Beyond protein synthesis: non-translational functions of threonyl-tRNA synthetases.

Aminoacyl-tRNA synthetases (AARSs) play an indispensable role in the translation of mRNAs into proteins. It has become amply clear that AARSs also have non-canonical or non-translational, yet essential, functions in a myriad of cellular and developmental processes. In this mini-review we discuss the current understanding of the roles of threonyl-tRNA synthetase (TARS) beyond protein synthesis and the underlying mechanisms. The two proteins in eukaryotes - cytoplasmic TARS1 and mitochondrial TARS2 - exert their non-canonical functions in the regulation of gene expression, cell signaling, angiogenesis, inflammatory responses, and tumorigenesis. The TARS proteins utilize a range of biochemical mechanisms, including assembly of a translation initiation complex, unexpected protein-protein interactions that lead to activation or inhibition of intracellular signaling pathways, and cytokine-like signaling through cell surface receptors in inflammation and angiogenesis. It is likely that new functions and novel mechanisms will continue to emerge for these multi-talented proteins.

Sex differences in skeletal muscle size, function, and myosin heavy chain isoform expression during post-injury regeneration in mice.

Skeletal muscle regeneration is an essential process to restore muscle function after injury and is influenced by various factors. Despite the known importance of sex hormones in muscle regeneration, whether and what sex difference exists in this process is still unclear. In this study, we provide evidence for a clear sex difference in muscle regeneration in mice. At 7 and 14 days after barium chloride-induced muscle injury, female mice showed a faster recovery of muscle fiber size than males. Consistently, muscle force in female mice was restored faster than in males after injury, and this functional difference was maintained at 14 months of age when regenerative capacity declined. Myosin heavy chain isoform profiling and fatigability test revealed dynamic remodeling of myosin heavy chain isoform expression including a type IIB to IIA/X MHC transition and reduced fatigability in regenerated muscles compared to uninjured muscles. A significant sex difference was detected in myosin heavy chain IIX content, although this did not lead to different fatigability. Together, our results suggest that sex is an important determinant of the recovery of regenerating skeletal muscle and is partially involved in the remodeling of myosin heavy chain isoforms during muscle regeneration.

In ovo inoculation of duck embryos with different strains of Bacillus cereus to analyse their synergistic post-hatch anti-allergic potentialities.

BACKGROUND: Bacillus cereus is a Gram-positive, facultative anaerobic bacteria with few strains reported to be used as probiotics for animals and birds in recent times if the doses are formulated properly. OBJECTIVES: To analyse the synergistic anti-allergic potentiality of different Bacillus cereus strains on experimental in ovo and in vitro duck model, as probiotic immune stimulant. MATERIALS AND METHODS: Different strains of Bacillus cereus from 29 isolates were identified through 16S rRNA gene sequencing from the milk samples of buffalo breeds of South Asia. The probiotic properties were tested in aspects of gram staining, catalase test, coagulase, test, bile salt tolerance, pH tolerance and phenol tolerance test. MIC50 and MIC90 levels were profiled using nine different antibiotics, and antimicrobial activity against eight different enteric pathogens was assessed. Finally, the test strains of Bacillus cereus (Colony Forming Unit [CFU] 30X1011 ) were combined-infused at different concentrations in embryonated duck eggs to assess the post-hatch anti-allergic effects against histamine-induced allergic reaction and their immunoglobulin E (IgE) level was tested. RESULTS: Molecular identification confirmed the test strains as B. cereus HKS 1-1, B. cereus LOCK 1,002 and B. cereus BF2, which were all motile, spore-forming, catalase-positive and rod-shaped. All were 0.3% bile salt, 0.4% phenol and pH tolerant. Two-way ANOVA test P values revealed that B. cereus BF2 was statistically significant (p < .0014) in bile salt tolerance test. B. cereus HKS 1-1 was significant in phenol and pH tolerance at p < .0002 and p < .0489, respectively. Besides, the test strains showed antibiotic sensitivity and antimicrobial activity to different enteric pathogens. In vivo model referred the test strains as effective in partial allergy reduction at same CFU but at different concentrations with p < .0001 among the groups. CONCLUSION: The isolated and characterized strains of B. cereus showed partial immune-stimulating potentiality against experimentally induced allergic reaction.

Antidiarrheal Efficacy of Probiotic Bacteria in Castor Oil Induced Diarrheal Mice.

Probiotics may offer a safe intervention for diarrheal diseases. The aim of the present study was the assessment of the antidiarrheal property of probiotic bacteria. For their antidiarrheal efficacy assessment, yogurt was prepared using the isolated bacteria from selective regional yogurt of Bangladesh, and mice model trails were conducted using castor oil induced diarrheal mice. The probiotic treatment was applied on three mice groups, each having 6 mice and their respective doses were 50 mL/kg body weight in treatment group (TG) 1, 100 mL/kg body weight in TG2, and 150 mL/kg body weight in TG3. A four week treatment of probiotic significantly (P<0.001) reduced the percentage (67.37%) of diarrhea in TG3 (150 mL yogurt/kg body weight). All the treatment groups showed a significant (P<0.001) increase in the latent periods, reduced the total fecal output, and frequency and fecal water content compared to the negative control group. Serum electrolytes (Na+ and K+) and total protein levels were higher in the TG3 compared to the negative control group. Further research regarding molecular characterization and identification of specific genes and proteins of interest may help to develop the next generation bacteriocins and antidiarrheal drugs.