SGLT2 inhibition and renal urate excretion: role of luminal glucose, GLUT9, and URAT1

Inhibitors of the Na+-glucose cotransporter SGLT2 enhance urinary glucose and urate excretion and lower plasma urate levels. The mechanisms remain unclear, but a role for enhanced glucose in the tubular fluid, which may interact with tubular urate transporters, such as the glucose transporter GLUT9 or the urate transporter URAT1, has been proposed. Studies were performed in nondiabetic mice treated with the SGLT2 inhibitor canagliflozin and in gene-targeted mice lacking the urate transporter Glut9 in the tubule or in mice with whole body knockout of Sglt2, Sglt1, or Urat1. Renal urate handling was assessed by analysis of urate in spontaneous plasma and urine samples and normalization to creatinine concentrations or by renal clearance studies with assessment of glomerular filtration rate by FITC-sinistrin. The experiments confirmed the contribution of URAT1 and GLUT9 to renal urate reabsorption, showing a greater contribution of the latter and additive effects. Genetic and pharmacological inhibition of SGLT2 enhanced fractional renal urate excretion (FE-urate), indicating that a direct effect of the SGLT2 inhibitor on urate transporters is not absolutely necessary. Consistent with a proposed role of increased luminal glucose delivery, the absence of Sglt1, which by itself had no effect on FE-urate, enhanced the glycosuric and uricosuric effects of the SGLT2 inhibitor. The SGLT2 inhibitor enhanced renal mRNA expression of Glut9 in wild-type mice, but tubular GLUT9 seemed dispensable for the increase in FE-urate in response to canagliflozin. First evidence is presented that URAT1 is required for the acute uricosuric effect of the SGLT2 inhibitor in mice.

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Increase in SGLT1-mediated transport explains renal glucose reabsorption during genetic and pharmacological SGLT2 inhibition in euglycemia

AJP Renal Physiology ◽

10.1152/ajprenal.00518.2013 ◽

2014 ◽

Vol 306 (2) ◽

pp. F188-F193 ◽

Cited By ~ 145

Author(s):

Timo Rieg ◽

Takahiro Masuda ◽

Maria Gerasimova ◽

Eric Mayoux ◽

Kenneth Platt ◽

...

Keyword(s):

Knockout Mice ◽

Plasma Concentrations ◽

Sglt2 Inhibitor ◽

Double Knockout ◽

Glucose Reabsorption ◽

Urinary Glucose ◽

Sglt2 Inhibition ◽

Renal Glucose Reabsorption ◽

Glucose Excretion ◽

Free Plasma

In the kidney, the sodium-glucose cotransporters SGLT2 and SGLT1 are thought to account for >90 and ∼3% of fractional glucose reabsorption (FGR), respectively. However, euglycemic humans treated with an SGLT2 inhibitor maintain an FGR of 40–50%, mimicking values in Sglt2 knockout mice. Here, we show that oral gavage with a selective SGLT2 inhibitor (SGLT2-I) dose dependently increased urinary glucose excretion (UGE) in wild-type (WT) mice. The dose-response curve was shifted leftward and the maximum response doubled in Sglt1 knockout (Sglt1−/−) mice. Treatment in diet with the SGLT2-I for 3 wk maintained 1.5- to 2-fold higher urine glucose/creatinine ratios in Sglt1−/− vs. WT mice, associated with a temporarily greater reduction in blood glucose in Sglt1−/− vs. WT after 24 h (−33 vs. −11%). Subsequent inulin clearance studies under anesthesia revealed free plasma concentrations of the SGLT2-I (corresponding to early proximal concentration) close to the reported IC50 for SGLT2 in mice, which were associated with FGR of 64 ± 2% in WT and 17 ± 2% in Sglt1−/−. Additional intraperitoneal application of the SGLT2-I (maximum effective dose in metabolic cages) increased free plasma concentrations ∼10-fold and reduced FGR to 44 ± 3% in WT and to −1 ± 3% in Sglt1−/−. The absence of renal glucose reabsorption was confirmed in male and female Sglt1/Sglt2 double knockout mice. In conclusion, SGLT2 and SGLT1 account for renal glucose reabsorption in euglycemia, with 97 and 3% being reabsorbed by SGLT2 and SGLT1, respectively. When SGLT2 is fully inhibited by SGLT2-I, the increase in SGLT1-mediated glucose reabsorption explains why only 50–60% of filtered glucose is excreted.

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Increase in endogenous glucose production with SGLT2 inhibition is attenuated in individuals who underwent kidney transplantation and bilateral native nephrectomy

Diabetologia ◽

10.1007/s00125-020-05254-w ◽

2020 ◽

Vol 63 (11) ◽

pp. 2423-2433 ◽

Cited By ~ 1

Author(s):

Giuseppe Daniele ◽

Carolina Solis-Herrera ◽

Angela Dardano ◽

Andrea Mari ◽

Andrea Tura ◽

...

Keyword(s):

Single Dose ◽

Renal Transplant ◽

Hepatic Glucose Production ◽

Sglt2 Inhibitor ◽

Glucose Production ◽

Bilateral Nephrectomy ◽

Native Kidney ◽

Urinary Glucose ◽

Hepatic Glucose ◽

Sglt2 Inhibition

Abstract Aims/hypothesis The glucosuria induced by sodium–glucose cotransporter 2 (SGLT2) inhibition stimulates endogenous (hepatic) glucose production (EGP), blunting the decline in HbA1c. We hypothesised that, in response to glucosuria, a renal signal is generated and stimulates EGP. To examine the effect of acute administration of SGLT2 inhibitors on EGP, we studied non-diabetic individuals who had undergone renal transplant with and without removal of native kidneys. Methods This was a parallel, randomised, double-blind, placebo-controlled, single-centre study, designed to evaluate the effect of a single dose of dapagliflozin or placebo on EGP determined by stable-tracer technique. We recruited non-diabetic individuals who were 30–65 years old, with a BMI of 25–35 kg/m2 and stable body weight (±2 kg) over the preceding 3 months, and HbA1c <42 mmol/mol (6.0%). Participants had undergone renal transplant with and without removal of native kidneys and were on a stable dose of immunosuppressive medications. Participants received a single dose of dapagliflozin 10 mg or placebo on two separate days, at a 5- to 14-day interval, according to randomisation performed by our hospital pharmacy, which provided dapagliflozin and matching placebo, packaged in bulk bottles that were sequentially numbered. Both participants and investigators were blinded to group assignment. Results Twenty non-diabetic renal transplant patients (ten with residual native kidneys, ten with bilateral nephrectomy) participated in the study. Dapagliflozin induced greater glucosuria in individuals with residual native kidneys vs nephrectomised individuals (8.6 ± 1.1 vs 5.5 ± 0.5 g/6 h; p = 0.02; data not shown). During the 6 h study period, plasma glucose decreased only slightly and similarly in both groups, with no difference compared with placebo (data not shown). Following administration of placebo, there was a progressive time-related decline in EGP that was similar in both nephrectomised individuals and individuals with residual native kidneys. Following dapagliflozin administration, EGP declined in both groups, but the differences between the decrement in EGP with dapagliflozin and placebo in the group with bilateral nephrectomy (Δ = 1.11 ± 0.72 μmol min−1 kg−1) was significantly lower (p = 0.03) than in the residual native kidney group (Δ = 2.56 ± 0.33 μmol min−1 kg−1). In the population treated with dapagliflozin, urinary glucose excretion was correlated with EGP (r = 0.34, p < 0.05). Plasma insulin, C-peptide, glucagon, prehepatic insulin:glucagon ratio, lactate, alanine and pyruvate concentrations were similar following placebo and dapagliflozin treatment. β-Hydroxybutyrate increased with dapagliflozin treatment in the residual native kidney group, while a small increase was observed only at 360 min in the nephrectomy group. Plasma adrenaline (epinephrine) did not change after dapagliflozin and placebo treatment in either group. Following dapagliflozin administration, plasma noradrenaline (norepinephrine) increased slightly in the residual native kidney group and decreased in the nephrectomy group. Conclusions/interpretation In nephrectomised individuals, the hepatic compensatory response to acute SGLT2 inhibitor-induced glucosuria was attenuated, as compared with individuals with residual native kidneys, suggesting that SGLT2 inhibitor-mediated stimulation of hepatic glucose production via efferent renal nerves occurs in an attempt to compensate for the urinary glucose loss (i.e. a renal–hepatic axis). Trial registration ClinicalTrials.gov NCT03168295 Funding This protocol was supported by Qatar National Research Fund (QNRF) Award No. NPRP 8-311-3-062 and NIH grant DK024092-38. Graphical abstract

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Increased glucose metabolism in Arid5b−/− skeletal muscle is associated with the down-regulation of TBC1 domain family member 1 (TBC1D1)

Biological Research ◽

10.1186/s40659-020-00313-3 ◽

2020 ◽

Vol 53 (1) ◽

Cited By ~ 1

Author(s):

Yuri Okazaki ◽

Jennifer Murray ◽

Ali Ehsani ◽

Jessica Clark ◽

Robert H. Whitson ◽

...

Keyword(s):

Skeletal Muscle ◽

Plasma Membrane ◽

Energy Metabolism ◽

Glucose Metabolism ◽

Family Member ◽

Glucose Transporter ◽

Whole Body ◽

Domain Family ◽

Glucose Transporter 1

Abstract Background Skeletal muscle has an important role in regulating whole-body energy homeostasis, and energy production depends on the efficient function of mitochondria. We demonstrated previously that AT-rich interactive domain 5b (Arid5b) knockout (Arid5b−/−) mice were lean and resistant to high-fat diet (HFD)-induced obesity. While a potential role of Arid5b in energy metabolism has been suggested in adipocytes and hepatocytes, the role of Arid5b in skeletal muscle metabolism has not been studied. Therefore, we investigated whether energy metabolism is altered in Arid5b−/− skeletal muscle. Results Arid5b−/− skeletal muscles showed increased basal glucose uptake, glycogen content, glucose oxidation and ATP content. Additionally, glucose clearance and oxygen consumption were upregulated in Arid5b−/− mice. The expression of glucose transporter 1 (GLUT1) and 4 (GLUT4) in the gastrocnemius (GC) muscle remained unchanged. Intriguingly, the expression of TBC domain family member 1 (TBC1D1), which negatively regulates GLUT4 translocation to the plasma membrane, was suppressed in Arid5b−/− skeletal muscle. Coimmunofluorescence staining of the GC muscle sections for GLUT4 and dystrophin revealed increased GLUT4 localization at the plasma membrane in Arid5b−/− muscle. Conclusions The current study showed that the knockout of Arid5b enhanced glucose metabolism through the downregulation of TBC1D1 and increased GLUT4 membrane translocation in skeletal muscle.

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Insulin enhances renal glucose excretion: relation to insulin sensitivity and sodium-glucose cotransport

BMJ Open Diabetes Research & Care ◽

10.1136/bmjdrc-2020-001178 ◽

2020 ◽

Vol 8 (1) ◽

pp. e001178 ◽

Cited By ~ 1

Author(s):

Ele Ferrannini ◽

Ricardo Pereira-Moreira ◽

Marta Seghieri ◽

Eleni Rebelos ◽

Aglécio L Souza ◽

...

Keyword(s):

Sodium Excretion ◽

Insulin Infusion ◽

Glucose Production ◽

Whole Body ◽

Glucose Disposal ◽

Sodium Glucose Cotransporter ◽

Urinary Glucose ◽

Patients With Diabetes ◽

Sglt2 Inhibition ◽

Glucose Excretion

IntroductionInsulin regulates renal glucose production and utilization; both these fluxes are increased in type 2 diabetes (T2D). Whether insulin also controls urinary glucose excretion is not known.MethodsWe applied the pancreatic clamp technique in 12 healthy subjects and 13 T2D subjects. Each participant received a somatostatin infusion and a variable glucose infusion to achieve (within 1 hour) and maintain glycemia at 22 mmol/L for 3 hours; next, a constant insulin infusion (240 pmol/min/kg) was added for another 3 hours. Urine was collected separately in each period for glucose and creatinine determination.ResultsDuring saline, glucose excretion was lower in T2D than controls in absolute terms (0.49 (0.32) vs 0.69 (0.18) mmol/min, median (IQR), p=0.01) and as a fraction of filtered glucose (16.2 (6.4) vs 19.9 (7.5)%, p<0.001). With insulin, whole-body glucose disposal rose more in controls than T2D (183 (48) vs 101 (48) µmol/kgFFM/min, p<0.0003). Insulin stimulated absolute and fractional glucose excretion in controls (p<0.01) but not in T2D. Sodium excretion paralleled glucose excretion. In the pooled data, fractional glucose excretion was directly related to whole-body glucose disposal and to fractional sodium excretion (r=0.52 and 0.54, both p<0.01). In another group of healthy controls, empagliflozin was administered before starting the pancreatic clamp to block sodium-glucose cotransporter 2 (SGLT2). Under these conditions, insulin still enhanced both glucose and sodium excretion.ConclusionsAcute exogenous insulin infusion jointly stimulates renal glucose and sodium excretion, indicating that the effect may be mediated by SGLTs. This action is resistant in patients with diabetes, accounting for their increased retention of glucose and sodium, and is not abolished by partial SGLT2 inhibition by empagliflozin.

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SGLT2 inhibitor empagliflozin reduces renal growth and albuminuria in proportion to hyperglycemia and prevents glomerular hyperfiltration in diabetic Akita mice

AJP Renal Physiology ◽

10.1152/ajprenal.00520.2013 ◽

2014 ◽

Vol 306 (2) ◽

pp. F194-F204 ◽

Cited By ~ 228

Author(s):

Volker Vallon ◽

Maria Gerasimova ◽

Michael A. Rose ◽

Takahiro Masuda ◽

Joseph Satriano ◽

...

Keyword(s):

Gene Knockout ◽

Sglt2 Inhibitor ◽

Streptozotocin Diabetes ◽

Glomerular Hyperfiltration ◽

Vehicle Group ◽

Renal Growth ◽

Kidney Growth ◽

Urinary Glucose ◽

Sglt2 Inhibition ◽

Akita Mice

Our previous work has shown that gene knockout of the sodium-glucose cotransporter SGLT2 modestly lowered blood glucose in streptozotocin-diabetic mice (BG; from 470 to 300 mg/dl) and prevented glomerular hyperfiltration but did not attenuate albuminuria or renal growth and inflammation. Here we determined effects of the SGLT2 inhibitor empagliflozin (300 mg/kg of diet for 15 wk; corresponding to 60–80 mg·kg−1·day−1) in type 1 diabetic Akita mice that, opposite to streptozotocin-diabetes, upregulate renal SGLT2 expression. Akita diabetes, empagliflozin, and Akita + empagliflozin similarly increased renal membrane SGLT2 expression (by 38–56%) and reduced the expression of SGLT1 (by 33–37%) vs. vehicle-treated wild-type controls (WT). The diabetes-induced changes in SGLT2/SGLT1 protein expression are expected to enhance the BG-lowering potential of SGLT2 inhibition, and empagliflozin strongly lowered BG in Akita (means of 187–237 vs. 517–535 mg/dl in vehicle group; 100–140 mg/dl in WT). Empagliflozin modestly reduced GFR in WT (250 vs. 306 μl/min) and completely prevented the diabetes-induced increase in glomerular filtration rate (GFR) (255 vs. 397 μl/min). Empagliflozin attenuated increases in kidney weight and urinary albumin/creatinine ratio in Akita in proportion to hyperglycemia. Empagliflozin did not increase urinary glucose/creatinine ratios in Akita, indicating the reduction in filtered glucose balanced the inhibition of glucose reabsorption. Empagliflozin attenuated/prevented the increase in systolic blood pressure, glomerular size, and molecular markers of kidney growth, inflammation, and gluconeogenesis in Akita. We propose that SGLT2 inhibition can lower GFR independent of reducing BG (consistent with the tubular hypothesis of diabetic glomerular hyperfiltration), while attenuation of albuminuria, kidney growth, and inflammation in the early diabetic kidney may mostly be secondary to lower BG.

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The Mammalian Facilitative Glucose Transporter Family

Physiology ◽

10.1152/physiologyonline.1995.10.2.67 ◽

1995 ◽

Vol 10 (2) ◽

pp. 67-71 ◽

Cited By ~ 2

Author(s):

DE James

Keyword(s):

Gene Family ◽

Glucose Homeostasis ◽

Glucose Transporter ◽

Whole Body ◽

Large Gene Family ◽

The Past ◽

Large Gene ◽

Transporter Family ◽

Definition Of

Over the past few years, cloning studies have revealed a large gene family of facilitative glucose transporters in mammals. The definition of the unique characteristics of each member of this family has increased dramatically our understanding of the role of individual organs in regulation of whole body glucose homeostasis.

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Improved glycemic control in mice lacking Sglt1 and Sglt2

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00439.2012 ◽

2013 ◽

Vol 304 (2) ◽

pp. E117-E130 ◽

Cited By ~ 89

Author(s):

David R. Powell ◽

Christopher M. DaCosta ◽

Jason Gay ◽

Zhi-Ming Ding ◽

Melinda Smith ◽

...

Keyword(s):

Glycemic Control ◽

Glucose Tolerance ◽

Glucose Transporter ◽

Fasting Blood Glucose ◽

Glucose Absorption ◽

Oral Glucose ◽

Diabetic Patients ◽

Oral Glucose Tolerance ◽

Urinary Glucose ◽

Sglt2 Inhibition

Sodium-glucose cotransporter 2 (SGLT2) is the major, and SGLT1 the minor, transporter responsible for renal glucose reabsorption. Increasing urinary glucose excretion (UGE) by selectively inhibiting SGLT2 improves glycemic control in diabetic patients. We generated Sglt1 and Sglt2 knockout (KO) mice, Sglt1/Sglt2 double-KO (DKO) mice, and wild-type (WT) littermates to study their relative glycemic control and to determine contributions of SGLT1 and SGLT2 to UGE. Relative to WTs, Sglt2 KOs had improved oral glucose tolerance and were resistant to streptozotocin-induced diabetes. Sglt1 KOs fed glucose-free high-fat diet (G-free HFD) had improved oral glucose tolerance accompanied by delayed intestinal glucose absorption and increased circulating glucagon-like peptide-1 (GLP-1), but had normal intraperitoneal glucose tolerance. On G-free HFD, Sglt2 KOs had 30%, Sglt1 KOs 2%, and WTs <1% of the UGE of DKOs. Consistent with their increased UGE, DKOs had lower fasting blood glucose and improved intraperitoneal glucose tolerance than Sglt2 KOs. In conclusion, 1) Sglt2 is the major renal glucose transporter, but Sglt1 reabsorbs 70% of filtered glucose if Sglt2 is absent; 2) mice lacking Sglt2 display improved glucose tolerance despite UGE that is 30% of maximum; 3) Sglt1 KO mice respond to oral glucose with increased circulating GLP-1; and 4) DKO mice have improved glycemic control over mice lacking Sglt2 alone. These data suggest that, in patients with type 2 diabetes, combining pharmacological SGLT2 inhibition with complete renal and/or partial intestinal SGLT1 inhibition may improve glycemic control over that achieved by SGLT2 inhibition alone.

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Selective SGLT2 inhibition by tofogliflozin reduces renal glucose reabsorption under hyperglycemic but not under hypo- or euglycemic conditions in rats

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00545.2012 ◽

2013 ◽

Vol 304 (4) ◽

pp. E414-E423 ◽

Cited By ~ 30

Author(s):

Takumi Nagata ◽

Masanori Fukazawa ◽

Kiyofumi Honda ◽

Tatsuo Yata ◽

Mio Kawai ◽

...

Keyword(s):

Plasma Concentrations ◽

Sglt2 Inhibitor ◽

Glucose Production ◽

Endogenous Glucose Production ◽

Sodium Glucose Cotransporter ◽

Glucose Reabsorption ◽

Urinary Glucose ◽

Sglt2 Inhibition ◽

Renal Glucose Reabsorption

To understand the risk of hypoglycemia associated with urinary glucose excretion (UGE) induced by sodium-glucose cotransporter (SGLT) inhibitors, it is necessary to know the relationship between the ratio of contribution of SGLT2 vs. SGLT1 to renal glucose reabsorption (RGR) and the glycemic levels in vivo. To examine the contributions of SGLT2 and SGLT1 in normal rats, we compared the RGR inhibition by tofogliflozin, a highly specific SGLT2 inhibitor, and phlorizin, an SGLT1 and SGLT2 (SGLT1/2) inhibitor, at plasma concentrations sufficient to completely inhibit rat SGLT2 (rSGLT2) while inhibiting rSGLT1 to different degrees. Under hyperglycemic conditions by glucose titration, tofogliflozin and phlorizin achieved ≥50% inhibition of RGR. Under hypoglycemic conditions by hyperinsulinemic clamp, RGR was reduced by 20–50% with phlorizin and by 1–5% with tofogliflozin, suggesting the smaller contribution of rSGLT2 to RGR under hypoglycemic conditions than under hyperglycemic conditions. Next, to evaluate the hypoglycemic potentials of SGLT1/2 inhibition, we measured the plasma glucose (PG) and endogenous glucose production (EGP) simultaneously after UGE induction by SGLT inhibitors. Tofogliflozin (400 ng/ml) induced UGE of about 2 mg·kg−1·min−1 and increased EGP by 1–2 mg·kg−1·min−1, resulting in PG in the normal range. Phlorizin (1,333 ng/ml) induced UGE of about 6 mg·kg−1·min−1 and increased EGP by about 4 mg·kg−1·min−1; this was more than with tofogliflozin, but the minimum PG was lower. These results suggest that the contribution of SGLT1 to RGR is greater under lower glycemic conditions than under hyperglycemic conditions and that SGLT2-selective inhibitors pose a lower risk of hypoglycemia than SGLT1/2 inhibitors.

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