Successful Superficial Blood Sampling to Localize a Fibroblast Growth Factor-23-Producing Tumor.

BACKGROUND Tumor-induced osteomalacia (TIO) is a paraneoplastic syndrome caused by aberrant fibroblast growth factor-23 (FGF-23)-producing tumors. Early surgical resection is the optimal strategy for preventing TIO progression. Thus, tumor localization is a priority for successful treatment. A simple and safe examination method to identify functional endocrine tumors is essential to achieve better outcomes in patients with TIO. CASE REPORT A 64-year-old Japanese man with recurrent fractures, hypophosphatemia, and elevated alkaline phosphatase and FGF-23 levels (109 pg/mL) was admitted to our university hospital and was diagnosed with FGF23-related hypophosphatemic osteomalacia. Notably, the superficial dorsal vein in the patient's left foot exhibited a high FGF-23 level (7510 pg/mL). Octreotide and ¹8F-fluorodeoxyglucose (FDG) scintigraphy and systemic venous sampling revealed that the tumor in the third basal phalanx of the left foot was responsible for FGF-23 overproduction. Tumor resection resulted in a rapid decrease in serum FGF-23 levels and an increase in serum phosphorus levels. CONCLUSIONS Octreotide scintigraphy, FDG-positron emission tomography, and systemic venous sampling are the standard methods for localizing functional endocrine tumors. However, the limited availability and invasive nature of these examinations hinder effective treatment. Here, we highlight the importance of peripheral superficial blood sampling as an alternative to conventional systemic methods for confirming the presence of FGF-23-producing tumors. Clinicians should consider TIO as a potential cause of acquired hypophosphatemic osteomalacia. Furthermore, peripheral superficial vein blood sampling may be useful for confirming the localization of FGF-23-producing tumors.

Metyrosine-associated endocrinological changes in pheochromocytoma and paraganglioma.

Objective: Metyrosine (alpha-methyl-para-tyrosine) effectively reduces catecholamine levels in patients with pheochromocytoma/paraganglioma. However, improvements in physiological and metabolic parameters and changes in endocrine function associated with metyrosine administration should be validated in comparison to surgery. This study was performed to confirm the effects of metyrosine on the physiological, metabolic, and endocrinological functions of patients with pheochromocytoma/paraganglioma in the perioperative period. Design: This retrospective cohort study was performed at a single university hospital. Methods: We included ten patients with pheochromocytoma/paraganglioma who received oral metyrosine after α-blocker therapy and consecutive surgeries. Urinary catecholamine metabolite levels and other clinical parameters were evaluated before and after metyrosine administration, and 1 week after surgery. Results: The mean age was 53.1 ± 16.1 years. Of the ten participants (four men and six women), nine had pheochromocytoma and one had paraganglioma. The median maximum metyrosine dose was 750 mg/day. Urinary catecholamine metabolite levels significantly decreased in a dose-dependent manner after metyrosine administration. Both systolic and diastolic blood pressure significantly decreased after metyrosine and surgical treatment. Metyrosine administration significantly improved insulin sensitivity, although surgery improved the the basal insulin secretion. Additionally, serum prolactin and thyroid-stimulatory hormone levels were significantly increased by metyrosine treatment, whereas plasma renin activity was decreased. Conclusions: Metyrosine significantly reduced catecholamines in patients with pheochromocytoma/paraganglioma and ensured the safety of the surgery. Adjustment of metyrosine administration may make surgical pretreatment more effective in achieving stabilized blood pressure and improving glucose metabolism. Endocrine parameters may manifest as the systemic effects of metyrosine administration.

Reduced Number of Remaining or Healthy Teeth in Patients with Type 2 Diabetes Mellitus: A Cross-sectional Study Assessed by Dentists or Dental Hygienists in Japan.

Objective This study assessed the relationships between oral health (number of remaining and healthy teeth and periodontal disease) and type 2 diabetes mellitus (T2DM) to contribute to improved patient care. Patients We conducted a cross-sectional cohort study of consecutive patients being regularly treated for chronic diseases (T2DM, hypertension, and dyslipidemia). A dentist or dental hygienist accurately evaluated the oral environment. Patients with fewer than 20 teeth were classified as having reduced remaining teeth (RRT). Results A total of 267 patients were enrolled, including 153 patients (57%) with T2DM and 114 without (43%). Patients with T2DM had 3 fewer remaining teeth on average than those without DM [median: 22 (interquartile range (IQR): 11-27) vs. median: 25 (IQR: 17.3-28), p=0.02]. In addition, patients with T2DM had 4 fewer healthy teeth on average than those without DM [median: 8 (IQR: 2.8-15) vs. median: 12 (IQR: 6-16), p=0.02]. The frequency of RRT was higher in the T2DM group (n=63; 41%) than in the non-DM group (n=31; 27%, p=0.02). Multivariable logistic regression for the presence of RRT in the T2DM group found that age [odds ratio (OR), 1.08; 95% confidence interval (CI), 1.03-1.13; p<0.01] and regular dental consultations (OR, 0.28; 95% CI, 0.10-0.76; p=0.01) were independently and significantly associated. Conclusion The number of remaining or healthy teeth was significantly lower in patients with T2DM than in those without T2DM in current Japanese clinical practice. Regular dental consultation is recommended to preserve remaining teeth in patients with T2DM.

Is the vesicular nucleotide transporter a molecular target of eicosapentaenoic acid?

Vesicular nucleotide transporter (VNUT), an active transporter for nucleotides in secretory vesicles, is responsible for the vesicular storage of ATP and plays an essential role in purinergic chemical transmission. Inhibition of VNUT decreases the concentration of ATP in the luminal space of secretory vesicles, followed by decreased vesicular ATP release, resulting in the blockade of purinergic chemical transmission. Very recently, Miyaji and colleagues reported that eicosapentaenoic acid (EPA) is a potent VNUT inhibitor and effective in treating neuropathic and inflammatory pain and insulin resistance through inhibition of vesicular storage and release of ATP. However, our validation study indicated that, in bovine adrenal chromaffin granule membrane vesicles, EPA inhibited the formation of an electrochemical gradient of protons across the membrane with the concentration of 50% inhibition (IC50) being 1.0 µM without affecting concanamycin B-sensitive ATPase activity. Essentially, similar results were obtained with proteoliposomes containing purified vacuolar H+-ATPase. Consistent with these observations, EPA inhibited the ATP-dependent uptakes of ATP and dopamine by chromaffin granule membrane vesicles, with ID50 being 1.2 and 1.0 µM, respectively. Furthermore, EPA inhibited ATP-dependent uptake of L-glutamate by mouse brain synaptic vesicles with ID50 being 0.35 µM. These results indicate that EPA at sub-µM acts as a proton conductor and increases proton permeability across the membrane, regardless of the presence or absence of VNUT, thereby inhibiting non-specifically the vesicular storage of neurotransmitters. Thus, EPA may affect a broader range of chemical transmission than proposed.

María Teresa Miras Portugal: a pioneer for vesicular nucleotide storage.

Chromaffin granules are secretory granules present in adrenal medulla chromaffin cells. They contain high contents of catecholamines and nucleotides and have been regarded as a model system for the study of vesicular transmitter uptake and release. In 1988, Dr. María Teresa Miras Portugal, when studying catecholamine biosynthesis, detected a novel group of nucleotides, the diadenosine polyphosphates, in the adrenal chromaffin granules. Based on this finding, she unraveled the existence of diadenosine polyphosphate-mediated chemical transmission, leading to a paradigm shift in the field of purinergic signaling. She is also a pioneer in the studies on vesicular nucleotide storage. First, María Teresa and her group characterized nucleotide transport in chromaffin granules and synaptic vesicles using fluorescent nucleotide derivatives such as 1, N6-ethenoadenosine triphosphates. Then, they revealed the presence of a hypothetical vesicular nucleotide transporter with unique properties in terms of substrate specificity. In this article, we will describe her contributions to vesicular nucleotide storage and the foundations she laid for future studies.

Effects of Elobixibat, an Inhibitor of Ileal Bile Acid Transporter, on Glucose and Lipid Metabolism: A Single-arm Pilot Study in Patients with T2DM.

PURPOSE: The ileal bile acid transporter inhibitor elobixibat was recently approved in Japan for use in the treatment of patients with chronic constipation. Elobixibat has been associated with increased plasma glucagon-like peptide 1 level through Takeda G protein receptor 5, which is a membrane receptor of bile acids. The present study assessed the metabolic effects of elobixibat in patients with type 2 diabetes mellitus (T2DM)-related constipation. METHODS: In this single-arm pilot study, 21 patients with T2DM and constipation were administered elobixibat 10 mg/d for 12 weeks (period 1). The primary end point was the change in hemoglobin (Hb) A1c at week 12. Secondary end points included physical parameters; constipation symptoms; and blood parameters, such as low-density lipoprotein cholesterol (LDL-C), arachidonic acid (AA), and fatty acid fractions. Thereafter, the study participants chose whether to continue therapy for an additional 12 weeks (period 2), at which point HbA1c and lipid levels were reevaluated. Safety information, including adverse events, discontinuation and interruption of the drug, was collected at each visit during the trial. FINDINGS: Period 1: the levels of HbA1c, LDL-C, and AA were significantly reduced after administration of elobixibat for 12 weeks (-0.2%, -21.4 mg/dL, and -16.1 µg/dL, respectively; P = 0.016, P < 0.001, and P = 0.010). Period 2: at week 24, the change from baseline in HbA1c was significantly greater among those who continued elobixibat treatment than in those who discontinued after 12 weeks (-0.23% vs +0.21%; P = 0.038). No serious or severe adverse events were observed. IMPLICATIONS: Elobixibat may benefit patients with T2DM by improving glucose metabolism and lowering serum LDL-C and AA levels, in addition to ameliorating constipation. This single-arm pilot study was of a small sample size. The findings provide a basis for designing a larger-scale study to confirm the effects of elobixibat on glucose and lipid metabolism. (UMIN Clinical Trials Registry identifier: UMIN000045508; https://www.umin.ac.jp/ctr/index.htm).

A simplified prediction model for end-stage kidney disease in patients with diabetes.

This study aimed to develop a simplified model for predicting end-stage kidney disease (ESKD) in patients with diabetes. The cohort included 2549 individuals who were followed up at Kyushu University Hospital (Japan) between January 1, 2008 and December 31, 2018. The outcome was a composite of ESKD, defined as an eGFR < 15 mL min-1 [1.73 m]-2, dialysis, or renal transplantation. The mean follow-up was 5.6 [Formula: see text] 3.7 years, and ESKD occurred in 176 (6.2%) individuals. Both a machine learning random forest model and a Cox proportional hazard model selected eGFR, proteinuria, hemoglobin A1c, serum albumin levels, and serum bilirubin levels in a descending order as the most important predictors among 20 baseline variables. A model using eGFR, proteinuria and hemoglobin A1c showed a relatively good performance in discrimination (C-statistic: 0.842) and calibration (Nam and D'Agostino [Formula: see text]2 statistic: 22.4). Adding serum albumin and bilirubin levels to the model further improved it, and a model using 5 variables showed the best performance in the predictive ability (C-statistic: 0.895, [Formula: see text]2 statistic: 7.7). The accuracy of this model was validated in an external cohort (n = 5153). This novel simplified prediction model may be clinically useful for predicting ESKD in patients with diabetes.

Eruptive xanthomas as a marker for metabolic disorders: A specific form of xanthoma that reflects hypertriglyceridemia.

Eruptive xanthomas are skin manifestations associated with hypertriglyceridemia. Accordingly, the improvement of hypertriglyceridemia can ameliorate this condition. We report a case of a patient with type 2 diabetes mellitus who was diagnosed with this skin lesion. Clinicians should be aware that eruptive xanthomas could indicate metabolic disorders associated with atherosclerosis.

Case Report: Myxedema Coma Caused by Immunoglobulin A Vasculitis in a Patient With Severe Hypothyroidism.

Myxedema coma is a critical disorder with high mortality rates. Disruption of the compensatory mechanism for severe and long-term hypothyroidism by various causes leads to critical conditions, including hypothermia, respiratory failure, circulatory failure, and central nervous system dysfunction. Infectious diseases, stroke, myocardial infarction, sedative drugs, and cold exposure are considered the main triggers for myxedema coma. A 59-year-old Japanese woman presented with bilateral painful purpura on her lower legs. She was diagnosed with coexisting immunoglobulin A (IgA) vasculitis and severe IgA vasculitis with nephritis and was consequently treated with intravenous methylprednisolone (125 mg/day). However, she rapidly developed multiple organ failure due to the exacerbation of severe hypothyroidism, i.e., myxedema. Her condition improved significantly following oral administration of prednisolone along with thyroxine. There was a delayed increase in the serum free triiodothyronine level, while the serum free thyroxine level was quickly restored to normal. Rapid deterioration of the patient's condition after admission led us to diagnose her as having myxedema coma triggered by IgA vasculitis. Hence, clinicians should be aware of the risks of dynamic exacerbations in patients with hypothyroidism. Furthermore, our study suggested that combination therapy with thyroxine and liothyronine might prove effective for patients with myxedema coma, especially for those who require high-dose glucocorticoid administration.

Quinacrine is not a vital fluorescent probe for vesicular ATP storage.

Quinacrine, a fluorescent amphipathic amine, has been used as a vital fluorescent probe to visualize vesicular storage of ATP in the field of purinergic signaling. However, the mechanism(s) by which quinacrine represents vesicular ATP storage remains to be clarified. The present study investigated the validity of the use of quinacrine as a vial fluorescent probe for ATP-storing organelles. Vesicular nucleotide transporter (VNUT), an essential component for vesicular storage and ATP release, is present in very low density lipoprotein (VLDL)-containing secretory vesicles in hepatocytes. VNUT gene knockout (Vnut-/-) or clodronate treatment, a VNUT inhibitor, disappeared vesicular ATP release (Tatsushima et al., Biochim Biophys Acta Molecular Basis of Disease 2021, e166013). Upon incubation of mice's primary hepatocytes, quinacrine accumulates in a granular pattern into the cytoplasm, sensitive to 0.1-µM bafilomycin A1, a vacuolar ATPase (V-ATPase) inhibitor. Neither Vnut-/- nor treatment of clodronate affected quinacrine granular accumulation. In vitro, quinacrine is accumulated into liposomes upon imposing inside acidic transmembranous pH gradient (∆pH) irrespective of the presence or absence of ATP. Neither ATP binding on VNUT nor VNUT-mediated uptake of ATP was affected by quinacrine. Consistently, VNUT-mediated uptake of quinacrine was negligible or under the detection limit. From these results, it is concluded that vesicular quinacrine accumulation is not due to a consequence of its interaction with ATP but due to ∆pH-driven concentration across the membranes as an amphipathic amine. Thus, quinacrine is not a vital fluorescent probe for vesicular ATP storage.

Dynamin-related protein 1 deficiency accelerates lipopolysaccharide-induced acute liver injury and inflammation in mice.

Mitochondrial fusion and fission, which are strongly related to normal mitochondrial function, are referred to as mitochondrial dynamics. Mitochondrial fusion defects in the liver cause a non-alcoholic steatohepatitis-like phenotype and liver cancer. However, whether mitochondrial fission defect directly impair liver function and stimulate liver disease progression, too, is unclear. Dynamin-related protein 1 (DRP1) is a key factor controlling mitochondrial fission. We hypothesized that DRP1 defects are a causal factor directly involved in liver disease development and stimulate liver disease progression. Drp1 defects directly promoted endoplasmic reticulum (ER) stress, hepatocyte death, and subsequently induced infiltration of inflammatory macrophages. Drp1 deletion increased the expression of numerous genes involved in the immune response and DNA damage in Drp1LiKO mouse primary hepatocytes. We administered lipopolysaccharide (LPS) to liver-specific Drp1-knockout (Drp1LiKO) mice and observed an increased inflammatory cytokine expression in the liver and serum caused by exaggerated ER stress and enhanced inflammasome activation. This study indicates that Drp1 defect-induced mitochondrial dynamics dysfunction directly regulates the fate and function of hepatocytes and enhances LPS-induced acute liver injury in vivo.

An Open-label Phase I/IIa Clinical Trial of 11ß-HSD1 Inhibitor for Cushing's Syndrome and Autonomous Cortisol Secretion.

CONTEXT: 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) inhibitors demonstrate antimetabolic and antisarcopenic effects in Cushing's syndrome (CS) and autonomous cortisol secretion (ACS) patients. OBJECTIVE: To confirm the efficacy and safety of S-707106 (11ß-HSD1 inhibitor) administered to CS and ACS patients. DESIGN: A 24-week single-center, open-label, single-arm, dose-escalation, investigator-initiated clinical trial on a database. SETTING: Kyushu University Hospital, Kurume University Hospital, and related facilities. PATIENTS: Sixteen patients with inoperable or recurrent CS and ACS, with mildly impaired glucose tolerance. INTERVENTION: Oral administration of 200 mg S-707106 after dinner, daily, for 24 weeks. In patients with insufficient improvement in oral glucose tolerance test results at 12 weeks, an escalated dose of S-707106 (200 mg twice daily) was administered for the residual 12 weeks. MAIN OUTCOME MEASURES: The rate of participants responding to glucose tolerance impairment, defined as those showing a 25% reduction in the area under the curve (AUC) of plasma glucose during the 75-g oral glucose tolerance test at 24 weeks. RESULTS: S-707106 administration could not achieve the primary endpoint of this clinical trial (>20% of responsive participants). AUC glucose decreased by -7.1% [SD, 14.8 (90% CI -14.8 to -1.0), P = 0.033] and -2.7% [14.5 (-10.2 to 3.4), P = 0.18] at 12 and 24 weeks, respectively. S-707106 administration decreased AUC glucose significantly in participants with a high body mass index. Body fat percentage decreased by -2.5% [1.7 (-3.3 to -1.8), P < 0.001] and body muscle percentage increased by 2.4% [1.6 (1.7 to 3.1), P < 0.001]. CONCLUSIONS: S-707106 is an effective insulin sensitizer and antisarcopenic and antiobesity medication for these patients.

Case Report: Metreleptin and SGLT2 Inhibitor Combination Therapy Is Effective for Acquired Incomplete Lipodystrophy.

Childhood cancer survivors (CCSs) who have undergone bone marrow transplantation with systemic chemotherapy and whole-body irradiation often experience impaired glucose tolerance with marked insulin resistance. Incomplete acquired diabetic lipodystrophy should be considered as a late complication of bone marrow transplantation. A 24-year-old Japanese female patient with incomplete acquired lipodystrophy, a CCS of acute lymphocytic leukemia at the age of 3 years, was treated for diabetes mellitus and dyslipidemia at our hospital. Administration of multiple daily insulin injections (70 units/day), and oral administration of 500 mg/day metformin, 15 mg/day pioglitazone, and 200 mg/day bezafibrate had proven ineffective for her metabolic disorders. Subcutaneous administration of metreleptin improved her insulin resistance and hypertriglyceridemia within a month; however, it failed to maintain adequate plasma glucose levels in the long term. When oral administration of 10 mg/day empagliflozin was added to the metreleptin supplementation, her HbA1c value (National Glycohemoglobin Standardization Program) improved from 11% to 8%, which was maintained for an additional 18 months. This is the first case report of incomplete lipodystrophy that shows efficacy of a combination therapy with metreleptin and a sodium glucose cotransporter 2 (SGLT2) inhibitor for the treatment of diabetes and dyslipidemia. An SGLT2 inhibitor attenuates hyperglycemia through urinary glucose excretion and has been suggested to enhance lipid catabolism in the extra-adipose tissues, especially in the liver and skeletal muscles. Furthermore, metreleptin supplementation could enhance the action of the SGLT2 inhibitor by promoting satiety and lipolysis through the central nervous system. Combination therapy with metreleptin and an SGLT2 inhibitor was suggested to recover the volume of adipose tissue, possibly through improvement of insulin resistance in the adipose tissue. This report highlights the pathophysiological mechanism of an SGLT2 inhibitor in the improvement of glucose metabolism in non-healthy lean CCSs with insulin resistance. Administration of SGLT2 inhibitor, along with metreleptin supplementation, could be a good alternative therapy for diabetic lipodystrophy observed in CCSs.

[VNUT Is a Therapeutic Target for Type 2 Diabetes and NASH].

ATP, used in cells as an energy currency, also acts as an extracellular signaling molecule. Studies of purinergic receptor subtypes have revealed that purinergic chemical transmission plays important roles in various cell types. The vesicular nucleotide transporter (VNUT), the ninth transporter in the SLC17 organic anion transporter family, is essential for vesicular ATP storage and its subsequent release. The VNUT is localized on the membrane of secretory vesicles and actively transports ATP into vesicles using an electrochemical gradient of protons supplied by vacuolar proton ATPase (V-ATPase) as a driving force. ATP acts as a damage-associated molecular pattern (DAMPs), contributing to the persistence of chronic inflammation. Chronic inflammation induces systemic insulin resistance, which is the underlying pathology of type 2 diabetes and non-alcoholic fatty liver disease (NAFLD), ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). We previously demonstrated that ATP transported in insulin granules via the VNUT negatively regulates insulin secretion. We also found that hepatocytes release ATP in a VNUT-dependent manner, which elicits hepatic insulin resistance and inflammation. VNUT-knockout mice exhibited improved glucose tolerance and were resistant to the development of high fat diet-induced NAFLD. In this article, we summarize recent advances in our understanding of the mechanism of the VNUT, the development of inhibitors, and its pathological involvement in type 2 diabetes and NAFLD. The pharmacological inhibition of the VNUT may represent a potential therapeutic approach for the treatment of metabolic diseases.

Clodronate, an inhibitor of the vesicular nucleotide transporter, ameliorates steatohepatitis and acute liver injury.

The vesicular nucleotide transporter (VNUT) is responsible for the vesicular storage and release of ATP from various ATP-secreting cells, and it plays an essential role in purinergic signaling. Although extracellular ATP and its degradation products are known to mediate various inflammatory responses via purinoceptors, whether vesicular ATP release affects steatohepatitis and acute liver injury is far less understood. In the present study, we investigated the effects of clodronate, a potent and selective VNUT inhibitor, on acute and chronic liver inflammation in mice. In a model of methionine/choline-deficient diet-induced non-alcoholic steatohepatitis (NASH), the administration of clodronate reduced hepatic inflammation, fibrosis, and triglyceride accumulation. Clodronate also protected mice against high-fat/high-cholesterol diet-induced steatohepatitis. Moreover, prophylactic administration of clodronate prevented D-galactosamine and lipopolysaccharide-induced acute liver injury by reducing inflammatory cytokines and hepatocellular apoptosis. In vitro, clodronate inhibited glucose-induced vesicular ATP release mediated by VNUT and reduced the intracellular level and secretion of triglycerides in isolated hepatocytes. These results suggest that VNUT-dependent vesicular ATP release plays a crucial role in the recruitment of immune cells, cytokine production, and the aggravation of steatosis in the liver. Pharmacological inhibition of VNUT may provide therapeutic benefits in liver inflammatory disorders, including NASH and acute toxin-induced injury.

Vesicular ATP release from hepatocytes plays a role in the progression of nonalcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) is becoming a growing public health problem along with the increase of metabolic syndrome worldwide. Extracellular nucleotides are known to serve as a danger signal by initiating purinergic signaling in many inflammatory disorders, although the role of purinergic signaling in the progression of NASH remains to be clarified. Vesicular nucleotide transporter (VNUT) is a key molecule responsible for vesicular ATP release to initiate purinergic signaling. Here, we studied the role of VNUT in the progression of nonalcoholic steatohepatitis. VNUT was expressed in mouse hepatocytes and associated, at least in part, with apolipoprotein B (apoB)-containing vesicles. High glucose stimulation evoked release of appreciable amount of ATP from hepatocytes, which disappeared in hepatocytes of Vnut knockout (Vnut-/-) mice. Glucose treatment also stimulated triglyceride secretion from hepatocytes, which was inhibited by PPADS and MRS211, antagonists of P2Y receptors, and clodronate, a VNUT inhibitor, and was significantly reduced in Vnut-/- mice. In vivo, postprandial secretion of triglyceride from hepatocytes was observed, while the serum triglyceride level was significantly reduced in Vnut-/- mice. On a high-fat diet, the liver of wild type mice exhibited severe inflammation, fibrosis, and macrophage infiltration, which is similar to NASH in humans, while this NASH pathology was not observed in Vnut-/- mice. These results suggest that VNUT-mediated vesicular ATP release regulates triglyceride secretion and involves in chronic inflammation in hepatocytes. Since blockade of vesicular ATP release protects against progression of steatohepatitis, VNUT may be a pharmacological target for NASH.

Pasireotide-induced hyperglycemia in a patient with Cushing's disease: Potential use of sodium-glucose cotransporter 2 inhibitor and glucagon-like peptide-1 receptor agonist for treatment.

Pasireotide improves hypercortisolemia and induces hyperglycemia via somatostatin receptor type-5 stimulation. GLP-1RA and SGLT2 inhibitor potentially help regulate hyperglycemia in patients with Cushing's disease, especially after pasireotide administration.

Physiopathological roles of vesicular nucleotide transporter (VNUT), an essential component for vesicular ATP release.

Vesicular nucleotide transporter (VNUT) is the last identified member of the SLC17 organic anion transporter family, which plays a central role in vesicular storage in ATP-secreting cells. The discovery of VNUT demonstrated that, despite having been neglected for a long time, vesicular ATP release represents a major pathway for purinergic chemical transmission, which had been mainly attributed to ATP permeation channels. This article summarizes recent advances in our understanding of the mechanism of VNUT and its physiopathological roles as well as the development of inhibitors. Regulating the activity and/or the expression of VNUT represents a new and promising therapeutic strategy for the treatment of multiple diseases.

Improvement of skeletal muscle insulin sensitivity by 1 week of SGLT2 inhibitor use.

BACKGROUND AND AIMS: It is currently unclear whether sodium-glucose co-transporter 2 (SGLT2) inhibitor administration can improve the insulin sensitivity as well as rapidly reduce plasma glucose concentrations in humans during the early phase of treatment initiation. This study aimed to investigate the effect of SGLT2 inhibitor on insulin sensitivity in the early phase of treatment initiation. METHODS AND RESULTS: This single-center, open label, and single-arm prospective study recruited 20 patients (14 men) with type 2 diabetes mellitus (T2DM). We examined the patients' metabolic parameters before and 1 week after SGLT2 inhibitor (10 mg/day of empagliflozin) administration. The glucose infusion rate (GIR) was evaluated using the euglycemic hyperinsulinemic glucose clamp technique. Changes in laboratory and anthropometric parameters before and after SGLT2 inhibitor administration were analyzed according to the change in the GIR. The BMI, body fat amount, skeletal muscle amount, systolic blood pressure, and triglyceride level significantly decreased along with the treatment, while urinary glucose level and log GIR value significantly increased. Notably, changes in the GIR after SGLT2 inhibitor administration, which indicated improvement in peripheral insulin sensitivity, were negatively correlated with T2DM duration and positively with reduction in fluctuation of daily plasma glucose profiles before and after treatment. CONCLUSION: SGLT2 inhibitor improved insulin sensitivity in the skeletal muscle independent of anthropometric changes. Patients with short duration of T2DM and insulin resistance can be good candidates for short-term SGLT2 inhibitor administration to improve insulin sensitivity in the skeletal muscle.

Macrophage (Drp1) Dynamin-Related Protein 1 Accelerates Intimal Thickening After Vascular Injury.

OBJECTIVE: Mitochondria consistently change their morphology in a process regulated by proteins, including Drp1 (dynamin-related protein 1), a protein promoting mitochondrial fission. Drp1 is involved in the mechanisms underlying various cardiovascular diseases, such as myocardial ischemia/reperfusion injury, heart failure, and pulmonary arterial hypertension. However, its role in macrophages, which promote various vascular diseases, is poorly understood. We therefore tested our hypothesis that macrophage Drp1 promotes vascular remodeling after injury. METHOD AND RESULTS: To explore the selective role of macrophage Drp1, we created macrophage-selective Drp1-deficient mice and performed femoral arterial wire injury. In these mice, intimal thickening and negative remodeling were attenuated at 4 weeks after injury when compared with control mice. Deletion of macrophage Drp1 also attenuated the macrophage accumulation and cell proliferation in the injured arteries. Gain- and loss-of-function experiments using cultured macrophages indicated that Drp1 induces the expression of molecules associated with inflammatory macrophages. Morphologically, mitochondrial fission was induced in inflammatory macrophages, whereas mitochondrial fusion was induced in less inflammatory/reparative macrophages. Pharmacological inhibition or knockdown of Drp1 decreased the mitochondrial reactive oxygen species and chemotactic activity in cultured macrophages. Co-culture experiments of macrophages with vascular smooth muscle cells indicated that deletion of macrophage Drp1 suppresses growth and migration of vascular smooth muscle cells induced by macrophage-derived soluble factors. CONCLUSIONS: Macrophage Drp1 accelerates intimal thickening after vascular injury by promoting macrophage-mediated inflammation. Macrophage Drp1 may be a potential therapeutic target of vascular diseases.