ジンコウ ヨウキ デノ バイヨウ カイシ ジキ ガ ニホンウズラハイ ノ ガイブ ケイソクチ ト カルシウム オヨビ マグネシウム ノ ガンユウリョウ ニ アタエル エイキョウ

希少鳥類を発生工学的な手法で増殖させる際に,人工容器による鳥類胚の培養は有用なツールになると考えられる。しかし,人工容器を用いて鳥類胚を胚盤葉期から培養し孵化させる方法は確立されていない。そこで本研究では,ニホンウズラを対象として人工容器培養した胚の形態,カルシウム(Ca)及びマグネシウム(Mg)の含有量を調べた。人工容器による培養は,胚盤葉期または通常の孵卵を 60 時間行った後に開始した。培養液にはニワトリ水様性卵白 1.5 ml 中に乳酸カルシウム 35 mg または乳酸カルシウム 25 mg+ ウズラ卵殻粉末 10 mg を添加したしたものを使用した。供試胚は,胚盤葉期から 60,120,240 及び 360 時間培養したのち,乾重量,全長,第 3 趾長,眼直径及び嘴峯長を計測した。対照群として操作を加えず通常孵卵した胚を用いた。胚の Ca と Mg 含有量は原子吸光分析法により測定した。胚の外部計測値は,120時間まで全ての培養方法において差は認められなかった。しかしながら,360時間では眼直径を除く全ての項目について,通常孵卵した胚に比べ人工容器で培養した胚で低い値を示した(p<0.05)。また,乾重量,全長及び発生段階の値は,胚盤葉期から人工容器培養を開始した胚,孵卵60時間後から人工容器培養を開始した胚,通常孵卵した胚の順に大きくなり,人工容器での培養時間が長いほど低い値を示した(p<0.05)。眼直径は胚盤葉期から培養した胚が最も低い値を示した(p<0.05)。Ca と Mg の含有量は120時間まで全ての培養方法において差は認められなかったが,240 から 360 時間にかけて急激な増加を示し,360時間においては人工容器で培養した胚が通常孵卵した胚に対して低い値を示した(p<0.05)。しかしながら,人工容器による培養では,すべての調査項目において乳酸カルシウムと卵殻粉末の添加量の違いによる差は認められなかった。以上の結果から,本実験で用いた穴の開いていない人工容器による培養では,人工容器での培養を開始する時期に関係なく,乳酸カルシウムや卵殻粉末を添加しても胚成長に必要な Ca や Mg が充分吸収されないことが明らかとなった。Avian embryos rely on the eggshell as their source of calcium, and the eggshell supplies about 80% of the calcium required for development and hatching. Therefore, the supply of calcium is a necessary condition for development and hatching in shell-less culture using an artificial vessel. In this study, we measured external measurements, calcium and magnesium contents of Japanese quail embryos cultured in vitro using an artificial vessel. Embryo culture was started from the blastoderm stage and 60 hours after incubation in the intact eggshell. The culture medium was chicken thin albumen supple-mented with 35 mg calcium lactate or 25 mg calcium lactate +10 mg quail eggshell powder. Intact eggs incubated in an incubator were used as control. The embryos were measured, as well as dry body weight, total length, third toe length, eye diameter, beak length, and mineral content at 60, 120, 240, and 360 hours after culture from the blastoderm stage. Calcium and magnesium contents were measured by atomic spectrophotometry. The physical dimension values showed no differences among the groups until 120 hours. At 360 hours of culture, the in vitro culture group showed lower values (p<0.05) compared with the control group for all dimensions except eye diameter. Moreover, in dry weight, total length, and developmental stage, the embryo was the smallest when cultured in vitro at the blastoderm stage, fol-lowed by the embryo cultured in vitro at 60 h, and control group (p<0.05). It was shown that the longer the embryo was cultured in vitro, the smaller was the embryo size. Eye diameter was the smallest (p<0.05) in embryos cultured in vitro from the blastoderm stage. Calcium and magnesium contents did not differ significantly between the groups until 120 hours of culturing. Rapid increase in calcium and magne-sium was observed from 240 to 360 hours, and embryos cultured in vitro had lower content than control embryos (p<0.05). However, no significant difference was observed in the external measurement for the calcium lactate and eggshell powder addition group. The above results revealed that in spite of calcium lactate and eggshell powder addition to the in vitro culture using non air vent artificial vessel, calcium and magnesium were not sufficiently absorbed for embryonic development

Preventive Effects of Collagen-Derived Dipeptide Prolyl-Hydroxyproline against Dexamethasone-Induced Muscle Atrophy in Mouse C2C12 Skeletal Myotubes

Glucocorticoids, commonly used to manage inflammatory diseases, can induce muscle atrophy by accelerating the breakdown of muscle proteins. This research delves into the influence of Prolyl-hydroxyproline (Pro-Hyp), a collagen-derived peptide, on muscle atrophy induced with dexamethasone (DEX), a synthetic glucocorticoid, in mouse C2C12 skeletal myotubes. Exposure to DEX (10 μM) for 6 days resulted in a decrease in myotube diameter, along with elevated mRNA and protein levels of two muscle-atrophy-related ubiquitin ligases, muscle atrophy F-box (MAFbx, also known as atrogin-1) and muscle ring finger 1 (MuRF-1). Remarkably, treatment with 0.1 mM of Pro-Hyp mitigated the reduction in myotube thickness caused by DEX, while promoting the phosphorylation of Akt, mammalian target of rapamycin (mTOR), and forkhead box O3a (Foxo3a). This led to the inhibition of the upregulation of the ubiquitin ligases atrogin-1 and MuRF-1. These findings indicate the potential significance of Pro-Hyp as a promising therapeutic target for countering DEX-induced muscle atrophy

Erucic Acid-Rich Yellow Mustard Oil Improves Insulin Resistance in KK-Ay Mice

Obesity is a major risk factor for some metabolic disorders including type 2 diabetes. Enhancement of peroxisome proliferator-activated receptor (PPAR) &gamma;, a master regulator of adipocyte differentiation, is known to increase insulin-sensitive small adipocytes. In contrast, decreased PPAR&gamma; activity is also reported to improve insulin resistance. We have previously identified erucic acid as a novel natural component suppressing PPAR&gamma; transcriptional activity. In this study, we investigated the effect of erucic acid-rich yellow mustard oil (YMO) on obese/diabetic KK-Ay mice. An in vitro luciferase reporter assay and mesenchymal stem cell (MSC) differentiation assay revealed that 25 &micro;g/mL YMO significantly inhibited PPAR&gamma; transcriptional activity and differentiation of MSCs into adipocytes but promoted their differentiation into osteoblasts. In KK-Ay mice, dietary intake of 7.0% (w/w) YMO significantly decreased the surrogate indexes for insulin resistance and the infiltration of macrophages into adipose tissue. Furthermore, 7.0% YMO increased bone mineral density. These results suggest that YMO can ameliorate obesity-induced metabolic disorders

Collagen-Derived Dipeptide Pro-Hyp Enhanced ATDC5 Chondrocyte Differentiation under Hypoxic Conditions

Chondrocytes are surrounded by a lower oxygen environment than other well-vascularized tissues with higher oxygenation levels. Prolyl-hydroxyproline (Pro-Hyp), one of the final collagen-derived peptides, has been previously reported to be involved in the early stages of chondrocyte differentiation. However, whether Pro-Hyp can alter chondrocyte differentiation under physiological hypoxic conditions is still unclear. This study aimed to investigate whether Pro-Hyp affects the differentiation of ATDC5 chondrogenic cells under hypoxic conditions. The addition of Pro-Hyp resulted in an approximately 18-fold increase in the glycosaminoglycan staining area compared to the control group under hypoxic conditions. Moreover, Pro-Hyp treatment significantly upregulated the expression of SOX9, Col2a1, Aggrecan, and MMP13 in chondrocytes cultured under hypoxic conditions. These results demonstrate that Pro-Hyp strongly promotes the early differentiation of chondrocytes under physiological hypoxic conditions. Therefore, Pro-Hyp, a bioactive peptide produced during collagen metabolism, may function as a remodeling factor or extracellular matrix remodeling signal that regulates chondrocyte differentiation in hypoxic cartilage

Collagen-derived dipeptide prolyl-hydroxyproline promotes osteogenic differentiation through Foxg1

Abstract Prolyl-hydroxyproline (Pro-Hyp) is one of the major constituents of collagen-derived dipeptides. We previously reported that Pro-Hyp promotes the differentiation of osteoblasts by increasing Runx2, osterix and Col1α1 mRNA expression levels. Here, to elucidate the mechanism of Pro-Hyp promotion of osteoblast differentiation, we focus on the involvement of Foxo1 in osteoblast differentiation via Runx2 regulation and the role of Foxg1 in Foxo1 regulation. The addition of Pro-Hyp had no effect on MC3T3-E1 cell proliferation in Foxo1- or Foxg1-knockdown cells. In Foxo1-knockdown cells, the addition of Pro-Hyp increased ALP activity, but in Foxg1-knockdown cells, it had no effect on ALP activity. An enhancing effect of Pro-Hyp on the Runx2 and osterix expression levels was observed in Foxo1-knockdown cells. However, no enhancing effect of Pro-Hyp on osteoblastic gene expression was observed when Foxg1 was knocked down. These results demonstrate that Pro-Hyp promotes osteoblastic MC3T3-E1 cell differentiation and upregulation of osteogenic genes via Foxg1 expression