👤 Manami Oya

The internal milieu of the body is controlled by a system of interoceptors coupled to motor outflows that drive compensatory adaptive responses. These include the arterial chemoreceptors, best known for sensing arterial oxygen. In cardiometabolic diseases, such as essential hypertension, the carotid bodies (CB) exhibit heightened reflex sensitivity and tonic activity without an apparent stimulus. The mechanisms behind CB sensitization in these conditions are not well understood. Guided by functional genomics, a range of functional assays is used to interrogate downstream intracellular and interorgan signaling pathways involved in arterial chemosensory function. Here, we report the presence of the MC4R (melanocortin 4 receptor) in the mammalian CB and show its elevated expression in experimental hypertension. We demonstrate that melanocortin agonists activate arterial chemosensory cells, modulating CB chemosensory afferent drive to influence chemoreflex-evoked sympathetic and ventilatory activity. Transcriptional analysis of hypertensive CB implicates the activation of the Mash1 (mammalian achaete-scute homolog 1; Collectively, our data indicate a primarily pathophysiological role of melanocortin signaling in arterial chemosensation, contributing to excess sympathetic activity in cardiometabolic disease. Show less

Advanced/metastatic urothelial cancer (a/m UC) still has a poor prognosis despite the recent medical advances. Recent studies demonstrated that fibroblast growth factor receptor (FGFR) gene alterations (GAs) may be driver genes for UC; however, the proportion of UC genetic panel testing in Japan remains low. We clarified the proportion of patients with FGFR2/3 GAs, treatment patterns, and clinical outcomes in a/m UC patients in Japan. This study was a descriptive epidemiological study using the MONSTAR-SCREEN database, and 138 patients with a/m UC were evaluated. The primary endpoint was the proportion of patients with FGFR2/3 GAs. The secondary endpoints included treatment patterns, clinical outcomes, genomic status before and after treatment, etc. The proportion of FGFR GA-positive patients in a/m UC was 11.9%. The most common FGFR mutation variant and fusion gene were S249C (4.4%) and FGFR3-TACC3 fusion (3.7%), respectively. Fifty-one patients were tested two or more times; a few changes were observed in the FGFR GA status, regardless of the treatment regimen. Co-occurrence association was observed in FGFR1 with TET2, and in FGFR3 with CHEK2 or MLL2. During the first-, second-, and third-line treatment, median progression-free survival (PFS) of GA-positive patients was 7.3, 2.9, and 6.2 months, while for GA-negative patients, 6.9, 3.1, and 6.9 months, respectively. This study revealed that one in eight a/m UC patients had FGFR2/3 GAs, and a few changes were observed in FGFR GA status before and after treatment. Genetic testing will be beneficial for the selection of appropriate treatments after a diagnosis of a/m UC. Show less

Obesity is often associated with aging. However, the mechanism of age-related obesity is unknown. The melanocortin-4 receptor (MC4R) mediates leptin-melanocortin anti-obesity signaling in the hypothalamus. Here, we discovered that MC4R-bearing primary cilia of hypothalamic neurons progressively shorten with age in rats, correlating with age-dependent metabolic decline and increased adiposity. This "age-related ciliopathy" is promoted by overnutrition-induced upregulation of leptin-melanocortin signaling and inhibited or reversed by dietary restriction or the knockdown of ciliogenesis-associated kinase 1 (CILK1). Forced shortening of MC4R-bearing cilia in hypothalamic neurons by genetic approaches impaired neuronal sensitivity to melanocortin and resulted in decreased brown fat thermogenesis and energy expenditure and increased appetite, finally developing obesity and leptin resistance. Therefore, despite its acute anti-obesity effect, chronic leptin-melanocortin signaling increases susceptibility to obesity by promoting the age-related shortening of MC4R-bearing cilia. This study provides a crucial mechanism for age-related obesity, which increases the risk of metabolic syndrome. Show less

Apolipoprotein A-V plays an important role in lipid metabolism regulation, particularly modulating triglyceride levels, as has been shown by many association studies in adults. The aim of this study was to analyse the effect of APOA5 on lipid profiles and fat-soluble vitamins (due to its strong relationship with triglyceride metabolism) in children. We determined polymorphisms -1131T>C and S19W in the APOA5 gene in 964 6-8-year-old participants of the 4P study and analysed the influence of the APOA5 gene on plasma lipid levels (total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides), apolipolipoproteins (apo A-I and apo B) and fat-soluble antioxidant vitamin (α-tocopherol, γ-tocopherol, lycopene, α-carotene, β-carotene and retinol) levels. The allele frequencies of both polymorphisms were comparable to those described in adult Caucasian populations (0.08 and 0.07 for -1131T>C and S19W, respectively). Boys carrying the -1131C allele have a 12% increase in circulating triglyceride levels (p=0.016) and a 7% decrease in HDL phospholipid levels (p=0.016). Linked to its effect on triglycerides, boys with the -1131C allele also have a 5% increase in plasma α-tocopherol levels (p=0.032). This effect was not observed in female participants. Boys carrying the rare allele for the S19W polymorphism have a 4% increase in circulating cholesterol levels (p=0.045), whereas girls have a 9% increase in circulating triglyceride levels (p=0.029). Linked to its effect on triglycerides, female carriers of the rare allele for S19W also have a 6% increase in α-tocopherol levels (p=0.009). In children, the effect of APOA5 gene variants on triglyceride levels is related to gender, and because of the strong relationship between lipid metabolism and fat-soluble antioxidant vitamins, it also involves a significant elevation in α-tocopherol concentrations. Show less