Cellular plasticity of the bone marrow niche promotes hematopoietic stem cell regeneration.

Hematopoietic stem cells (HSCs) regenerate after myeloablation, a procedure that adversely disrupts the bone marrow and drives leptin receptor-expressing cells, a key niche component, to differentiate extensively into adipocytes. Regeneration of the bone marrow niche is associated with the resolution of adipocytes, but the mechanisms remain poorly understood. Using Plin1-creER knock-in mice, we followed the fate of adipocytes in the regenerating niche in vivo. We found that bone marrow adipocytes were highly dynamic and dedifferentiated to leptin receptor-expressing cells during regeneration after myeloablation. Bone marrow adipocytes could give rise to osteolineage cells after skeletal injury. The cellular fate of steady-state bone marrow adipocytes was also plastic. Deletion of adipose triglyceride lipase (Atgl) from bone marrow stromal cells, including adipocytes, obstructed adipocyte dedifferentiation and led to severely compromised regeneration of HSCs as well as impaired B lymphopoiesis after myeloablation, but not in the steady state. Thus, the regeneration of HSCs and their niche depends on the cellular plasticity of bone marrow adipocytes.

Antihypertensive drug prescription trends for pregnant women with hypertension in acute hospitals in Japan.

Hypertensive disorders of pregnancy cause maternal organ damage. Therefore, appropriate management with antihypertensive medication is required from the first trimester. We aimed to clarify the antihypertensive drug prescription trends in pregnant women with hypertension in Japan. The administrative data of pregnant outpatients aged 16-49 years who visited acute hospitals between 2013 and 2020 were included. The annual antihypertensive drug prescription trends were evaluated based on their prescription proportions. The most prescribed drug in 2020 was nifedipine, followed by methyldopa and amlodipine. The proportion of nifedipine prescriptions significantly increased from 33.5 to 40.8% during the study period, whereas that of methyldopa significantly decreased from 16.6 to 11.6%. There was no change in the prescription trend of amlodipine. Dihydropyridine calcium channel blockers were the most commonly prescribed drug for pregnant women with hypertension.

Spatiotemporal dynamics of SETD5-containing NCoR-HDAC3 complex determines enhancer activation for adipogenesis.

Enhancer activation is essential for cell-type specific gene expression during cellular differentiation, however, how enhancers transition from a hypoacetylated "primed" state to a hyperacetylated-active state is incompletely understood. Here, we show SET domain-containing 5 (SETD5) forms a complex with NCoR-HDAC3 co-repressor that prevents histone acetylation of enhancers for two master adipogenic regulatory genes Cebpa and Pparg early during adipogenesis. The loss of SETD5 from the complex is followed by enhancer hyperacetylation. SETD5 protein levels were transiently increased and rapidly degraded prior to enhancer activation providing a mechanism for the loss of SETD5 during the transition. We show that induction of the CDC20 co-activator of the ubiquitin ligase leads to APC/C mediated degradation of SETD5 during the transition and this operates as a molecular switch that facilitates adipogenesis.

Adipsin promotes bone marrow adiposity by priming mesenchymal stem cells.

Background: Marrow adipose tissue (MAT) has been shown to be vital for regulating metabolism and maintaining skeletal homeostasis in the bone marrow (BM) niche. As a reflection of BM remodeling, MAT is highly responsive to nutrient fluctuations, hormonal changes, and metabolic disturbances such as obesity and diabetes mellitus. Expansion of MAT has also been strongly associated with bone loss in mice and humans. However, the regulation of BM plasticity remains poorly understood, as does the mechanism that links changes in marrow adiposity with bone remodeling. Methods: We studied deletion of Adipsin, and its downstream effector, C3, in C57BL/6 mice as well as the bone-protected PPARγ constitutive deacetylation 2KR mice to assess BM plasticity. The mice were challenged with thiazolidinedione treatment, calorie restriction, or aging to induce bone loss and MAT expansion. Analysis of bone mineral density and marrow adiposity was performed using a µCT scanner and by RNA analysis to assess adipocyte and osteoblast markers. For in vitro studies, primary bone marrow stromal cells were isolated and subjected to osteoblastogenic or adipogenic differentiation or chemical treatment followed by morphological and molecular analyses. Clinical data was obtained from samples of a previous clinical trial of fasting and high-calorie diet in healthy human volunteers. Results: We show that Adipsin is the most upregulated adipokine during MAT expansion in mice and humans in a PPARγ acetylation-dependent manner. Genetic ablation of Adipsin in mice specifically inhibited MAT expansion but not peripheral adipose depots, and improved bone mass during calorie restriction, thiazolidinedione treatment, and aging. These effects were mediated through its downstream effector, complement component C3, to prime common progenitor cells toward adipogenesis rather than osteoblastogenesis through inhibiting Wnt/ß-catenin signaling. Conclusions: Adipsin promotes new adipocyte formation and affects skeletal remodeling in the BM niche. Our study reveals a novel mechanism whereby the BM sustains its own plasticity through paracrine and endocrine actions of a unique adipokine. Funding: This work was supported by the National Institutes of Health T32DK007328 (NA), F31DK124926 (NA), R01DK121140 (JCL), R01AR068970 (BZ), R01AR071463 (BZ), R01DK112943 (LQ), R24DK092759 (CJR), and P01HL087123 (LQ).

Ubiquitination-dependent and -independent repression of target genes by SETDB1 reveal a context-dependent role for its methyltransferase activity during adipogenesis.

The lysine methyltransferase SETDB1, an enzyme responsible for methylation of histone H3 at lysine 9, plays a key role in H3K9 tri-methylation-dependent silencing of endogenous retroviruses and developmental genes. Recent studies have shown that ubiquitination of human SETDB1 complements its catalytic activity and the silencing of endogenous retroviruses in human embryonic stem cells. However, it is not known whether SETDB1 ubiquitination is essential for its other major role in epigenetic silencing of developmental gene programs. We previously showed that SETDB1 contributes to the formation of H3K4/H3K9me3 bivalent chromatin domains that keep adipogenic Cebpa and Pparg genes in a poised state for activation and restricts the differentiation potential of pre-adipocytes. Here, we show that ubiquitin-resistant K885A mutant of SETDB1 represses adipogenic genes and inhibits pre-adipocyte differentiation similar to wild-type SETDB1. We show this was due to a compensation mechanism for H3K9me3 chromatin modifications on the Cebpa locus by other H3K9 methyltransferases Suv39H1 and Suv39H2. In contrast, the K885A mutant did not repress other SETDB1 target genes such as Tril and Gas6 suggesting SETDB1 represses its target genes by two mechanisms; one that requires its ubiquitination and another that still requires SETDB1 but not its enzyme activity.

Myofiber androgen receptor increases muscle strength mediated by a skeletal muscle splicing variant of Mylk4.

Androgens have a robust effect on skeletal muscles to increase muscle mass and strength. The molecular mechanism of androgen/androgen receptor (AR) action on muscle strength is still not well known, especially for the regulation of sarcomeric genes. In this study, we generated androgen-induced hypertrophic model mice, myofiber-specific androgen receptor knockout (cARKO) mice supplemented with dihydrotestosterone (DHT). DHT treatment increased grip strength in control mice but not in cARKO mice. Transcriptome analysis by RNA-seq, using skeletal muscles obtained from control and cARKO mice treated with or without DHT, identified a fast-type muscle-specific novel splicing variant of Myosin light-chain kinase 4 (Mylk4) as a target of AR in skeletal muscles. Mylk4 knockout mice exhibited decreased maximum isometric torque of plantar flexion and passive stiffness of myofibers due to reduced phosphorylation of Myomesin 1 protein. This study suggests that androgen-induced skeletal muscle strength is mediated with Mylk4 and Myomesin 1 axis.

A novel electron emission-based cell culture device promotes cell proliferation and differentiation of pre-osteoblastic MC3T3-E1 cells.

In this report we demonstrate the effect of a novel electron emission-based cell culture device on the proliferation and differentiation of pre-osteoblastic MC3T3-E1 cells. Our device has an electron emission element that allows, for the first time, stable emission of electrons into an atmosphere. Atmospheric electrons react with gas molecules to generate radicals and negative ions, which induce a variety of biochemical reactions in the attached cell culture system. In this study, we demonstrated the effect of this new electron emission-based cell culture device on cell proliferation and differentiation using pre-osteoblastic MC3T3-E1 cells. Electron emission stimulation (EES) was applied directly to culture medium containing plated cells, after which the number of living cells, the mRNA levels of osteogenesis-related genes, and the alkaline phosphatase (ALP) activity were evaluated. The growth rate of EES-exposed cells increased by approximately 20% in comparison with unexposed control cells. We also found the mRNA levels of osteogenic specific genes such as collagen type I α-1, core-binding factor α-1, and osteocalcin to be up-regulated following EES. ALP activity, a marker for osteogenic activity, was significantly enhanced in EES-treated cells. Furthermore, reactive oxygen species generated by EES were measured to determine their effect on MC3T3-E1 cells. These results suggest that our new electron emission-based cell culture device, while providing a relatively weak stimulus in comparison with atmospheric plasma systems, promotes cell proliferation and differentiation. This system is expected to find application in regenerative medicine, specifically in relation to bone regeneration.

Nedaplatin as a Single-Agent Chemotherapy May Support Palliative Therapy for Patients with Adenoid Cystic Carcinoma: A Case Report.

Adenoid cystic carcinoma (ACC) is a rare form of adenocarcinoma, which is a broad term describing any cancer that begins in the glandular tissues. It can be found in the head and neck. We report a patient with recurrent ACC arising from the submandibular gland, treated with 100 mg/m2 nedaplatin every 4 weeks. Although our patient's lactate dehydrogenase levels, which is produced by ACC, showed a rising trend throughout the treatment, the level decreased for approximately 2 weeks immediately after administration of nedaplatin every 4 weeks. Thus, there is a possibility that the agent may be effective. Complications such as anorexia and nausea were observed, but they were tolerated and manageable. Nedaplatin may be considered as a supportive agent during palliative therapy for patients with ACC. More clinical trials regarding nedaplatin are necessary, as this study may indicate that a medical approach works well for ACC.

[A Case of Merkel Cell Carcinoma Complicated with Severe Thrombocytopenia Treated with Carboplatin/Etoposide Regimen after Surgery].

Thrombocytopenia is often caused by myelosuppression during chemotherapy. However, when platelet transfusions are required, pathological conditions such as idiopathic thrombocytopenic purpura(ITP)and thrombotic thrombocytopenic purpura( TTP)also occur. We report a case of Merkel cell carcinoma complicated with severe thrombocytopenia treated with carboplatin/etoposide regimen after surgery. The patient's platelet count did not increase in spite of platelet transfusions. However, the platelet count increased after steroid treatment was chosen under the diagnosis of ITP. Subsequent examinations revealed that the patient had HLA antibody, which caused the platelet transfusion refractoriness. When the platelet count does not increase in spite of platelet transfusions during chemotherapy, the possibility that the platelet transfusion refractoriness is due to the presence of HLA antibody should be considered.

Antiretroviral Therapy Containing HIV Protease Inhibitors Enhances Fracture Risk by Impairing Osteoblast Differentiation and Bone Quality.

Long-term antiretroviral therapy is associated with increased fracture risk, but the mechanism remains elusive. We measured serum undercarboxylated osteocalcin and pentosidine (markers of poor bone quality) in human immunodeficiency virus-infected patients treated with protease inhibitors (PIs) or an integrase strand transfer inhibitor-containing regimen. The results demonstrated significantly higher undercarboxylated osteocalcin and pentosidine in PI-treated patients. Switching to integrase strand transfer inhibitor significant decreased these markers. We also showed impaired bone mechanical properties with higher undercarboxylated osteocalcin level in PI-treated mice and inhibited osteoblast differentiation in PI-treated osteogenic cells. The results confirmed the adverse effects of PIs on bone quality and osteoblast differentiation.

A DPP-4 inhibitor suppresses fibrosis and inflammation on experimental autoimmune myocarditis in mice.

Myocarditis is a critical inflammatory disorder which causes life-threatening conditions. No specific or effective treatment has been established. DPP-4 inhibitors have salutary effects not only on type 2 diabetes but also on certain cardiovascular diseases. However, the role of a DPP-4 inhibitor on myocarditis has not been investigated. To clarify the effects of a DPP-4 inhibitor on myocarditis, we used an experimental autoimmune myocarditis (EAM) model in Balb/c mice. EAM mice were assigned to the following groups: EAM mice group treated with a DPP-4 inhibitor (linagliptin) (n = 19) and those untreated (n = 22). Pathological analysis revealed that the myocardial fibrosis area ratio in the treated group was significantly lower than in the untreated group. RT-PCR analysis demonstrated that the levels of mRNA expression of IL-2, TNF-α, IL-1ß and IL-6 were significantly lower in the treated group than in the untreated group. Lymphocyte proliferation assay showed that treatment with the DPP-4 inhibitor had no effect on antigen-induced spleen cell proliferation. Administration of the DPP-4 inhibitor remarkably suppressed cardiac fibrosis and reduced inflammatory cytokine gene expression in EAM mice. Thus, the agents present in DPP-4 inhibitors may be useful to treat and/or prevent clinical myocarditis.

Intensive rehabilitation for dementia improved cognitive function and reduced behavioral disturbance in geriatric health service facilities in Japan.

AIM: To examine the efficacy of rehabilitation for elderly individuals with dementia at intermediate facilities between hospitals and home, based on the policies for elderly individuals to promote community-based care at home and dehospitalization. METHODS: Participants were older adults with dementia newly admitted to intermediate facilities. A total of 158 in the intervention group who claimed Long-Term Care Insurance for three consecutive months, and 54 in the control group were included in the analysis. The interventions were carried out in a tailor-made manner to meet individual needs. The personal sessions were carried out three times a week for 3 months after admission by physical, occupational or speech therapists. Outcome measures were cognitive tests (Hasegawa Dementia Scale revised [HDS-R] and Mini-Mental State Examination), and observational assessments of dementia severity, activities of daily living (ADL), social activities, behavioral and psychological symptoms of dementia (BPSD) using a short version of the Dementia Disturbance Scale (DBD13), depressive mood, and vitality. RESULTS: Significant improvement in the intervention group was shown in cognitive function measured by HDS-R (interaction F[1, 196] = 5.190, P = 0.024), observational evaluation of dementia severity (F[1,198] = 9.550, P = 0.002) and BPSD (DBD13; F[1,197] = 4.506, P = 0.035). Vitality, social activities, depressive mood and ADL were significantly improved only in the intervention group, although interaction was not significant. CONCLUSIONS: Significant improvement by intervention was shown in multiple domains including cognitive function and BPSD. Cognitive decline and worsening of BPSD are predictors of care burden and hospitalization, thus intensive rehabilitation for dementia was beneficial for both individuals with dementia and their caregivers.

Psychosocial factors associated with suicidal ideation in clinical patients with depression.

BACKGROUND: Depression is a major risk factor for suicide, but few studies have examined psychosocial risk factors for suicide in clinical patients with depression. The purpose of this study was to investigate psychosocial factors which could be associated with suicidal ideation in clinical patients with depression including: sick-leave, help-seeking behavior, and reluctance to admit mental health problems. METHODS: A multi-center cross-sectional survey using self-report questionnaire was conducted at 54 outpatient psychiatric clinics in Tokyo in 2012. Adult outpatients who were diagnosed by psychiatrists as mood disorders (F30-F39) in the International Classification of Diseases-10 (ICD-10) were included in the study. Those who met the criteria for current hypomanic or manic episode were excluded from the study. RESULTS: A total of 189 patients with depression participated in the survey. Multivariable logistic regression analysis showed that taking sick-leave and having sought help from family were associated with decreased odds of current suicidal ideation. Moderate or more severe depression was associated with increased odds of suicidal ideation, and reluctance to admit own mental health problem tended to increase odds of suicidal ideation. LIMITATIONS: Living status and suicidal ideation before consultation with psychiatrist were not investigated. Severity of suicidal ideation and comorbid psychiatric disorders were not assessed. CONCLUSIONS: Importance of treatment of more severe depression for suicide prevention was confirmed. Industrial health staffs should consider the possibility of positive effect of taking sick-leave when they see employees with depression. Promoting help-seeking for family and reducing stigma of mental illness may be effective for suicide prevention.

Immunohistochemical collagen analysis of the most superficial layer in adult articular cartilage.

We investigated immunohistochemically the collagen type of the most superficial layer in 10 normal adult human articular cartilage specimens obtained from eight femoral heads and one each of the femoral condyle and the talus using routine light microscopy and polarizing microscopy. A membrane-like structure with strong bire-fringence covering the articular surface was observed under polarizing microscopy in each specimen. This structure was stained with anti-type I and anti-type III collagen antibodies but not with anti-type II collagen antibody. This immunohistochemical finding was identical to that in synovial tissue. The results of this study confirm that the most superficial layer of adult normal articular cartilage consists not of type II collagen but of types I and III, and that this layer is absolutely independent from its deeper layer.