Tubular CPT1A deletion minimally affects aging and chronic kidney injury

Kidney tubules use fatty acid oxidation (FAO) to support their high energetic requirements. Carnitine palmitoyltransferase 1A (CPT1A) is the rate-limiting enzyme for FAO, and it is necessary to transport long-chain fatty acids into mitochondria. To define the role of tubular CPT1A in aging and injury, we generated mice with tubule-specific deletion of Cpt1a (Cpt1aCKO mice), and the mice were either aged for 2 years or injured by aristolochic acid or unilateral ureteral obstruction. Surprisingly, Cpt1aCKO mice had no significant differences in kidney function or fibrosis compared with wild-type mice after aging or chronic injury. Primary tubule cells from aged Cpt1aCKO mice had a modest decrease in palmitate oxidation but retained the ability to metabolize long-chain fatty acids. Very-long-chain fatty acids, exclusively oxidized by peroxisomes, were reduced in kidneys lacking tubular CPT1A, consistent with increased peroxisomal activity. Single-nuclear RNA-Seq showed significantly increased expression of peroxisomal FAO enzymes in proximal tubules of mice lacking tubular CPT1A. These data suggest that peroxisomal FAO may compensate in the absence of CPT1A, and future genetic studies are needed to confirm the role of peroxisomal β-oxidation when mitochondrial FAO is impaired

Blocking cell cycle progression through CDK4/6 protects against chronic kidney disease

Acute and chronic kidney injuries induce increased cell cycle progression in renal tubules. While increased cell cycle progression promotes repair after acute injury, the role of ongoing tubular cell cycle progression in chronic kidney disease is unknown. Two weeks after initiation of chronic kidney disease, we blocked cell cycle progression at G1/S phase by using an FDA-approved, selective inhibitor of CDK4/6. Blocking CDK4/6 improved renal function and reduced tubular injury and fibrosis in 2 murine models of chronic kidney disease. However, selective deletion of cyclin D1, which complexes with CDK4/6 to promote cell cycle progression, paradoxically increased tubular injury. Expression quantitative trait loci (eQTLs) for CCND1 (cyclin D1) and the CDK4/6 inhibitor CDKN2B were associated with eGFR in genome-wide association studies. Consistent with the preclinical studies, reduced expression of CDKN2B correlated with lower eGFR values, and higher levels of CCND1 correlated with higher eGFR values. CDK4/6 inhibition promoted tubular cell survival, in part, through a STAT3/IL-1β pathway and was dependent upon on its effects on the cell cycle. Our data challenge the paradigm that tubular cell cycle progression is beneficial in the context of chronic kidney injury. Unlike the reparative role of cell cycle progression following acute kidney injury, these data suggest that blocking cell cycle progression by inhibiting CDK4/6, but not cyclin D1, protects against chronic kidney injury

Traumatic Gastric Perforation Associated with Cardiopulmonary Resuscitation: A Case Report

Sternal and rib fractures are well-known complications of cardiopulmonary resuscitation (CPR). We experienced a rare case of traumatic gastric perforation associated with CPR that required emergency laparotomy. In this case, we examined whether surgery is essential for gastric perforation associated with CPR. A 67-year-old man experienced cardiopulmonary arrest in the workplace, and bystander CPR was performed by his colleagues. He was then transported by ambulance to our hospital. A large amount of free air was found in the peritoneal cavity on computed tomography at presentation, and perforation of the gastrointestinal tract was suspected. During emergency laparotomy, a 2-cm serosal-muscular layer tear was found in the gastric lesser curvature. The damaged stomach wall was repaired, the abdominal cavity was lavaged, and surgery was completed by placing a drainage tube. The patient’s postoperative course was good and he was discharged on the 26th postoperative day. Emergency laparotomy has been performed frequently for traumatic gastric perforation associated with CPR. However, emergency laparotomy may be avoided by conservative treatment in some cases. Traumatic gastric perforation associated with CPR is a serious complication; however, the life prognosis of cardiopulmonary arrest patients depends on the original disease and the success of CPR. Traumatic gastric perforation associated with CPR is rarely fatal, and bystanders should not hesitate to initiate CPR

小胞体関連分解の抑制はムコ多糖症II型原因タンパク質変異型イズロン酸2スルファターゼの機能を回復する

広島大学(Hiroshima University)博士(医学)Doctor of Philosophy in Medical Sciencedoctora

Organoids as an ex vivo model for studying the serotonin system in the murine small intestine and colon epithelium

Intestinal organoids were recently established as an ex vivo model of the intestinal epithelium. The present study investigated the serotonin (5-hydroxytryptamine, 5-HT) system using organoids. Organoids from murine small intestinal and colonic crypts were successfully cultured. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that small intestinal and colonic organoids express mRNAs encoding tryptophan hydroxylase-1 (TPH1) (the rate-limiting enzyme of 5-HT synthesis), serotonin reuptake transporter (SERT), 5-HT receptor (HTR)2A, HTR2B, and HTR4. SERT mRNA levels were significantly higher in the small intestine than in the colon in both the mucosal tissues and organoids, as estimated by quantitative real-time RT-PCR. Although the 5-HT concentration and levels of chromogranin A (CgA) (an enteroendocrine cell marker), TPH1, and HTR4 mRNAs were significantly higher in the colonic mucosa than the small intestinal mucosa, they were the same in small intestinal and colonic organoids. There were no significant differences in HTR2A and HTR2B mRNA levels between the small intestine and colon in either the mucosal tissues or organoids. Immunofluorescence staining showed that the number of CgA-positive cells in the colonic organoids appeared to increase upon culturing with acetate. Acetate supplementation significantly increased CgA, TPH1, and HTR4 mRNA levels in the colonic organoids. We propose that organoids are useful for investigating the 5-HT system in the intestinal epithelium, even though colonic organoids may require gut microbiota derived factors such as short-chain fatty acids

Obesity and Cardiovascular Risk Factors among Men and Women Aged 40 Years and Older in a Rural Area of Japan

Obesity is one of the most common health problems, and is recognized worldwide as an "escalating epidemic." For the establishment of an obesity-prevention strategy in Japan, it is important to assess the association between obesity and cardiovascular risk factors. Therefore, we conducted anthropometric measures of obesity and investigated the association of obesity with cardiovascular risk factors such as hypertension, diabetes, and dyslipidemia among community-dwelling men (N=85) and women (N=173) aged 40 years and older. Height, weight, and waist circumference (WC) were measured, and body mass index (BMI) was calculated. Subjects with a BMI≥25kg/m^2 were considered obese (BMI obesity), while men with a WC≥85cm and women with a WC≥90cm were classified as obese (WC obesity). In the present study, we defined \u27obesity\u27 as a BMI≥25kg/m^2 or a WC≥85cm for men, and a BMI≥25kg/m^2 or a WC≥90cm for women. The results of an age- and sex-adjusted logistic regression analysis indicated that BMI obesity was associated with dyslipidemia (p=0.04), WC obesity was associated with dyslipidemia (p=0.07), and \u27obesity\u27 was associated with diabetes (p=0.06) and dyslipidemia (p=0.01). These results emphasize the importance of preventing obesity in Japan. Therefore, healthcare professionals should measure BMI and WC in order to enhance their assessment of cardiovascular risk

A method package for electrophysiological evaluation of reconstructed or regenerated facial nerves in rodents

Compound muscle action potential (CMAP) recording via reconstructed or regenerated motor axons is a critical examination to evaluate newly developed surgical and regeneration techniques. However, there is currently no documentation on technical aspects of CMAP recordings via reconstructed or regenerated facial nerves. We have studied new techniques of plastic surgery and nerve regeneration using a rat facial nerve defect model for years, standardizing an evaluation pipeline using CMAP recordings. Here we describe our CMAP recording procedure in detail as a package including surgical preparation, data acquisition, analysis and troubleshooting. Each resource is available in public repositories and is maintained as a version control system. In addition, we demonstrate that our analytical pipeline can not only be applied to rats, but also mice. Finally, we show that CMAP recordings can be practically combined with other behavioral and anatomical examinations. For example, retrograde motor neuron labeling provides anatomical evidence for physical routes between the facial motor nucleus and its periphery through reconstructed or regenerated facial nerves, in addition to electrophysiological evidence by CMAP recordings from the same animal. • Standardized surgical, recording and analytical procedures for the functional evaluation of reconstructed or regenerated facial nerves of rats, extended to mice. • The functional evaluation can be combined with anatomical evaluations. • The methods described here are maintained in public repositories as version control systems. Method name: Compound muscle action potential recordings via reconstructed or regenerated facial nerves, Keywords: Facial nerve, Reconstruction, Regeneration, Compound muscle action potential, Retrograde tracer, Rat, Mouse, Analysis, Igor Pro, MATLAB, Version control syste