Role In Renal Glucose Reabsorption Research Articles

Analysis of the effect of canagliflozin on renal glucose reabsorption and progression of hyperglycemia in zucker diabetic Fatty rats.

Sodium-glucose cotransporter 2 (SGLT2) plays a major role in renal glucose reabsorption. To analyze the potential of insulin-independent blood glucose control, the effects of the novel SGLT2 inhibitor canagliflozin on renal glucose reabsorption and the progression of hyperglycemia were analyzed in Zucker diabetic fatty (ZDF) rats. The transporter activity of recombinant human and rat SGLT2 was inhibited by canagliflozin, with 150- to 12,000-fold selectivity over other glucose transporters. Moreover, in vivo treatment with canagliflozin induced glucosuria in mice, rats, and dogs in a dose-dependent manner. It inhibited apparent glucose reabsorption by 55% in normoglycemic rats and by 94% in hyperglycemic rats. The inhibition of glucose reabsorption markedly reduced hyperglycemia in ZDF rats but did not induce hypoglycemia in normoglycemic animals. The change in urinary glucose excretion should not be used as a marker to predict the glycemic effects of this SGLT2 inhibitor. In ZDF rats, plasma glucose and HbA1c levels progressively increased with age, and pancreatic β-cell failure developed at 13 weeks of age. Treatment with canagliflozin for 8 weeks from the prediabetic stage suppressed the progression of hyperglycemia, prevented the decrease in plasma insulin levels, increased pancreatic insulin contents, and minimized the deterioration of islet structure. These results indicate that selective inhibition of SGLT2 with canagliflozin controls the progression of hyperglycemia by inhibiting renal glucose reabsorption in ZDF rats. In addition, the preservation of β-cell function suggests that canagliflozin treatment reduces glucose toxicity via an insulin-independent mechanism.

SHR3824, a novel selective inhibitor of renal sodium glucose cotransporter 2, exhibits antidiabetic efficacy in rodent models.

The sodium glucose cotransporter 2 (SGLT2) plays an important role in renal glucose reabsorption, thus serves as a new target for the treatment of diabetes. The purpose of this study was to evaluate SHR3824 as a novel selective SGLT2 inhibitor and to characterize its in vivo effects on glucose homeostasis. The effects of chronic administration of SHR3824 on peripheral insulin sensitivity and pancreatic β-cell function were also investigated. The in vitro potency and selectivity of SHR3824 were assessed in HEK293 cells transfected with human SGLT2 or SGLT1. Acute and multi-dose studies were performed on ICR mice, GK rats and db/db mice to assess the ability of SHR3824 to enhance urinary glucose excretion and improve blood glucose levels. 2-Deoxyglucose uptake and insulin immunohistochemical staining were performed in the soleus muscle and pancreas, respectively, of db/db mice. A selective SGLT2 inhibitor BMS512148 (dapagliflozin) was taken as positive control. SHR3824 potently inhibited human SGLT2 in vitro, but exerted much weak inhibition on human SGLT1 (the IC50 values of SHR3824 against human SGLT2 and SGLT1 were 2.38 and 4324 nmol/L, respectively). Acute oral administration of SHR3824 (0.3, 1.0, 3.0 mg/kg) dose-dependently improved glucose tolerance in ICR mice, and reduced hyperglycemia by increasing urinary glucose excretion in GK rats and db/db mice. Chronic oral administration of SHR3824 (0.3, 1.0, 3.0 mg·kg(-1)·d(-1)) dose-dependently reduced blood glucose and HbA1c levels in GK rats and db/db mice, and significantly increased insulin-stimulated glucose uptake in the soleus muscles and enhanced insulin staining in the islet cells of db/db mice. SHR3824 is a potent and selective SGLT2 inhibitor and exhibits antidiabetic efficacy in several rodent models, suggesting its potential as a new therapeutic agent for the treatment of type 2 diabetes.

Effects of sodium-glucose cotransporter 2 selective inhibitor ipragliflozin on hyperglycaemia, oxidative stress, inflammation and liver injury in streptozotocin-induced type 1 diabetic rats

Sodium-glucose cotransporter (SGLT) 2 plays an important role in renal glucose reabsorption and has been highlighted as a therapeutic target for the treatment of diabetes. Here, we investigated the therapeutic effects of SGLT2 selective inhibitor ipragliflozin in type 1 diabetic rats. Type 1 diabetic rats were prepared by intravenous administration of streptozotocin (STZ). Ipragliflozin was acutely or chronically administered, and therapeutic effects were investigated. Single administration of ipragliflozin significantly increased urinary glucose excretion, and its effect lasted over 12 h. In addition, ipragliflozin improved glucose tolerance and sustainably reduced hyperglycaemia. Repeated administration of ipragliflozin to diabetic rats for 4 weeks significantly improved not only hyperglycaemia, but also hyperlipidaemia and hepatic steatosis with concomitant increases in urinary glucose excretion. In addition, ipragliflozin ameliorates renal glomerular hyperfiltration and albuminuria. Further, ipragliflozin reduced liver levels of oxidative stress biomarkers and plasma levels of inflammatory markers, and improved liver injury as assessed by plasma levels of aminotransferases. These results suggest that SGLT2 selective inhibitor ipragliflozin exerts a beneficial effect on glycaemic control and ameliorates diabetes-associated metabolic abnormalities and complications in STZ-induced diabetic rats, and would be a potential agent for the treatment of type 1 diabetes.

Pharmacological Characterization of YM543, a Newly Synthesized, Orally Active SGLT2 Selective Inhibitor

Background and aim. Sodium-glucose cotransporter (SGLT) 2 is a specifically expressed transporter in the kidney that plays an important role in renal glucose reabsorption, and its inhibition may present a novel therapeutic strategy for treating diabetes. Here, we pharmacologically characterized YM543, a newly synthesized SGLT2 selective inhibitor to test this theory. Results. In vitro studies revealed that YM543 potently and selectively inhibited mouse and human SGLT2 activities at nanomolar ranges. In vivo single oral administration of YM543 dose-dependently and significantly reduced blood glucose levels and improved glucose tolerance with a concomitant increase in urinary glucose excretion in KK/Ay type 2 diabetic mice, effects that were sustained even after 12 h. Repeated once-daily oral administration of YM543 for 5 weeks significantly reduced hyperglycemia in type 2 diabetic mice. In addition, combination treatment of YM543 with rosiglitazone or metformin additively improved diabetic symptoms. In contrast, YM543 did not affect normoglycemia at pharmacological doses in normal mice. Conclusions. Results from the present study suggest that YM543 is an orally active SGLT2 selective inhibitor which reduces hyperglycemia with a concomitant increase in urinary glucose excretion, indicating its promise as an effective treatment against type 2 diabetes.

Pharmacodynamics and Subchronic Toxicity in Mice and Monkeys of ISIS 388626, a Second-Generation Antisense Oligonucleotide That Targets Human Sodium Glucose Cotransporter 2

ISIS 388626, a 2'-methoxyethyl (MOE)-modified antisense oligonucleotide (ASO) that targets human sodium glucose cotransporter 2 (SGLT2) mRNA, is in clinical trials for the management of diabetes. SGLT2 plays a pivotal role in renal glucose reabsorption, and inhibition of SGLT2 is anticipated to reduce hyperglycemia in diabetic subjects by increasing urinary glucose elimination. To selectively inhibit SGLT2 in the kidney, ISIS 388626 was designed as a "shortmer" ASO, consisting of only 12 nucleotides with two 2'-MOE-modified nucleotides at the termini. Mice and monkeys received up to 30 mg/kg/week ISIS 388626 via subcutaneous injection for 6 or 13 weeks. Dose-dependent decreases in renal SGLT2 mRNA expression were observed, which correlated with dose-related increases in glucosuria without concomitant hypoglycemia. There were no histologic changes in the kidney attributed to SGLT2 inhibition after 6 or 13 weeks of treatment. The remaining changes observed in these studies were typical of those produced in these species by the administration of oligonucleotides, correlated with high doses of ISIS 388626, and were unrelated to the inhibition of SGLT2 expression. The kidney contained the highest concentration of ISIS 388626, and dose-dependent basophilic granule accumulation in tubular epithelial cells of the kidney, which is evidence of oligonucleotide accumulation in these cells, was the only histologic change identified. No changes in kidney function were observed. These results revealed only readily reversible changes after the administration of ISIS 388626 and support the continued investigation of the safety and efficacy of ISIS 388626 in human trials.

Antidiabetic Effects of SGLT2-Selective Inhibitor Ipragliflozin in Streptozotocin–Nicotinamide-Induced Mildly Diabetic Mice

Sodium-glucose cotransporter (SGLT) 2 plays an important role in renal glucose reabsorption, and inhibition of renal SGLT2 activity represents an innovative strategy for the treatment of hyperglycemia in diabetic patients. The present study investigated the antidiabetic effects of ipragliflozin, a SGLT2-selective inhibitor, in streptozotocin–nicotinamide-induced mildly diabetic mice, which exhibited a mild decline in glucose tolerance associated with the loss of early-phase insulin secretion. Oral administration of ipragliflozin increased urinary glucose excretion in a dose-dependent manner, an effect which was significant at doses of 0.3 mg/kg or higher and lasted over 12 h. In addition, ipragliflozin dose-dependently improved hyperglycemia and glucose intolerance with concomitant decreases in plasma insulin levels without causing hypoglycemia. Once-daily dosing of ipragliflozin (0.1 – 3 mg/kg) for 4 weeks attenuated hyperglycemia, glucose intolerance, and impaired insulin secretion. These results suggest that the SGLT2-selective inhibitor ipragliflozin increases urinary glucose excretion by inhibiting renal glucose reabsorption, improves hyperglycemia in streptozotocin–nicotinamide-induced mildly diabetic mice, and may be useful for treating type 2 diabetes.

Exploring Newer Target Sodium Glucose Transporter 2 for the Treatment of Diabetes Mellitus

Diabetes mellitus is an independent risk factor for the development of coronary artery disease, myocardial infarction, hypertension, and dyslipidemia. The treatment of diabetes has been mainly focused on maintaining normal blood glucose concentrations. Insulin and hypoglycemic agents have been used as standard therapeutic strategies. However, these are characterized by limited efficacy and adverse side effects, making the development of new therapeutic alternatives mandatory. Inhibition of glucose reabsorption in the kidney, mediated by Sodium Glucose Transporters (SGLT's), represents a promising therapeutic approach. The high-affinity sodium glucose cotransporter (SGLT1) is expressed to some extent in the kidney and contributes to glucose reabsorption, However Genetic mutations in the SGLT1 gene leading to a functional defect are responsible for glucose/galactose malabsorption. The low-affinity sodium glucose cotransporter (SGLT2), which is expressed specifically in the kidney, plays a major role in renal glucose reabsorption in the proximal tubule. We focused on SGLT2 as a molecular target for this review because it plays a major role in renal glucose reabsorption, and its tissue distribution is limited in the kidney to reduce the likelihood for mechanism-based side effects. Phlorizin, a natural phenolic O-glucoside has been known to induce glucosuria for more than 100 years. As it is not a specific SGLT inhibitor, later on o-glucoside is replaced by c-glycoside as it is resistant to hydrolysis by β-glucosidases. The present review summarizes the concept of SGLT2 selective target based therapy for diabetes mellitus and the current clinical and preclinical development of SGLT2 inhibitors.

Sodium–glucose co‐transporter‐2 inhibitors: an emerging new class of oral antidiabetic drug

The sodium-glucose co-transporter-2 (SGLT2) is a low-affinity transport system that is specifically expressed in the kidney and plays an important role in renal glucose reabsorption in the proximal tubule. Competitive inhibition of SGLT2 therefore represents an innovative therapeutic strategy for the treatment of hyperglycaemia and/or obesity in patients with type 1 or type 2 diabetes by enhancing glucose and energy loss through the urine. The observation that individuals with familial renal glycosuria maintain normal long-term kidney function provides some reassurance that this mode of action will not adversely affect renal function. Intense research in this therapeutic area has led to the discovery of novel SGLT2 inhibitors, each with different chemical, pharmacodynamic and pharmacokinetic profiles. This review outlines the biology, expression and pleotropic activity of the SGLT system and the pharmacological profile of SGLT2 inhibitors and provides a summary of preclinical and limited clinical data available to characterize the efficacy, safety and potential clinical utility of SGLT2 inhibitors in the management of diabetes.

Remogliflozin Etabonate, in a Novel Category of Selective Low-Affinity Sodium Glucose Cotransporter (SGLT2) Inhibitors, Exhibits Antidiabetic Efficacy in Rodent Models

The low-affinity sodium glucose cotransporter (SGLT2) plays an important role in renal glucose reabsorption and is a remarkable transporter as a molecular target for the treatment of diabetes. We have discovered remogliflozin etabonate, which is a novel category of selective SGLT2 inhibitors. Remogliflozin etabonate is a prodrug based on benzylpyrazole glucoside and is metabolized to its active form, remogliflozin, in the body. We identified remogliflozin to be a potent and highly selective SGLT2 inhibitor by examining COS-7 cells transiently expressing either high-affinity sodium glucose cotransporter (SGLT1) or SGLT2. Orally administered remogliflozin etabonate increased urinary glucose excretion in a dose-dependent manner in both mice and rats. By increasing urinary glucose excretion, remogliflozin etabonate inhibited the increase in plasma glucose after glucose loading without stimulating insulin secretion in normal rats. Remogliflozin etabonate also showed antihyperglycemic effects in both streptozotocin-induced diabetic rats in oral glucose tolerance and in db/db mice in the fed condition. Chronic treatment with remogliflozin etabonate reduced the levels of fasting plasma glucose and glycated hemoglobin, and it ameliorated glucosuria in db/db mice. In high-fat diet-fed Goto-Kakizaki rats, remogliflozin etabonate improved hyperglycemia, hyperinsulinemia, hypertriglyceridemia, and insulin resistance. This study demonstrates that treatment with remogliflozin etabonate exhibits antidiabetic efficacy in several rodent models and suggests that remogliflozin etabonate may be a new and useful drug for the treatment of diabetes.

Sergliflozin, a Novel Selective Inhibitor of Low-Affinity Sodium Glucose Cotransporter (SGLT2), Validates the Critical Role of SGLT2 in Renal Glucose Reabsorption and Modulates Plasma Glucose Level

The low-affinity sodium glucose cotransporter (SGLT2), which is expressed specifically in the kidney, plays a major role in renal glucose reabsorption in the proximal tubule. We have discovered sergliflozin, a prodrug of a novel selective SGLT2 inhibitor, based on benzylphenol glucoside. In structure, it belongs to a new category of SGLT2 inhibitors and its skeleton differs from that of phlorizin, a nonselective SGLT inhibitor. We investigated its pharmacological properties and potencies in vitro and in vivo. By examining a Chinese hamster ovary-K1 cell line stably expressing either human SGLT2 or human high-affinity sodium glucose cotransporter (SGLT1), we found sergliflozin-A (active form) to be a highly selective and potent inhibitor of human SGLT2. At pharmacological doses, sergliflozin, sergliflozin-A, and its aglycon had no effects on facilitative glucose transporter 1 activity, which was inhibited by phloretin (the aglycon of phlorizin). The transport maximum for glucose in the kidney was reduced by sergliflozin-A in normal rats. As a result of this effect, orally administered sergliflozin increased urinary glucose excretion in mice, rats, and dogs in a dose-dependent manner. In an oral glucose tolerance test in diabetic rats, sergliflozin exhibited glucose-lowering effects independently of insulin secretion. Any glucose excretion induced by sergliflozin did not affect normoglycemia or electrolyte balance. These data indicate that selective inhibition of SGLT2 increases urinary glucose excretion by inhibiting renal glucose reabsorption. As a representative of a new category of antidiabetic drugs, sergliflozin may provide a new and unique approach to the treatment of diabetes mellitus.