[Mechanism of Tougu Xiaotong Capsules in delaying degeneration of osteoarthritis by regulating cholesterol metabolism in chondrocytes through lncRNA MALAT1].

From the perspective of lncRNA MALAT1 regulating cholesterol metabolism in chondrocytes, this paper explores the effect and mechanism of Tougu Xiaotong Capsules(TGXTC) in delaying the degeneration of osteoarthritis. After one week of adaptive feeding, 48(8-week-old) C57BL/6 mice were randomly divided into a blank group(12 mice) and a model group(36 mice) by random number table method. The mice in the model group were anesthetized by inhalation of 5% isoflurane, and the OA model was induced by Hulth method. The experiment randomly divided the mice into a model group(12 mice), a drug-positive group(taururso-deoxycholic acid)(12 mice), and a TGXTC group(12 mice). The drug-positive group was given 500 mg·kg~(-1) taurodeoxycholic acid by intragastric administration. TGXTC group was given TGXTC 368 mg·kg~(-1) by gavage. The blank group and model group were given the same amount of normal saline for four weeks. After the intervention, the mice in each group were killed under anesthesia, and the knee cartilage tissue was separated and collected. The morphologic changes of knee cartilage were observed. The level of lncRNA MALAT1 in the cartilage tissue was detected by real-time PCR. The protein expressions of ABCA1, ApoA1, LXRß, CHOP, and caspase-3 in mouse articular cartilage were detected by Western blot. Lentivirus-coated plasmid was used to transfect mouse chondrocytes with sh-MALAT1. The gene levels of lncRNA MALAT1 in mouse chondrocytes transfected with sh-MALAT1 were detected by real-time PCR. Western blot was used to detect the effect of TGXTC on the protein content of ABCA1, ApoA1, LXRß, CHOP, and caspase-3 in thapsigargin(TG)-induced mouse chondrocytes after lncRNA MALAT1 knockdown. Flow cytometry was used to detect the effect of TGXTC on apoptosis of TG-induced mouse chondrocytes after lncRNA MALAT1 knockdown. The results of HE and saffranine O staining showed that compared with the model group, the structure of the cartilage layer was basically intact; the damage degree of joint structure was significantly improved, and the cartilage matrix was significantly enhanced by saffranine O staining in the TGXTC group and drug-positive group. Compared with the model group, the lncRNA MALAT1 level was significantly decreased in the TGXTC group and drug-positive group. Compared with the model group, the protein content of ABCA1, ApoA1, and LXRß was significantly increased, while that of CHOP and caspase-3 in the TGXTC group and drug-positive group significantly decreased. Compared with the TG group, the lncRNA MALAT1 level in the TG+sh-MALAT1 group was decreased. The lncRNA MALAT1 level in the TG+sh-MA-LAT1+TGXTC group was increased compared with the TG+TGXTC group. Western blot results showed that compared with the model group, protein expressions of ABCA1, ApoA1, LXRß, CHOP, and caspase-3 in the TGXTC group were significantly decreased, after lncRNA MALAT1 knockdown, the regulation and apoptosis of ABCA1, ApoA1, LXRß, CHOP, and caspase-3 in TG-induced mouse chondrocytes were weakened by TGXTC. TGXTC can improve the disorder of cholesterol metabolism in OA chondrocytes and delay OA degeneration, which is closely related to the regulation of lncRNA MALAT1.

A 90-Day Feeding Study in Rats to Assess the Safety of Genetically Engineered Pork.

Our laboratory recently produced genetically engineered (GE) Meishan pigs containing a ZFN-edited myostatin loss-of-function mutant. These GE pigs develop and grow as normal as wild type pigs but produce pork with greater lean yield and lower fat mass. To assess any potential subchronic toxicity risks of this GE pork, a 90-day feeding study was conducted in Sprague-Dawley rats. Rats were randomly divided into five groups, and fed for 90 days with basic diet and basic diets formulated with low dose and high dose pork prepared from wild type pigs and GE pigs, respectively. Animal behaviors and clinical signs were monitored twice daily, and body weight and food consumption were measured and recorded weekly. At days 45 and 90, blood tests (lipid panel, electrolytes, parameters related to liver and kidney functions, and complete blood counts) were performed. Additionally, gross pathology and histopathological analyses were performed for major organs in each group. Data analysis shows that there were no significant differences in growth rate, food consumption, and blood test parameters between rat groups fed with GE pork and wild type pork. Although differences in some liver function parameters (such as aspartate aminotransferase, total proteins, albumin, and alkaline phosphatase) and white blood cell counts (such as lymphocyte percentage and monocyte percentage) were observed between rats fed with high dose GE pork and basic diet, all test results in rats fed with GE pork are in the normal range. Additionally, there are no apparent lesions noted in all organs isolated from rats in all five feeding groups on days 45 and 90. Overall, our results clearly indicate that food consumption of GE pork produced by ZFN-edited myostatin loss-of-function mutant pigs did not have any long-term adverse effects on the health status in rats.