井出 真太郎

AIM: Whether sex differences exist in hereditary progeroid syndromes remains unclear. In this study, we investigated sex differences in patients with Werner syndrome (WS), a model of human aging, using patient data at the time of diagnosis. METHODS: The presence of six cardinal signs in the diagnostic criteria was retrospectively evaluated. RESULTS: We found that the percentage of patients with all cardinal signs was higher in males than in females (54.2% vs. 21.2%). By the age of 40 years, 57.1% of male patients with WS presented with all the cardinal signs, whereas none of the female patients developed all of them. In particular, the frequency of having a high-pitched, hoarse voice, a characteristic of WS, was lower in female patients. The positive and negative predictive values for clinical diagnosis were 100% for males and females, indicating the helpfulness of diagnostic criteria regardless of sex. More female patients than male (86.7% vs. 64%) required genetic testing for their diagnosis because their clinical symptoms were insufficient, suggesting the importance of genetic testing for females even if they do not show typical symptoms of WS. Finally, the frequency of abnormal voice was lower in patients with WS harboring the c.3139-1G > C homozygous mutation. CONCLUSION: These results indicate, for the first time, that there are sex differences in the phenotypes of hereditary progeroid syndromes. The analysis of this mechanism in this human model of aging may lead to the elucidation of sex differences in the various symptoms of normal human aging. Geriatr Gerontol Int 2023; ••: ••-••.

Werner syndrome (WS) is a hereditary premature aging disorder characterized by visceral fat accumulation and subcutaneous lipoatrophy, resulting in severe insulin resistance. However, its underlying mechanism remains unclear. In this study, we show that senescence-associated inflammation and suppressed adipogenesis play a role in subcutaneous adipose tissue reduction and dysfunction in WS. Clinical data from four Japanese patients with WS revealed significant associations between the decrease of areas of subcutaneous fat and increased insulin resistance measured by the glucose clamp. Adipose-derived stem cells from the stromal vascular fraction derived from WS subcutaneous adipose tissues (WSVF) showed early replicative senescence and a significant increase in the expression of senescence-associated secretory phenotype (SASP) markers. Additionally, adipogenesis and insulin signaling were suppressed in WSVF, and the expression of adipogenesis suppressor genes and SASP-related genes was increased. Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), alleviated premature cellular senescence, rescued the decrease in insulin signaling, and extended the lifespan of WS model of C. elegans. To the best of our knowledge, this study is the first to reveal the critical role of cellular senescence in subcutaneous lipoatrophy and severe insulin resistance in WS, highlighting the therapeutic potential of rapamycin for this disease.

AIMS: The effects of the sodium-dependent glucose transporter-2 inhibitor ipragliflozin were compared with metformin in a previous study, which revealed that ipragliflozin reduced visceral fat content by 12%; however, the underlying mechanism was unclear. Therefore, this sub-analysis aimed to compare metabolomic changes associated with ipragliflozin and metformin that may contribute to their biological effects. MATERIALS AND METHODS: In the previous study, 103 patients with type 2 diabetes were randomly assigned to receive ipragliflozin 50 mg or metformin 1000 mg daily. Of the 103 patients, 15 patients in the ipragliflozin group with the highest reduction in visceral fat areas and 15 patients in the metformin group with matching characteristics, such as age, sex, baseline A1C, baseline visceral fat area, smoking status, and concomitant medication, were selected. The clinical data were reanalyzed, and metabolomic analysis of serum samples collected before and 24 weeks after drug administration was performed using capillary electrophoresis time-of-flight mass spectrometry. RESULTS: The reduction in the mean visceral fat area after 24 weeks of treatment was significantly larger (P=0.002) in the ipragliflozin group (-19.8%) than in the metformin group (-2.5%), as were the subcutaneous fat area and body weight. The A1C and blood glucose levels decreased in both groups. Glutamic pyruvic oxaloacetic transaminase, γ-glutamyl transferase, uric acid, and triglyceride levels decreased in the ipragliflozin group. Low-density lipoprotein cholesterol level decreased in the metformin group. After ipragliflozin administration, N2 -phenylacetylglutamine, inosine, guanosine, and 1-methyladenosine levels increased, whereas galactosamine, glucosamine, 11-aminoundecanoic acid, morpholine, and choline levels decreased. After metformin administration, metformin, hypotaurine, methionine, methyl-2-oxovaleric acid, 3-nitrotyrosine, and cyclohexylamine levels increased, whereas citrulline, octanoic acid, indole-3-acetaldehyde, and hexanoic acid levels decreased. CONCLUSIONS: Metabolites that may affect visceral fat reduction were detected in the ipragliflozin group. Studies are required to further elucidate the underlying mechanisms.

The most common cause of acute kidney injury (AKI) in critically ill patients is sepsis. Kidney macrophages consist of both F4/80hi and CD11bhi cells. The role of macrophage subpopulations in septic AKI pathogenesis remains unclear. As F4/80hi macrophages are reported to contribute to immunomodulation following injury, we hypothesized that selective depletion of F4/80hi macrophages would worsen septic AKI. F4/80hi macrophages were depleted via diphtheria toxin injection in CD11cCre(+)/CX3CR1dtr/wt (F4/80 MKO mice) compared to CD11cCre(-)/CX3CR1dtr/wt (F4/80 MWT) mice. F4/80 MWT and F4/80 MKO mice were subjected to sham or cecal ligation and puncture to induce sepsis. Compared to F4/80 MWT mice, F4/80 MKO mice displayed worsened septic AKI at 24 hours as measured by serum creatinine and histologic injury scoring. Kidneys from F4/80 MKO mice elaborated higher kidney interleukin-6 levels. Mechanistically, single cell RNA sequencing identified a macrophage-endothelial cell immunoregulatory axis that underlies interleukin-6 expression. F4/80hi macrophages expressed interleukin-1 receptor antagonist and limited interleukin-6 expression in endothelial cells. In turn, anti-interleukin-6 therapy ameliorated septic AKI in F4/80 MKO mice. Thus, F4/80hi macrophages express interleukin-1 receptor antagonist and constrain interleukin-6 generation from endothelial cells to limit septic AKI, representing a targetable cellular crosstalk in septic AKI. These findings are particularly relevant owing to the efficacy of anti-interleukin-6 therapies during COVID-19 infection, a disease associated with high rates of AKI and endothelial dysfunction.

The transcription factor Twist1 regulates several processes that could impact kidney disease progression, including epithelial cell differentiation and inflammatory cytokine induction. Podocytes are specialized epithelia that exhibit features of immune cells and could therefore mediate unique effects of Twist1 on glomerular disease. To study Twist1 functions in podocytes during proteinuric kidney disease, we employed a conditional mutant mouse in which Twist1 was selectively ablated in podocytes (Twist1-PKO). Deletion of Twist1 in podocytes augmented proteinuria, podocyte injury, and foot process effacement in glomerular injury models. Twist1 in podocytes constrained renal accumulation of monocytes/macrophages and glomerular expression of CCL2 and the macrophage cytokine TNF-α after injury. Deletion of TNF-α selectively from podocytes had no impact on the progression of proteinuric nephropathy. By contrast, the inhibition of CCL2 abrogated the exaggeration in proteinuria and podocyte injury accruing from podocyte Twist1 deletion. Collectively, Twist1 in podocytes mitigated urine albumin excretion and podocyte injury in proteinuric kidney diseases by limiting CCL2 induction that drove monocyte/macrophage infiltration into injured glomeruli. Myeloid cells, rather than podocytes, further promoted podocyte injury and glomerular disease by secreting TNF-α. These data highlight the capacity of Twist1 in the podocyte to mitigate glomerular injury by curtailing the local myeloid immune response.

Overwhelming lipid peroxidation induces ferroptotic stress and ferroptosis, a non-apoptotic form of regulated cell death that has been implicated in maladaptive renal repair in mice and humans. Using single-cell transcriptomic and mouse genetic approaches, we show that proximal tubular (PT) cells develop a molecularly distinct, pro-inflammatory state following injury. While these inflammatory PT cells transiently appear after mild injury and return to their original state without inducing fibrosis, after severe injury they accumulate and contribute to persistent inflammation. This transient inflammatory PT state significantly downregulates glutathione metabolism genes, making the cells vulnerable to ferroptotic stress. Genetic induction of high ferroptotic stress in these cells after mild injury leads to the accumulation of the inflammatory PT cells, enhancing inflammation and fibrosis. Our study broadens the roles of ferroptotic stress from being a trigger of regulated cell death to include the promotion and accumulation of proinflammatory cells that underlie maladaptive repair.

Aims/Introduction: Recent randomized clinical trials have suggested that sodium–glucose cotransporter 2 inhibitors might reduce cardiovascular events and heart failure, and have renal protective effects. Despite these remarkable benefits, the effects of sodium–glucose cotransporter 2 inhibitors on bone and muscle are unclear. Materials and Methods: A subanalysis of a randomized controlled study was carried out to evaluate the effects of the sodium–glucose cotransporter 2 inhibitor, ipragliflozin, versus metformin on bone and muscle in Japanese patients with type 2 diabetes mellitus (baseline body mass index ≥22 kg/m2 and hemoglobin A1c 7–10%) who were already receiving sitagliptin. These patients were randomly administered ipragliflozin 50 mg or metformin 1,000–1,500 mg daily. The effects of these medications on the bone formation marker, bone alkali phosphatase; the bone resorption marker, tartrate-resistant acid phosphatase 5b (TRACP-5b); handgrip strength; abdominal cross-sectional muscle area; and bone density of the fourth lumbar vertebra were evaluated. Results: After 24 weeks of treatment, the changes in bone density of the fourth lumbar vertebra, handgrip strength and abdominal cross-sectional muscle area were not significantly different between the two groups. However, TRACP-5b levels increased in patients treated with ipragliflozin compared with patients treated with metformin (median 11.94 vs −10.30%, P < 0.0001), showing that ipragliflozin can promote bone resorption. Conclusions: There were no adverse effects on bone or muscle when sitagliptin was used in combination with either ipragliflozin or metformin. However, ipragliflozin combination increased the levels of TRACP-5b. A long-term study is required to further understand the effects of this TRACP-5b increase caused by ipragliflozin.

Introduction: To compare the effects of ipragliflozin, a sodium-glucose transporter 2 inhibitor, with those of metformin on visceral fat (as well as muscles and bones) in Japanese elderly patients with type 2 diabetes (T2D), we conducted a sub-analysis of a prospective, multicenter, blinded-endpoint randomized-controlled study. Methods: In total, 103 patients with T2D (body mass index ≥ 22 kg/m2; glycated hemoglobin, 7–10%) and being treated with sitagliptin (a dipeptidyl peptidase-4 inhibitor) were included and randomized to receive ipragliflozin or metformin. The primary outcome was the change in visceral fat area measured using computed tomography 24 weeks following treatment. The secondary outcomes included changes in subcutaneous and total fat area, muscle volume, bone density measured using computed tomography, handgrip strength, bone markers, plasma glucose, insulin, homeostasis model assessment (HOMA)2-beta, HOMA2-R, glycated hemoglobin, lipid panel, uric acid, blood pressure, adiponectin, and high-sensitivity C-reactive protein. All patients aged 65–74 years were selected for sub-analysis. Results: The sub-analysis included 15 and 14 patients in the ipragliflozin and metformin groups, respectively. The patients’ backgrounds were well balanced. Visceral fat area reduction was greater in the ipragliflozin group than in the metformin group (− 10.58% vs. − 6.93%; P = 0.034). There were significant differences in the changes in bone absorption markers, uric acid, and total cholesterol levels between the groups. Conclusion: Ipragliflozin significantly reduced the visceral fat area compared with metformin when added to sitagliptin in elderly patients with T2D. Long-term and large-scale studies are required to elucidate whether ipragliflozin is suitable for elderly patients. Trial Registration: The study was registered at https://www.umin.ac.jp/ctr/ (UMIN-ID: UMIN 000015170).

Background and Objectives: Red yeast rice contains monacolin K, an inhibitor of cholesterol synthesis, and gamma-aminobutyric acid, a neurotransmitter. The daily dose of red yeast rice and monacolin K in previous studies was relatively high; therefore, there were safety concerns. We aimed to examine the effects of low daily dose red yeast rice on arteriosclerosis in patients with mild dyslipidemia. Methods and Study Design: Eighteen patients without known cardiovascular disease and unsatisfactory low-density lipoprotein cholesterol (3.96±0.19 mmol/L) controlled only by diet therapy were randomly allocated to receive low dose red yeast rice (200 mg/day) containing 2 mg monacolin K or diet therapy alone for 8 weeks. The primary outcome was the absolute change in low-density lipoprotein cholesterol. Secondary outcomes included total cholesterol, apolipoprotein B, and blood pressure. Results: Low-density lipoprotein cholesterol decreased significantly in the red yeast rice group than in the diet therapy group (median [interquartile range]: control −0.20 [−0.62, 1.19] mmol/L vs. red yeast rice −0.96 [−1.05, −0.34] mmol/L, p=0.030). The red yeast rice group also exhibited significant decreases in total cholesterol, apolipoprotein B, and blood pressure. No severe treatment-related adverse effects on muscles, liver, or renal function were observed. Conclusions: We found that patients in the red yeast rice group exhibited significant reductions in lowdensity lipoprotein cholesterol, total cholesterol, apolipoprotein B, and blood pressure without any recognised adverse effect. This suggests that low daily dose red yeast rice could reduce cardiovascular risk in patients with dyslipidemia.

Spermatogonia, which produce sperm throughout the male lifetime, are regulated inside a niche composed of Sertoli cells, and other testis cell types. Defects in Sertoli cells often lead to infertility, but replacement of defective cells has been limited by the inability to deplete the existing population. Here, we use an FDA-approved non-toxic drug, benzalkonium chloride (BC), to deplete testis cell types in vivo. Four days after BC administration, Sertoli cells are preferentially depleted, and can be replaced to promote spermatogenesis from surviving (host) spermatogonia. Seven days after BC treatment, multiple cell types can be engrafted from fresh or cryopreserved testicular cells, leading to complete spermatogenesis from donor cells. These methods will be valuable for investigation of niche-supporting cell interactions, have the potential to lead to a therapy for idiopathic male infertility in the clinic, and could open the door to production of sperm from other species in the mouse.

Renal macrophages represent a highly heterogeneous and specialized population of myeloid cells with mixed developmental origins from the yolk-sac and hematopoietic stem cells (HSC). They promote both injury and repair by regulating inflammation, angiogenesis, and tissue remodeling. Recent reports highlight differential roles for ontogenically distinct renal macrophage populations in disease. However, little is known about how these populations change over time in normal, uninjured kidneys. Prior reports demonstrated a high proportion of HSC-derived macrophages in the young adult kidney. Unexpectedly, using genetic fate-mapping and parabiosis studies, we found that yolk-sac-derived macrophages progressively expand in number with age and become a major contributor to the renal macrophage population in older mice. This chronological shift in macrophage composition involves local cellular proliferation and recruitment from circulating progenitors and may contribute to the distinct immune responses, limited reparative capacity, and increased disease susceptibility of kidneys in the elderly population.

In chronic kidney disease (CKD), elevated serum levels of the phosphate regulating hormone fibroblast growth factor (FGF) 23 have emerged as powerful risk factors for cardiovascular disease and death. Mechanistically, FGF23 can bind and activate fibroblast growth factor receptor (FGFR) 4 independently of α-klotho, the canonical co-receptor for FGF23 in the kidney, which stimulates left ventricular hypertrophy and hepatic production of inflammatory cytokines. FGF23 has also been shown to independently predict progression of renal disease, however, whether FGF23 and FGFR4 also contribute to CKD remains unknown. Here, we generated a mouse model with dual deletions of FGFR4 and α-klotho, and we induced CKD in mice with either global deletion or constitutive activation of FGFR4. We demonstrate that FGF23 is not capable of inducing phosphaturia via FGFR4 and that FGFR4 does not promote or mitigate renal injury in animal models of CKD. Taken together our results suggest FGFR4 inhibition as a safe alternative strategy to target cardiovascular disease and chronic inflammation in patients with CKD without interrupting the necessary phosphaturic effects of FGF23.

A prospective, multicentre, open-label, blinded-endpoint, randomized controlled study was conducted to evaluate the efficacy of treatment with ipragliflozin (sodium-dependent glucose transporter-2 inhibitor) versus metformin for visceral fat reduction and glycaemic control among Japanese patients with type 2 diabetes treated with sitagliptin, HbA1c levels of 7%-10%, and body mass index (BMI) ≥ 22 kg/m2. Patients were randomly assigned (1:1) to receive ipragliflozin 50 mg or metformin 1000-1500 mg daily. The primary outcome was change in visceral fat area as measured by computed tomography after 24 weeks of therapy. The secondary outcomes were effects on glucose metabolism and lipid metabolism. Mean percentage reduction in visceral fat area was significantly greater in the ipragliflozin group than in the metformin group (−12.06% vs. −3.65%, P = 0.040). Ipragliflozin also significantly reduced BMI, subcutaneous fat area, waist circumference, fasting insulin, and homeostatic model assessment (HOMA)-resistance, and increased HDL-cholesterol levels. Metformin significantly reduced HbA1c and LDL-cholesterol levels and increased HOMA-beta. There were no severe adverse events. The use of ipragliflozin or metformin in combination with dipeptidyl peptidase-4 inhibitors, widely used in Japan, may have beneficial effects in ameliorating multiple cardiovascular risk factors.

Background The mammalian kidney develops through reciprocal inductive signals between the metanephric mesenchyme and ureteric bud. Transcription factor 21 (Tcf21) is highly expressed in the metanephric mesenchyme, including Six2-expressing cap mesenchyme and Foxd1-expressing stromal mesenchyme. Tcf21 knockout mice die in the perinatal period from severe renal hypodysplasia. In humans, Tcf21 mRNA levels are reduced in renal tissue from human fetuses with renal dysplasia. The molecular mechanisms underlying these renal defects are not yet known. Methods Using a variety of techniques to assess kidney development and gene expression, we compared the phenotypes of wild-type mice, mice with germline deletion of the Tcf21 gene, mice with stromal mesenchyme–specific Tcf21 deletion, and mice with cap mesenchyme–specific Tcf21 deletion. Results Germline deletion of Tcf21 leads to impaired ureteric bud branching and is accompanied by downregulated expression of Gdnf-Ret-Wnt11, a key pathway required for branching morphogenesis. Selective removal of Tcf21 from the renal stroma is also associated with attenuation of the Gdnf signaling axis and leads to a defect in ureteric bud branching, a paucity of collecting ducts, and a defect in urine concentration capacity. In contrast, deletion of Tcf21 from the cap mesenchyme leads to abnormal glomerulogenesis and massive proteinuria, but no downregulation of Gdnf-Ret-Wnt11 or obvious defect in branching. Conclusions Our findings indicate that Tcf21 has distinct roles in the cap mesenchyme and stromal mesenchyme compartments during kidney development and suggest that Tcf21 regulates key molecular pathways required for branching morphogenesis.

Podocytes are essential for maintaining kidney glomerular functions. Injuries to podocyte are closely related to the pathological process of proteinuria. However, a treatment for podocyte injury has still not been established. Cilostazol (CSZ) and probucol (PBC) have been shown to possess renoprotective effects. Therefore, we evaluated these drugs in a lipopolysaccharide (LPS)-induced podocyte injury model. 7-week-old female C57BL/6J mice were fed a normal diet or a diet containing 0.3% CSZ, 0.5% PBC, or both for 10 days. Then, mice were intraperitoneally injected with 13 μg g−1 body weight LPS. Both CSZ and PBC decreased LPS-induced albuminuria and co-administration was found to be most effective. These treatments ameliorated the upregulation of monocyte chemoattractant protein 1. In cultured podocytes, CSZ suppressed LPS-induced activation of nuclear factor-kappa B (NF-κB) and phosphorylation of p44/42 mitogen-activated protein kinase (MAPK). PBC reduced LPS-induced activation of NF-κB and reactive oxygen species production. Furthermore, PBC decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase4 expression. Our findings suggest that CSZ and PBC are able to inhibit podocyte-injury through different mechanisms, indicating that a combination of these two old drugs is a good treatment option to protect podocytes from injury.

Kidney diseases including diabetic nephropathy have become huge medical problems, although its precise mechanisms are still far from understood. In order to increase our knowledge about the patho-physiology of kidney, we have previously identified >300 kidney glomerulus-enriched transcripts through large-scale sequencing and microarray profiling of the mouse glomerular transcriptome. One of the glomerulus-specific transcripts identified was semaphorin 3G (Sema3G) which belongs to the semaphorin family. The aim of this study was to analyze both the in vivo and in vitro functions of Sema3G in the kidney. Sema3G was expressed in glomerular podocytes. Although Sema3G knockout mice did not show obvious glomerular defects, ultrastructural analyses revealed partially aberrant podocyte foot processes structures. When these mice were injected with lipopolysaccharide to induce acute inflammation or streptozotocin to induce diabetes, the lack of Sema3G resulted in increased albuminuria. The lack of Sema3G in podocytes also enhanced the expression of inflammatory cytokines including chemokine ligand 2 and interleukin 6. On the other hand, the presence of Sema3G attenuated their expression through the inhibition of lipopolysaccharide-induced Toll like receptor 4 signaling. Taken together, our results surmise that the Sema3G protein is secreted by podocytes and protects podocytes from inflammatory kidney diseases and diabetic nephropathy.