PubMed · 4281374
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M G Giro, A Peserico, D Volpin. 1974. Collagen and elastin in scleroderma.. https://doi.org/10.3109/03008207409152260
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Decellularized tissues provide biological cues owing to the wealth of structural and regulatory factors that promote angiogenesis, adipogenesis, and myogenesis and facilitate neurite outgrowth. Here, we demonstrated the advantages of decellularized adipose tissue (adipoECM) over defined collagen-based biomaterials for host tissue integration. Three batches of human adipose tissue were decellularized using a rapid decellularization protocol and analyzed using mass spectrometry. To assess the biological activity of the decellularized materials, adipoECM and a reference standard of care biomaterial (Integra®DRT, also containing collagen I and glycosaminoglycans) were implanted subcutaneously, but far from the wound bed (in anatomical potential spaces) of immunocompetent BALB/c mice. The mice were euthanized in the acute (1 day) and chronic (day 60) inflammatory reaction phases, followed by biomaterial excision and Masson’s trichrome immunohistofluorescence imaging of the paraffin-embedded specimens. Each batch of processed tissue passed a quality control check, showing a low level of donor genomic DNA, lack of nuclei, lipids, endotoxins, and bacterial contamination. Mass spectrometry revealed that all batches of decellularized tissue mainly contained collagen I and, to a lesser degree, collagen III, collagen IV, collagen V, laminin, fibrillin, fibronectin, tenascin, and elastin. No acute inflammatory reaction was observed in either material one day post-transplantation. At 60 days post-implantation, different cell types were detected in adipoECM specimens, whereas Integra®DRT remained acellular. Additional immunohistochemical staining of adipoECM revealed CD31-positive cells in the blood vessels. Mesenchymal (CD90 positive) and myeloid (CD14 positive) cells were also detected. Primary cell types involved in soft tissue healing and remodeling were found in the adipoECM-treated group. The ingrowth of blood vessels and mesenchymal cells confirmed the effective integration of adipoECM with host tissues. Our results demonstrate that decellularized adipose tissue implanted away from the wound bed possesses contextual biological activities that promote efficient integration with host tissues.
In 2001, samples of liver (n = 38) and perirenal fat (n = 25) (only in males) were taken from European roe deer (Capreolus capreolus) populating a hilly, wooded protected area in the Emilia-Romagna region of Northern Italy. Samples were analyzed for organochlorine pesticides dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), hexachlorocycloexane alpha-, beta- and gamma-isomers (alpha-, beta- and gamma-HCH), alpha-endosulfan, aldrin, dieldrin and endrin, and the seven PCB 'indicator' congeners IUPAC Nos. 28, 52, 101, 118, 138, 153 and 180, in order to investigate the current state of contamination of the area and to assess the possible toxicological risks for the monitored species. p,p'-DDE was detected in 95% of the liver and perirenal fat samples (n = 63), at concentrations ranging from < dl to 629.3 ng/g lipid weight, which were much higher than those found for HCB and gamma-HCH. The concentrations of the other measured organochlorine pesticides and metabolites were below the detection limit in all the samples. PCBs were found in 97% of the liver and perirenal fat samples, at total levels ranging between < dl to 414.5 ng/g lipid weight. The hepta- and hexa-chlorinated congeners 180, 153 and 138 were predominant and comprised more than 70% of the total seven PCBs in both the liver and perirenal fat samples. In the male roe deer, significantly higher concentrations of HCB, p,p'-DDE and PCBs were found in the liver than in the perirenal fat (P < 0.001). Hepatic levels of p,p'-DDE and PCBs were significantly higher in males than in females (P < 0.05 and P < 0.001, respectively). No significant differences in organochlorine concentrations were observed between juvenile and adult males in either tissue sample (P > 0.05). Females were not statistically tested because they were all adults. The levels of organochlorine contaminants were well below those associated with adverse reproductive effects and lethality in mammals.
The expression of SREBP-1 (sterol-regulatory-element-binding protein-1) isoforms differs between tissues and cultured cell lines in that SREBP-1a is the major isoform in established cell lines, whereas SREBP-1c predominates in liver and most other human tissues. SREBP-1c is transcriptionally less active than SREBP-1a, but is a main mediator of hepatic insulin action and is selectively up-regulated by LXR (liver X receptor) agonists. LXR-mediated transactivation is co-activated by PGC-1alpha (peroxisome-proliferator-activated receptor-gamma co-activator-1alpha), which displays deficient expression in skeletal-muscle-derived cell lines. In the present paper, we show that PGC-1alpha expression is also deficient in HepG2 cells and in a human brown adipocyte cell line (PAZ6). In transient transfection studies, PGC-1alpha selectively amplified the LXR-mediated transcription from the human SREBP-1c promoter in HepG2 and PAZ6 cells via two LXR-response elements with extensive similarity to the respective murine sequence. Mutational analysis showed that the human LXR-response element-1 (hLXRE-1) was essential for co-activation of LXR-mediated SREBP-1c gene transcription by PGC-1alpha. Ectopic overexpression of PGC-1alpha in HepG2 cells enhanced basal SREBP-1c and, to a lesser extent, -1a mRNA expression, but only SREBP-1c expression was augmented further in an LXR/RXR (retinoic X receptor)-dependent fashion, thereby inducing mRNA abundance levels of SREBP-1c target genes, fatty acid synthase and acetyl-CoA carboxylase. These results indicate that PGC-1alpha contributes to the regulation of SREBP-1 gene expression, and can restore the SREBP-1 isoform expression pattern of HepG2 cells to that of human liver.