1.Ras Guanine Nucleotide-Releasing Protein-4 Inhibits Erythropoietin Production in Diabetic Mice with Kidney Disease by Degrading HIF2A
Junmei WANG ; Shuai HUANG ; Li ZHANG ; Yixian HE ; Xian SHAO ; A-Shan-Jiang A-NI-WAN ; Yan KONG ; Xuying MENG ; Pei YU ; Saijun ZHOU
Diabetes & Metabolism Journal 2025;49(3):421-435
Background:
In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods:
The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results:
RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion
RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
2.Ras Guanine Nucleotide-Releasing Protein-4 Inhibits Erythropoietin Production in Diabetic Mice with Kidney Disease by Degrading HIF2A
Junmei WANG ; Shuai HUANG ; Li ZHANG ; Yixian HE ; Xian SHAO ; A-Shan-Jiang A-NI-WAN ; Yan KONG ; Xuying MENG ; Pei YU ; Saijun ZHOU
Diabetes & Metabolism Journal 2025;49(3):421-435
Background:
In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods:
The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results:
RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion
RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
3.Ras Guanine Nucleotide-Releasing Protein-4 Inhibits Erythropoietin Production in Diabetic Mice with Kidney Disease by Degrading HIF2A
Junmei WANG ; Shuai HUANG ; Li ZHANG ; Yixian HE ; Xian SHAO ; A-Shan-Jiang A-NI-WAN ; Yan KONG ; Xuying MENG ; Pei YU ; Saijun ZHOU
Diabetes & Metabolism Journal 2025;49(3):421-435
Background:
In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods:
The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results:
RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion
RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
4.Ras Guanine Nucleotide-Releasing Protein-4 Inhibits Erythropoietin Production in Diabetic Mice with Kidney Disease by Degrading HIF2A
Junmei WANG ; Shuai HUANG ; Li ZHANG ; Yixian HE ; Xian SHAO ; A-Shan-Jiang A-NI-WAN ; Yan KONG ; Xuying MENG ; Pei YU ; Saijun ZHOU
Diabetes & Metabolism Journal 2025;49(3):421-435
Background:
In acute and chronic renal inflammatory diseases, the activation of inflammatory cells is involved in the defect of erythropoietin (EPO) production. Ras guanine nucleotide-releasing protein-4 (RasGRP4) promotes renal inflammatory injury in type 2 diabetes mellitus (T2DM). Our study aimed to investigate the role and mechanism of RasGRP4 in the production of renal EPO in diabetes.
Methods:
The degree of tissue injury was observed by pathological staining. Inflammatory cell infiltration was analyzed by immunohistochemical staining. Serum EPO levels were detected by enzyme-linked immunosorbent assay, and EPO production and renal interstitial fibrosis were analyzed by immunofluorescence. Quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of key inflammatory factors and the activation of signaling pathways. In vitro, the interaction between peripheral blood mononuclear cells (PBMCs) and C3H10T1/2 cells was investigated via cell coculture experiments.
Results:
RasGRP4 decreased the expression of hypoxia-inducible factor 2-alpha (HIF2A) via the ubiquitination–proteasome degradation pathway and promoted myofibroblastic transformation by activating critical inflammatory pathways, consequently reducing the production of EPO in T2DM mice.
Conclusion
RasGRP4 participates in the production of renal EPO in diabetic mice by affecting the secretion of proinflammatory cytokines in PBMCs, degrading HIF2A, and promoting the myofibroblastic transformation of C3H10T1/2 cells.
5.Endo-beta-N-acetylglucosaminidase: Possible Functions and Mechanisms
Xin-Rong LU ; Yong-Liang TONG ; Wei-Li KONG ; Lin ZOU ; Dan-Feng SHEN ; Shao-Xian LÜ ; Rui-Jie LIU ; Shao-Xing ZHANG ; Yu-Xin ZHANG ; Lin-Lin HOU ; Gui-Qin SUN ; Li CHEN
Progress in Biochemistry and Biophysics 2024;51(5):985-999
Endo-beta-N-acetylglucosaminidase (ENGase) is widely distributed in various organisms. The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971. The protein (Endo D) was purified and its peptide sequence was determined in 1974. Three ENGases (Endo F1-F3) were discovered in Flavobacterium meningosepticum from 1982 to 1993. After that, the activity was detected from different species of bacteria, yeast, fungal, plant, mice, human, etc. Multiple ENGases were detected in some species, such as Arabidopsis thaliana and Trichoderma atroviride. The first preliminary crystallographic analysis of ENGase was conducted in 1994. But to date, only a few ENGases structures have been obtained, and the structure of human ENGase is still missing. The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate-Active enZyme (CAZy) database. GH18 ENGase only has hydrolytic activity, but GH85 ENGase has both hydrolytic and transglycosylation activity. Although ENGases of the two families have similar (β/α)8-TIM barrel structures, the active sites are slightly different. ENGase is an effective tool for glycan detection andglycan editing. Biochemically, ENGase can specifically hydrolyze β‑1,4 glycosidic bond between the twoN-acetylglucosamines (GlcNAc) on core pentasaccharide presented on glycopeptides and/or glycoproteins. Different ENGases may have different substrate specificity. The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc. Conditionally, it can use the two products to produce a new glycopeptides or glycoprotein. Although ENGase is a common presentation in cell, its biological function remains unclear. Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation. No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species. Its expression was extremely low in lung. As glycoproteins are not produced by prokaryotic cells, a role for nutrition and/or microbial-host interaction was predicted for bacterium produced enzymes. In the embryonic lethality phenotype of the Ngly1-deficient mice can be partially rescued by Engase knockout, suggesting down regulation of Engase might be a solution for stress induced adaptation. Potential impacts of ENGase regulation on health and disease were presented. Rabeprazole, a drug used for stomach pain as a proton inhibitor, was identified as an inhibitor for ENGase. ENGases have been applied in vitro to produce antibodies with a designated glycan. The two step reactions were achieved by a pair of ENGase dominated for hydrolysis of substrate glycoprotein and synthesis of new glycoprotein with a free glycan of designed structure, respectively. In addition, ENGase was also been used in cell surface glycan editing. New application scenarios and new detection methods for glycobiological engineering are quickly opened up by the two functions of ENGase, especially in antibody remodeling and antibody drug conjugates. The discovery, distribution, structure property, enzymatic characteristics and recent researches in topical model organisms of ENGase were reviewed in this paper. Possible biological functions and mechanisms of ENGase, including differentiation, digestion of glycoproteins for nutrition and stress responding were hypothesised. In addition, the role of ENGase in glycan editing and synthetic biology was discussed. We hope this paper may provide insights for ENGase research and lay a solid foundation for applied and translational glycomics.
6.Clinical phenotypes and genetic analysis of 25 children with ring chromosomes
Chaojie WANG ; Ding ZHAO ; Rui LI ; Zhenhua ZHANG ; Jinghui KONG ; Bo ZHANG ; Xian LI ; Linfei LI ; Yaodong ZHANG
Chinese Journal of Applied Clinical Pediatrics 2024;39(7):528-532
Objective:To investigate the correlation between clinical phenotypes and genetic characteristics of children with ring chromosomes (RCs).Methods:Case series study.The clinical data of 11 434 children who received treatment and peripheral blood chromosome karyotype detection in Henan Children′s Hospital from October 2008 to October 2023 due to growth retardation, intellectual impairment or congenital malformation were analyzed retrospectively.A total of 25 children with RCs were selected.Their age at diagnosis, karyotype distribution, clinical manifestations, and genetic detection results were analyzed.Results:RCs were detected in 25 out of 11 434 children, with a detection rate of 0.21%.The genome-wide copy number variation (CNV) analysis was performed on 7 RCs cases, and it found that pathogenic variation existed in all of them.Among the 25 RC cases (11 males and 14 females of social gender), the age at diagnosis ranged from 2 months to 14 years; there were 20 autosomal rings and 5 sex chromosome rings; 13 cases had chimeric karyotypes, and 12 cases had non-chimeric karyotypes.Most of the 25 children showed clinical manifestations of mental or developmental retardation, and some also presented with specific clinical manifestations, such as short stature, congenital malformation, and epilepsy.Conclusions:The pathogenesis of RCs is complex.The clinical manifestations are determined by both RCs syndrome and specific phenotypes caused by the dose effect and exhibit high heterogeneity, so it is easy to miss or misdiagnose.The combined application of cellular and molecular genetic detection technology can facilitate early diagnosis and treatment of RCs, and the correlation analysis of phenotypes and genetic characteristics can provide guidance for genetic counseling.
7.Application of quality control circle in reducing the surface extravasation rate of"bolus-type"intravenous injection of radiopharmaceuticals
Yuxian ZHANG ; Dan KONG ; Weiying LIU ; Jialang XIAN
Journal of Practical Radiology 2024;40(12):2062-2065
Objective To explore the role of quality control circle in reducing the rate of extravasation during"bolus-type"intravenous injection of radiopharmaceuticals.Methods A total of 624 patients who underwent emission computed tomography(ECT)examinations were retrospectively selected as the pre-quality control circle use analysis group,125 patients who underwent ECT examinations were selected as the post-quality control circle use experiment group,and 70 patients were selected as the control group.This study applied the continuous quality improvement tools of the quality control circle,including grasping the current situation,selecting injection tools,personnel training,brainstorming,root cause analysis,key factor evaluation,true cause verification,strategy formulation and measure implementation,to continuously improve the quality of"bolus-type"radioisotope injection and reduce the rate of radiopharmaceuticals extravasation.Results In the experiment group,the rate of radioisotope extravasation after nurses performed"bolus-type"intravenous injection was 14.2%,compared to 33.3%in the control group,an improvement of 19%,and the situation of radiopharmaceuticals extravasation was significantly improved.Skillful use of quality improvement tools,especially in areas such as insufficient compression time,improper compression method,slow blood flow speed in fine blood vessels,and failed puncture,was crucial for radioisotope sur-face imaging.Conclusion Through continuous quality improvement by the quality control circle,this study successfully reduces the rate of extravasation during"bolus-type"intravenous injection of radiopharmaceuticals,reduces skin contamination,and improves the quality of nuclear medicine images,which is of great significance for improving the safety and diagnostic accuracy of nuclear medicine ECT examinations.
8.Diagnostic value of vena contracta area measurement for grading tricuspid regurgitation severity under different etiologies:a three-dimensional echocardiography study
Bei-Qi CHEN ; Yu LIU ; Wu-Xu ZUO ; Quan LI ; Yuan-Feng WU ; De-Hong KONG ; Cui-Zhen PAN ; Li-Li DONG ; Xian-Hong SHU
Fudan University Journal of Medical Sciences 2024;51(4):484-493,504
Objective To explore the cut-off value of three dimensional(3D)vena contracta area(VCA)in diagnosing severe tricuspid regrugitation(TR)under different etiologies and its accuracy and practicality in clinical application.Methods From Mar 2019 to May 2021,ninety-two patients with confirmed TR underwent two dimensional(2D)and 3D transthoracic echocardiography.The correlation and consistency between 3D VCA 3D calculated based on the proximal isokinetic surface area(PISA)effective regurgitant orifice area(EROA)was calculated.Comprehensive 2D multi-parameter method was used as a reference method to calculate the cut-off value of the diagnosis of severe TR.Results A total of 85 patients were ultimately included.3D VCA and 3D PISA EROA had similar and acceptable correlations in both primary TR and secondary TR(primary TR:r=0.831,P<0.01;secondary TR:r=0.806,P<0.01).Bland-Altman analysis showed that 3D VCA overestimated TR compared with 3D PISA EROA(62%overestimated in the total patient population,51%overestimated in primary TR,and 74%overestimated in secondary TR).In secondary TR,the cut-off value of 3D VCA for diagnosing severe TR was 0.45 cm2(sensitivity 89%,specificity 82%);combining clinical symptoms,positive 2D PISA EROA results and 3D VCA results for severe TR,the chi-square value was higher than those only included clinical symptoms or incorporated clinical symptoms and positive 2D PISA EROA results(42.168 vs.26.059 and 16.759,P<0.01).Conclusion 3D VCA would overestimate TR,and had high and incremental diagnostic value for evaluating severe TR in secondary TR.
9.Analysis and clinical application of preimplantation genetic testing for monogenic disorders in a case with Spinal muscular atrophy "2+ 0" genotype
Shaoying LI ; Jianchun HE ; Wenzhi HE ; Jiajia XIAN ; Lingling HUANG ; Gengye ZHAO ; Xin ZHANG ; Renqian DU ; Liming CHU ; Yueqiang WANG ; Lingyin KONG ; Bo LIANG ; Qing LI
Chinese Journal of Medical Genetics 2024;41(3):294-299
Objective:To explore the clinical application of preimplantation genetic testing for monogenic disorders (PGT-M) in an unique case with Spinal muscular atrophy (SMA) type 2+ 0.Methods:A special SMA family presented at the Third Affiliated Hospital of Guangzhou Medical University on October 19, 2020 was selected as the study subject. Multiple ligation-dependent probe amplification (MLPA) and molecular tagging linkage analysis were carried out to identify the SMN1 genotype of the couple and their fetus. Subsequently, next-generation sequencing (NGS), molecular tagging linkage analysis, and chromosomal microarray analysis were employed to determine the haplotypes and validate the result of PGT-M on the 11 embryos derived for the couple. Results:The female partner was identified as a carrier of the rare SMN1[2+ 0] variant, and prenatal diagnosis confirmed the fetus to be affected by SMA. Ultimately, PGT-M has successfully selected four embryos free from the pathogenic SMN1 variants and X chromosome deletion. Conclusion:PGT-M can effectively prevent the transmission of rare genetic variants such as the SMA 2+ 0 subtype in the families. Above finding has provided guidance for genetic counseling and family planning for the couple.
10.Gut dysbiosis aggravates cognitive deficits,amyloid pathology and lipid metabolism dysregulation in a transgenic mouse model of Alzheimer's disease
Chang QU ; Qing-Qing XU ; Wen YANG ; Mei ZHONG ; Qiuju YUAN ; Yan-Fang XIAN ; Zhi-Xiu LIN
Journal of Pharmaceutical Analysis 2023;13(12):1526-1547
Gut dysbiosis,a well-known risk factor to triggers the progression of Alzheimer's disease(AD),is strongly associated with metabolic disturbance.Trimethylamine N-oxide(TMAO),produced in the dietary choline metabolism,has been found to accelerate neurodegeneration in AD pathology.In this study,the cognitive function and gut microbiota of TgCRND8(Tg)mice of different ages were evaluated by Morris water maze task(MWMT)and 16S rRNA sequencing,respectively.Young pseudo germ-free(PGF)Tg mice that received faecal microbiota transplants from aged Tg mice and wild-type(WT)mice were selected to determine the role of the gut microbiota in the process of neuropathology.Excessive choline treatment for Tg mice was used to investigate the role of abnormal choline metabolism on the cognitive functions.Our results showed that gut dysbiosis,neuroinflammation response,Aβ deposition,tau hyper-phosphorylation,TMAO overproduction and cyclin-dependent kinase 5(CDK5)/transcription 3(STAT3)activation occurred in Tg mice age-dependently.Disordered microbiota of aged Tg mice accelerated AD pathology in young Tg mice,with the activation of CDK5/STAT3 signaling in the brains.On the contrary,faecal microbiota transplantation from WT mice alleviated the cognitive deficits,attenuated neuro-inflammation,Aβ deposition,tau hyperphosphorylation,TMAO overproduction and suppressed CDK5/STAT3 pathway activation in Tg mice.Moreover,excessive choline treatment was also shown to aggravate the cognitive deficits,Aβ deposition,neuroinflammation and CDK5/STAT3 pathway activation.These findings provide a novel insight into the interaction between gut dysbiosis and AD progression,clarifying the important roles of gut microbiota-derived substances such as TMAO in AD neuropathology.

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