Characterization of Sox9‐overexpressing human umbilical cord blood‐derived mesenchymal stem cells‐based engineered cartilage both in vitro and in vivo

Abstract

The source of seed cells is a critical factor for tissue engineering. The goal of this study was to evaluate the chondrogenesis of Sox9-overexpressing human umbilical cord mesenchymal stem cells (hUCMSCs) seeded onto bone matrix gelatin (BMG)/fibrin hybrid scaffolds both in vitro and in vivo. hUCMSCs were stably transfected with Sox9-expressing plasmid and grown on the three-dimensional BMG/fibrin hybrid scaffold for 8 weeks. Scanning electron microscopy and histochemistry were performed. The hUCMSC-loaded scaffolds were implanted into the subcutaneous layer of immunocompetent rats and chondrogenesis and host immune responses were monitored for 8 weeks. We found that hUCMSCs spread well and proliferated from 2 weeks after culturing. They produced abundant glycosaminoglycans and collagen II. At 8 weeks after implanting into rats, the hUCMSCs on the scaffolds formed cartilage-like tissue and displayed positive staining for toluidine blue, safranin O, Masson's trichrome, and collagen II. No significant changes in serum levels of lgG, lgA, lgM, C3, and C4 were observed after implantation of the hUCMSC-loaded scaffolds. Xenogeneic implantation of Sox9-overexpressing hUCMSCs embedded in the BMG/fibrin scaffolds promotes the formation of cartilage-like tissue without inducing evident host immune response. Therefore, Sox9-overexpressing hUCMSCs represent a promising cell candidate for cartilage tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1150-1155, 2017.

Tendon microstructural disruption promotes tendon‐derived stem cells to express chondrogenic genes by activating endoplasmic reticulum stress

“…ATF‐4 could directly bind to the putative motif region on the SOX9 promoter, which transcriptionally activated the expression of SOX9 27,28 . SOX9 is a cartilage‐specific transcription factor and implicates in the expression of cartilage‐related genes including aggrecan and collagen II 29 . Overexpression of SOX9 induces chondrogenic differentiation of stem cells 30 …”

“…27,28 SOX9 is a cartilage-specific transcription factor and implicates in the expression of cartilage-related genes including aggrecan and collagen II. 29 Overexpression of SOX9 induces chondrogenic differentiation of stem cells. 30 We hypothesized that the tendon microdamage could trigger ER stress and subsequently promoted chondrogenic gene expression through ATF-4.…”

Construction of tissue-engineered cartilage with different biological scaffolds in vitro

“…12 The degradation products showed no toxic or side effects on the human body. [21][22] However, due to poor hydrophilia and low degradation velocity of pure chitosan material, it is challenging to meet the requirements of tissue engineering. Many scholars attempted to combine chitosan material with various materials and obtained favorable results.…”

An in vivo comparative study of the gelatin microtissue‐based bottom‐up strategy and top‐down strategy in bone tissue engineering application

“…Then, specimens were suffered from a graded series of ethanol for dehydration and embedded in paraffin, sectioned to 5 μm. Finally, sections were stained with hematoxylin and eosin (H&E; Sigma) and Masson's Trichrome (Sigma) to examine the morphology of tissue and formation of new bone …”

“…Finally, sections were stained with hematoxylin and eosin (H&E; Sigma) and Masson's Trichrome (Sigma) to examine the morphology of tissue and formation of new bone. 23 CD31 staining. Sections were incubated with primary antibodies against CD31 and horseradish peroxidase-conjugated anti-rat secondary antibody (1:200 in PBS containing 1% bovine serum albumin, Santa Cruz), followed by diaminobenzidine tetrahydrochloride to achieve color development.…”