Analysis of the differential expression profile of miRNAs in myocardial tissues of rats with burn injury

Reduced Expression of miR-146a Potentiates Intestinal Inflammation following Alcohol and Burn Injury

MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively regulate gene expression. Within the intestinal epithelium, miRNAs play a critical role in gut homeostasis, and aberrant miRNA expression has been implicated in various disorders associated with intestinal inflammation and barrier disruption. In this study, we sought to profile changes in intestinal epithelial cell miRNA expression after alcohol and burn injury and elucidate their impact on inflammation and barrier integrity. Using a mouse model of acute ethanol intoxication and burn injury, we found that small intestinal epithelial cell expression of miR-146a is significantly decreased 1 d following injury. Using in vitro studies, we show that reduced miR-146a promotes intestinal epithelial cell inflammation by promoting p38 MAPK signaling via increased levels of its target TRAF6 (TNFR-associated factor 6). Furthermore, we demonstrate that in vivo miR-146a overexpression significantly inhibits intestinal inflammation 1 d following combined injury and potentially supports intestinal barrier homeostasis. Overall, this study highlights the important impact that miRNA expression can have on intestinal homeostasis and the valuable potential of harnessing aberrant miRNA expression as a therapeutic target to control intestinal inflammation.

Significant role of some miRNAs as biomarkers for the degree of obesity

BACKGROUND

Obesity is one of the most serious problems over the world. MicroRNAs have developed as main mediators of metabolic processes, playing significant roles in physiological processes. Thus, the present study aimed to evaluate the expressions of (miR-15a, miR-Let7, miR-344, and miR-365) and its relationship with the different classes in obese patients.

METHODS

A total of 125 individuals were enrolled in the study and classified into four groups: healthy non-obese controls (n = 50), obese class I (n = 24), obese class II (n = 17), and obese class III (n = 34) concerning body mass index (BMI < 30 kg/m2, BMI 30-34.9 kg/m2, BMI 35-39.9 kg/m2 and BMI ≥ 40 kg/m2, respectively). BMI and the biochemical measurements (fasting glucose, total cholesterol, triglycerides, HDL and LDL, urea, creatinine, AST, and ALT) were determined. The expressions of (miR-15a, miR-Let7, miR-344, and miR-365) were detected through quantitative real-time PCR (RT-qPCR).

RESULTS

There was a significant difference between different obese classes and controls (P < 0.05) concerning (BMI, TC, TG, HDL, and LDL). In contrast, fasting glucose, kidney, and liver functions had no significant difference. Our data revealed that the expression of miR-15a and miR-365 were significantly associated with different obese classes. But the circulating miR-Let7 and miR-344 were not significantly related to obesity in different classes.

CONCLUSION

Our study indicated that miR-15a and miR-365 might consider as biomarkers for the obesity development into different obese classes. Thus, the relationship between regulatory microRNAs and disease has been the object of intense investigation.

miR-31, miR-155, and miR-221 expression profiles and their association with graft skin tolerance in a syngeneic vs. allogeneic murine skin transplantation model

Grafting is the gold standard for the treatment of severe skin burns. Frequently, allogeneic tissue is the only transient option for wound coverage, but their use risks damage to surrounding tissues. MicroRNAs have been associated with acute rejection of different tissues/organs. In this study, we analyzed the expression of miR-31, miR-155, and miR-221 and associate it with graft tolerance or rejection using a murine full-thickness skin transplantation model. Recipient animals for the syngeneic and allogeneic groups were BALB/c and C57BL/6 mice, respectively; donor tissues were obtained from BALB/c mice. After 7 days post-transplantation (DPT), the recipient skin and grafts in the syngeneic group maintained most of their structural characteristics and transforming growth factor (TGF)β1 and TGFβ3 expression. Allografts were rejected early (Banff grades II and IV at 3 and 7 DPT, respectively), showing damage to the skin architecture and alteration of TGFβ3 distribution. miRNAs skin expression changed in both mouse strains; miR-31 expression increased in the recipient skin of syngeneic grafts relative to that of allogeneic grafts at 3 and 7 DPT (p < 0.05 and p < 0.01, respectively); miR-221 expression increased in the same grafts at 7 DPT (p < 0.05). The only significant difference between donor tissues was observed for miR-155 expression at 7 DPT which was associated with necrotic tissue. Only miR-31 and miR-221 levels were increased in the blood of BALB/c mice that received syngeneic grafts after 7 DPT. Our data suggest that local and systemic miR-31 and miR-221 overexpression are associated with graft tolerance.