[Impact of deep slow-wave sleep deprivation on oxidative stress response of the testis tissue in rats].

OBJECTIVE: To investigate the influence of deep slow-wave sleep deprivation on the oxidative stress of testicular tissue in rats. METHODS: Thirty-six 5-week-old male Wistar rats were equally randomized into deep slow-wave sleep deprivation group (SD1), deep slow-wave sleep and duration sleep deprivation group ( SD2), and a cage control group (CC). The rat model of deep slow-wave sleep deprivation was established using the flowerpot technique. The rats in the SD1 group were interfered every 24 minutes and deprived of 12 hours of sleep at night, those in the SD2 group deprived of 8 minutes of sleep at an interval of 24 minutes and 12 hours of sleep at night, and those in the CC group exposed to 12 hours of daylight and 12 hours of darkness. After 28 days, all the rats were executed for measurement of the testis volume and protein content, determination of the methane dicarboxylic aldehyde (MDA) level and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and observation of the pathological changes in the testicular tissue under the microscope. RESULTS: Compared with the CC group, the rats in the SD1 and SD2 groups showed significantly reduced body weight (ï¼»268.5 ± 1.6ï¼½ vs ï¼»248.1 ± 25.1ï¼½andï¼»232.9 ± 10.1ï¼½g, P<0.05) and increased relative testis mass (ï¼»50.0 ± 1.3ï¼½ vs ï¼»57.9 ± 6.1ï¼½ and ï¼»54.9 ± 3.5ï¼½ ×10⁻², P<0.05). Statistically significant differences were found between the CC and SD2 groups in the contents of protein (ï¼»6.3 ± 1.4ï¼½ vs ï¼»4.5 ± 0.9ï¼½ gpro/L, P<0.05) and MDA (ï¼»1.1 ± 0.1ï¼½ vs ï¼»1.3 ± 0.3ï¼½ nmol/mgpro, P<0.05) and the activities of SOD (ï¼»104.3 ± 33.1ï¼½ vs ï¼»135.2 ± 26.9ï¼½ U/mgpro, P<0.05) and GSH-Px (ï¼»15.6 ± 4.0ï¼½ vs ï¼»21.7 ± 4.3ï¼½ U/mgpro, P<0.05), but not between the CC and SD1 groups (P>0.05). The lumens in the testis were narrowed, with obvious hyperplasia, hyperemia and edema in the peripheral interstitial tissue, but no significant pathologic changes were observed in the testis tissue of the SD1 group. CONCLUSIONS: Long-term deprivation of deep slow-wave sleep impairs the structure of the testis tissue and induces oxidative stress response in rats.

Feasibility of ß-sheet breaker peptide-H102 treatment for Alzheimer's disease based on ß-amyloid hypothesis.

ß-amyloid hypothesis is the predominant hypothesis in the study of pathogenesis of Alzheimer's disease. This hypothesis claims that aggregation and neurotoxic effects of amyloid ß (Aß) is the common pathway in a variety of etiological factors for Alzheimer's disease. Aß peptide derives from amyloid precursor protein (APP). ß-sheet breaker peptides can directly prevent and reverse protein misfolding and aggregation in conformational disorders. Based on the stereochemical structure of Aß1-42 and aggregation character, we had designed a series of ß-sheet breaker peptides in our previous work and screened out a 10-residue peptide ß-sheet breaker peptide, H102. We evaluated the effects of H102 on expression of P-tau, several associated proteins, inflammatory factors and apoptosis factors, and examined the cognitive ability of APP transgenic mice by behavioral test. This study aims to validate the ß-amyloid hypothesis and provide an experimental evidence for the feasibility of H102 treatment for Alzheimer's disease.

Expression of organic anion transporting polypeptide 1c1 and monocarboxylate transporter 8 in the rat placental barrier and the compensatory response to thyroid dysfunction.

Thyroid hormones (THs) must pass from mother to fetus for normal fetal development and require the expression of placental TH transporters. We investigate the compensatory effect of placental organic anion transporting polypeptide 1c1 (Oatp1c1) and monocarboxylate transporter 8 (Mct8) on maternal thyroid dysfunction. We describe the expressions of these two transporters in placental barriers and trophoblastic cell populations in euthyroidism and thyroid dysfunction resulting from differential iodine nutrition at gestation day (GD) 16 and 20, that is, before and after the onset of fetal thyroid function. Immunohistochemistry revealed that in the blood-placenta barrier, these two TH transporters were strongly expressed in the villous interstitial substance and were weakly expressed in trophoblast cells. Levels of Oatp1c1 protein obviously increased in the placental fetal portion during maternal thyroid deficiency at GD16. Under maternal thyroid deficiency after the production of endogenous fetal TH, quantitative PCR analysis revealed down-regulation of Oatp1c1 occurred along with up-regulation of Mct8 in trophoblast cell populations isolated by laser capture microdissection (LCM); this was consistent with the protein levels in the fetal portion of the placenta. In addition, decreased D3 mRNA at GD16 and increased D2 mRNA on two gestational days were observed in trophoblast cells with thyroid dysfunction. However, levels of Oatp1c1 mRNA at GD16 and D3 mRNA at GD20 were too low to be detectable in trophoblast cells. In conclusion, placental Oatp1c1 plays an essential compensatory role when the transplacental passage of maternal THs is insufficient at the stage before the fetal TH production. In addition, the coordinated effects of Oatp1c1, Mct8, D2 and D3 in the placental barrier may regulate both transplacental TH passage and the development of trophoblast cells during thyroid dysfunction throughout the pregnancy.

[The combined effects of beta-sheet breaker and hUCMSC on APP transgenic mice].

OBJECTIVE: To study the effect of combining the injection of beta-sheet breaker H102 with human umbilical cord mesenchymal stem cell (hUCMSC) on APP transgenic mice behavior, P-tau, apoptosis and the expression of relevant enzymes in the brain. METHODS: APP transgenic mice were randomly divided into model group, hUCMSC group, H102 group, H102 with hUCMSC group and a group of C57BL/6J mice with the same age and background was set as normal. After two weeks and four weeks, the ability of spatial reference memory was tested by Morris Water Maze. After four weeks, immunohistochemical stain and Western blot were done to detect the content of Bad, Bax, Bcl-2, Bcl-xl, P-tau, GSK-3beta, PP-2A and PP-1 in mice brain. RESULTS: The ability of memory of hUCMSC in 2 weeks group was slightly improved than that in the model group. hUCMSC in four weeks group, H102 group and H102 with hUCMSC group significantly improved the ability of and memory, and reduced the phosphorylation of tau and brain cell's apoptosis of the Alzheimer disease (AD) mice. CONCLUSION: Beta-sheet breaker H102 together with transplanting hUCMSC is an effective therapeutic strategy for AD.

Effect of different iodine nutrition on cerebellum Pcp-2 in rat offspring during lactation.

The thyroid functions of breastfed infants, as well as (indirectly) the development of their central nervous system, are dependent on the iodine status of the lactating mother. Purkinje cell protein-2 is a cell-specific marker of the cerebellum Purkinje cell and is a suitable indicator for observing the postnatal development of the cerebellum after birth. We measured the Purkinje cell protein-2 mRNA and protein levels in the rat cerebellum in the critical postnatal (14 days after birth) and maturation periods (28 days after birth) to determine the effect of different nutritional iodine levels on cerebellum growth in the offspring during lactation. We found that severe iodine deficiency resulted in thyroid dysfunction in lactating rats and their offspring on both 14 and 28 days, showing maternal total T(4) 16.7 ± 12.0 vs 36.4 ± 15.0, P < 0.05 (14 days) and 22.6 ± 18.7 vs 53.4 ± 9.4, P < 0.01 (28 days), and neonatal total T(4) 10.6 ± 2.3 vs 16.4 ± 4.7, P < 0.01(14 days) and 12.8 ± 2.9 vs 16.7 ± 3.4, P < 0.05 (28 days), respectively. The Purkinje cell protein-2 mRNA and its protein levels in offspring rats were significantly reduced that showed Purkinje cell protein-2 mRNA 1.12 ± 0.04 vs 2.25 ± 0.53, P < 0.05 (14 days) and 1.74 ± 0.94 vs 8.69 ± 2.71, P < 0.01 (28 days). However, mild iodine deficiency and excessive iodine maintained almost normal thyroid function in maternal and neonatal rats and normal Purkinje cell protein-2 mRNA and protein levels in offspring's cerebellum. We conclude that severe iodine deficiency could significantly reduce Purkinje cell protein-2 mRNA and its protein levels, indicating that the cerebellum development was retarded, but mild iodine deficiency and excessive iodine could maintain them at an approximately normal level by the mother's and offspring's compensations, especially by the mother's mammary glands.

Trimester- and method-specific reference intervals for thyroid tests in pregnant Chinese women: methodology, euthyroid definition and iodine status can influence the setting of reference intervals.

OBJECTIVE: The importance of diagnosis and treatment of thyroid dysfunction during pregnancy has been widely recognized. We therefore established trimester- and method-specific reference intervals for thyroid testing in pregnant women according to the NACB recommended criteria. Several factors can affect the setting of reference intervals, in particular manufacturer's methodology, euthyroid definition and iodine status. DESIGN: Cross-sectional dataset analysis. SUBJECTS: Five hundred and five normal pregnant women at different stages of gestation were rigorously selected for setting reference intervals. All were healthy, iodine sufficient, euthyroid and negative for both serum thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb). MEASUREMENTS: Thyrotrophin (TSH), total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3) and anti-TPOAb and anti-TgAb were measured using the Bayer ADVIA Centaur system. Iodine content in drinking water, salt and urine was determined by national standard methods. The 2·5th and 97·5th percentiles were calculated as the reference intervals for thyroid hormone levels during each trimester. RESULTS: All participants had long-term consumption of iodized salt and median urinary iodine of 150-200 µg/l during each three trimester. The reference intervals for the first, second and third trimesters were, respectively, TSH 0·03-4·51, 0·05-4·50 and 0·47-4·54 mIU/l and FT4 11·8-21·0, 10·6-17·6 and 9·2-16·7 pmol/l. The manufacturer's method, euthyroid definition and iodine status may influence TSH and FT4 reference intervals. Alterations in thyroid hormone concentrations during pregnancy differed at different stage of gestation and to those of a nonpregnant state. CONCLUSIONS: The trimester- and method-based reference intervals for thyroid tests during pregnancy are clinically appropriate. Some variables should be controlled when establishing reference intervals.