[Expression of transcription factor SOX5 in human semen].

Objective: To study and analyze the transcript and expression pattern of SOX5 in human semen, thus to provide evidence for exploring the role of transcription factor SOX5 in the process of spermatogenesis in testis. Methods: A total of 61 semen samples and 3 blood samples (as controls) collected from healthy volunteer donors at Shanghai Human Sperm Bank in September 2015 were randomly selected. Expression of SOX5 in the semen samples was detected and quantified using agarose gel electrophoresis and real time-quantitative PCR (RT-qPCR) analysis. Results: In the human semen samples, SOX5 was found in two different transcript forms: long transcript (L-SOX5) and short transcript (S-SOX5). Moreover, the S-SOX5 was specifically expressed in human semen, not detected in the control blood samples. L-SOX5 and S-SOX5 were primarily found in seminal plasma, with low expression level in sperms. The results of RT-qPCR analysis showed obviously higher mRNA expression levels of L-SOX5 than S-SOX5 in semen (0.280±0.232 vs 0.147±0.103), however, not significantly(P=0.132). Conclusion: SOX5 is expressed as different transcripts in human semen, and different transcripts may play different roles in the process of spermatogenesis in testis.

Pharmacokinetic analysis of the cardioprotective effect of 3-(2,2, 2-trimethylhydrazinium) propionate in mice: inhibition of carnitine transport in kidney.

The site of action of 3-(2,2,2-trimethylhydrazinium) propionate (THP), a new cardioprotective agent, was investigated in mice and rats. I.p. administration of THP decreased the concentrations of free carnitine and long-chain acylcarnitine in heart tissue. In isolated myocytes, THP inhibited free carnitine transport with a Ki of 1340 microM, which is considerably higher than the observed serum concentration of THP. The major cause of the decreased free carnitine concentration in heart was found to be the decreased serum concentration of free carnitine that resulted from the increased renal clearance of carnitine by THP. The estimated Ki of THP for inhibiting the reabsorption of free carnitine in kidneys was 52.2 microM, which is consistent with the serum THP concentration range. No inhibition of THP on the carnitine palmitoyltransferase activity in isolated mitochondrial fractions was observed. These results indicate that the principal site of action of THP as a cardioprotective agent is the carnitine transport carrier in the kidney, but not the carrier in the heart.

A missense mutation of mouse OCTN2, a sodium-dependent carnitine cotransporter, in the juvenile visceral steatosis mouse.

Carnitine is an essential cofactor for the mitochondrial beta-oxidation of long-chain fatty acids. The juvenile visceral steatosis (JVS) mouse, an animal model of systemic carnitine deficiency, is inherited in an autosomal recessive manner. Recently, a human OCTN2 gene encoding a sodium-dependent carnitine cotransporter was isolated and mapped to human chromosome 5q31. Since the mouse jvs locus was assigned to the region of chromosome 11 where it is syntenic to human chromosome 5q31, we isolated the mouse octn2 gene and screened for its mutation in the jvs mouse. DNA sequencing analysis disclosed a missense mutation from CTG (Leu) to CGG (Arg) at codon 352 located within the sixth transmembrane domain of octn2. This amino acid replacement possibly causes the conformational change of the protein that leads to dysfunction of the gene product. Hence, we conclude that octn2 is a candidate gene responsible for the JVS mouse.

[Alterations in the sorbitol pathway and Na(+)-K(+)-ATPase activity of peripheral nerve of alloxan-induced diabetic rats].

Sorbitol pathway activity, myo-inositol content and ouabain-sensitive and ouabain-resistant ATPase activities were measured in homogenates of the sciatic nerve from alloxan-induced diabetic rats for 4, 8 and 12 weeks. Compared with the age-matched control, glucose, fructose and sorbitol contents of the sciatic nerve from diabetic rats for 4, 8 and 12 weeks were increased respectively to a level of 3-4 fold, 3-5 fold and 6-9 fold of those of the control rats. Myo-inositol was reduced approximately 50%. There was a significant decrease (P less than 0.01) in total ATPase, ouabain-sensitive and ouabain-resistant ATPase activities. These changes could be relevant to the development of diabetic neuropathy.