Seasonal change of circulating leptin associated with testicular activities of the wild ground squirrels (Citellus dauricus).

The purpose of this study was to explore the variations in the circulating leptin concentrations of the wild ground squirrels in relation to seasonal changes in testicular activities. Hematoxylin-eosin staining showed all types of elongated spermatids and spermatogenic cells existed in the testis in April, while the primary spermatocytes and spermatogonia were most advanced stages of germ cells in June. In addition, the primary spermatocytes, secondary spermatocytes, and spermatogonia were most advanced stages of germ cells in September. The highest circulating leptin concentration was consistent with the maximum body weight results from accumulation of adipose tissue in September. The mRNA expression level of leptin receptor (Ob-R) and STAT3 was lowest in June, raised in September, and remained increased in April. Ob-R and STAT3 were stronger staining in the Leydig cells in July. Moreover, the concentrations of testosterone (T) showed the maximum values in April, the minimum values in June, and significant increases in September. Furthermore, it is worth noting that the levels of T increased with the mRNA levels of Ob-R, STAT3, StAR, and testicular steroidogenic enzymes (3ß-HSD, P450c17, and P450scc). Moreover, RNA-seq analyses of testis during the different periods showed that a total of 4209 genes were differentially expressed genes (DEGs); further analysis revealed that DEGs related with the Jak/STAT pathways and reproduction were altered. Taken together, the results suggested that the leptin regulated testicular function through the Jak/STAT pathways and testicular steroidogenic factor expressions.

Rabbit hemorrhagic disease virus VP60 protein expressed in recombinant swinepox virus self-assembles into virus-like particles with strong immunogenicity in rabbits.

Rabbit Hemorrhagic Disease (RHD) is an economically significant infectious disease of rabbits, and its infection causes severe losses in the meat and fur industry. RHD Virus (RHDV) is difficult to proliferate in cell lines in vitro, which has greatly impeded the progress of investigating its replication mechanism and production of inactivated virus vaccines. RHDV VP60 protein is a major antigen for developing RHD subunit vaccines. Herein, we constructed a TK-deactivated recombinant Swinepox virus (rSWPV) expressing VP60 protein and VP60 protein coupled with His-tag respectively, and the expression of foreign proteins was confirmed using immunofluorescence assay and western blotting. Transmission electron microscopy showed that the recombinant VP60, with or without His-tag, self-assembled into virus-like particles (VLPs). Its efficacy was evaluated by comparison with available commercial vaccines in rabbits. ELISA and HI titer assays showed that high levels of neutralizing antibodies were induced at the first week after immunization with the recombinant strain and were maintained during the ongoing monitoring for the following 13 weeks. Challenge experiments showed that a single immunization with 106 PFU of the recombinant strain protected rabbits from lethal RHDV infection, and no histopathological changes or antigenic staining was found in the vaccine and rSWPV groups. These results suggest that rSWPV expressing RHDV VP60 could be an efficient candidate vaccine against RHDV in rabbits.

A computational investigation about the effect of metal substitutions on the electronic spectra of porphyrin donors in the visible and near infrared regions.

Porphyrin compounds have unique advantages because of their wide absorption range (about 300-1000 nm) and good planarity. At present, the effects of metal substitutions of porphyrin compounds on their photovoltaic properties are still not clear. In this paper, we have systematically modelled a series of porphyrin donors MP-TBO (M = 2H, Mg, Cu, Fe, Co, Zn and Ni), in which ZnP-TBO has been experimentally synthesized and the power conversation efficiency of organic solar cell based on it is up to 12.08 %. The photovoltaic properties of these MP-TBO molecules have been investigated via density functional theory (DFT) and time-dependent DFT. We find that CoP-TBO and NiP-TBO both have worse planarity and smaller dipole moments than other compounds. The electronic absorption spectra of these porphyrin donors all show three main absorption peaks. However, metal substitutions blue-shift the wavelength of absorption peaks and lower total absorption strength in the visible and near-infrared regions. Finally, we find that MgP-TBO and H2P-TBO seem to be potential donors because both have more red-shifted wavelength of absorption peaks and higher absorption strength than other metal substitutions.

The effect of 3-Methyl-4-Nitrophenol on the early ovarian follicle development in mice by disrupting the clock genes expression.

3-Methyl-4-Nitrophenol (PNMC) is the main degradation product of organophosphate insecticide fenitrothion and a major component of diesel exhaust particles, which is now becoming a widely spread environmental endocrine disruptor. Previous reports showed PNMC exposure can affect the female reproductive system and ovarian function; however, the mechanism remains unclear. The main purpose of this study is to clarify the mechanism underlying the adverse effects of neonatal PNMC treatment on ovarian functions. The neonatal female mice were exposed to 10 mg/kg PNMC and the ovaries were collected on the 7th day after birth. The changes of follicular composition in mice ovaries were analyzed by histological staining, which showed that the proportion of primordial follicles in the ovaries treated by PNMC decreased, while the proportion of secondary follicles increased. The ovarian function was also investigated by detecting the expressions of steroidogenic enzymes (Star, Cyp11a1, Hsd3b1, Cyp17a1, Cyp19a1), gonadotropin receptors (Fshr and Lhr), androgen receptor (Ar), and estrogen receptors (Esr1 and Esr2) by immunohistochemistry or/and real-time quantitative PCR. The expression of Hsd3b1, Cyp17a1 and Esr2 were increased significantly in the PNMC exposed ovaries. Moreover, the expression patterns of clock genes (Bmal1, Clock, Per1, Per2, Cry1, Cry2 and Nr1d1) were disrupted in the ovaries after PNMC exposure. Furthermore, either the expression of DNA Methyltransferase Dnmt3b, or the methylation ratio of CpG islands in the upstream of Cry1 promoter regions were significantly decreased in PNMC exposed ovaries. Altogether, these results indicate that PNMC exposure affects follicle development and ovarian function by interfering with the epigenetic modification and disrupting the expression of clock genes.

Seasonal expressions of SPAG11A and androgen receptor in the epididymis of the wild ground squirrels (Citellus dauricus Brandt).

Sperm-associated antigen 11A (SPAG11A) is expressed exclusively in the epididymis, which can specifically regulate sperm maturation. The aim of this study was to investigate the seasonal expressions of beta-defensin (SPAG11A) and androgen receptor (AR) in the epididymis of the wild ground squirrels (Citellus dauricus Brandt). Morphologically, the results showed that epididymis length and weight in the breeding season were significantly higher than those of the non-breeding season. Histologically, the results revealed that enlarged lumen diameters, thickened epithelial and abundant sperm in the breeding season while reduced lumen diameters and epithelial with no sperm in the non-breeding season. SPAG11A was intensely expressed in cytoplasm and nucleus of epithelial cells in the breeding season, and weaker staining in the non-breeding season. The immunostaining of AR was only presented in nucleus of smooth muscle cells and epithelial cells in the whole epididymis with stronger staining in the breeding season. The results of real-time quantitative PCR also showed that the mRNA levels of SPAG11A and AR in the epididymis during the breeding season were significantly higher than those of the non-breeding season. In addition, the levels of testosterone (T), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the serum were higher during the breeding season. Taken together, these results suggested that SPAG11A might play an important role to regulate seasonal changes in epididymal function of the wild ground squirrels.

Seasonal expressions of oxytocin and oxytocin receptor in the epididymides in the wild ground squirrels (Citellus Dauricus Brandt).

The aim of this study was to detect the seasonal expressions of oxytocin (OT), oxytocin receptor (OTR), extracellular signal-regulated kinase1 and 2 (ERK1/2) and phospho-ERK1/2 (pERK1/2) in the epididymis of the wild ground squirrels (Citellus Dauricus Brandt) during the breeding season and non-breeding season. Histological results showed that size, weight, cell number and lumen diameter of epididymis underwent acute seasonal changes, which were all peaked in the breeding season. Immunohistochemical results suggested that strong staining of OT, OTR, ERK1/2, and pERK1/2 were observed in the epithelial layer in the whole epididymis, along with intense OT and OTR signal in smooth muscle cell (Smc) in caudal epididymis in the breeding season. The protein expression levels of OTR, ERK1/2, and pERK1/2 in the epididymis were higher in the breeding season than those of the non-breeding season. Besides, hormone assay revealed that there was no significant serum concentration of OT in these two periods, while epididymal concentration showed higher value in the breeding season. In summary, the identified localization and local concentration of OT in the epididymis in the wild ground squirrel suggested that epididymis may assume as a source of OT, and OT could act via OTR to activate ERK1/2 signaling to regulate seasonal epididymal functions.

Seasonal expressions of androgen receptor, estrogen receptors, 5α-reductases and P450arom in the epididymis of the male muskrat (Ondatra zibethicus).

The steroid hormones not only exert various endocrine functions but also act as the autocrine or paracrine factors in different tissues of mammals. In the present study, the seasonal expressions of androgen receptor (AR), estrogen receptors alpha and beta (ERα and ERß), aromatase cytochrome P450 (P450arom) and 5α-reductase 1, 2 were investigated in the epididymis of the muskrat. HE staining showed enlarged lumen and abundant sperm in the breeding season while reduced lumen with no sperm in the non-breeding season. The staining of AR was presented in nuclei of epithelial cells of the epididymis in both seasons. The immunostaining of ERα was localized in both nuclei and cytoplasm of epithelial cells of the epididymis during the breeding season, while the weak staining of ERα was only in the nuclei of epithelial cells during the non-breeding season. In contrast, ERß signal was negative in the epididymis of the muskrat in both seasons. The positive signals for P450arom and 5α-reductase 1, 2 were found in the cytoplasm of epithelial and smooth muscle cells during both seasons. Moreover, the protein and mRNA expression levels of AR, ERα, P450arom and 5α-reductase 1, 2 were significantly higher in the epididymis during the breeding season than those of the non-breeding season, and the expression level of 5α-reductase 1 was higher when compared with 5α-reductase 2. In addition, the levels of testosterone (T) and dihydrotestosterone (DHT) in the epididymis and serum were remarkably higher during the breeding season. Taken together, these findings suggested androgen and estrogen might play an important endocrine or autocrine/paracrine role to regulate the epididymal functions of the muskrat.

Seasonal expressions of androgen receptor, estrogen receptors and cytochrome P450 aromatase in the uteri of the wild Daurian ground squirrels (Spermophilus dauricus).

The reproductive tissues including the uterus undergo dramatic changes in seasonal breeders from the breeding to non-breeding seasons. Classically, sex steroid hormones play important roles in the uterine morphology and functions. To clarify the relationship between sex steroid hormones and seasonal changes in the uterine morphology and functions, the wild Daurian ground squirrels (Spermophilus dauricus) were used as seasonal breeder model. And the immunolocalizations and expression levels of androgen receptor (AR), estrogen receptors α and ß (ERα and ERß) and cytochrome P450 aromatase (P450arom) were investigated in the uteri of the wild Daurian ground squirrels in the breeding (April) and the non-breeding (June) seasons via immunohistochemistry, Western blot and RT-PCR. Histologically, the uterine weight, the thickness of endometrium and the glandular density were significantly higher in the uteri of the breeding season than those of the non-breeding season. In both seasons, the immunostaining of AR was only presented in stromal cells of the uteri; the positive staining of ERα and ERß were localized in stromal cells and glandular cells; P450arom was merely immunolocalized in glandular cells. The protein and mRNA expression levels of ERα, ERß and P450arom were higher in the uteri of the breeding season than those of the non-breeding season; conversely, the expressions of AR were higher in the uteri of the non-breeding season comparing with those of the breeding season in both protein and mRNA levels. The AR: ER ratio in the uteri of the non-breeding season exceeded the AR: ER ratio in the uteri of the breeding season in the wild Daurian ground squirrels. These results suggested that seasonal changes in the expression levels of AR, ERs and P450arom might be correlated with the uterine morphology and histology changes, and estrogen may play an important autocrine/paracrine role in regulating the uterine functions of the wild Daurian ground squirrels.

Inositol hexaphosphate suppresses colorectal cancer cell proliferation via the Akt/GSK-3ß/ß-catenin signaling cascade in a 1,2-dimethylhydrazine-induced rat model.

Colorectal cancer (CRC) is common worldwide, and most treatments for CRC have undesirable side effects. Many researchers have demonstrated that inositol hexaphosphate (IP6) has potent anticarcinogenic activity against CRC and no apparent toxicity to normal cells. However, the underlying mechanism is still unclear. In this study, we investigated the anticancer and anti-proliferative properties of IP6 in CRC and its possible mechanisms during this chemopreventive process. We examined the expression of genes related to the PI3K/Akt and Wnt pathways at the transcriptional and translational levels in a DMH-induced rat CRC model following IP6 administration. In addition, we also conducted cell proliferation analysis. The results demonstrated that IP6 could inhibit tumors, in terms of tumor incidence, number, weight and volume in DMH-induced rats. Additionally, Akt and c-Myc mRNA levels were significantly decreased. IP6 was also shown to downregulate Akt, pAkt, pGSK-3ß, and c-Myc protein expression and upregulate pß-catenin protein expression. Furthermore, tumor tissues from IP6-treated rats showed decreased proliferation. In conclusion, the anti-proliferative effect of IP6 may be related to crosstalk between the PI3K/Akt and Wnt pathways, revealing a potential mechanism of CRC inhibition by IP6 in our model.

Seasonal and spatial differences in source contributions to PM2.5 in Wuhan, China.

Fine particle (PM2.5) samples were collected in 2011 and 2012 simultaneously at three sites in Wuhan in an industrial area (ID), downtown Wuhan (DT), and the Wuhan botanical gardens (BG). The annual average concentration of PM2.5 was highest in the industrial area at 180µgm-3 and lowest in the botanical gardens, with an average of 93µgm-3. The average downtown PM2.5 concentration was 113µgm-3. All sites had concentrations well above the World Health Organization (WHO) guidelines and the Chinese air quality standard. The concentration of major constituents of PM2.5 varied seasonally across all sites; specifically, sulfate, nitrate, and organic carbon varied most strongly during spring, followed by summer and fall. Organic carbon varied the most across sites for all seasons, which is attributable to large differences in local source emissions. The major primary sources contributing to OC were vehicle emissions (38.1±8.3%), coal combustion (7.0±6.2%), meat cooking (3.0±1.6%), and biomass burning (3.0±1.0%). All these sources had large seasonal variations across the three sites. Biomass burning had the largest impact at BG, mobile sources had the largest impact at DT, and coal combustion had the largest impact at ID. Mineral dust was a major contributor to PM2.5 (average 16.8±9.6µgm-3) and had very homogenous concentrations across the sites during springtime due to regional dust storms, but had much higher concentration at ID during the summer and fall. The results demonstrate the need for both regional and local air pollution control strategies to reduce air pollution in Wuhan. This research contributes to the field of particulate matter studies by providing information about seasonal and regional fluctuations in PM2.5 in large urban areas, which helps advance understanding of the sources responsible for urban haze.