft increased significantly with each dose of peptide(18.9% ± 9.8%, P < 0.01 and 14.2% ± 7.9%, P < 0.01 for low dose; 23.7% ±10.7%, P < 0.001 and 15.8% ± 6.1%, P < 0.001 for middle dose; 19.0% ± 6.9%, P < 0.01 and 16.2% ± 9.7%, P < 0.001 for high dose)and with PTH(25.8% ± 9.2%, P < 0.001 and 19.4% ± 8.8%, P < 0.001). Histomorphometry showed that the lowest dose of peptide stimulated BV/TV, trabecular thickness, mineral apposition rate(MAR), bone formation rate/bone surface(BFR/BS), number of osteoblasts/bone perimeter(N.ob/B.pm), and decreased osteoclast surface/bone perimeter(Oc.S/B.Pm). The highest dose stimulated each of these parameters except MAR and BFR/BS. Thus, the heparin-binding domain receptor region of IGFBP-2 accounts for its anabolic activity in bone. Importantly, this peptide enhances bone mass in estrogen-deficient animals.

SATB2-associated syndrome caused by a novel SATB2 mutation in a Chinese boy:A case report and literature review

BACKGROUND Special AT-rich sequence binding protein 2(SATB2)-associated syndrome(SAS;OMIM 612313)is an autosomal dominant disorder.Alterations in the SATB2 gene have been identified as causative.CASE SUMMARY We report a case of a 13-year-old Chinese boy with lifelong global developmental delay,speech and language delay,and intellectual disabilities.He had short stature and irregular dentition,but no other abnormal clinical findings.A de novo heterozygous nonsense point mutation was detected by genetic analysis in exon 6 of SATB2,c.687C>A(p.Y229X)(NCBI reference sequence:NM_001172509.2),and neither of his parents had the mutation.This mutation is the first reported and was evaluated as pathogenic according to the guidelines from the American College of Medical Genetics and Genomics.SAS was diagnosed,and special education performed.Our report of a SAS case in China caused by a SATB2 mutation expanded the genotype options for the disease.The heterogeneous manifestations can be induced by complicated pathogenic involvements and functions of SATB2 from reviewed literatures:(1)SATB2 haploinsufficiency;(2)the interference of truncated SATB2 protein to wild-type SATB2;and(3)different numerous genes regulated by SATB2 in brain and skeletal development in different developmental stages.CONCLUSION Global developmental delays are usually the initial presentations,and the diagnosis was challenging before other presentations occurred.Regular follow-up and genetic analysis can help to diagnose SAS early.Verification for genes affected by SATB2 mutations for heterogeneous manifestations may help to clarify the possible pathogenesis of SAS in the future.

miR-125a-5p通过靶向调控GAB2抑制乳腺癌细胞的迁移能力

miR-125a-5p可负性调节GAB2表达,抑制胶质瘤细胞的侵袭和转移。本研究旨在证明miR-125a-5p抑癌作用的普遍性,即miR-125a-5p是否可通过靶向抑制GAB2抑制乳腺癌细胞的迁移。荧光素酶实验结果显示,miR-125a-5p可特异识别GAB2的3'-UTR,抑制报告酶的表达。荧光定量PCR结果揭示,与正常乳腺上皮细胞MCF-10A比较,miR-125a-5p在乳腺癌细胞MDA231和MCF-7中的表达明显降低;与迁移能力相对较低的MCF-7细胞比较,miR-125a-5p在迁移能力较高的MDA231细胞中的表达量更低。Western印迹结果证明,与空载体(对照)和anti-miR125a-5p转染细胞比较,转染miR-125a-5p明显抑制GAB2蛋白在乳腺癌细胞中的表达。Transwell结果显示,与空载体转染的对照细胞比较,转染miR-125a-5p的乳腺癌细胞穿过基质胶的细胞数明显减少;相反,转染anti-miR125a-5p的细胞穿过基质胶的细胞数却明显增多。上述结果提示,miR-125a-5p在正常的乳腺细胞中高表达,而在乳腺癌细胞中低表达,其表达水平与癌细胞的迁移能力和GAB2表达呈反向关系。本研究结果还提示,miR-125a-5p通过靶向负调控GAB2抑制乳腺癌细胞的迁移能力。总之,本研究证明,miR-125a-5p在肿瘤中发挥抑癌作用。

BTEB2 antisense RNA inhibits intimal hyperplasia in a rat carotid balloon injury model

Objective： To investigate the effects of basic transcriptional element binding protein-2 （BTEB2） antisense RNA on vascular smooth muscle cells （VSMCs） proliferation and the neointimal formation after carotid balloon injury in rats. Methods： The cultured VSMCs were transfected with an adenoviral vector containing BTEB2 antisense gene, Ad ASBTEB2. Effects of BTEB2 antisense RNA on the expression of BTEB2 were investigated by Western blot analysis. The cell cycle was analyzed using flow cytometry. Ad ASBTEB2, control adenoviral vector Ad. LacZ or PBS was transduced into the rat carotid artery after balloon injury. The expression of BTEB2 at 7, 14, and 21 d after gene transfer was detected by immunohistochemistry and neointima-to-media （I/M） area ratio at these time points was calculated. Resuits： The cell cycle was arrested in G0/G1 phase and the expression of BETB2 was downregulated after transfection with Ad ASBTEB2. Ad ASBTEB2 treatment reduced I/M area ratios on day 7, 14, and 21 after injury by 45%, 50% and 53% respectively, whereas the Ad LacZ treatment did not significantly alter these ratios compared with control group. Conclusion： BTEB2 antisense RNA mediated by adenoviral vector inhibits proliferation of VSMCs and significantly reduces neointimal hyperplasia in the rat carotid balloon injury model. BTEB2 antisense RNA is a potential therapeutic approach to preventing neointimal formation after balloon injury.

GAB2在卵巢癌组织中的表达及其与预后的相关性

目的评估卵巢癌组织中Grb相关结合蛋白2(Grb-associated binding protein 2,GAB2)的表达及其与预后的关系。方法收集南通大学附属肿瘤医院2013年1月—2016年1月手术切除的119例卵巢癌组织及癌旁组织,利用免疫组织化学染色法检测组织中GAB2的表达情况,并分析其表达量与临床特征和总生存期(Overall survival,OS)的关系。利用Cox比例风险模型分析影响卵巢癌患者OS的危险因素。构建基于Cox比例风险模型的Nomogram预后模型预测卵巢癌患者3年和5年生存率。结果与癌旁组织相比,GAB2在癌组织中表达增加(P<0.001)。我们还发现GAB2表达量与FIGO分期(P=0.004)、初诊时CA125水平(P=0.005)和铂耐药性复发(P<0.001)有关。Kaplan-Meier生存曲线表明GAB2的高表达与患者OS的下降有关(P<0.001)。单因素分析结果显示,GAB2表达量、FIGO分期、初诊时CA125水平和铂耐药性复发与卵巢癌患者OS相关(P<0.05)。多因素分析显示,GAB2表达水平是影响卵巢癌患者OS的独立因素。Nomogram预后模型对卵巢癌患者3年和5年生存率的预测能力较好(C指数为0.801)。结论GAB2的表达水平能预测卵巢癌患者的预后,有望成为卵巢癌治疗的潜在靶点。

Study on C/EBPα and FOXC2 expression in colon cancer lesions andpreliminary analysis of their downstream target genes

Objective: To study the C/EBPα and FOXC2 expression in colon cancer lesions and explore their downstream target genes. Methods: Colon cancer specimens surgically removed in Weinan Central Hospital between March 2014 and February 2017 were selected, and adjacent tissue specimens more than 5cm from tumor lesion margin were selected as control. The RNA in the clinical specimens was extracted and the mRNA expression of C/EBPα, FOXC2 as well as endoplasmic reticulum stress molecules and epithelial-mesenchymal transition molecules were determined. Results: C/EBPα, Bax, Bak, GRP78, PERK and ATF6 mRNA expression levels in colon cancer specimens were significantly lower than those in adjacent samples while FOXC2, FAK, SphK1, N-cadherin and Vimentin mRNA expression levels were significantly higher than those in adjacent specimens;Bax, Bak, GRP78, PERK and ATF6 mRNA expression levels in colon cancer specimens with high C/EBPα expression were significantly higher than those in colon cancer specimens with low C/EBPα expression;FAK, SphK1, N-cadherin and Vimentin mRNA expression levels in colon cancer specimens with high FOXC2 expression were significantly higher than those in colon cancer specimens with low FOXC2 expression. Conclusion: Lowly expressed C/EBPα and highly expressed FOXC2 in colon cancer lesions can inhibit the apoptosis mediated by endoplasmic reticulum stress and promote the cell invasion mediated by epithelial-mesenchymal transition.

Loss of GRB2 associated binding protein 1 in arteriosclerosis obliterans promotes host autophagy

Background:Arteriosclerosis obliterans(ASO)is a major cause of adult limb loss worldwide.Autophagy of vascular endothelial cell(VEC)contributes to the ASO progression.However,the molecular mechanism that controls VEC autophagy remains unclear.In this study,we aimed to explore the role of the GRB2 associated binding protein 1(GAB1)in regulating VEC autophagy.Methods:In vivo and in vitro studies were applied to determine the loss of adapt protein GAB1 in association with ASO progression.Histological GAB1 expression was measured in sclerotic vascular intima and normal vascular intima.Gain-and loss-of-function of GAB1 were applied in VEC to determine the effect and potential downstream signaling of GAB1.Results:The autophagy repressor p62 was significantly downregulated in ASO intima as compared to that in healthy donor(0.80 vs.0.20,t=6.43,P<0.05).The expression level of GAB1 mRNA(1.00 vs.0.24,t=7.41,P<0.05)and protein(0.72 vs.0.21,t=5.97,P<0.05)was significantly decreased in ASO group as compared with the control group.Loss of GAB1 led to a remarkable decrease in LC3II(1.19 vs.0.68,t=5.99,P<0.05),whereas overexpression of GAB1 significantly led to a decrease in LC3II level(0.41 vs.0.93,t=7.12,P<0.05).Phosphorylation levels of JNK and p38 were significantly associated with gain-and loss-of-function of GAB1 protein.Conclusion:Loss of GAB1 promotes VEC autophagy which is associated with ASO.GAB1 and its downstream signaling might be potential therapeutic targets for ASO treatment.

Association of sterol regulatory element binding protein 2 and insulin-like growth factor binding protein 3 genetic polymorphisms with avascular necrosis of the femoral head in the Chinese population

Background Sterol regulatory element binding protein （SREBP）-2 plays a key role in lipid homeostasis by stimulating gene expression of cholesterol biosynthetic pathways. The insulin-like growth factor binding protein （IGFBP） family regulates growth and metabolism, especially bone cell metabolism, and correlates with osteonecrosis. However, association of their gene polymorphisms with risk of avascular necrosis of the femoral head （ANFH） has rarely been reported. We determined whether SREBP-2 and IGFBP-3 gene polymorphisms were associated with increased ANFH risk in the Chinese population. Methods Two single nucleotide polymorphisms of SREBP2 gene, rs2267439 and rs2267443, and one of IGFBP-3 gene, rs2453839, were selected and genotyped in 49 ANFH patients and 42 control individuals by direct sequencing assay. Results The frequencies of rs2267439 TT and rs2267443 GA of SREBP2 and rs2453839 TT and CT of IGFBP-3 in the ANFH group showed increased and decreased tendencies （against normal control group）, respectively. Interaction analysis of genes revealed that the frequency of carrying rs2267439 TT and rs2267443 GA genotypes of SREBF-2 in ANFH patients was significantly higher than in the control group （P 〈0.05）. Association analysis between polymorphisms and clinical phenotype demonstrated that the disease course in ANFH patients with the rs2453839 TT genotype of IGFBP-3 was significantly shorter than that of CT＋CC carriers （P 〈0.01）. CT＋CC genotype frequency in patients with stage Ill/IV bilateral hip lesions was significantly higher than in those with stage Ill/IV unilateral lesions and stage II/111 bilateral lesions （P 〈0.05-0.02）. Conclusions Our results suggested that interaction of SREBP-2 gene polymorphisms and the relationship between the polymorphisms and clinical phenotype of IGFBP-3 were closely related to increased ANFH risk in the Chinese population. The most significant finding was that the CT＋CC genotype carriers of IGFBP-3 rs2453839 were highly associated with the development of ANFH.

Mechanisms of dysregulation of low-density lipoprotein receptor expression in HepG2 cells induced by inflammatory cytokines

Background Low-density lipoprotein （LDL） receptor is normally regulated via a feedback system that is dependent on intracellular cholesterol levels. We have demonstrated that cytokines disrupt cholesterol-mediated LDL receptor feedback regulation causing intracellular accumulation of unmodified LDL in peripheral cells. Liver is the central organ for lipid homeostasis. The aim of this study was to investigate the regulation of cholesterol exogenous uptake via LDL receptor and its underlying mechanisms in human hepatic cell line （HepG2） cells under physiological and inflammatory conditions. Methods Intracellular total cholesterol （TC）, free cholesterol （FC） and cholesterol ester （CE） were measured by an enzymic assay. Oil Red O staining was used to visualize lipid droplet accumulation in cells. Total cellular RNA was isolated from cells for detecting LDL receptor, sterol regulatory element binding protein （SREBP）-2 and SREBP cleavage-activating protein （SCAP） mRNA levels using real-time quantitative PCR. LDL receptor and SREBP-2 protein expression were examined by Western blotting. Confocal microscopy was used to investigate the translocation of SCAP-SREBP complex from the endoplasmic reticulum （ER） to the Golgi by dual staining with anti-human SCAP and anti-Golgin antibodies. Results LDL loading increased intracellular cholesterol level, thereby reduced LDL receptor mRNA and protein expression in HepG2 cells under physiological conditions. However, interleukin 1β （IL-1β） further increased intracellular cholesterol level in the presence of LDL by increasing both LDL receptor mRNA and protein expression in HepG2. LDL also reduced the SREBP and SCAP mRNA level under physiological conditions. Exposure to IL-1β caused over-expression of SREBP-2 and also disrupted normal distribution of SCAP-SREBP complex in HepG2 by enhancing translocation of SCAP-SREBP from the ER to the Golgi despite a high concentration of LDL in the culture medium. Conclusions IL-1β disrupts cholesterol-mediated LDL receptor feedback regulation by enhancing SCAP-SREBP complex translocation from the ER to the Golgi, thereby increasing SREBP-2 mediated LDL receptor expression even in the presence of high concentration of LDL. This results in LDL cholesterol accumulation in hepatic cells via LDL receptor pathway under inflammatory stress.

Resveratrol and fenofibrate ameliorate fructose-induced nonalcoholic steatohepatitis by modulation of genes expression

AIM: To evaluate the effect of resveratrol, alone and in combination with fenofibrate, on fructose-induced metabolic genes abnormalities in rats.METHODS: Giving a fructose-enriched diet (FED) to rats for 12 wk was used as a model for inducing hepatic dyslipidemia and insulin resistance. Adult male albino rats (150-200 g) were divided into a control group and a FED group which was subdivided into 4 groups, a control FED, fenofibrate (FENO) (100 mg/kg), resveratrol (RES) (70 mg/kg) and combined treatment (FENO + RES) (half the doses). All treatments were given orally from the 9th week till the end of experimental period. Body weight, oral glucose tolerance test (OGTT), liver index, glucose, insulin, insulin resistance (HOMA), serum and liver triglycerides (TGs), oxidative stress (liver MDA, GSH and SOD), serum AST, ALT, AST/ALT ratio and tumor necrosis factor-α (TNF-α) were measured. Additionally, hepatic gene expression of suppressor of cytokine signaling-3 (SOCS-3), sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), malonyl CoA decarboxylase (MCD), transforming growth factor-β1 (TGF-β1) and adipose tissue genes expression of leptin and adiponectin were investigated. Liver sections were taken for histopathological examination and steatosis area were determined.RESULTS: Rats fed FED showed damaged liver, impairment of glucose tolerance, insulin resistance, oxidative stress and dyslipidemia. As for gene expression, there was a change in favor of dyslipidemia and nonalcoholic steatohepatitis (NASH) development. All treatment regimens showed some benefit in reversing the described deviations. Fructose caused deterioration in hepatic gene expression of SOCS-3, SREBP-1c, FAS, MDA and TGF-β1 and in adipose tissue gene expression of leptin and adiponectin. Fructose showed also an increase in body weight, insulin resistance (OGTT, HOMA), serum and liver TGs, hepatic MDA, serum AST, AST/ALT ratio and TNF-α compared to control. All treatments improved SOCS-3, FAS, MCD, TGF-β1 and leptin genes expression while only RES and FENO + RES groups showed an improvement in SREBP-1c expression. Adiponectin gene expression was improved only by RES. A decrease in body weight, HOMA, liver TGs, AST/ALT ratio and TNF-α were observed in all treatment groups. Liver index was increased in FENO and FENO + RES groups. Serum TGs was improved only by FENO treatment. Liver MDA was improved by RES and FENO + RES treatments. FENO + RES group showed an increase in liver GSH content.CONCLUSION: When resveratrol was given with half the dose of fenofibrate it improved NASH-related fructose-induced disturbances in gene expression similar to a full dose of fenofibrate.