Cell fragments and collagen structure of cell-free dermal substitutes

The antigenicity of inartificial dermis can be minimized by removing cell components while keeping the intrinsic structures. To minimize the antigenicity, the cell fragments must be wiped off as clearly as possible. Thus, the test of cell fragments is very important for the evaluation of dermal matrix production. And in the process of the production, the structure must be kept integrated to avoid scar formation resulting from breakage. By new methods, we have produced swine acellular dermal matrix （SADM） and goat acellular dermal matrix （GADM） without using glutaraldehyde. In this study, we tested the cell fragments and collagen structure of these two dermal substitutes.

Fabrication of initial trabecular bone-inspired three-dimensional structure with cell membrane nano fragments

The extracellular matrix of trabecular bone has a large surface exposed to the bone marrow and plays important roles such as hematopoietic stem cell niche formation and maintenance.In vitro reproduction of trabecular bone microenvironment would be valuable not only for developing a functional scaffold for bone marrow tissue engineering but also for understanding its biological functions.Herein,we analyzed and reproduced the initial stages of trabecular bone formation in mouse femur epiphysis.We identified that the trabecular bone formation progressed through the following steps:(i)partial rupture of hypertrophic chondrocytes;(ii)calcospherite formation on cell membrane nano fragments(CNFs)derived from the ruptured cells;and(iii)calcospherite growth and fusion to form the initial three-dimensional(3D)structure of trabecular bones.For reproducing the initial trabecular bone formation in vitro,we collected CNFs from cultured cells and used as nucleation sites for biomimetic calcospherite formation.Strikingly,almost the same 3D structure of the initial trabecular bone could be obtained in vitro by using additional CNFs as a binder to fuse biomimetic calcospherites.

CIDE gene expression in adipose tissue,liver,and skeletal muscle from obese and lean pigs

The expression of the cell death-inducing DNA fragmentation factorα-like effector（CIDE）family including Cidea,Cideb,and Cidec was significantly increased in mouse and human models of obesity.However,there was less information on these genes’expression in pigs.Here,we hypothesized that different fat accumulation between lean（Duroc×Landrace×Yorkshire gilts,DLY）and obese（Lantang）pigs was attributed to porcine CIDE-modulating lipid metabolism.Our data showed that Cidea and Cidec were expressed at a high level in adipose tissue,and at a relatively high level in skeletal muscle,whereas Cideb was mainly expressed in the liver in both breeds of pig.Lantang pigs had higher white adipose and skeletal muscle Cidea and Cidec mR NA abundance,and hepatic and muscle Cideb mR NA than DLY pigs.Lipid metabolism-related genes including sterol regulatory element binding protein 1c（SREBP-1c）,hepatocyte nuclear factor-4α（HNF-4α）,peroxisome proliferator-activated receptorγcoactivator-1α（PGC-1α）,fatty acid synthase（FASN）,diacylglycerol O-acyltransferase 1（DGAT1）,and DGAT2 showed a higher expression level in adipose tissue from obese pigs than in that from lean pigs.Lantang pigs exhibited higher mR NA abundance for liver SREBP-1c,HNF-4α,and PGC-1α,and higher skeletal muscle SREBP-1c,HNF-4α,PGC-1α,and DGAT2 expression,as compared with DLY pigs.However,the perlipin2 mR NA levels in adipose tissues,liver,and skeletal muscle were significantly lower in obese pigs than in their lean counterparts.Furthermore,plasma non-esterified fatty acid（NEFA）,glucose,and triacylglycerol（TAG）levels were greater in obese pigs than in lean pigs.Finally,data from correlation analysis further found that CIDE mR NA expression was positively correlated with back fat thickness（BFT）,abdominal fat mass（AFM）,and the levels of NEFA,TAG,and glucose in the two breeds.Collectively,these data revealed that the porcine CIDEs possibly modulated lipid metabolism and contributed to the development of fat deposition and obesity in Lantang pigs.