Enpp1 is an anti-aging factor that regulates Klotho under phosphate overload conditions

Control of phosphate metabolism is crucial to regulate aging in mammals. Klotho is a well-known anti-aging factor that regulates phosphate metabolism: mice mutant or deficient in Klotho exhibit phenotypes resembling human aging. Here we show that ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1) is required for Klotho expression under phosphate overload conditions. Loss-of-function Enpp1 ttw/ttw mice under phosphate overload conditions exhibited phenotypes resembling human aging and Klotho mutants, such as short life span, arteriosclerosis and osteoporosis, with elevated serum 1,25(OH)2D3 levels. Enpp1ttw/ttw mice also exhibited significantly reduced renal Klotho expression under phosphate overload conditions, and aging phenotypes in these mice were rescued by Klotho overexpression, a low vitamin D diet or vitamin D receptor knockout. These findings indicate that Enpp1 plays a crucial role in regulating aging via Klotho expression under phosphate overload conditions

Selective localization of Alzheimer's amyloid beta in membrane lateral compartments

Model membrane systems revealed that lateral heterogeneity of the membrane mediates the localization of amyloid beta peptides in a peptide aggregation-dependent manner

Draxin regulates hippocampal neurogenesis in the postnatal dentate gyrus by inhibiting DCC-induced apoptosis

Hippocampal neurogenesis in the dentate gyrus (DG) is controlled by diffusible molecules that modulate neurogenic processes, including cell proliferation, differentiation and survival. To elucidate the mechanisms underlying hippocampal neurogenesis, we investigated the function of draxin, originally identified as a neural chemorepellent, in the regulation of neuronal survival in the DG. Draxin was expressed in Tbr2 (+) late progenitors and NeuroD1 (+) neuroblasts in the dentate granule cell lineage, whereas expression of its receptor DCC (deleted in colorectal cancer) was mainly detectable in neuroblasts. Our phenotypic analysis revealed that draxin deficiency led to enhanced apoptosis of DCC-expressing neuroblasts in the neurogenic areas. Furthermore, in vitro assays using a hippocampal neural stem/progenitor cell (HNSPC) line indicated that draxin inhibited apoptosis in differentiating HNSPCs, which express DCC. Taken together, we postulate that draxin plays a pivotal role in postnatal DG neurogenesis as a dependence receptor ligand for DCC to maintain and promote survival of neuroblasts

Influence of Discontinuation of Cardiac Rehabilitation in Elderly Outpatients Due to the COVID-19 Pandemic

Background: The coronavirus disease 2019 (COVID-19) pandemic has restricted people’s activities and necessitated the discontinuation of cardiac rehabilitation (CR) programs for outpatients. In our hospital, CR for outpatients had to be discontinued for 3 months. We investigated the influence of this discontinuation of CR on physical activity, body composition, and dietary intake in cardiovascular outpatients. Method: Seventy-eight outpatients who restarted CR were investigated. We measured body composition, balance test, stage of locomotive syndrome, and food frequency questionnaire (FFQ) results at restart and 3 months later. We also investigated the results of examination that were obtained before discontinuation. Results: With regard to baseline characteristics, the percentage of male was 62.7% (n = 49), and average age and body mass index were 74.1 ± 8.5 years and 24.9 ± 7.0 kg/m2, respectively. Stage of locomotive syndrome and the results of FFQ did not change significantly. The one-leg standing time with eyes open test significantly worsened at restart (p < 0.001) and significantly improved 3 months later (p = 0.007). With regard to body composition, all limb muscle masses were decreased at restart and decreased even further 3 months later. Conclusions: Discontinuation of CR influenced standing balance and limb muscle mass. While the restart of CR may improve a patient’s balance, more time is required for additional daily physical activities. The recent pandemic-related interruption of CR should inspire the development of alternatives that could ensure the continuity of CR in a future crisis

Difference in Prognosis between Continuation and Discontinuation of A 5-Month Cardiac Rehabilitation Program in Outpatients with Heart Failure with Preserved Ejection Fraction

Background: Cardiac rehabilitation (CR) is a requisite component of care for patients with heart failure (HF). We aimed to evaluate the clinical outcomes in outpatients with HF with preserved ejection fraction (HFpEF) compared to those in patients with non-HFpEF who did and did not continue a 5-month CR program. Methods: 173 outpatients with HF who participated in a 5-month CR program were registered. We divided them into two groups: HFpEF (n = 84, EF 63 ± 7%) and non-HFpEF (n = 89, EF 31 ± 11%). We further divided the patients into those who continued the CR program (continued group) and those who did not (discontinued group) in the HFpEF and non-HFpEF groups. The clinical outcomes at 5 months were compared among the groups. Results: There were no significant differences in patient characteristics at baseline between the continued and discontinued groups in the HFpEF and non-HFpEF groups except for % diabetes mellitus in the non-HFpEF group. The rates of all-cause death and hospital admissions in the continued group in both the HFpEF and non-HFpEF groups were significantly lower than those in the discontinued group. The all-cause death and hospital admissions in each group were independently associated with the continuation of the CR program. Conclusions: The continuation of a 5-month CR program was associated with the prevention of all-cause death and hospital admissions in both the HFpEF and non-HFpEF groups

Selective Estrogen Receptor Modulators Suppress Hif1α Protein Accumulation in Mouse Osteoclasts.

Anti-bone resorptive drugs such as bisphosphonates, the anti-RANKL antibody (denosumab), or selective estrogen receptor modulators (SERMs) have been developed to treat osteoporosis. Mechanisms underlying activity of bisphosphonates or denosumab in this context are understood, while it is less clear how SERMs like tamoxifen, raloxifene, or bazedoxifene inhibit bone resorption. Recently, accumulation of hypoxia inducible factor 1 alpha (Hif1α) in osteoclasts was shown to be suppressed by estrogen in normal cells. In addition, osteoclast activation and decreased bone mass seen in estrogen-deficient conditions was found to require Hif1α. Here, we used western blot analysis of cultured osteoclast precursor cells to show that tamoxifen, raloxifene, or bazedoxifene all suppress Hif1α protein accumulation. The effects of each SERM on osteoclast differentiation differed in vitro. Our results suggest that interventions such as the SERMs evaluated here could be useful to inhibit Hif1α and osteoclast activity under estrogen-deficient conditions