Identification and validation of putative biomarkers by in silico analysis, mRNA expression and oxidative stress indicators for negative energy balance in buffaloes during transition period

OBJECTIVE

Transition period is considered from 3 weeks prepartum to 3 weeks postpartum, characterized with dramatic events (endocrine, metabolic, and physiological) leading to occurrence of production diseases (negative energy balance/ketosis, milk fever etc). The objectives of our study were to analyze the periodic concentration of serum beta-hydroxy butyric acid (BHBA), glucose and oxidative markers along with identification, and validation of the putative markers of negative energy balance in buffaloes using in-silico and quantitative real time-polymerase chain reaction (qRT-PCR) assay.

METHODS

Out of 20 potential markers of ketosis identified by in-silico analysis, two were selected and analyzed by qRT-PCR technique (upregulated; acetyl serotonin o-methyl transferase like and down regulated; guanylate cyclase activator 1B). Additional two sets of genes (carnitine palmotyl transferase A; upregulated and Insulin growth factor; downregulated) that have a role of hepatic fatty acid oxidation to maintain energy demands via gluconeogenesis were also validated. Extracted cDNA (complementary deoxyribonucleic acid) from the blood of the buffaloes were used for validation of selected genes via qRTPCR. Concentrations of BHBA, glucose and oxidative stress markers were identified with their respective optimized protocols.

RESULTS

The analysis of qRT-PCR gave similar trends as shown by in-silico analysis throughout the transition period. Significant changes (p<0.05) in the levels of BHBA, glucose and oxidative stress markers throughout this period were observed. This study provides validation from in-silico and qRT-PCR assays for potential markers to be used for earliest diagnosis of negative energy balance in buffaloes.

CONCLUSION

Apart from conventional diagnostic methods, this study improves the understanding of putative biomarkers at the molecular level which helps to unfold their role in normal immune function, fat synthesis/metabolism and oxidative stress pathways. Therefore, provides an opportunity to discover more accurate and sensitive diagnostic aids.

Comparison of toxic reaction of Tripterygium wilfordii multiglycoside in normal and adjuvant arthritic rats

AIM OF THE STUDY

Tripterygium wilfordii multiglycoside (GTW), an authorized Chinese patent drug, is used for treatment of rheumatoid arthritis and other immune disease. This study was to determine whether GTW induced different toxic reactions in adjuvant arthritis rats (AA rats) compared to those in normal rats.

MATERIALS AND METHODS

To prepare arthritic rat model, male Sprague-Dawley (SD) rats were immunized by injecting complete Freund's Adjuvant into right hind footpad. And then, GTW was given to rats intragastrically at dosage of 7 or 105 mg kg(-1)day(-1) from day 15 to day 28 after immunization. Routine clinical parameters and histopathologic changes of liver, kidney and testis were examined. Metabolic profiling in serum of groups was analyzed by LC-MS. A principal component analysis (PCA) and partial-least-squares discriminate analysis (PLS-DA) were carried out combined with mass spectrometry (MS) data set. All the quantitative data were performed by two-way ANOVA analysis following Student's t-test.

RESULTS AND CONCLUSIONS

Treatment with GTW at both doses could diminish the right and left hind paws swelling. There was slight lipoid degeneration in hepatic tissue of normal rats treated by high dose of GTW, but there were not distinctly pathological changes in hepatic tissue of AA rats treated by GTW. Compared normal rats administered with GTW, no statistically significant difference in the serum alanine aminotransferase (ALT), creatinine (CRE), and blood urea nitrogen (BUN) levels were observed. However, the serum aspartate aminotransferase (AST) level was significant decreased in AA rats under exposure GTW compared with normal rats in the same conditions (p<0.05), which indicated that GTW could offer a different liver toxic reaction in normal and AA rats. The metabolic analysis showed that a clear separation of PCA and PLS-DA score spot in normal rats, but not separation was seen in AA rats perturbed with low dosage GTW. The result indicated low dosage GTW might arouse a general toxic in normal rats but not in AA rats. The biomarker analysis showed that the level of lysophosphatidylcholines (LPCs) was down-regulated, but the level of ursodeoxycholic acid (UDCA) and chenodexycholic acid (CDCA) was up-regulated in AA rats compared with normal rats under exposure GTW. According to pathway analysis of metabolic markers, we conceived that LPC, UDCA and CDCA were the critical intermediates of choline and fatty acid metabolism. And the lipid metabolism was a correlative outcome of GTW induced toxicity in the liver in physiological condition animals. Taken together, GTW could induce different toxic reactions between normal and AA rats, and the lipid metabolism might be part of the mechanism for the hepatic lipidosis or the other liver injury.