Prolyl and lysyl hydroxylases in collagen synthesis

Collagens are the most abundant proteins in the extracellular matrix. They provide a framework to build organs and tissues and give structural support to make them resistant to mechanical load and forces. Several intra‐ and extracellular modifications are needed to make functional collagen molecules, intracellular post‐translational modifications of proline and lysine residues having key roles in this. In this article, we provide a review on the enzymes responsible for the proline and lysine modifications, that is collagen prolyl 4‐hydroxylases, 3‐hydroxylases and lysyl hydroxylases, and discuss their biological functions and involvement in diseases.     

不同照射方式下核黄素-A波紫外线兔巩膜胶原交联术对兔巩膜成纤维细胞生物力学特性的影响

目的　研究不同照射方式下核黄素-A波紫外线兔巩膜胶原交联术对兔巩膜成纤维细胞生物力学特性的影响。方法　取健康新西兰大白兔24只，随机将兔平均分为A、B两组，每组选取左眼为实验眼，右眼为对照眼。麻醉后暴露左眼鼻上方巩膜。在该处巩膜滴加5-磷酸核黄素5 min后，用波长为370 nm的紫外线灯照射。A组的照射时间为30 min，能量密度为3.0 mW·cm^-2；B组的照射时间为9 min，能量密度为10.0 mW·cm^-2。照射期间，每2 min滴加1次5-磷酸核黄素溶液，以保持巩膜的湿润。术后60 d，处死实验兔，培养实验眼交联部位及对照眼相应部位的巩膜成纤维细胞，用细胞微管吸吮实验检测巩膜成纤维细胞的杨氏模量、表观黏性。结果　A、B两组实验眼巩膜细胞的杨氏模量、表观黏性均较各自对照眼显著增强，差异均有统计学意义（均为P＜0.05）；而A、B两组实验眼间、及对照眼间巩膜细胞的杨氏模量、表观黏性差异无统计学意义（均为P＞0.05）。以上结果表明，交联术后巩膜细胞的黏弹性发生了明显的变化，黏弹性显著升高。而两种照射方式之间巩膜细胞的黏弹性无显著差异。结论　两种不同的照射方式，均能使巩膜成纤维细胞的生物力学性能发生显著增强，而两种照射方式之间并未见明显的差别。     

In silico repurposing the Rac1 inhibitor NSC23766 for treating PTTG1-high expressing clear cell renal carcinoma

The pituitary tumor-transforming gene 1 (PTTG1), also known as Securin, is considered an oncogene. This study aimed to investigate the role of PTTG1 in clear cell renal cell carcinoma (ccRCC) using in silico bioinformatics approaches. A pan-cancer analysis using The Cancer Genome Atlas (TCGA) data indicated that among all cancer types copy number amplification of PTTG1 gene was most frequently found in ccRCC. However, amplification of PTTG1 gene copy number did not correlate with the increase of mRNA level in ccRCC, and did not predict the patients' overall survival. Instead, ccRCC was correlated with overexpression of PTTG1 mRNA, and its expression level was stage-dependent increased in cancer patients. An outlier analysis using the Oncomine database suggested that PTTG1 mRNA expression served as a good biomarker for ccRCC. Pathway analysis for upregulated genes enriched in PTTG1-high expressing ccRCC patients found that PTTG1 overexpression was associated with mitotic defects. Mining drug sensitivity data using the Cancer Therapeutics Response Portal (CTRP) discovered that PTTG1-high expressing ccRCC cell lines were susceptible to a Rac1 (Ras-related C3 botulinum toxin substrate 1) inhibitor NSC23766. Therefore, this study provides an in silico insight into the role of PTTG1 in ccRCC, and repurposes the Rac1 inhibitor NSC23766 for treating PTTG1-high expressing ccRCC.     

Tumor‐associated macrophages promote bladder tumor growth through PI3K/AKT signal induced by collagen

The tumor microenvironment is associated with various tumor progressions, including cancer metastasis, immunosuppression, and tumor sustained growth. Tumor‐associated macrophages (TAMs) are considered an indispensable component of the tumor microenvironment, participating in the progression of tumor microenvironment remodeling and creating various compounds to regulate tumor activities. This study aims to observe enriched TAMs in tumor tissues during bladder cancer development, which markedly facilitated the proliferation of bladder cancer cells and promoted tumor growth in vivo. We determined that TAMs regulate tumor sustained growth by secreting type I collagen, which can activate the prosurvival integrin α2β1/PI3K/AKT signaling pathway. Furthermore, traditional chemotherapeutic drugs combined with integrin α2β1 inhibitor showed intensive anticancer effects, revealing an innovative approach in clinical bladder cancer treatment.     

桑根酮C对博莱霉素诱导小鼠肺纤维化改善作用及机制研究

目的观察桑根酮C对博莱霉素诱导的小鼠肺纤维化的影响,并探讨其可能的作用机制。方法 C57BL/6小鼠随机分为4组,即假手术组、模型组和桑根酮C(100、50 mg/kg)组,每组20只。假手术组小鼠气管内注射生理盐水,模型组小鼠气管内注射博莱霉素诱导肺纤维化模型。术后第4天开始给药,连续给药28d后检测小鼠呼吸功能;检测肺内羟脯氨酸含量;HE染色观察肺内炎症表现;Masson染色观察肺内胶原活性;免疫组化法检测肺内转化生长因子-β1(TGF-β1)蛋白表达量;免疫蛋白印迹法检测肺内α平滑肌肌动蛋白(α-SMA)、核转录因子-κB p65(NF-κB p65)、磷酸化的核转录因子-κB p65(p-NF-κB p65)、Ⅰ型胶原和Ⅲ型胶原表达量。结果与模型组比较,桑根酮C能够改善经博莱霉素诱导形成肺纤维化后小鼠的呼吸功能,能够明显降低肺内羟脯氨酸含量,明显减轻肺内炎症和胶原沉积,肺内TGF-β1、α-SMA、NF-κBp65、p-NF-κBp65、Ⅰ型胶原和Ⅲ型胶原蛋白表达量明显降低。结论桑根酮C能够明显改善博莱霉素诱导小鼠肺纤维化,改善呼吸功能,其机制可能与抑制TGF-β1过表达和降低炎症转录因子NF-κB及磷酸化表达有关。     

Optimization of immunohistochemical detection of collagen type II in osteochondral sections by comparing decalcification and antigen retrieval agent combinations

Bone containing tissues such as osteochondral joint are resistant to routine tissue processing, therefore require decalcification. This technique causes removal of mineral salts, but in the process may macerate the organic tissue, hence the need for tissue fixation. Such severe processing demands careful antigen retrieval to necessitate optimal staining. The aim of our study was to compare five different antigen retrieval protocols (heat retrieval and protein digestion) following decalcification of rabbit knee joints using two different techniques (20% formic acid and 10% ethylenediamine-tetra acetic acid: EDTA). Osteochondral sections were compared based on time required for decalcification, ease of sectioning, morphological integrity using HE staining and antigen preservation (Collagen type II) using immunohistochemistry. The two decalcification solutions did not impair the tissue morphology and ease of sectioning. Joints processed with formic acid decalcified four times faster than EDTA. Among the five antigen retrieval approaches, maximal collagen II uptake with minimal nonspecific staining was found with protein digestion (pronase and hyaluronidase) in both formic acid and EDTA sections. For osteo-chondral sections, we recommend using 10% EDTA for decalcification and pronase plus hyaluronidase for antigen retrieval if maintaining tissue morphology is crucial, whereas if time is of the essence, 20% FA with pronase plus hyaluronidase is the faster option while still preserving structural integrity. Clin. Anat. 33:343–349, 2020. © 2019 Wiley Periodicals, Inc.