KEIO JOURNAL OF MEDICINE最新文献

Congenital heart disease (CHD) is the most common birth defect, affecting 1 in 100 babies. Among CHDs, single ventricle (SV) physiologies, such as hypoplastic left heart syndrome and tricuspid atresia, are particularly severe conditions that require multiple palliative surgeries, including the Fontan procedure. Although the management strategies for SV patients have markedly improved, the prevalence of ventricular dysfunction continues to increase over time, especially after the Fontan procedure. At present, the final treatment for SV patients who develop heart failure is heart transplantation; however, transplantation is difficult to achieve because of severe donor shortages. Recently, various regenerative therapies for heart failure have been developed that increase cardiomyocytes and restore cardiac function, with promising results in adults. The clinical application of various forms of regenerative medicine for CHD patients with heart failure is highly anticipated, and the latest research in this field is reviewed here. In addition, regenerative therapy is important for children with CHD because of their natural growth. The ideal pediatric cardiovascular device would have the potential to adapt to a child's growth. Therefore, if a device that increases in size in accordance with the patient's growth could be developed using regenerative medicine, it would be highly beneficial. This review provides an overview of the available regenerative technologies for CHD patients.

Living organisms enantioselectively employ L-amino acids as the molecular architecture of protein synthesized in the ribosome. Although L-amino acids are dominantly utilized in most biological processes, accumulating evidence points to the distinctive roles of D-amino acids in non-ribosomal physiology. Among the three domains of life, bacteria have the greatest capacity to produce a wide variety of D-amino acids. In contrast, archaea and eukaryotes are thought generally to synthesize only two kinds of D-amino acids: D-serine and D-aspartate. In mammals, D-serine is critical for neurotransmission as an endogenous coagonist of N-methyl D-aspartate receptors. Additionally, D-aspartate is associated with neurogenesis and endocrine systems. Furthermore, recognition of D-amino acids originating in bacteria is linked to systemic and mucosal innate immunity. Among the roles played by D-amino acids in human pathology, the dysfunction of neurotransmission mediated by D-serine is implicated in psychiatric and neurological disorders. Non-enzymatic conversion of L-aspartate or L-serine residues to their D-configurations is involved in age-associated protein degeneration. Moreover, the measurement of plasma or urinary D-/L-serine or D-/L-aspartate levels may have diagnostic or prognostic value in the treatment of kidney diseases. This review aims to summarize current understanding of D-amino-acid-associated biology with a major focus on mammalian physiology and pathology.

Radical esophagectomy for thoracic esophageal cancer is invasive and frequently results in postoperative pulmonary complications. Postoperative pneumonia is the most common such complication and affects hospital mortality and survival rates. Oral care has been very effective in reducing pneumonia. In Japan, preoperative professional oral care is highly recommended. However, there are few studies on the effect of preoperative improvements in oral hygiene as a result of intervention on the incidence of postoperative pneumonia. The primary end-point of this retrospective study was the incidence of postoperative pneumonia after radical esophagectomy. The oral health levels of 46 patients were individually categorized, and then patients were grouped according to whether they maintained or improved their oral hygiene. At the first dental examination, oral health levels were classified as good in 22 patients and bad in 24. Of the 46 patients studied, 39 patients maintained or improved their oral hygiene (good control group), whereas 7 showed no improvement (bad control group). Postoperative pneumonia occurred in eight patients: four in the good control group and four in the bad control group. Statistical analysis with postoperative pneumonia as a dependent variable showed a significant effect of oral hygiene improvement on the incidence of pneumonia. Logistic regression analysis with this factor as an independent variable demonstrated that the risk of postoperative pneumonia was reduced in the good control group (OR 0.086, 95% CI 0.014-0.529). Therefore, preoperative professional oral care may improve oral hygiene and oral health, which may in turn reduce the incidence of postoperative pneumonia.

A series of our studies on IL-6 have revealed that it has a pleiotropic activity in various tissues and cells and its deregulated expression is responsible for several chronic inflammations and hemopoietic malignancies.Humanized antibody against 80kd IL-6R (Tocilizumab) has shown significant therapeutic effect in RA, JIA, Castleman's diseases and several other autoimmune inflammatory diseases, such as, giant cell arteritis, reactive arthritis, polymyalgia rheumatica and adult still's disease. Cytokine storm induced by CAR-T cell therapy has been shown to be controlled by Tocilizumab.Therapeutic effect of Tocilizumab confirmed that over and constitutive-production of IL-6 is responsible for the pathogenesis of autoimmune diseases.Then, the question to be asked is how is IL-6 production regulated. We identified a novel molecule called Arid5a which binds with the 3'-UTR of IL-6 mRNA and protects its degradation by competing with Regnase-1. Interestingly, this molecule is present in nuclei and inflammatory stimulation induced translocation of Arid5a from nuclei into cytoplasm and it competes with Regnase-1 for the protection of mRNA of IL-6.Our study indicates that Arid5a is one of the key molecules for inflammation as well as the development of septic shock.The results also suggest the therapeutic potential of anti-agonistic agents for Arid5a in the prevention of various inflammatory diseases and septic shock.

Although sleep is a ubiquitous behavior in animal species with well-developed central nervous systems, many aspects in the neurobiology of sleep remain mysterious. Our discovery of orexin, a hypothalamic neuropeptide involved in the maintenance of wakefulness, has triggered an intensive research examining the exact role of the orexinergic and other neural pathways in the regulation of sleep/wakefulness. The orexin receptor antagonist suvorexant, which specifically block the endogenous waking system, has been approved as a new drug to treat insomnia. Also, since the sleep disorder narcolepsy-cataplexy is caused by orexin deficiency, orexin receptor agonists are expected to provide mechanistic therapy for narcolepsy; they will likely be also useful for treating excessive sleepiness due to other etiologies.Despite the fact that the executive neurocircuitry and neurochemistry for sleep/wake switching has been increasingly revealed in recent years, the mechanism for homeostatic regulation of sleep, as well as the neural substrate for "sleepiness" (sleep need), remains unknown. To crack open this black box, we have initiated a large-scale forward genetic screen of sleep/wake phenotype in mice based on true somnographic (EEG/EMG) measurements. We have so far screened >8,000 heterozygous ENU-mutagenized founders and established a number of pedigrees exhibiting heritable and specific sleep/wake abnormalities. By combining linkage analysis and the next-generation whole exome sequencing, we have molecularly identified and verified the causal mutation in several of these pedigrees. Biochemical and neurophysiological analyses of these mutations are underway. Since these dominant mutations cause strong phenotypic traits, we expect that the mutated genes will provide new insights into the elusive pathway regulating sleep/wakefulness. Indeed, through a systematic cross-comparison of the Sleepy mutants and sleep-deprived mice, we have recently found that the cumulative phosphorylation state of a specific set of mostly synaptic proteins may be the molecular substrate of sleep need.

Development of the skeleton is mediated through two distinct ossification mechanisms. Craniofacial bones are formed mainly through intramembranous ossification, a mechanism different from endochondral ossification required for development of the body skeleton. The skeletal structures are quite distinct between the two, thus they are likely to have their unique stem cell populations. The sutures serve as the growth center critical for healthy development of the craniofacial skeleton. Defects in suture morphogenesis cause its premature closure, resulting in development of craniosynostosis, a devastating disease affecting 1 in ~2,500 individuals. The suture mesenchyme has been postulated to act as the niche of skeletal stem cells essential for calvarial morphogenesis. However, very limited knowledge is available for suture biology and suture stem cells (SuSCs) have yet to be isolated. Here we report the first evidence for identification and isolation of a stem cell population residing in the suture midline. Genetic labeling of SuSCs shows their ability to self-renew and continually give rise to mature cell types over a 1-year monitoring period. They maintain their localization in the niches constantly produce skeletogenic descendants during calvarial development and homeostastic maintenance. Upon injury, SuSCs expand drastically surrounding the skeletogenic mesenchyme, migrate to the damaged site and contribute directly to skeletal repair in a cell autonomous fashion. The regeneration, pluripotency and frequency of SuSCs are also determined using limiting dilution transplantation. In vivo clonal expansion analysis demonstrates a single SuSC capable of generating bones. Furthermore, SuSC transplantation into injured calvaria facilitates the healing processes through direct engraftments. Our findings demonstrate SuSCs are bona fide skeletal stem cells ideally suited for cell-based craniofacial bone therapy as they possess abilities to engraft, differentiate.(Presented at the 1980th Meeting, April 16, 2019).

Stem cells are the foundation of all mammalian life. Stem cells build and maintain our bodies throughout life. Two types of stem cells are discerned.1) Embryonic stem cells (ES cells) are briefly present in the early human or mouse embryo, a few days after fertilization. These ES cells can be grown indefinitely in the lab and have the potential to build each and every tissue in our body. Because of this 'pluripotency', ES cells hold great promise for therapeutic application in the field of regenerative medicine. It is also possible to take skin cells (or other cells) from adults and convert these in the lab into cells with ES properties, so called iPS cells. Many of the hurdles that ES cell technology have faced, do not exist for iPS cells.2) Adult stem cells. Every organ in our body is believed to harbor its own dedicated stem cells. These adult stem cells replace tissue that is lost due to wear and tear, trauma and disease. Adult stem cells are highly specialized and can only produce the tissue in which they reside; they are 'multipotent'. Examples are bone marrow stem cells that make all blood cells, skin stem cells and gut stem cells. Even the brain is now known to harbor its specialized stem cells. The adult stem cells allow us to live 80-90 years, but this comes at a cost: they are the cells that most easily transform into cancer cells.Both types of stem cells can be used to establish 'organoids', 3D structures established in a dish, that recapitulate many aspects of the organ they represent. Pluripotent stem cells can be taken through the developmental steps that establish organs during embryogenesis. This has worked particularly well for parts of the the central nervous system, the kidney and GI organs. We have shown that adult epithelial stem cells carrying the generic Lgr5 marker can be cultured under tissue-repair conditions and generate epithelial organoids directly from healthy and diseased organs such as the gut, the liver, the lung and the pancreas. Organoid technology opens a range of avenues for the study of development, physiology and disease, for drug development and for personalized medicine. In the long run, cultured mini-organs may replace transplant organs from donors and hold promise in gene therapy.