SGLT2 inhibitors, sodium and off-target effects: an overview

Antifibrotic effects of sodium-glucose cotransporter-2 inhibitors: A comprehensive review

BACKGROUND AND AIMS

Scar tissue accumulation in organs is the underlying cause of many fibrotic diseases. Due to the extensive array of organs affected, the long-term nature of fibrotic processes and the large number of people who suffer from the negative impact of these diseases, they constitute a serious health problem for modern medicine and a huge economic burden on society. Sodium-glucose cotransporter-2 inhibitors (SGLT2is) are a relatively new class of anti-diabetic pharmaceuticals that offer additional benefits over and above their glucose-lowering properties; these medications modulate a variety of diseases, including fibrosis. Herein, we have collated and analyzed all available research on SGLT2is and their effects on organ fibrosis, together with providing a proposed explanation as to the underlying mechanisms.

METHODS

PubMed, ScienceDirect, Google Scholar and Scopus were searched spanning the period from 2012 until April 2023 to find relevant articles describing the antifibrotic effects of SGLT2is.

RESULTS

The majority of reports have shown that SGLT2is are protective against lung, liver, heart and kidney fibrosis as well as arterial stiffness. According to the results of clinical trials and animal studies, many SGLT2 inhibitors are promising candidates for the treatment of fibrosis. Recent studies have demonstrated that SGLT2is affect an array of cellular processes, including hypoxia, inflammation, oxidative stress, the renin-angiotensin system and metabolic activities, all of which have been linked to fibrosis.

CONCLUSION

Extensive evidence indicates that SGLT2is are promising treatments for fibrosis, demonstrating protective effects in various organs and influencing key cellular processes linked to fibrosis.

Pharmacokinetics of Henagliflozin in Dialysis Patients with Diabetes

AIM

This study aimed to assess the pharmacokinetics of henagliflozin in dialysis patients with diabetes.

METHODS

In this prospective, randomized, open-label study where 10 hemodialysis and 10 peritoneal dialysis patients with diabetes were randomized in a 1:1:1:1 ratio to oral administration of henagliflozin in doses of 5 and 10 mg/day. The pharmacokinetics of a single dose of henagliflozin on Days 1 and 2, the minimum plasma concentration (Cmin) of the steady state on Day 10, and single hemodialysis clearance of henagliflozin were measured.

RESULTS

The mean values of Cmax were 70.2-77.0 ng/mL and 105-143 ng/mL in the 5 mg and 10 mg henagliflozin groups, respectively; the mean values of AUCinf were 777-811 h*ng/mL and 1290-1730 h*ng/mL in the 5 mg and 10 mg henagliflozin groups, respectively. The median Tmax values ranged from 1 to 3 h across the dose range. The mean values of T1/2 of henagliflozin were 14.1-14.5 and 16.2-21.0 h in the 5 mg and 10 mg groups, respectively. The Cmin values of the steady state in dialysis patients taking 5 mg and 10 mg of henagliflozin were 15.0 ± 4.4 ng/mL and 26.8 ± 16.3 ng/mL, respectively, which were 123.8% and 131.0% higher than those in diabetic patients with normal renal function, respectively. Henagliflozin concentration was decreased by 1.1% after hemodialysis treatment. No treatment-related serious adverse events or discontinuations occurred.

CONCLUSIONS

Henagliflozin at the current recommended dosage may be safe, although it is possible to result in slight accumulation in patients on dialysis.

REGISTRATION

Chinese Clinical Trial Registry number ChiCTR2200062872. The date of registration: August 22, 2022.

Mechanisms of benefits of sodium-glucose cotransporter 2 inhibitors in heart failure with preserved ejection fraction

For decades, heart failure with preserved ejection fraction (HFpEF) proved an elusive entity to treat. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have recently been shown to reduce the composite of heart failure hospitalization or cardiovascular death in patients with HFpEF in the landmark DELIVER and EMPEROR-Preserved trials. While improvements in blood sugar, blood pressure, and attenuation of kidney disease progression all may play some role, preclinical and translational research have identified additional mechanisms of these agents. The SGLT2 inhibitors have intriguingly been shown to induce a nutrient-deprivation and hypoxic-like transcriptional paradigm, with increased ketosis, erythropoietin, and autophagic flux in addition to altering iron homeostasis, which may contribute to improved cardiac energetics and function. These agents also reduce epicardial adipose tissue and alter adipokine signalling, which may play a role in the reductions in inflammation and oxidative stress observed with SGLT2 inhibition. Emerging evidence also indicates that these drugs impact cardiomyocyte ionic homeostasis although whether this is through indirect mechanisms or via direct, off-target effects on other ion channels has yet to be clearly characterized. Finally, SGLT2 inhibitors have been shown to reduce myofilament stiffness as well as extracellular matrix remodelling/fibrosis in the heart, improving diastolic function. The SGLT2 inhibitors have established themselves as robust, disease-modifying therapies and as recent trial results are incorporated into clinical guidelines, will likely become foundational in the therapy of HFpEF.

[Clinical and practical management of sodium-glucose cotransporter type 2 inhibitors in patients with chronic kidney disease]

The discovery of the nephroprotective role of sodium-glucose cotransporter type 2 (iSGLT2) inhibitor drugs in people with type 2 diabetes mellitus (DM 2) following the results obtained in the respective cardiovascular safety trials led to a change in the approach to diabetic kidney disease in recent years, positioning this group in the first step in the treatment of this comorbidity. The publication of the results of the DAPA-CKD study with dapagliflozin, demonstrating its benefit in slowing the progression of chronic kidney disease (CKD) in patients with and without DM, has opened a new age in the management of this pathology. These drugs are also safe and easy to use for the clinician. This article reviews the management of iSGLT2 in patients with diabetic and non-diabetic CKD.

Empagliflozin reduces podocyte lipotoxicity in experimental Alport syndrome

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are anti-hyperglycemic agents that prevent glucose reabsorption in proximal tubular cells. SGLT2i improves renal outcomes in both diabetic and non-diabetic patients, indicating it may have beneficial effects beyond glycemic control. Here, we demonstrate that SGLT2i affects energy metabolism and podocyte lipotoxicity in experimental Alport syndrome (AS). In vitro, we found that the SGLT2 protein was expressed in human and mouse podocytes to a similar extent in tubular cells. Newly established immortalized podocytes from Col4a3 knockout mice (AS podocytes) accumulate lipid droplets along with increased apoptosis when compared to wild-type podocytes. Treatment with SGLT2i empagliflozin reduces lipid droplet accumulation and apoptosis in AS podocytes. Empagliflozin inhibits the utilization of glucose/pyruvate as a metabolic substrate in AS podocytes but not in AS tubular cells. In vivo, we demonstrate that empagliflozin reduces albuminuria and prolongs the survival of AS mice. Empagliflozin-treated AS mice show decreased serum blood urea nitrogen and creatinine levels in association with reduced triglyceride and cholesterol ester content in kidney cortices when compared to AS mice. Lipid accumulation in kidney cortices correlates with a decline in renal function. In summary, empagliflozin reduces podocyte lipotoxicity and improves kidney function in experimental AS in association with the energy substrates switch from glucose to fatty acids in podocytes.

The Role of Sodium-Glucose Cotransporter-2 Inhibitors in Heart Failure Management: The Continuing Challenge of Clinical Outcome Endpoints in Heart Failure Trials

The introduction of sodium-glucose cotransporter-2 (SGLT2) inhibitors in the management of heart failure with preserved ejection fraction (HFpEF) may be regarded as the first effective treatment in these patients. However, this proposition must be evaluated from the perspective of the complexity of clinical outcome endpoints in heart failure. The major goals of heart failure treatment have been categorized as: (1) reduction in (cardiovascular) mortality, (2) prevention of recurrent hospitalizations due to worsening heart failure, and (3) improvement in clinical status, functional capacity, and quality of life. The use of the composite primary endpoint of cardiovascular death and hospitalization for heart failure in SGLT2 inhibitor HFpEF trials flowed from the assumption that hospitalization for heart failure is a proxy for subsequent cardiovascular death. The use of this composite endpoint was not justified since the effect of the intervention on both components was clearly distinct. Moreover, the lack of convincing and clinically meaningful effects of SGLT2 inhibitors on metrics of heart failure-related health status indicates that the effect of this class of drugs in HFpEF patients is essentially restricted to an effect on hospitalization for heart failure. In conclusion, SGLT2 inhibitors do not represent a substantial breakthrough in the management of HFpEF.

Canagliflozin promotes osteoblastic MC3T3-E1 differentiation via AMPK/RUNX2 and improves bone microarchitecture in type 2 diabetic mice

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of bone metabolic disorders and bone fracture due to disease progression and clinical treatment. The effect of sodium-glucose cotransporter 2 (SGLT2) inhibitors, now greatly prescribed for the treatment of T2DM, on bone metabolism is not clear. This study aimed to explore the possible influence of bone metabolic disorder and the underlying mechanism through a comparison of three different SGLT2 inhibitors (canagliflozin, dapagliflozin, and empagliflozin) in the treatment of type 2 diabetic mice. For the in vivo experiments, four groups (DM, DM+Cana, DM+Dapa, and DM+Empa) were established using micro-CT to detect the bone microarchitecture and bone-related parameters. The study results indicated that canagliflozin, but not dapagliflozin or empagliflozin, increased bone mineral density (p<0.05) and improved bone microarchitecture in type 2 diabetic mice. Furthermore, canagliflozin promoted osteoblast differentiation at a concentration of 5 μM under high glucose concentration (HG). Phosphorylated adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) α (Thr172) has been confirmed to activate run-related transcription factor-2 (RUNX2) to perform this function. This effect can be partially reversed by the AMPK inhibitor dorsomorphin (compound C) and strengthened by the AMPK activator acadesine (AICAR) in vitro. The level trend of RUNX2 and p-AMPK in vivo were consistent with those in vitro. This study suggested that canagliflozin played a beneficial role in bone metabolism in type 2 diabetic mice compared with dapagliflozin and empagliflozin. It provides some theoretical support for the chosen drugs, especially for patients with osteoporosis or a high risk of fracture.

Anti-Inflammatory Properties of the SGLT2 Inhibitor Empagliflozin in Activated Primary Microglia

Sodium-glucose cotransporter 2 (SGLT2) inhibitors, including empagliflozin, are routinely used as antidiabetic drugs. Recent studies indicate that beside its beneficial effects on blood glucose level, empagliflozin may also exert vascular anti-inflammatory and neuroprotective properties. In the brain, microglia are crucial mediators of inflammation, and neuroinflammation plays a key role in neurodegenerative disorders. Dampening microglia-mediated inflammation may slow down disease progression. In this context, we investigated the immunomodulatory effect of empagliflozin on activated primary microglia. As a validated experimental model, rat primary microglial cells were activated into a pro-inflammatory state by stimulation with LPS. The influence of empagliflozin on the expression of pro-inflammatory mediators (NO, Nos2, IL6, TNF, IL1B) and on the anti-inflammatory mediator IL10 was assessed using quantitative PCR and ELISA. Further, we investigated changes in the activation of the ERK1/2 cascade by Western blot and NFkB translocation by immunostaining. We observed that empagliflozin reduces the expression of pro- and anti-inflammatory mediators in LPS-activated primary microglia. These effects might be mediated by NHE-1, rather than by SGLT2, and by the further inhibition of the ERK1/2 and NFkB pathways. Our results support putative anti-inflammatory effects of empagliflozin on microglia and suggest that SGLT2 inhibitors may exert beneficial effects in neurodegenerative disorders.

Impact of sodium-glucose co-transporter inhibitors on cardiac autonomic function and mortality: no time to die

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have been shown to improve cardiovascular outcomes not only in patients with diabetes but also in those with heart failure, irrespective of diabetic status. However, the mechanisms underlying the cardioprotective effects of these newer anti-diabetic drugs remain to be fully elucidated. One exciting avenue that has been recently explored in both preclinical and clinical studies is the modulation of the cardiovascular autonomic nervous system. A reduction in sympathetic nervous system activity by SGLT2 inhibitors may potentially translate into a reduction in arrhythmic risk and sudden arrhythmic death, which may explain, at least partly, the cardioprotection shown in the cardiovascular outcome trials with different SGLT2 inhibitors. Although some of the data from the preclinical and clinical studies are promising, overall the findings can be contradictory. This highlights the need for more studies to address gaps in our knowledge of these novel drugs. The present review offers an in depth overview of the existing literature regarding the role of SGLT2 inhibitors in modulating cardiovascular autonomic function as one of the possible pathways of their cardioprotective effects.

Review of SGLT2i for the Treatment of Renal Complications: Experience in Patients with and Without T2D

The management of type 2 diabetes (T2D) involves decreasing plasma glucose levels and reducing cardiovascular and microvascular complications. Diabetic kidney disease (DKD), defined as presence of albuminuria, impaired glomerular filtration, or both, is an insidious microvascular complication of diabetes that generates a substantial personal and clinical burden. The progressive reduction in renal function and increased albuminuria results in an increase of cardiovascular events. Thus, patients with DKD require exhaustive control of the associated cardiovascular risk factors. People with diabetes and renal impairment have fewer options of antidiabetic drugs because of contraindications, adverse effects, or altered pharmacokinetics. Sodium-glucose cotransporter type 2 inhibitors (SGLT2i) reduce blood glucose concentrations by blocking the uptake of sodium and glucose in the proximal tubule and promoting glycosuria, and these agents now have an important role in the management of T2D. The results of several cardiovascular outcomes trials suggested that SGLT2i are associated with improvements in renal endpoints in addition to their reduction in cardiovascular events and mortality, which represents a major advance in the care of this population. The dedicated kidney outcomes trials have confirmed the renoprotective action of SGLT2i across different glomerular filtration and albuminuria values, even in patients with non-diabetic chronic kidney disease. Notably, this improvement in kidney function may indirectly benefit cardiac function through multifaceted interorgan cross talk, which can break the cardiorenal vicious circle linked to T2D. In this article, we briefly review the different mechanisms of action that may explain the renal beneficial effects of SGLT2i and disclose the results of the key renal outcome trials and the subsequent update of related clinical guidelines.

Sodium-glucose Cotransporter Type 2 Inhibitors: A New Insight into the Molecular Mechanisms of Diabetic Nephropathy

Diabetic nephropathy is one of the chronic microvascular complications of diabetes and is a leading cause of end-stage renal disease. Fortunately, clinical trials have demonstrated that sodium-glucose cotransporter type 2 inhibitors could decrease proteinuria and improve renal endpoints and are promising agents for the treatment of diabetic nephropathy. The renoprotective effects of sodium-glucose cotransporter type 2 inhibitors cannot be simply attributed to their advantages in aspects of metabolic benefits, such as glycemic control, lowering blood pressure, and control of serum uric acid, or improving hemodynamics associated with decreased glomerular filtration pressure. Some preclinical evidence suggests that sodium-glucose cotransporter type 2 inhibitors exert their renoprotective effects by multiple mechanisms, including attenuation of oxidative and endoplasmic reticulum stresses, anti-fibrosis and anti-inflammation, protection of podocytes, suppression of megalin function, improvement of renal hypoxia, restored mitochondrial dysfunction and autophagy, as well as inhibition of sodium-hydrogen exchanger 3. In the present study, the detailed molecular mechanisms of sodium-glucose cotransporter type 2 inhibitors with the actions of diabetic nephropathy were reviewed, with the purpose of providing the basis for drug selection for the treatment of diabetic nephropathy.

Characteristics and molecular mechanisms through which SGLT2 inhibitors improve metabolic diseases: A mechanism review

Metabolic diseases, such as diabetes, gout and hyperlipidemia are global health challenges. Among them, diabetes has been extensively investigated. Type 2 diabetes mellitus (T2DM), which is characterized by hyperglycemia, is a complex metabolic disease that is associated with various metabolic disorders. The newly developed oral hypoglycemic agent, sodium-glucose cotransporter 2 (SGLT2) inhibitor, has been associated with glucose-lowering effects and it affects metabolism in various ways. However, the potential mechanisms of SGLT2 inhibitors in metabolic diseases have not fully reviewed. Many of the effects beyond glycemic control must be considered off-target effects. Therefore, we reviewed the effects of SGLT2 inhibition on metabolic diseases such as obesity, hypertension, hyperlipidemia, hyperuricemia, fatty liver disease, insulin resistance, osteoporosis and fractures. Moreover, we elucidated their molecular mechanisms to provide a theoretical basis for metabolic disease treatment.

Recent Advances in Diabetic Kidney Diseases: From Kidney Injury to Kidney Fibrosis

Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease and end-stage renal disease. The natural history of DKD includes glomerular hyperfiltration, progressive albuminuria, declining estimated glomerular filtration rate, and, ultimately, kidney failure. It is known that DKD is associated with metabolic changes caused by hyperglycemia, resulting in glomerular hypertrophy, glomerulosclerosis, and tubulointerstitial inflammation and fibrosis. Hyperglycemia is also known to cause programmed epigenetic modification. However, the detailed mechanisms involved in the onset and progression of DKD remain elusive. In this review, we discuss recent advances regarding the pathogenic mechanisms involved in DKD.

Polypharmacology of clinical sodium glucose co-transport protein 2 inhibitors and relationship to suspected adverse drug reactions

Sodium glucose co-transporter 2 inhibitors (SGLT2i) are a promising second-line treatment strategy for type 2 diabetes mellitus (T2DM) with a developing landscape of both beneficial cardio- and nephroprotective properties and emerging adverse drug reactions (ADRs) including diabetic ketoacidosis (DKA), genetic mycotic infections, and amputations among others. A national register study (MHRA Yellow Card, UK) was used to quantify the SGLT2i's suspected ADRs relative to their Rx rate (OpenPrescribing, UK). The polypharmacology profiles of SGLT2i were data-mined (ChEMBL) for the first time. The ADR reports (n = 3629) and prescribing numbers (Rx n = 5,813,325) for each SGLT2i in the United Kingdom (from launch date to the beginning December 2019) were determined. Empagliflozin possesses the most selective SGLT2/SGLT1 inhibition profile at ~2500-fold, ~10-fold more selective than cangliflozin (~260-fold). Canagliflozin was found to also inhibit CYP at clinically achievable concentrations. We find that for overall ADR rates, empagliflozin versus dapagliflozin and empagliflozin versus canagliflozin are statistically significant (χ2 , p < .05), while dapagliflozin versus canagliflozin is not. In terms of overall ADRs, there is a greater relative rate for canagliflozin > dapagliflozin > empagliflozin. For fatalities, there is a greater relative rate for dapagliflozin > canagliflozin > empagliflozin. An organ classification that resulted in a statistically significant difference between SGLT2i was suspected infection/infestation ADRs between empagliflozin and dapagliflozin. Our findings at this stage of SGLT2i usage in the United Kingdom suggest that empagliflozin, the most selective SGLT2i, had the lowest suspected ADR incident rate (relative to prescribing) and in all reported classes of ADRs identified including infections, amputations, and DKA.

NQO1 Deficiency Aggravates Renal Injury by Dysregulating Vps34/ATG14L Complex during Autophagy Initiation in Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the causes of end-stage renal failure, featuring renal fibrosis. However, autophagy, a vital process for intracellular homeostasis, can counteract renal fibrosis. Moreover, NAD(P)H: quinone dehydrogenase 1 (NQO1) modulates the ratios of reduced/oxidized nicotinamide nucleotides, exerting a cytoprotective function. Here, to examine the role of NQO1 genes in DN progression, the levels of autophagy-related proteins and pro-fibrotic markers were assessed in silencing or overexpression of NQO1 in human proximal tubular cells (HK2), and C57BL/6 (wild-type) and Nqo1 knockout (KO) mice injected to streptozotocin (50 mg/kg). NQO1 deficiency impaired the autophagy process by suppressing basal expression of ClassⅢ PI 3-kinase (Vps34) and autophagy-related (ATG)14L and inducing the expressions of transforming growth factor beta (TGF-β1), Smad3, and matrix metallopeptidase9 (MMP9) in high-glucose (HG) -treated HK2 cells. Meanwhile, NQO1 overexpression increased the expression of Vps34 and ATG14L, while, reducing TGF-β1, Smad3 and MMP9 expression. In vivo, the expression of Vps34 and ATG14L were suppressed in Nqo1 KO mice indicating aggravated glomerular changes and interstitial fibrosis. Therefore, NQO1 deficiency dysregulated autophagy initiation in HK2 cells, with consequent worsened renal cell damage under HG condition. Moreover, STZ-treated Nqo1 KO mice showed that NQO1 deficiency aggravated renal fibrosis by dysregulating autophagy.