Empagliflozin and liraglutide ameliorate HFpEF in mice via augmenting the Erbb4 signaling pathway.

Heart failure with preserved ejection fraction (HFpEF) is closely associated with metabolic derangement. Sodium glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) exert anti-HFpEF effects, but the underlying mechanisms remain unclear. In this study, we explored the anti-HFpEF effects of empagliflozin and liraglutide and the underlying molecular mechanisms in a mouse model of HFpEF. This model was established by high-fat diet (HFD) feeding plus Nω-nitro-L-arginine methyl ester (L-NAME) treatment. The mice were treated with empagliflozin (20 mg·kg-1·d-1, i.g.) or liraglutide (0.3 mg·kg-1·d-1, i.p.) or their combination for 4 weeks. At the end of the experimental protocol, cardiac function was measured using ultrasound, then mice were euthanized and heart, liver, and kidney tissues were collected. Nuclei were isolated from frozen mouse ventricular tissue for single-nucleus RNA-sequencing (snRNA-seq). We showed that administration of empagliflozin or liraglutide alone or in combination significantly improved diastolic function, ameliorated cardiomyocyte hypertrophy and cardiac fibrosis, as well as exercise tolerance but no synergism was observed in the combination group. Furthermore, empagliflozin and/or liraglutide lowered body weight, improved glucose metabolism, lowered blood pressure, and improved liver and kidney function. After the withdrawal of empagliflozin or liraglutide for 1 week, these beneficial effects tended to diminish. The snRNA-seq analysis revealed a subcluster of myocytes, in which Erbb4 expression was down-regulated under HFpEF conditions, and restored by empagliflozin or liraglutide. Pseudo-time trajectory analysis and cell-to-cell communication studies confirmed that the Erbb4 pathway was a prominent pathway essential for both drug actions. In the HFpEF mouse model, both empagliflozin and liraglutide reversed Erbb4 down-regulation. In rat h9c2 cells, we showed that palmitic acid- or high glucose-induced changes in PKCα and/or ERK1/2 phosphorylation at least in part through Erbb4. Collectively, the single-cell atlas reveals the anti-HFpEF mechanism of empagliflozin and liraglutide, suggesting that Erbb4 pathway represents a new therapeutic target for HFpEF. Effects and mechanisms of action of empagliflozin and liraglutide in HFpEF mice. HFpEF was induced with a high-fat diet and L-NAME for 15 weeks, and treatment with empagliflozin and liraglutide improved the HFpEF phenotype. Single nucleus RNA sequencing (snRNA-seq) was used to reveal the underlying mechanism of action of empagliflozin and liraglutide.

Co-delivery of a tumor microenvironment-responsive disulfiram prodrug and CuO2 nanoparticles for efficient cancer treatment.

Disulfiram (DSF) has been used as a hangover drug for more than seven decades and was found to have potential in cancer treatment, especially mediated by copper. However, the uncoordinated delivery of disulfiram with copper and the instability of disulfiram limit its further applications. Herein, we synthesize a DSF prodrug using a simple strategy that could be activated in a specific tumor microenvironment. Poly amino acids are used as a platform to bind the DSF prodrug through the B-N interaction and encapsulate CuO2 nanoparticles (NPs), obtaining a functional nanoplatform Cu@P-B. In the acidic tumor microenvironment, the loaded CuO2 NPs will produce Cu2+ and cause oxidative stress in cells. At the same time, the increased reactive oxygen species (ROS) will accelerate the release and activation of the DSF prodrug and further chelate the released Cu2+ to produce the noxious copper diethyldithiocarbamate complex, which causes cell apoptosis effectively. Cytotoxicity tests show that the DSF prodrug could effectively kill cancer cells with only a small amount of Cu2+ (0.18 µg mL-1), inhibiting the migration and invasion of tumor cells. In vitro and in vivo experiments have demonstrated that this functional nanoplatform could kill tumor cells effectively with limited toxic side effects, showing a new perspective in DSF prodrug design and cancer treatment.

Corrigendum: MicroRNAs as Regulators of Immune and Inflammatory Responses: Potential Therapeutic Targets in Diabetic Nephropathy.

[This corrects the article DOI: 10.3389/fcell.2020.618536.].

Berberine regulates mesangial cell proliferation and cell cycle to attenuate diabetic nephropathy through the PI3K/Akt/AS160/GLUT1 signalling pathway.

High glucose (HG) is one of the basic factors of diabetic nephropathy (DN), which leads to high morbidity and disability. During DN, the expression of glomerular glucose transporter 1 (GLUT1) increases, but the relationship between HG and GLUT1 is unclear. Glomerular mesangial cells (GMCs) have multiple roles in HG-induced DN. Here, we report prominent glomerular dysfunction, especially GMC abnormalities, in DN mice, which is closely related to GLUT1 alteration. In vivo studies have shown that BBR can alleviate pathological changes and abnormal renal function indicators of DN mice. In vitro, BBR (30, 60 and 90 µmol/L) not only increased the proportion of G1 phase cells but also reduced the proportion of S phase cells under HG conditions at different times. BBR (60 µmol/L) significantly reduced the expression of PI3K-p85, p-Akt, p-AS160, membrane-bound GLUT1 and cyclin D1, but had almost no effect on total protein. Furthermore, BBR significantly declined the glucose uptake and retarded cyclin D1-mediated GMC cell cycle arrest in the G1 phase. This study demonstrated that BBR can inhibit the development of DN, which may be due to BBR inhibiting the PI3K/Akt/AS160/GLUT1 signalling pathway to regulate HG-induced abnormal GMC proliferation and the cell cycle, supporting BBR as a potential therapeutic drug for DN.

China experts' consensus on preventive and interceptive orthodontic treatments of malocclusions of children.

Malocclusion is one of the three most common oral diseases reported by World Health Organization(WHO). In China, its incidence rate is rising. Malocclusion seriously affects the dental and maxillofacial function, facial appearance and growth development of nearly 260 million children in China, and what is more, it affects their physical and mental health development. Malocclusion occurrence is related to genetic and environmental factors. Early treatment of malocclusion can create a good dental and maxillofacial development environment, correct abnormal growth and control the adverse effects of abnormal genetic factors. It can effectively reduce the prevalence of children's malocclusion and enhance their physical and mental health. This is an urgent need from the economic perspective of our society, so it has great practical and social significance. Experts from the project group "standard diagnose and treatment protocols for early orthodontic intervention of malocclusions of children" which initiated by China National Health Institute of Hospital Administration wrote the "China Experts' Consensus on Preventive and Interceptive Orthodontic Treatments of Malocclusions of Children", which aims to guide and popularize the clinical practice, improve the clinical theory and practice level, and accelerate the disciplinary development of early treatment of children's malocclusion in China. The consensus elaborates the harmfulness of malocclusion and the necessity of early treatment, and brings up the principles and fundamental contents. Based on the law of dental and maxillofacial development, this paper puts forward the guiding suggestions of preventive and interceptive treatments in different stages of dental development ranging from fetus to early permanent dentition. It is a systematic project to promote and standardize the early treatment of malocclusion. Through scientific and comprehensive stratified clinical practice and professional training, the clinical system of early treatment of malocclusion in China will eventually be perfected, so as to comprehensively care for children's dental and maxillofacial health, and improve their oral and physical health in China.

Berberine mitigates high glucose-induced podocyte apoptosis by modulating autophagy via the mTOR/P70S6K/4EBP1 pathway.

AIMS: This study aimed to investigate the characteristics and mechanism of autophagy on podocyte apoptosis under high glucose (HG) conditions and further explore the effect of berberine on podocyte autophagy, apoptosis and the potential mechanism. MATERIALS AND METHODS: The levels of LC3II/I in podocytes stimulated with HG were detected at 0, 2, 4, 8, 12, 24, 36 and 48 h by western blotting. CCK-8 was used to detect the viability of podocytes. The level of autophagy was detected by western blotting, transmission electron microscopy and immunofluorescence. Podocyte apoptosis was analysed by using Hoechst staining, western blotting, annexin V/propidium iodide dual staining, and confocal microscopy. Then, podocytes were transfected with siRNA to silence mTOR, and the expression levels of proteins and mRNA involved in the mTOR/P70S6K/4EBP1 pathway were further investigated by western blotting and qRT-PCR. KEY FINDINGS: In this study, we found significantly reduced LC3II/LC3I and increased p62 in podocytes stimulated with HG for 24 h, and the level of autophagy reached a minimum at 24 h. Berberine restored podocyte viability and significantly attenuated HG-mediated inhibition of autophagy, as evidenced by the increased expression of LC3II/LC3I, the number of autophagosomes and the inhibition of p62. Moreover, berberine counteracted HG-induced podocyte apoptosis and injury, which was negatively correlated with the autophagy effect. Notably, silencing mTOR with siRNA augmented the inhibition of P70S6k and 4EBP1 phosphorylation, which was similar to the effect of berberine. SIGNIFICANCE: Berberine activates podocyte autophagy by inhibiting the mTOR/P70S6K/4EBP1 signaling pathway, thereby alleviating podocyte apoptosis.

MicroRNAs as Regulators of Immune and Inflammatory Responses: Potential Therapeutic Targets in Diabetic Nephropathy.

Diabetic nephropathy (DN) is the principal cause of end-stage renal disease and results in high morbidity and mortality in patients, causing a large socioeconomic burden. Multiple factors, such as metabolic abnormalities, inflammation, immunoregulation and genetic predisposition, contribute to the pathogenesis of DN, but the exact mechanism is unclear, and the therapeutic strategies are not satisfactory. Accordingly, there is an unmet need for new therapeutic targets and strategies for DN. MicroRNAs (miRNAs) act as major epigenetic mechanisms that regulate gene expression and provide novel insights into our understanding of the molecular and signaling pathways that are associated with various diseases, including DN. Studies in the past decade have shown that different miRNAs affect the progression of DN by modulating different aspects of immune and inflammatory responses. Therefore, in this review, we summarized the pivotal roles of miRNAs in inflammatory and immune processes, with an integrative comprehension of the detailed signaling network. Additionally, we discussed the possibilities and significance of these miRNAs as therapeutic targets in the treatment of DN. This review will facilitate the identification of new therapeutic targets and novel strategies that can be translated into clinical applications for DN treatment.

Berberine ameliorates renal impairment and inhibits podocyte dysfunction by targeting the phosphatidylinositol 3-kinase-protein kinase B pathway in diabetic rats.

AIMS/INTRODUCTION: Amelioration of renal impairment is the key to diabetic nephropathy (DN) therapy. The progression of DN is closely related to podocyte dysfunction, but the detailed mechanism has not yet been clarified. The present study aimed to explore the renal impairment amelioration effect of berberine and related mechanisms targeting podocyte dysfunction under the diabetic state. MATERIALS AND METHODS: Streptozotocin (35 mg/kg) was used to develop a DN rat model together with a high-glucose/high-lipid diet. Renal functional parameters and glomerular ultrastructure changes were recorded. The alterations of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt) and phosphorylated Akt in the kidney cortex were determined by western blot. Meanwhile, podocyte dysfunction was induced and treated with berberine and LY294002. After that, podocyte adhesion functional parameters, protein biomarker and the alterations of the PI3K-Akt pathway were detected. RESULTS: Berberine reduces the increased levels of biochemical indicators, and significantly improves the abnormal expression of PI3K, Akt and phosphorylated Akt in a rat kidney model. In vitro, a costimulating factor could obviously reduce the podocyte adhesion activity, including decreased expression of nephrin, podocin and adhesion molecule α3ß1 levels, to induce podocyte dysfunction, and the trends were markedly reversed by berberine and LY294002 therapy. Furthermore, reduction of PI3K and phosphorylated Akt levels were observed in the berberine (30 and 60 µmol/L) and LY294002 (40 µmol/L) treatment group, but the Akt protein expression showed little change. CONCLUSIONS: Berberine could be a promising antidiabetic nephropathy drug through ameliorating renal impairment and inhibiting podocyte dysfunction in diabetic rats, and the underlying molecular mechanisms might be involved in the regulation of the PI3K-Akt signaling pathway.

Influence of life-style factors, including second-hand smoke, on dental caries among 3-year-old children in Wuxi, China.

AIM: To examine the association of life-style factors, including second-hand smoke, with dental caries among 3-year-old children in Wuxi, China. METHODS: A multi-stage stratified random cluster sampling method was used, and 283 children were recruited. The prevalence of dental caries was 29.3% (83/283). RESULTS: Univariate analysis indicated that the possible related factors of dental caries included sleep duration, interest in snacks, candy, exposure to second-hand smoke and weight of birth (all P < 0.05). Meanwhile, multivariate logistic regression analysis suggested that children who had used fluoride were less susceptible to dental caries than those who had not used fluoride before (P < 0.05). Moreover, the risk of dental caries in children who were very interested in snacks was greater than those with little interest in snacks (P < 0.05). CONCLUSIONS: Life-style behaviours are crucial factors and should attract enough attention. There might be a potential negative effect of second-hand smoke on the deciduous caries, but it still requires further studies. A co-ordinated effort by health-care providers, policymakers and health institutions has successfully improved children's oral health and the awareness of hygiene knowledge among citizens in Wuxi city.

Berberine attenuates podocytes injury caused by exosomes derived from high glucose-induced mesangial cells through TGFß1-PI3K/AKT pathway.

Diabetic nephropathy is the most common microvascular complications of diabetes. Berberine is the main active ingredient of Coptis chinensis and previous studies have been showed that berberine could delay the progression of diabetic nephropathy by regulating related cytokines and signaling pathways. Glomerular mesangial cells and podocytes are two vital indigenous cells of kidney and interaction between these two cellular components via exosomes might affect function of glomerulus in diabetic nephropathy condition. On the basis of our previous studies, transwell systems were used to demonstrate that the exosomes released by glomerular mesangial cells induced by the high glucose were involved in podocytes injury. The current study demonstrates that berberine can reduce TGFß1 in exosomes released by high glucose-induced glomerular mesangial cells. Berberine-treated high glucose-induced exosomes which are secreted by glomerular mesangial cells can protect damage of podocytes by reducing apoptosis and increasing adhesion. These results suggest that berberine could protect the function of podocytes through inhibiting the transfer of TGFß1 from the glomerular mesangial cells to the podocytes, which is one of the potential mechanisms of protective effect of berberine on diabetic nephropathy.

Berberine exerts renoprotective effects by regulating the AGEs-RAGE signaling pathway in mesangial cells during diabetic nephropathy.

In this study, we explored the effect of berberine treatment on the AGEs-RAGE pathway in a rat model of diabetic nephropathy, and we investigated the mechanism by which key factors caused kidney injury and the effects of berberine. In vivo, berberine improved fasting blood glucose, body weight, the majority of biochemical and renal function parameters and histopathological changes in the diabetic kidney. Western blotting and immunohistochemistry revealed significant increases in the levels of AGEs, RAGE, P-PKC-ß and TGF-ß1 in injured kidneys, and these levels were markedly decreased by treatment with berberine. In vitro, berberine inhibited mesangial cell proliferation. Cells treated with berberine showed reduced levels of AGEs, accompanied by decreased RAGE, p-PKC and TGF-ß1 levels soon afterwards. Berberine exhibited renoprotective effects in diabetic nephropathy rats, and the molecular mechanism was associated with changes in the levels and regulation of the AGEs-RAGE-PKC-ß-TGF-ß1 signaling pathway.

Roles of the NLRP3 inflammasome in the pathogenesis of diabetic nephropathy.

Diabetic nephropathy (DN) is a serious complication of diabetes mellitus, and persistent inflammation in circulatory and renal tissues is an important pathophysiological basis for DN. The essence of the microinflammatory state is the innate immune response, which is central to the occurrence and development of DN. Members of the inflammasome family, including both "receptors" and "regulators", are key to the inflammatory immune response. Nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) and other inflammasome components are able to detect endogenous danger signals, resulting in activation of caspase-1 as well as interleukin (IL)-1ß, IL-18 and other cytokines; these events stimulate the inflammatory cascade reaction, which is crucial for DN. Hyperglycaemia, hyperlipidaemia and hyperuricaemia can activate the NLRP3 inflammasome, which then mediates the occurrence and development of DN through the K+ channel model, the lysosomal damage model and the active oxygen cluster model. In this review, we survey the involvement of the NLRP3 inflammasome in various signalling pathways and highlight different aspects of their influence on DN. We also explore the important effects of the NLRP3 inflammasome on kidney function and structural changes that occur during DN development and progression. It is becoming more evident that NLRP3 inflammasome targeting has therapeutic potential for the treatment of DN.

Renoprotective effect of berberine via regulating the PGE2 -EP1-Gαq-Ca(2+) signalling pathway in glomerular mesangial cells of diabetic rats.

G-protein coupled receptor-mediated pathogenesis is of great importance in the development of diabetic complications, but the detailed mechanisms have not yet been clarified. Therefore, we aimed to explore the roles of the prostaglandin E2 receptor 1 (EP1)-mediated signalling pathway and develop a corresponding treatment for diabetic nephropathy (DN). To create the DN model, rats fed a high-fat and high-glucose diet were injected with a single dose of streptozotocin (35 mg/kg, i.p.). Then, rats were either treated or not with berberine (100 mg/kg per day, i.g., 8 weeks). Cells were isolated from the renal cortex and cultured in high-sugar medium with 20% foetal bovine serum. Prostaglandin E2 (PGE2 ) levels were determined by ELISA, and cells were identified by fluorescence immunoassay. We measured the biochemical characteristics and observed morphological changes by periodic-acid-Schiff staining. The expression of the EP1 receptor and the roles of GRK2 and ß-arrestin2 were identified using western blotting and flow cytometry. Downstream proteins were detected by western blot, while molecular changes were assessed by ELISA and laser confocal scanning microscopy. Berberine not only improved the majority of biochemical and renal functional parameters but also improved the histopathological alterations. A significant increase in PGE2 level, EP1 membrane expression and Gαq expression, and concentration of Ca(2+) were observed, accompanied by increased GRK2 and ß-arrestin2 levels soon afterwards. Berberine decreased the abnormal concentration of Ca(2+) , the increased levels of PGE2 , the high expression of EP1 and Gαq and suppressed the proliferation of mesangial cells. The EP1 receptor, a critical therapeutic target of the signalling pathway, contributed to mesangial cell abnormalities, which are linked to renal injury in DN. The observed renoprotective effects of berberine via regulating the PGE2 -EP1-Gαq-Ca(2+) signalling pathway indicating that berberine could be a promising anti-DN medicine in the future.

Renoprotective effects of berberine and its potential effect on the expression of ß-arrestins and intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in streptozocin-diabetic nephropathy rats.

BACKGROUND: Berberine has been shown to exert protective effects against diabetic nephropathy (DN), but the mechanisms involved have not been fully characterized. The aim of the present study was to explore the effects of berberine on the expression of ß-arrestins, intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in DN rat kidneys and investigate the underlying molecular mechanisms. METHODS: To create the DN model, rats fed a high-fat and high-glucose diet were injected with a single dose of streptozotocin (35 mg/kg, i.p.). Then, DN rats were either treated or not with berberine (50, 100, 200 mg/kg per day, i.g., 8 weeks). Periodic acid-Schiff staining was used to evaluate renal histopathological changes. Renal tissue levels of ß-arrestin 1 and ß-arrestin 2 were determined by Western blot analysis, whereas immunohistochemistry was used to determine renal ICAM-1 and VCAM-1 levels. RESULTS: Berberine (100, 200 mg/kg) ameliorated the histopathological changes in the diabetic kidney. Western blot analysis revealed significant increases in ICAM-1 and VCAM-1 levels in the kidneys of DN rats, which were reversed by treatment with 100 and 200 mg/kg berberine. In addition, berberine treatment (50, 100, 200 mg/kg) increased diabetic-induced decreases in ß-arrestin 1 and ß-arrestin 2. CONCLUSIONS: Berberine exhibited renoprotective effects in DN rats. The underlying molecular mechanisms may be associated with changes in the levels and regulation of ß-arrestin expression, as well as ICAM-1 and VCAM-1 levels in the rat kidney.

G protein-coupled receptors: potential therapeutic targets for diabetic nephropathy.

Diabetic nephropathy, a lethal microvascular complication of diabetes mellitus, is characterized by progressive albuminuria, excessive deposition of extracellular matrix, thickened glomerular basement membrane, podocyte abnormalities, and podocyte loss. The G protein-coupled receptors (GPCRs) have attracted considerable attention in diabetic nephropathy, but the specific effects have not been elucidated yet. Likewise, abnormal signaling pathways are closely interrelated to the pathologic process of diabetic nephropathy, despite the fact that the mechanisms have not been explored clearly. Therefore, GPCRs and its mediated signaling pathways are essential for priority research, so that preventative strategies and potential targets might be developed for diabetic nephropathy. This article will give us comprehensive overview of predominant GPCR types, roles, and correlative signaling pathways in diabetic nephropathy.

Renoprotective effects of berberine through regulation of the MMPs/TIMPs system in streptozocin-induced diabetic nephropathy in rats.

Berberine has proven protective effects on diabetic nephropathy, but the mechanism for its effects has not been comprehensively established. Hence, we aimed to explore the renoprotective mechanism of berberine on the accumulation of extracellular matrix, alterations of its major components and corresponding changes in the regulatory system, including the matrix metalloproteinases/tissue inhibitor of matrix metalloproteinases (MMPs/TIMPs) system, in diabetic nephropathy rats. In the experiments, diabetic nephropathy rats were treated with berberine (0, 50, 100, 200 mg/kg) respectively. The protein levels of transforming growth factor-ß1 were then detected by Western blot, while fibronectin and type IV collagen levels were assessed using immunohistochemistry. Changes in the MMP2/9 and TIMP1/2 levels were detected using two forms simultaneously. In addition, we also measured the characteristics and biochemical indicators of the diabetic nephropathy rats. The results showed that berberine could ameliorate the fasting blood glucose, and the majority of biochemical and renal function parameters, but did not have an effect on body weight. Immunohistochemistry and Western blot examination revealed a significant increase in the MMP9 and TIMP1/2 levels, with an obvious decrease in MMP2 expression in the diabetic nephropathy rats. Berberine (100 and 200 mg/kg) could significantly improve the abnormal changes in the MMPs/TIMPs system. Meanwhile, reductions in the transforming growth factor-ß1, fibronectin and type IV collagen expression levels were observed in the berberine treatment groups. Therefore, the renoprotective effects of berberine on diabetic nephropathy might be associated with changes in the extracellular matrix through the regulation of the MMPs/TIMPs system in the rat kidney.

[Regulatory effect of compound Coptidis Rhizoma capsule on unbalanced expression of renal tissue TGF-ß1/BMP-7 and Smad signaling pathway in rats with early diabetic nephropathy].

OBJECTIVE: To investigate the effect of compound Coptidis Rhizoma capsule (CCRC) on unbalanced expression of renal tissue TGF-ß1/BMP-7 and Smad signaling pathway in rats with early diabetic nephropathy (DN), and discuss CCRC's effect on DN rats with early diabetic nephropathy and its possible mechanism. METHOD: DN model rats were established by injecting streptozotocin (STZ). The rats were randomly divided into seven groups: the normal group, the model group, the enalapril treatment group, the xiaoke pill treatment group and three CRCC treatment groups. They were orally administered once a day for five weeks. The fasting blood glucose (FBG), blood urea nitrogen (BUN), serum creatinine (Scr), insulin (Ins), 24 h urinary protein (24 h Upro) and 24 h urinary microalbumin (24 h UmAlb) were tested. The pathological changes in renal tissues were examined by optical microscopy. Immuno- histochemical measures were used to detect the expressions of TGF-ß1, BMP-7, Smad2/3, Smad1/5, and Smad7 protein, and RT-PCR was used to detect TGF-ß1 mRNA and BMP-7 mRNA in renal tissues. RESULT: Compared with model group, BUN, Scr, Ins, 24 h Upro and 24 h UmAlb levels decreased at different degrees in CCRC treatment groups; the abnormal pathomorphology in renal tissue was improved; immunohistochemistry results showed that the expression of TGF-ß1 and Smad2/3 were reduced, while the expression of BMP-7, Smad1/5 and Smad7 increased in CRCC treatment groups; the expression of TGF-ß1 mRNA were reduced, but the expression of BMP-7 mRNA had no obvious change in CRCC treatment groups. CONCLUSION: CRCC can improve the early renal function, delay the progression of chronic renal pathology and maintain the dynamic balance of TGF-ß1/BMP-7 expression in renal tissues of DN rats. The mechanism may be related to down-regulation of renal TGF-ß1 and up-regulation of BMP-7 through Smad signaling pathway.

Berberine as a promising anti-diabetic nephropathy drug: An analysis of its effects and mechanisms.

Diabetic nephropathy is a progressive kidney disorder and is pathologically characterized by thickened glomerular and tubular basement membranes, accumulation of the extracellular matrix and increased mesangial hypertrophy. Growing evidence has suggested that diabetic nephropathy is induced by multiple factors, such as dyslipidemia, hyperglycemia, hemodynamic abnormalities and oxidative stress, based on genetic susceptibility. Berberine (BBR; [C20H18NO4](+)), an isoquinoline alkaloid, is the major active constituent of Rhizoma coptidis and Cortex phellodendri. Recent studies have demonstrated that berberine has various pharmacological activities, including lowering blood glucose, regulating blood lipids and reducing inflammation in addition to its antioxidant activity. These findings suggest that berberine has potential applications as a therapeutic drug for diabetic nephropathy, and has significant research value. However, the possible mechanisms have not been fully established. The purpose of this paper is to investigate the renoprotective mechanisms of berberine in diabetic nephropathy and highlight the importance of berberine as a potential therapeutic reagent for diabetic nephropathy treatment.

Research progress in signalling pathway in diabetic nephropathy.

Diabetic nephropathy, a lethal diabetic complication, is a leading cause of end-stage renal disease, which is pathologically characterized by thickened tubular basal and glomerular membranes, accumulated extracellular matrix, and progressive mesangial hypertrophy. Growing evidence indicates that diabetic nephropathy is induced by multiple conditions, such as glucose metabolism disorder, oxidative stress, numerous inflammatory factors and cytokines, and haemodynamic changes that lead to the occurrence and development of diabetic nephropathy based on genetic susceptibility. A variety of abnormalities in the signalling pathway may interact to produce these pathologic processes. Research has aimed to highlight the signalling pathway mechanisms that lead to diabetic nephropathy so that preventative strategies and effective therapies might be developed. In this review, important pathways that appear to be involved in driving these processes are discussed.

Berberine regulates the expression of E-prostanoid receptors in diabetic rats with nephropathy.

Diabetic nephropathy (DN) is a major cause of morbidity and mortality in diabetic patients. Effective therapies to prevent the development of this disease and to improve advanced kidney injury are required. Berberine (BBR) has preventive effects on diabetes and its complications. This study is to investigate the effects of BBR on the expression of E-prostanoid receptors (EPs) in rats with high-fat diet and streptozotocin (STZ)-induced DN and underlying molecular mechanisms of BBR on DN rats. DN model was induced in male Sprague-Dawley rats with high-fat diet and low dose of STZ injection. BBR (50, 100, 200 mg/kg/d) were orally administered to rats after STZ injection and conducted for 8 weeks. The levels of interleukin-6 (IL-6) and prostaglandin E2 (PGE2) in renal cortex were measured by enzyme-linked immunosorbent assay. Expression of EPs receptors (EP1-EP4) were determined by western blotting. Remarkable renal damage, hyperglycemia and hyperlipidemia were observed in DN rats. BBR could restore renal functional parameters, suppress alterations in histological and ultrastructural changes in the kidney tissues, improve glucose and lipid metabolism disorders, and increase cAMP levels compared with those of DN model group (Wang et al. in Mol Biol Rep 40:2405-2418, 2013). The level of IL-6 and PGE2 were significantly increased in DN model group compared with normal group, BBR could apparently reduced the level of IL-6 and PGE2. Furthermore, the expression of EP1 and EP3 were both increased and EP4 was lessened in the DN model group compared with normal group, BBR could down-regulate total protein expression of EP1 and EP3 of renal cortex in DN rats and up-regulate the expression of EP4, and there is no significant difference on the expression of EP2 among all groups. These studies demonstrate, for the first time, that BBR exerts renoprotection in high-fat diet and STZ-induced DN rats by modulating the proteins expression of EPs in EP-G protein-cAMP signaling pathway.