Comprehensive analysis of histophysiology, transcriptome and metabolome tolerance mechanisms in black porgy (Acanthopagrus schlegelii) under low temperature stress

Low temperature stress has adverse effects on fish growth and reproduction, causing huge economic losses to the aquaculture industry. Especially, black porgy (Acanthopagrus schlegelii) farming industry in north of Yangtze River has been severely affected by low temperature for a long time. To explore the tolerance mechanism of black porgy to low temperature stress, the experiment was designed. The liver and gill tissues of black porgy were taken from the water temperature point of 15 °C (control group named as CG), 3.8 °C (cold sensitive group named as CS) and 2.8 °C (cold tolerant group named as CT) with a cooling rate of 3 °C/d from 15 °C for histophysiology, transcriptomics and metabolomics analysis. After cold stress, the histological results showed that the nucleus of the black porgy liver tissue appeared swelling, the cell arrangement was disordered; meanwhile the gill lamellae were twisted and broken, the epidermis was detached and aneurysm appeared. In addition, the expression of antioxidant, glucose metabolism and immune-related enzymes in the liver and gill of black porgy also changed significantly after low temperature stress. By analyzing the transcriptome and metabolome dates of black porgy liver, 3474 differentially expressed genes (DEGs) and 689 differentially expressed metabolites (DEMs) involved in low temperature stress were identified, respectively. The results of the transcriptome and metabolome combined analysis showed that individuals in the CS group mainly supplied energy to the body through lipid metabolism and amino acid metabolism, and meanwhile the apoptosis pathway was activated. While, individuals in the CT group mainly through glucose metabolism and steroid hormone biosynthesis to supply energy for the body. The validation results of qPCR on eight functional genes further demonstrated the reliability of RNA-Seq data. In summary, the results provide molecular information about adaptation to climate change and genetic selection of black porgy.

Melatonin associated with a high-fat diet during pregnancy and lactation prevents liver changes in the offspring

In the present study, we set out to determine whether melatonin combined with a high-fat diet during pregnancy and lactation can prevent liver disorders in offspring. Forty rats were divided into four groups: DC - pregnant rats submitted to the standard diet; DC + Mel - pregnant rats submitted to the standard diet combined with melatonin; HFD - pregnant rats submitted to a high-fat diet; HFD + Mel - pregnant rats submitted to a high-fat diet combined with melatonin. Morphophysiological and biochemical parameters were analyzed. Melatonin (5 mg/kg) was administered intraperitoneally. The HFD group offspring showed an increase in AST, ALT, alkaline phosphatase, cholesterol, triglycerides, LDL and glucose levels, and a reduction in HDL and lipase levels. In the liver obseved steatosis, hepatocellular ballooning, increased lobular parenchyma and reduced non-lobular parenchyma, beside reduced liver glycogen and fibrosis. These changes were not observed in the HFD + Mel group. In conclusion, melatonin combined with a high-fat diet preserves the liver architecture and function in the offspring.

The urothelium: anatomy, review of the literature, perspectives for veterinary medicine

Over time, much knowledge has been accumulated about the active role of the urothelium, principally in rodents and human. Far from being a mere passive barrier, this specialized epithelium can alter the ion and protein composition of the urine, is able to sense and respond to mechanical stimuli such as pressure, and react to mechanical stimuli by epithelial cell communication with the nervous system. Most of the specialized functions of the urothelium are linked to a number of morpho-physiologic properties exhibited by the superficial umbrella cells, including specialized membrane lipids, asymmetric unit membrane particles and a plasmalemma with stiff plaques which function as a barrier to most substances found in urine, thus protecting the underlying tissues. Moreover, the entire mucosa lining the low urinary tract, composed of urothelium and sub-urothelium, forms a functional transduction unit, able to respond to eso- and endogenous physical and chemical stimuli in a manner assuring an adequate functional response. This review will summarize the available information on each area of inquiry from a morpho-functional point of view. Possible considerations pertaining to species of veterinary interest are reviewed as well. The review was prepared consulting the electronic databases PubMed and Cab Abstracts and retrieving all pertinent reports and the relative reference lists, in order to identify any potential additional studies that could be included. Full-length research articles and thematic reviews were considered. Information on the urothelium of some domestic animal species was also included.