Vascular endothelial growth factor B improves impaired glucose tolerance through insulin-mediated inhibition of glucagon secretion

BACKGROUND Impaired glucose tolerance(IGT)is a homeostatic state between euglycemia and hyperglycemia and is considered an early high-risk state of diabetes.When IGT occurs,insulin sensitivity decreases,causing a reduction in insulin secretion and an increase in glucagon secretion.Recently,vascular endothelial growth factor B(VEGFB)has been demonstrated to play a positive role in improving glucose metabolism and insulin sensitivity.Therefore,we constructed a mouse model of IGT through high-fat diet feeding and speculated that VEGFB can regulate hyperglycemia in IGT by influencing insulin-mediated glucagon secretion,thus contributing to the prevention and cure of prediabetes.AIM To explore the potential molecular mechanism and regulatory effects of VEGFB on insulin-mediated glucagon in mice with IGT.METHODS We conducted in vivo experiments through systematic VEGFB knockout and pancreatic-specific VEGFB overexpression.Insulin and glucagon secretions were detected via enzyme-linked immunosorbent assay,and the protein expression of phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)was determined using western blot.Further,mRNA expression of forkhead box protein O1,phosphoenolpyruvate carboxykinase,and glucose-6 phosphatase was detected via quantitative polymerase chain reaction,and the correlation between the expression of proteins was analyzed via bioinformatics.RESULTS In mice with IGT and VEGFB knockout,glucagon secretion increased,and the protein expression of PI3K/AKT decreased dramatically.Further,in mice with VEGFB overexpression,glucagon levels declined,with the activation of the PI3K/AKT signaling pathway.CONCLUSION VEGFB/vascular endothelial growth factor receptor 1 can promote insulin-mediated glucagon secretion by activating the PI3K/AKT signaling pathway to regulate glucose metabolism disorders in mice with IGT.

Role of vascular endothelial growth factor B in nonalcoholic fatty liver disease and its potential value

Nonalcoholic fatty liver disease(NAFLD)refers to fatty liver disease caused by liver injury factors other than alcohol.The disease is characterized by diffuse fat infiltration,including simple steatosis(no inflammatory fat deposition),nonalcoholic fatty hepatitis,liver fibrosis,and so on,which may cause liver cirrhosis,liver failure,and even liver cancer in the later stage of disease progression.At present,the pathogenesis of NAFLD is still being studied.The"two-hit"theory,represented by lipid metabolism disorder and inflammatory reactions,is gradually enriched by the"multiple-hit"theory,which includes multiple factors,such as insulin resistance and adipocyte dysfunction.In recent years,vascular endothelial growth factor B(VEGFB)has been reported to have the potential to regulate lipid metabolism and is expected to become a novel target for ameliorating metabolic diseases,such as obesity and type 2 diabetes.This review summarizes the regulatory role of VEGFB in the onset and development of NAFLD and illustrates its underlying molecular mechanism.In conclusion,the signaling pathway mediated by VEGFB in the liver may provide an innovative approach to the diagnosis and treatment of NAFLD.

Vascular endothelial growth factor B inhibits insulin secretion in MIN6 cells and reduces Ca2+ and cyclic adenosine monophosphate levels through PI3K/AKT pathway

BACKGROUND Type 2 diabetes(T2 D) is characterized by insufficient insulin secretion caused by defective pancreatic β-cell function or insulin resistance,resulting in an increase in blood glucose.However,the mechanism involved in this lack of insulin secretion is unclear.The level of vascular endothelial growth factor B(VEGF-B) is significantly increased in T2 D patients.The inactivation of VEGF-B could restore insulin sensitivity in db/db mice by reducing fatty acid accumulation.It is speculated that VEGF-B is related to pancreatic β-cell dysfunction and is an important factor affecting β-cell secretion of insulin.As an in vitro model of normal pancreatic β-cells,the MIN6 cell line can be used to analyze the mechanism of insulin secretion and related biological effects.AIM To study the role of VEGF-B in the insulin secretion signaling pathway in MIN6 cells and explore the effect of VEGF-B on blood glucose regulation.METHODS The MIN6 mouse pancreatic islet β-cell line was used as the model system.By administering exogenous VEGF-B protein or knocking down VEGF-B expression in MIN6 cells,we examined the effects of VEGF-B on insulin secretion,Ca2+ and cyclic adenosine monophosphate(cAMP) levels,and the insulin secretion signaling pathway.RESULTS Exogenous VEGF-B inhibited the secretion of insulin and simultaneously reduced the levels of Ca2+ and cAMP in MIN6 cells.Exogenous VEGF-B also reduced the expression of phospholipase C gamma 1(PLCγ1),phosphatidylinositol 3-kinase(PI3 K),serine/threonine kinase(AKT),and other proteins in the insulin secretion pathway.Upon knockdown of VEGF-B,MIN6 cells exhibited increased insulin secretion and Ca2+ and cAMP levels and upregulated expression of PLCγ1,PI3 K,AKT,and other proteins.CONCLUSION VEGF-B can regulate insulin secretion by modulating the levels of Ca2+ and cAMP.VEGF-B involvement in insulin secretion is related to the expression of PLCγ1,PI3 K,AKT,and other signaling proteins.These results provide theoretical support and an experimental basis for the study of VEGF-B in the pathogenesis of T2 D.

Peptide RL-QN15 promotes wound healing of diabetic foot ulcers through p38 mitogen-activated protein kinase and smad3/miR-4482-3p/vascular endothelial growth factor B axis

Background:Wound management of diabetic foot ulcers(DFUs)is a complex and challenging task,and existing strategies fail to meet clinical needs.Therefore,it is important to develop novel drug candidates and discover new therapeutic targets.However,reports on peptides as molecular probes for resolving issues related to DFUs remain rare.This study utilized peptide RL-QN15 as an exogenous molecular probe to investigate the underlying mechanism of endogenous non-coding RNA in DFU wound healing.The aim was to generate novel insights for the clinical management of DFUs and identify potential drug targets.Methods:We investigated the wound-healing efficiency of peptide RL-QN15 under diabetic con-ditions using in vitro and in vivo experimental models.RNA sequencing,in vitro transfection,quantitative real-time polymerase chain reaction,western blotting,dual luciferase reporter gene detection,in vitro cell scratches,and cell proliferation and migration assays were performed to explore the potential mechanism underlying the promoting effects of RL-QN15 on DFU repair.Results:Peptide RL-QN15 enhanced the migration and proliferation of human immortalized keratinocytes(HaCaT cells)in a high-glucose environment and accelerated wound healing in a DFU rat model.Based on results from RNA sequencing,we defined a new microRNA(miR-4482-3p)related to the promotion of wound healing.The bioactivity of miR-4482-3p was verified by inhibiting and overexpressing miR-4482-3p.Inhibition of miR-4482-3p enhanced the migration and proliferation ability of HaCaT cells as well as the expression of vascular endothelial growth factor B(VEGFB).RLQN15 also promoted the migration and proliferation ability of HaCaT cells,and VEGFB expression was mediated via inhibition of miR-4482-3p expression by the p38 mitogen-activated protein kinase(p38MAPK)and smad3 signaling pathways.Conclusions:RL-QN15 is an effective molecule for the treatment of DFUs,with the underlying mechanism related to the inhibition of miR-4482-3p expression via the p38MAPK and smad3 signaling pathways,ultimately promoting re-epithelialization,angiogenesis and wound healing.This study provides a theoretical basis for the clinical application of RL-QN15 as a molecular probe in promoting DFU wound healing.

The vascular endothelial growth factor system-a new player in the pathogenesis and development of metabolic dysfunction-associated steatotic liver disease

The pathogenesis of liver disease from simple steatosis-metabolic dysfunction-associated steatotic liver disease(MASLD)-and the transition to inflammation and fibrosis-metabolic dysfunction-associated steatohepatitis(MASH)-is not well understood.However,cross-talk between subcutaneous white adipose tissue(WAT)and the liver may be of importance.

VEGF-B antibody and interleukin-22 fusion protein ameliorates diabetic nephropathy through inhibiting lipid accumulation and inflammatory responses

Diabetic nephropathy(DN)is considered the primary causes of end-stage renal disease(ESRD)and is related to abnormal glycolipid metabolism,hemodynamic abnormalities,oxidative stress and chronic inflammation.Antagonism of vascular endothelial growth factor B(VEGF-B)could effi-ciently ameliorate DN by reducing renal lipotoxicity.However,this pharmacological strategy is far from satisfactory,as it ignores numerous pathogenic factors,including anomalous reactive oxygen species(ROS)generation and inflammatory responses.We found that the upregulation of VEGF-B and downregulation of interleukin-22(IL-22)among DN patients were significantly associated with the progression of DN.Thus,we hypothesized that a combination of a VEGF-B antibody and IL-22 could protect against DN not only by regulating glycolipid metabolism but also by reducing the accumulation of inflammation and ROS.To meet these challenges,a novel anti-VEGFB/IL22 fusion protein was developed,and its therapeutic effects on DN were further studied.We found that the anti-VEGFB/IL22 fusion protein reduced renal lipid accumulation by inhibiting the expression of fatty acid transport proteins and ameliorated inflammatory responses via the inhibition of renal oxidative stress and mitochondrial dysfunction.Moreover,the fusion protein could also improve diabetic kidney disease by increasing insulin sensitivity.Collectively,our findings indicate that the bifunctional VEGF-B antibody and IL-22 fusion protein could improve the progression of DN,which highlighted a novel therapeutic approach to DN.