Current understanding on pathogenesis and effective treatment of glycogen storage disease type Ib with empagliflozin: new insights coming from diabetes for its potential implications in other metabolic disorders

A holistic view of SGLT2 inhibitors: From cardio-renal management to cognitive and andrological aspects

Type 2 diabetes mellitus (T2DM) is a multifactorial disease associated with complications that significantly affect both survival and quality of life, including cardiovascular, renal, cognitive, sexual, and reproductive dysfunctions. Sodium-glucose cotransporter 2 (SGLT2) inhibitors (SGLT2is) have emerged as a transformative class of drugs, demonstrating benefits that extend beyond glycemic control. Large clinical trials have shown that SGLT2is reduce hospitalization for heart failure by 25-35% and slow progression of chronic kidney disease by 30-45%, with variation based on the specific agent, dose, and patient population. This narrative review examines not only these well-established benefits but also emerging evidence regarding their effects in less-explored domains. SGLT2is have been associated with improved cognitive performance, potentially through reductions in neuroinflammation and oxidative stress. In the sexual and reproductive domains, studies in men with diabetes mellitus suggest potential benefits of SGLT2is in improving erectile function, sperm motility, and testosterone levels, likely mediated by antioxidant and anti-inflammatory mechanisms. By integrating current evidence across multiple systems, this review emphasizes the role of SGLT2is in a holistic, multidisciplinary approach to the management of patients with T2DM.

Empagliflozin as treatment in glycogen storage disease type IB patients

Background

Glycogen Storage Disease Ib (GSD Ib) is a disease that associates both neutropenia and neutrophil dysfunction, thereby causing recurrent infections and inflammatory bowel disease (IBD). As of now, the standard treatment of these complications has been the administration of granulocyte-stimulating factor (GCSF). However, recent studies have found that the use of empagliflozin, an antidiabetic drug, may have benefits by reducing the levels of 1,5 anhydroglucitol-6-phosphate (1,5-AG6P), a metabolite that accumulates in the cytosol of neutrophils and blocks the use of glucose.

Results

We therefore report our experience with three patients, one of them being a liver and kidney transplant recipient, with promising results. Morbidity has been greatly reduced in all cases consisting in weight gain, better neutrophil count and management of respiratory, osteoarticular and gastrointestinal comorbidities. Overall, an improvement in quality of life has been observed.

Conclusion

SGLT2 inhibitors, and specifically empagliflozin offer promising results in improving morbidity and quality of life in patients with GSD Ib. In the cases presented, including a patient with double liver-kidney transplant, a good profile of tolerance, safety and effectiveness has been observed.

Synopsis

Empagliflozin offers promising results in improving morbidity and quality of life in patients with GSD Ib, including the first double organ transplant patient treated with this drug.

Effects of Tinospora cordifolia (giloy) on metabolic syndrome components: a mechanistic review

Metabolic syndrome is a cluster of some conditions such as high blood sugar, high blood triglycerides, low HDL cholesterol, abdominal obesity, and high blood pressure. Introducing a drug or a food that manages the majority of these medical conditions is invaluable. Tinospora cordifolia, known as guduchi and giloy, is a medicinal herb in ayurvedic medicine that is used in the treatment of various diseased conditions and also as a food for the maintenance of health. Here, we reviewed the current evidence supporting the role of giloy in the development and treatment of metabolic syndrome components. Appropriate articles that have been published until May 2024 were carefully extracted from PubMed, Scopus, and WOS databases to write a narrative review systematically. Gathered data showed the beneficial effects of giloy on metabolic syndrome components: hyperlipidemia, obesity, atherosclerosis, hypertension, and especially diabetes mellitus. As diabetes and insulin resistance seem to be a central feature of metabolic syndrome and in turn, can cause dyslipidemia, obesity, and, atherosclerosis, these beneficial effects are predictable with the anti-diabetogenic property of giloy. In this review, the main mechanisms of action of giloy in metabolic syndrome components are discussed. Based on the results, although giloy has been less investigated, considerable studies provide evidence of its beneficial effects on different components of metabolic syndrome. Relevant clinical trials are necessary to validate the mentioned effects, safety, and optimum dose of this herbal medicine and its components in managing different components of metabolic syndrome and transition from bench to bedside.

Sodium-glucose co-transporters (SGLT2) inhibitors prevent lipid droplets formation in vascular inflammation or lipid overload by SGLT2-independent mechanism

BACKGROUND

The formation of vascular lipid droplets (LDs) induced by vascular inflammation or lipid overload contributes to vascular pathophysiology in diabetes and cardiometabolic diseases, while sodium-glucose co-transporter 2 inhibitors (SGLT2-I) are beneficial in treating these conditions. Thus, we hypothesized that SGLT2-I would directly modify vascular LDs formation during vascular inflammation or lipid overload, and explored underlying mechanisms.

METHODS

LDs formation in isolated murine aorta from wild-type or SGLT2-KO animals was induced by either treatment with tumour necrosis factor (TNF) to induce vascular inflammation or using oleic acid (OA) to mimic lipid overload. Vascular LDs and markers of vascular inflammation were monitored through fluorescence microscopy. Pharmacological inhibitors of sodium-hydrogen exchanger 1 (NHE1), endothelial sodium channels (EnNaC), sodium-calcium exchanger (NCX), protein kinase C (PKC), and NOX1/4 were used to test their role in empagliflozin's effects on vascular LDs.

RESULTS

Empagliflozin, dapagliflozin or ertugliflozin inhibited LDs formation in aorta exposed to TNF or OA. Empagliflozin reduced vascular inflammation (based on ICAM-1) and TNF/OA-induced LDs formation. These effects persisted in SGLT2-KO mice. Inhibition of NHE1, PKC or NOX1/4 recapitulated empagliflozin's effects on TNF-induced vascular inflammation, without additional effects of empagliflozin. However, NHE1 inhibition was not involved in the SGLT2-independent reduction of OA-induced LDs formation by empagliflozin.

CONCLUSIONS

This is the first report demonstrating that SGLT2-I prevent the formation of LDs in the vasculature. Empagliflozin downregulates LDs formation in vascular inflammation or lipid overload via an SGLT2-independent mechanism. Empagliflozin's protective effects involve the NHE1/PKC/NOX pathway in the TNF response but not in the OA response.

Endocrine Complications in Hepatic Glycogen Storage Diseases: A Long-term Perspective

Patients with a hepatic type of glycogen storage diseases (GSDs) can manifest endocrine features such as hypoglycemia, dyslipidemia, or osteoporosis. This study aimed to investigate the long-term endocrine consequences in patients with hepatic GSDs.This study included 64 patients from 52 families with hepatic GSDs including GSD type Ia (41 patients from 37 families), Ib (3 unrelated), III (8 from 6 families), IV (1 patient), and IX (11 from 5 families). All patients were genetically confirmed. Clinical and endocrine findings were retrospectively analyzed.The median age at diagnosis and current age were 2.4 years (range, 0.1-42.4 years) and 17.6 years (range, 1.0-47.8 years), respectively. The mean height SDS at diagnosis was -3.5±1.4, and short stature was observed in 35.6% of patients. Patients diagnosed after the age of 3.4 years exhibited a high risk of short stature (OR=36.1; P-value<0.001). Among 33 patients who reached the final height, 23 (69.7%) showed delayed puberty. Hypertriglyceridemia was observed in 46 patients (71.9%), whereas 25 patients (39%) had elevated low-density lipoprotein cholesterol levels during the follow-up period. Among 24 patients who underwent dual-energy X-ray absorptiometry, 22 showed a low bone mineral density Z-score of -3.0±1.3 at the L-spine.This study described the long-term endocrine consequences in patients with hepatic GSDs. Pediatric endocrinologists should be aware of the presenting features and long-term endocrine sequelae of GSDs to provide proper management and decrease its morbidities.

Diacylglycerol kinase alpha regulates post-hepatectomy liver regeneration

Diacylglycerol kinases (DGKs) phosphorylate diacylglycerol to generate phosphatidic acid, which plays important roles in intracellular signal transduction. DGKα is reportedly associated with progression of tumors, including hepatocellular carcinomas, but its relationship with liver regeneration has not been examined. The purpose of this research is to elucidate the role of DGKα in liver regeneration. Here, we provide a detailed examination of C57BL/6 wild-type and DGKα knockout (KO) mice subjected to 70% partial hepatectomy (70% PH) modeling, including survival rates, hematological marker and gene expression levels, and histological analyses of factors related to liver regeneration. Following 70% PH, DGKα KO mice produce higher levels of hepatobiliary enzymes and have a higher incidence of jaundice compared with wild-type mice, with a death rate of ~ 40%. Furthermore, they exhibit impaired glycogen and lipid consumption, low liver energy charge, and hepatocyte hypertrophy disorder, accompanied by significantly reduced liver expression of proliferating cell nuclear antigen and cyclin D. We conclude that DGKα is a key molecule in the post-PH liver regeneration process and may have potential as a therapeutic target for the acceleration of liver regeneration.

Mitochondrial Dysfunction in Glycogen Storage Disorders (GSDs)

Glycogen storage disorders (GSDs) are a group of inherited metabolic disorders characterized by defects in enzymes involved in glycogen metabolism. Deficiencies in enzymes responsible for glycogen breakdown and synthesis can impair mitochondrial function. For instance, in GSD type II (Pompe disease), acid alpha-glucosidase deficiency leads to lysosomal glycogen accumulation, which secondarily impacts mitochondrial function through dysfunctional mitophagy, which disrupts mitochondrial quality control, generating oxidative stress. In GSD type III (Cori disease), the lack of the debranching enzyme causes glycogen accumulation and affects mitochondrial dynamics and biogenesis by disrupting the integrity of muscle fibers. Malfunctional glycogen metabolism can disrupt various cascades, thus causing mitochondrial and cell metabolic dysfunction through various mechanisms. These dysfunctions include altered mitochondrial morphology, impaired oxidative phosphorylation, increased production of reactive oxygen species (ROS), and defective mitophagy. The oxidative burden typical of GSDs compromises mitochondrial integrity and exacerbates the metabolic derangements observed in GSDs. The intertwining of mitochondrial dysfunction and GSDs underscores the complexity of these disorders and has significant clinical implications. GSD patients often present with multisystem manifestations, including hepatomegaly, hypoglycemia, and muscle weakness, which can be exacerbated by mitochondrial impairment. Moreover, mitochondrial dysfunction may contribute to the progression of GSD-related complications, such as cardiomyopathy and neurocognitive deficits. Targeting mitochondrial dysfunction thus represents a promising therapeutic avenue in GSDs. Potential strategies include antioxidants to mitigate oxidative stress, compounds that enhance mitochondrial biogenesis, and gene therapy to correct the underlying mitochondrial enzyme deficiencies. Mitochondrial dysfunction plays a critical role in the pathophysiology of GSDs. Recognizing and addressing this aspect can lead to more comprehensive and effective treatments, improving the quality of life of GSD patients. This review aims to elaborate on the intricate relationship between mitochondrial dysfunction and various types of GSDs. The review presents challenges and treatment options for several GSDs.

Osteoporotic osseointegration: therapeutic hallmarks and engineering strategies

Osteoporosis is a systemic skeletal disease caused by an imbalance between bone resorption and formation. Current treatments primarily involve systemic medication and hormone therapy. However, these systemic treatments lack directionality and are often ineffective for locally severe osteoporosis, with the potential for complex adverse reactions. Consequently, treatment strategies using bioactive materials or external interventions have emerged as the most promising approaches. This review proposes twelve microenvironmental treatment targets for osteoporosis-related pathological changes, including local accumulation of inflammatory factors and reactive oxygen species (ROS), imbalance of mitochondrial dynamics, insulin resistance, disruption of bone cell autophagy, imbalance of bone cell apoptosis, changes in neural secretions, aging of bone cells, increased local bone tissue vascular destruction, and decreased regeneration. Additionally, this review examines the current research status of effective or potential biophysical and biochemical stimuli based on these microenvironmental treatment targets and summarizes the advantages and optimal parameters of different bioengineering stimuli to support preclinical and clinical research on osteoporosis treatment and bone regeneration. Finally, the review addresses ongoing challenges and future research prospects.

Neutrophil functions in patients with neutropenia due to glycogen storage disease type 1b treated with empagliflozin

ABSTRACT

Neutropenia and neutrophil dysfunction in glycogen storage disease type 1b (GSD1b) are caused by the accumulation of 1,5-anhydroglucitol-6-phosphate in granulocytes. The antidiabetic drug empagliflozin reduces the concentration of 1,5-anhydroglucitol (1,5-AG), thus restoring neutrophil counts and functions, leading to promising results in previous case reports. Here, we present a comprehensive analysis of neutrophil function in 7 patients with GSD1b and 11 healthy donors, aiming to evaluate the immediate (after 3 months) and long-term (after 12 months) efficacy of empagliflozin compared with the reference treatment with granulocyte-colony stimulating factor (G-CSF). We found that most patients receiving G-CSF remained neutropenic with dysfunctional granulocytes, whereas treatment with empagliflozin increased neutrophil counts and improved functionality by inhibiting apoptosis, restoring phagocytosis and the chemotactic response, normalizing the oxidative burst, and stabilizing cellular and plasma levels of defensins and lactotransferrin. These improvements correlated with the decrease in serum 1,5-AG levels. However, neither G-CSF nor empagliflozin overcame deficiencies in the production of cathelicidin/LL-37 and neutrophil extracellular traps. Given the general improvement promoted by empagliflozin treatment, patients were less susceptible to severe infections. G-CSF injections were therefore discontinued in 6 patients (and the dose was reduced in the seventh) without adverse effects. Our systematic analysis, the most extensive reported thus far, has demonstrated the superior efficacy of empagliflozin compared with G-CSF, restoring the neutrophil population and normal immune functions. This trial was registered as EudraCT 2021-000580-78.

Empagliflozin in children with glycogen storage disease-associated inflammatory bowel disease: a prospective, single-arm, open-label clinical trial

Glycogen storage disease type Ib (GSD-Ib) is a rare inborn error of glycogen metabolism caused by mutations in SLC37A4. Patients with GSD-Ib are at high risk of developing inflammatory bowel disease (IBD). We evaluated the efficacy of empagliflozin, a renal sodium‒glucose cotransporter protein 2 (SGLT2) inhibitor, on colonic mucosal healing in patients with GSD-associated IBD. A prospective, single-arm, open-label clinical trial enrolled eight patients with GSD-associated IBD from Guangdong Provincial People's Hospital in China from July 1, 2022 through December 31, 2023. Eight patients were enrolled with a mean age of 10.34 ± 2.61 years. Four male and four female. The endoscopic features included deep and large circular ulcers, inflammatory hyperplasia, obstruction and stenosis. The SES-CD score significantly decreased at week 48 compared with before empagliflozin. Six patients completed 48 weeks of empagliflozin therapy and endoscopy showed significant improvement or healing of mucosal ulcers, inflammatory hyperplasia, stenosis, and obstruction. One patient had severe sweating that required rehydration and developed a urinary tract infection. No serious or life-threatening adverse events. This study suggested that empagliflozin may promote colonic mucosal healing and reduce hyperplasia, stenosis, and obstruction in children with GSD-associated IBD.

DBS are suitable for 1,5-anhydroglucitol monitoring in GSD1b and G6PC3-deficient patients taking SGLT2 inhibitors to treat neutropenia

Glycogen storage disease type Ib (GSD1b) and G6PC3-deficiency are rare autosomal recessive diseases caused by inactivating mutations in SLC37A4 (coding for G6PT) and G6PC3, respectively. Both diseases are characterized by neutropenia and neutrophil dysfunction due to the intracellular accumulation of 1,5-anhydroglucitol-6-phosphate (1,5-AG6P), a potent inhibitor of hexokinases. We recently showed that the use of SGLT2 inhibitor therapy to reduce tubular reabsorption of its precursor, 1,5-anhydroglucitol (1,5-AG), a glucose analog present in blood, successfully restored the neutropenia and neutrophil function in G6PC3-deficient and GSD1b patients. The intra-individual variability of response to the treatment and the need to adjust the dose during treatment, especially in pediatric populations, can only be efficiently optimized if the concentration of 1,5-AG in blood is monitored during treatment, together with the patients' clinical signs and symptoms. Monitoring the 1,5-AG levels would be greatly simplified if it could be performed on dry blood spots (DBS) which are easy to collect, store and transport. The challenge is to know if a suitable method can be developed to perform accurate and reproducible assays for 1,5-AG using DBS. Here, we describe and validate an assay that quantifies 1,5-AG in DBS using isotopic dilution quantitation by LC-MS/MS that should greatly facilitate patients' follow-up. 1,5-AG levels measured in plasma and DBS give comparable values. This assay was used to monitor the levels of 1,5-AG in DBS from 3 G6PC3-deficient and 6 GSD1b patients during treatment with SGLT2 inhibitors. We recommend this approach to verify the adequate therapeutical response and compliance to the treatment in G6PC3-deficient and GSD1b patients treated with SGLT2 inhibitors.