ブラダー・ウイリー ショウコウグン ニオケル セイチョウ ホルモン リョウホウ ト ソクワンショウ トノ カンケイ

成長ホルモン(GH)療法がプラダー・ウイリー症候群(PWS)の低身長に対して適応され5年が経過し,様々な効果が報告されてきている.しかし一方で, GH治療が側弯症を誘発または増悪させる可能性が問題になってきている.今回我々は,獨協医科大学越谷病院小児科でフォロー中のPWS患者72名(男性46名,女性26名,年齢1歳から49歳)を対象にGH治療と側弯症の関係を検討した.対象の72名中, GH療法を受けた者は41名,受けなかった者は31名であった. 72名中33名(45.8%)にコブ角10度以上の側弯症を認めた.側弯症は, GH療法を受けた41名中20名(48.8%)に, GH療法を受けなかった31名中13名(41.9%)に認められ,両群間に統計学的有意差は認められなかった. GH療法を受けた患者中,側弯症あり群となし群間でのGH療法開始後1年目の身長増加の比較では,それぞれ8.59±1.92cmと10.70±2.54cmであった.側弯なし群のGH療法開始後1年目の身長は側弯あり群より有意に増加していた.したがって,統計学上では身長の加速は側弯症を悪化させていなかった. GH開始年齢と側弯症発症との関係では,側弯症なし群でGH療法開始年齢が有意に低かった(p=0.029). GH療法を受けている群で,側弯症を認めた20名のコブ角の経過は,変動なし10名,増悪6名,増悪軽快1名,軽快3名であった. PWS患者においてGH療法は身長増加をもたらすが側弯症増悪因子になっていないと考えられた.Growth hormone (GH) therapy for Prader-Willi syndrome (PWS) has started worldwide and various favorable effects have been reported. But the possibility of progression of scoliosis is being new problems for GH treatment. In this study we analyzed 72 patients who are followed at our hospital (46 males and 26 females, aged from 1 year old to 49 years old, 41 patients with GH use and 31 without GH). We studied 1. The overall frequency of scoliosis in PWS, 2. The frequency of scoliosis with and without GH therapy, 3. The two factors (i.e. height velocity of the first year of GH therapy and the starting age of GH) which may be related to the progression of scoliosis, and 4. The prognosis of the scoliosis. The results are ; 1. Out of 72 patients, 33 patients (45.8%) showed scoliosis more than 10 degree of Cobb angle. 2. Out of 41 patients with GH therapy 20 patients (48.8 %) had scoliosis and out of 31 patients without GH therapy 13 patients (41.9 %) showed scoliosis. No statistical difference was detected between two groups. 3. Height velocities of the first year of treatment were 8.59±1.92 cm and 10.70±2.54 cm with and without scoliosis, respectively (p<0.001). GH therapy was started earlier in patients without scoliosis than with scoliosis (p<0.0001). 4. Out of 20 patients with scoliosis and GH use, the degree of scoliosis progressed in six patients, improved in three, and fluctuated in one during the GH treatment. Our results show that there is a high frequency of scoliosis in PWS with and without GH treatment, Increased height velocity by GH does not develop scoliosis, and early start of GH is not an exacerbating factor of scoliosis. Many patients showed progression of scoliosis with age irrespective of the use of GH and at least some patients improved their scoliosis in degree by GH

Characterization of Arabidopsis CTP:3-deoxy-D-manno-2-octulosonate cytidylyltransferase (CMP-KDO synthetase), the enzyme that activates KDO during rhamnogalacturonan II biosynthesis.

In plant cells, boron (B) occurs predominantly as a borate ester associated with rhamnogalacturonan II (RG-II), but the function of this B-RG-II complex has yet to be investigated. 3-Deoxy-D-manno-2-octulosonic acid (KDO) is a specific component monosaccharide of RG-II. Mutant plants defective in KDO biosynthesis are expected to have altered RG-II structure, and would be useful for studying the physiological function of the B-RG-II complex. Here, we characterized Arabidopsis CTP:KDO cytidylyltransferase (CMP-KDO synthetase; CKS), the enzyme activating KDO as a nucleotide sugar prior to its incorporation into RG-II. Our analyses localized the Arabidopsis CKS protein to mitochondria. The Arabidopsis CKS gene occurs as a single-copy gene in the genome, and we could not obtain cks null mutants from T-DNA insertion lines. Analysis using +/cks heterozygotes in the quartet1 background demonstrated that the cks mutation rendered pollen infertile through the inhibition of pollen tube elongation. These results suggest that KDO is an indispensable component of RG-II, and that the complete B-RG-II complex is essential for the cell wall integrity of rapidly growing tissues

Downregulation of Mitochondrial Fusion Protein Expression Affords Protection from Canonical Necroptosis in H9c2 Cardiomyoblasts

Necroptosis, a form of necrosis, and alterations in mitochondrial dynamics, a coordinated process of mitochondrial fission and fusion, have been implicated in the pathogenesis of cardiovascular diseases. This study aimed to determine the role of mitochondrial morphology in canonical necroptosis induced by a combination of TNFα and zVAD (TNF/zVAD) in H9c2 cells, rat cardiomyoblasts. Time-course analyses of mitochondrial morphology showed that mitochondria were initially shortened after the addition of TNF/zVAD and then their length was restored, and the proportion of cells with elongated mitochondria at 12 h was larger in TNF/zVAD-treated cells than in non-treated cells (16.3 ± 0.9% vs. 8.0 ± 1.2%). The knockdown of dynamin-related protein 1 (Drp1) and fission 1, fission promoters, and treatment with Mdivi-1, a Drp-1 inhibitor, had no effect on TNF/zVAD-induced necroptosis. In contrast, TNF/zVAD-induced necroptosis was attenuated by the knockdown of mitofusin 1/2 (Mfn1/2) and optic atrophy-1 (Opa1), proteins that are indispensable for mitochondrial fusion, and the attenuation of necroptosis was not canceled by treatment with Mdivi-1. The expression of TGFβ-activated kinase (TAK1), a negative regulator of RIP1 activity, was upregulated and the TNF/zVAD-induced RIP1-Ser166 phosphorylation, an index of RIP1 activity, was mitigated by the knockdown of Mfn1/2 or Opa1. Pharmacological TAK1 inhibition attenuated the protection afforded by Mfn1/2 and Opa1 knockdown. In conclusion, the inhibition of mitochondrial fusion increases TAK1 expression, leading to the attenuation of canonical necroptosis through the suppression of RIP1 activity

Downregulation of extramitochondrial BCKDH and its uncoupling from AMP deaminase in type 2 diabetic OLETF rat hearts

Abstract Systemic branched‐chain amino acid (BCAA) metabolism is dysregulated in cardiometabolic diseases. We previously demonstrated that upregulated AMP deaminase 3 (AMPD3) impairs cardiac energetics in a rat model of obese type 2 diabetes, Otsuka Long‐Evans‐Tokushima fatty (OLETF). Here, we hypothesized that the cardiac BCAA levels and the activity of branched‐chain α‐keto acid dehydrogenase (BCKDH), a rate‐limiting enzyme in BCAA metabolism, are altered by type 2 diabetes (T2DM), and that upregulated AMPD3 expression is involved in the alteration. Performing proteomic analysis combined with immunoblotting, we discovered that BCKDH localizes not only to mitochondria but also to the endoplasmic reticulum (ER), where it interacts with AMPD3. Knocking down AMPD3 in neonatal rat cardiomyocytes (NRCMs) increased BCKDH activity, suggesting that AMPD3 negatively regulates BCKDH. Compared with control rats (Long‐Evans Tokushima Otsuka [LETO] rats), OLETF rats exhibited 49% higher cardiac BCAA levels and 49% lower BCKDH activity. In the cardiac ER of the OLETF rats, BCKDH‐E1α subunit expression was downregulated, while AMPD3 expression was upregulated, resulting in an 80% lower AMPD3‐E1α interaction compared to LETO rats. Knocking down E1α expression in NRCMs upregulated AMPD3 expression and recapitulated the imbalanced AMPD3‐BCKDH expressions observed in OLETF rat hearts. E1α knockdown in NRCMs inhibited glucose oxidation in response to insulin, palmitate oxidation, and lipid droplet biogenesis under oleate loading. Collectively, these data revealed previously unrecognized extramitochondrial localization of BCKDH in the heart and its reciprocal regulation with AMPD3 and imbalanced AMPD3‐BCKDH interactions in OLETF. Downregulation of BCKDH in cardiomyocytes induced profound metabolic changes that are observed in OLETF hearts, providing insight into mechanisms contributing to the development of diabetic cardiomyopathy

Nuclear translocation of MLKL enhances necroptosis by a RIP1/RIP3-independent mechanism in H9c2 cardiomyoblasts

Accumulating evidence suggests that necroptosis of cardiomyocytes contributes to cardiovascular diseases. Lethal disruption of the plasma membrane in necroptosis is induced by oligomers of mixed lineage kinase domain-like (MLKL) that is translocated to the membrane from the cytosol. However, the role played by cytoplasmic-nuclear shuttling of MLKL is unclear. Here, we tested the hypothesis that translocation of MLKL to the nucleus promotes the necroptosis of cardiomyocytes. Activation of the canonical necroptotic signaling pathway by a combination of TNF-α and zVAD (TNF/zVAD) increased nuclear MLKL levels in a RIP1-activity-dependent manner in H9c2 cells, a rat cardiomyoblast cell line. By use of site-directed mutagenesis, we found a nuclear export signal sequence in MLKL and prepared its mutant (MLKL-L280/283/284A), though a search for a nuclear import signal was unsuccessful. MLKL-L280/283/284A localized to both the cytosol and the nucleus. Expression of MLKL-L280/283/284A induced necroptotic cell death, which was attenuated by GppNHp, an inhibitor of Ran-mediated nuclear import, but not by inhibition of RIP1 activity or knockdown of RIP3 expression. GppNHp partly suppressed H9c2 cell death induced by TNF/zVAD treatment. These results suggest that MLKL that is translocated to the nucleus via RIP1-mediated necroptotic signaling enhances the necroptosis of cardiomyocytes through a RIP1-/RIP3-independent mechanism