脂肪间质干细胞修复犬关节软骨损伤的研究

以手术方法建立2对共4处犬关节软骨组织损伤;使用无血清细胞培养液为对照,以标记有绿色荧光蛋白的犬脂肪间充质干细胞进行移植治疗试验。病理模型犬进行常规饲养15周后,对病理模型进行取样并系统检测。结果显示,试验组较对照组有更大面积和体积的新生关节软骨组织。新生软骨样组织呈绿色荧光蛋白(GFP)阳性。试验组与对照组的新生组织HE染色显示,试验组的细胞外基质染色较对照组更加均一,基质切面更加平整光滑。透明软骨的标志性基因COL2a1的免疫荧光染色显示,试验组可见较强的COL2a1阳性染色,而对照组仅有少量微弱的阳性染色。实时荧光定量PCR检测结果显示,试验组的COL2a1含量显著高于对照组(P<0.05)。试验结果表明,直接移植原代犬脂肪间充质干细胞到关节腔可有效修复犬软骨组织缺损,为干细胞治疗临床软骨组织损伤提供了科学依据。

Transcription factor Dmrt1 triggers the SPRY1-NF-κB pathway to maintain testicular immune homeostasis and male fertility

Bacterial or viral infections,such as Brucella,mumps virus,herpes simplex virus,and Zika virus,destroy immune homeostasis of the testes,leading to spermatogenesis disorder and infertility.Of note,recent research shows that SARS-CoV-2 can infect male gonads and destroy Sertoli and Leydig cells,leading to male reproductive dysfunction.Due to the many side effects associated with antibiotic therapy,finding alternative treatments for inflammatory injury remains critical.Here,we found that Dmrt1 plays an important role in regulating testicular immune homeostasis.Knockdown of Dmrt1 in male mice inhibited spermatogenesis with a broad inflammatory response in seminiferous tubules and led to the loss of spermatogenic epithelial cells.Chromatin immunoprecipitation sequencing(ChIP-seq)and RNA sequencing(RNA-seq)revealed that Dmrt1 positively regulated the expression of Spry1,an inhibitory protein of the receptor tyrosine kinase(RTK)signaling pathway.Furthermore,immunoprecipitation-mass spectrometry(IP-MS)and co-immunoprecipitation(Co-IP)analysis indicated that SPRY1 binds to nuclear factor kappa B1(NF-κB1)to prevent nuclear translocation of p65,inhibit activation of NF-κB signaling,prevent excessive inflammatory reaction in the testis,and protect the integrity of the blood-testis barrier.In view of this newly identified Dmrt1-Spry1-NF-κB axis mechanism in the regulation of testicular immune homeostasis,our study opens new avenues for the prevention and treatment of male reproductive diseases in humans and livestock.

Melatonin alleviates heat stress‑induced testicular damage in dairy goats by inhibiting the PI3K/AKT signaling pathway

Current measures mainly focus on how melatonin reduces physiological heat stress in animals,but its effects on reproductive damage to male dairy goats have been neglected.This study aimed to determine the protective effect of melatonin on male reproduction during heat stress in dairy goats and to further explore its mechanisms.A natural heat stress model of Saanen dairy goats was used to assess testicular tissue damage 7days after heat stress and to examine semen quality changes during a spermatogenic cycle.RNA-seq,Western blot,RT–qPCR,and immunofluo-rescence staining were used to explore the mechanism by which melatonin protects against heat stress-induced reproductive damage and to validate the results.The data suggested that melatonin significantly alleviated the heat stress-induced decrease in sperm quality,protected varicose tubule structure,reduced the levels of heat shock proteins and apoptotic proteins and protected the spermatocytes and round spermatozoa,which are mainly affected by heat stress.RNA-seq results suggest that melatonin inhibits the PI3K/AKT signaling pathway,reduces the level of p-AKT,and promotes elevated BCL-2.In addition,melatonin treatment could upregulate the gene expression of MT2 which was downregulated by heat stress and improve the change in extracellular matrix components and restore serum testosterone levels.Our results suggest that melatonin can protect against testicular and spermatogenic cell damage and improve semen quality in male dairy goats under heat stress.This study provides an important reference for subsequent studies on the molecular mechanisms of melatonin in protecting male reproductive processes under heat stress and using exogenous melatonin to prevent heat stress.