Effects of exercise on sex hormones and expression of relevant genes in the hypothalamus in obese mice.

This study aimed to investigate the effect of different exercise loads on sex hormones and expressions of relevant genes in hypothalamus in obese mice. Sixty weaning male C57BL/6 mice were used as subjects. Among them, 15 mice were randomly classified into the normal diet group (CON group), and the remaining 45 mice into high-fat diet group (MOB group). The obesity was successfully achieved by high-fat diet 10 weeks later. Then the rats were randomly divided into three groups based on weight, namely, obesity control group (OBC group), obesity with moderate-intensity exercise group (MOBC group), and obesity with high-intensity exercise group (HOBC group), with 15 mice in each group. Mice in the MOBC group and HOBC group were offered 8 weeks of swimming training, and the exercise time increased incrementally until 2 h and 4 h per day. After the training was over, ELISA method was used to determine the serum levels of Adiponectin (Adipo), luteotropic hormone (LH), follicle-stimulating hormone (FSH) and testosterone (T). Real-time PCR was implemented to detect the transcriptional levels of genes of Adipo and other relevant proteins in the hypothalamus. The result showed that compared with the CON group, there was a significant reduction in the serum levels of Adipo, LH, FSH and T in the OBC group (P<0.05). As compared with the OBC group, the serum levels of Adipo, LH, FSH and T increased significantly in the OBC group (P<0.05). There was a significant increase in the transcriptional levels of Adipo, Adipo receptor 1 (Adipo R1), and AMP-activated protein kinase (AMPK) in the OBC group (P<0.05) compared to in the CON group; meanwhile, the transcriptional levels of kisspeptin (Kiss) and gonadotropin-releasing hormone (GnRH) decreased significantly (P<0.05). In conclusion, long-term moderate-intensity exercise could improve the negative effect of obesity on sex development. Long-term high-intensity exercises could not improve the inhibitory effect of obesity on sex development.

Identification of an orally available compound with potent and broad FLT3 inhibition activity.

FLT3 internal tandem duplication (FLT3-ITD) is an activating mutation found in 20-30% of patients with acute myeloid leukemia (AML), which makes FLT3 an attractive target for the treatment of AML. Although FLT3-mutant patients respond to current FLT3 inhibitors, relapse usually happens because of the acquisition of resistant secondary mutations at the FLT3 catalytic domain, which is mainly on D835. In the search for compounds with broad FLT3 inhibition activities, we screened a kinase inhibitor library by using our unique FLT3 substrate and identified JAK3 inhibitor VI (designated JI6 hereafter) as a novel FLT3 inhibitor, which selectively targets FLT3 D835 mutants as well as FLT3-ITD. JI6 effectively inhibited FLT3-ITD-containing MV4-11 cells and HCD-57 cells transformed with FLT3-ITD and D835 mutants. Furthermore, administration of JI6 effectively targeted FLT3 signaling in vivo and suppressed the myeloproliferative phenotypes in FLT3-ITD knock-in mice, and significantly prolonged the survival of immunodeficient mice implanted with the transformed HCD-57 cells. Therefore, JI6 is a promising candidate for the development of next-generation anti-AML drugs.

Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P.

Our understanding of when and how humans adapted to living on the Tibetan Plateau at altitudes above 2000 to 3000 meters has been constrained by a paucity of archaeological data. Here we report data sets from the northeastern Tibetan Plateau indicating that the first villages were established only by 5200 calendar years before the present (cal yr B.P.). Using these data, we tested the hypothesis that a novel agropastoral economy facilitated year-round living at higher altitudes since 3600 cal yr B.P. This successful subsistence strategy facilitated the adaptation of farmers-herders to the challenges of global temperature decline during the late Holocene.

Effects of the consumption of rice from non-KBD areas and selenium supplementation on the prevention and treatment of paediatric Kaschin-Beck disease: an epidemiological intervention trial in the Qinghai Province.

OBJECTIVE: Based on the aetiological hypothesis of Kaschin-Beck disease (KBD), different interventions were adopted, and the preventive and therapeutic effects of interventions was observed and evaluated in this trial. DESIGN: A total of 358 children from seven villages of Qinghai Province in China were examined, and 280 children aged 6-11 years old were eligible for the trial. The children were divided into three groups that received either no intervention (n = 64), 150 kg/person of rice from non-KBD areas (n = 103) or 7 kg/family of selenium-iodine salt (n = 113) for 12 months. Data were collected and used to calculate the proportion of patients with X-ray lesions, the proportion of new patients and the metaphyseal repair rate. All indicators were analysed with Pearson chi-square or Fisher's exact tests. The registration number of this trial is ChiCTR-PNRC-12002309 (http://www.chictr.org). RESULTS: After interventions, the proportion of patients with X-ray lesions increased dramatically in the control group and decreased significantly in two intervention groups; significant differences were seen between the control group and two intervention groups (P < 0.05). Moreover, significant differences were observed in the proportions of new patients and the metaphyseal repair rates between the control group and two intervention groups (P < 0.05). Additionally, the proportion of new patients was lowest and the metaphyseal repair rate was highest in group B. CONCLUSIONS: The effects of eating rice from non-KBD areas and selenium supplementation on the prevention and treatment of paediatric KBD were notable, the consumption of rice might be the most effective and safest intervention and should be encouraged.

Dissecting the interaction of SHP-2 with PZR, an immunoglobulin family protein containing immunoreceptor tyrosine-based inhibitory motifs.

Tyrosine phosphorylation of membrane proteins plays a crucial role in cell signaling by recruiting Src homology 2 (SH2) domain-containing signaling molecules. Recently, we have isolated a transmembrane protein designated PZR that specifically binds tyrosine phosphatase SHP-2, which has two SH2 domains (Zhao, Z. J., and Zhao, R. (1998) J. Biol. Chem. 273, 29367-29372). PZR belongs to the immunoglobulin superfamily. Its intracellular segment contains four putative sites of tyrosine phosphorylation. By site-specific mutagenesis, we found that the tyrosine 241 and 263 embedded in the consensus immunoreceptor tyrosine-based inhibitory motifs VIYAQL and VVYADI, respectively, accounted for the entire tyrosine phosphorylation of PZR. The interaction between PZR and SHP-2 requires involvement of both tyrosyl residues of the former and both SH2 domains of the latter, since its was disrupted by mutating a single tyrosyl residue or an SH2 domain. Overexpression of catalytically inactive but not active forms of SHP-2 bearing intact SH2 domains in cells caused hyperphosphorylation of PZR. In vitro, tyrosine-phosphorylated PZR was efficiently dephosphorylated by the full-length form of SHP-2 but not by its SH2 domain-truncated form. Together, the data indicate that PZR serves not only as a specific anchor protein of SHP-2 on the plasma membrane but also as a physiological substrate of the enzyme. The coexisting binding and dephosphorylation of PZR by SHP-2 may function to terminate signal transduction initiated by PZR and SHP-2 and to set a threshold for the signal transduction to be initiated.

Purification and cloning of PZR, a binding protein and putative physiological substrate of tyrosine phosphatase SHP-2.

Overexpression of a catalytically inactive mutant of tyrosine phosphatase SHP-2 in 293 cells resulted in hyperphosphorylation of a glycoprotein specifically associated with the enzyme. The protein has been purified to near homogeneity. Based on the amino acid sequences of peptides obtained from the protein, a full-length cDNA was isolated. The cDNA encodes a protein with a single transmembrane segment and a signal sequence. The extracellular portion of the protein contains a single immunoglobulin-like domain displaying 46% sequence identity to that of myelin P0, a major structural protein of peripheral myelin. The intracellular segment of the protein shows no significant sequence identity to any known protein except for two immunoreceptor tyrosine-based inhibitory motifs. We name the protein PZR for protein zero related. Transfection of the PZR cDNA in Jurkat cells gave rise to a protein of expected molecular size. Stimulation of cells with pervanadate resulted in tyrosine phosphorylation of PZR and a near-stoichiometric association of PZR with SHP-2. Northern blotting analyses revealed that PZR is widely expressed in human tissues and is particularly abundant in heart, placenta, kidney, and pancreas. As a binding protein and a putative substrate of SHP-2, PZR protein may have an important role in cell signaling.