Biomechanism of abnormal stress on promoting osteoarthritis of temporomandibular joint through Piezo1 ion channel.

OBJECTIVE: This study aimed to investigate whether flow fluid shear stress (FFSS)-mediated signal transduction affects the function of Piezo1 ion channel in chondrocyte and to further explore the role of mechanical overloading in development of temporomandibular joint osteoarthritis (TMJ OA). METHODS: Immunohistochemical staining was used to determine the expression of Piezo1 in TMJ OA tissue collected from rat unilateral anterior crossbite (UAC) models. Chondrocytes harvested from normal adult SD rats were treated with FFSS (0, 4, 8, 12 dyn/cm2) in vitro. Immunofluorescent staining, real-time polymerase chain reaction, western blotting, flow cytometry and phalloidin assay were performed to detect the changes of cellular morphology as well as the expression of Piezo1 and certain pro-inflammatory and degradative factors in chondrocyte. RESULTS: Immunohistochemical analysis revealed that significantly increased Piezo1 expression was associated with UAC stimulation (p < .05). As applied FFSS escalated (4, 8 and 12 dyn/cm2), the expression levels of Piezo1, ADAMTS-5, MMP-13 and Col-X gradually increased, compared with the non-FFSS group (p < .05). Administering Piezo1 ion channel inhibitor to chondrocytes beforehand, it was observed that expression of ADAMTS-5, MMP-13 and Col-X was substantially decreased following FFSS treatment (p < .05) and the effect of cytoskeletal thinning was counteracted. The activated Piezo1 ion channel enhanced intracellular Ca2+ excess in chondrocytes during abnormal mechanical stimulation and the increased intracellular Ca2+ thinned the cytoskeleton of F-actin. CONCLUSIONS: Mechanical overloading activates Piezo1 ion channel to promote pro-inflammation and degradation and to increase Ca2+ concentration in chondrocyte, which may eventually result in TMJ OA.

Application of topical betaxolol to cure superficial infantile hemangioma: A pilot study.

BACKGROUND: Beta-blockers have gradually become an attractive option for the treatment of infantile hemangiomas. Topical application is preferred to oral administration because of their potential systemic adverse effects. The aim of this study is to investigate the effect of betaxolol in treating superficial infantile hemangioma. METHODS: Seventy-four infants admitted to the First Affiliated Hospital of Xinjiang Medical University from 2018 to 2019 were observed and recorded. Variables such as color, size, tension, and thickness were recorded monthly and evaluated using visual analog scales. Multi-factor analysis of variance with repeated measurements and the non-parametric Kruskal-Wallis H test were used to compare clinical effectiveness across the different groups. RESULTS: After 6 months of treatment, 33.78% (25/74) showed excellent results, 55.41% (41/74) had good responses, 8.11% (6/74) had moderate responses, and 2.70% (2/74) had poor responses. Local discomfort and systemic complications were not found. There was no significant difference in gender and location of occurrence among groups (p > 0.05), and the effect of topical application of betaxolol was optimum in the children aged 0-3 months (p = 0.002). None of three age groups had statistically significant difference in heart rate and blood pressure after accepting treatment (1 month, p = 0.618; 4 months, p = 0.138; 6 months, p = 0.757). CONCLUSIONS: Our study showed that topical administration of betaxolol was effective and well tolerated for superficial infantile hemangiomas, particularly in the early proliferative stage. However, its safety and efficacy need further research.

Knockout of glutathione peroxidase 5 down-regulates the piRNAs in the caput epididymidis of aged mice.

The mammalian epididymis not only plays a fundamental role in the maturation of spermatozoa, but also provides protection against various stressors. The foremost among these is the threat posed by oxidative stress, which arises from an imbalance in reactive oxygen species and can elicit damage to cellular lipids, proteins, and nucleic acids. In mice, the risk of oxidative damage to spermatozoa is mitigated through the expression and secretion of glutathione peroxidase 5 (GPX5) as a major luminal scavenger in the proximal caput epididymidal segment. Accordingly, the loss of GPX5-mediated protection leads to impaired DNA integrity in the spermatozoa of aged Gpx5-/- mice. To explore the underlying mechanism, we have conducted transcriptomic analysis of caput epididymidal epithelial cells from aged (13 months old) Gpx5-/- mice. This analysis revealed the dysregulation of several thousand epididymal mRNA transcripts, including the downregulation of a subgroup of piRNA pathway genes, in aged Gpx5-/- mice. In agreement with these findings, we also observed the loss of piRNAs, which potentially bind to the P-element-induced wimpy testis (PIWI)-like proteins PIWIL1 and PIWIL2. The absence of these piRNAs was correlated with the elevated mRNA levels of their putative gene targets in the caput epididymidis of Gpx5-/- mice. Importantly, the oxidative stress response genes tend to have more targeting piRNAs, and many of them were among the top increased genes upon the loss of GPX5. Taken together, our findings suggest the existence of a previously uncharacterized somatic piRNA pathway in the mammalian epididymis and its possible involvement in the aging and oxidative stress-mediated responses.

Mechanistic target of rapamycin kinase (Mtor) is required for spermatogonial proliferation and differentiation in mice.

Spermatogonial development is a vital prerequisite for spermatogenesis and male fertility. However, the exact mechanisms underlying the behavior of spermatogonia, including spermatogonial stem cell (SSC) self-renewal and spermatogonial proliferation and differentiation, are not fully understood. Recent studies demonstrated that the mTOR complex 1 (mTORC1) signaling pathway plays a crucial role in spermatogonial development, but whether MTOR itself was also involved in any specific process of spermatogonial development remained undetermined. In this study, we specifically deleted Mtor in male germ cells of mice using Stra8-Cre and assessed its effect on the function of spermatogonia. The Mtor knockout (KO) mice exhibited an age-dependent perturbation of testicular development and progressively lost germ cells and fertility with age. These age-related phenotypes were likely caused by a delayed initiation of Mtor deletion driven by Stra8-Cre. Further examination revealed a reduction of differentiating spermatogonia in Mtor KO mice, suggesting that spermatogonial differentiation was inhibited. Spermatogonial proliferation was also impaired in Mtor KO mice, leading to a diminished spermatogonial pool and total germ cell population. Our results show that MTOR plays a pivotal role in male fertility and is required for spermatogonial proliferation and differentiation.

An epididymis-specific carboxyl esterase CES5A is required for sperm capacitation and male fertility in the rat.

Despite the fact that the phenomenon of capacitation was discovered over half century ago and much progress has been made in identifying sperm events involved in capacitation, few specific molecules of epididymal origin have been identified as being directly involved in this process in vivo . Previously, our group cloned and characterized a carboxyl esterase gene Ces5a in the rat epididymis. The CES5A protein is mainly expressed in the corpus and cauda epididymidis and secreted into the corresponding lumens. Here, we report the function of CES5A in sperm maturation. By local injection of Lentivirus -mediated siRNA in the CES5A -expressing region of the rat epididymis, Ces5a -knockdown animal models were created. These animals exhibited an inhibited sperm capacitation and a reduction in male fertility. These results suggest that CES5A plays an important role in sperm maturation and male fertility.

Different effects of androgen on the expression of Fut1, Fut2, Fut4 and Fut9 in male mouse reproductive tract.

The α-(1,2) fucosyltransferases (Fut1 and Fut2) and α-(1,3) fucosyltransferases (Fut4, Fut9) are responsible for the synthesis of Lewis X (LeX) and Lewis Y (LeY) conjugated to glycoproteins. We recently reported that these fucosyltransferases were differentially expressed in the reproductive tract of male mouse. Here, we studied the effect of androgen on fucosyltransferase expression through the use of mouse castration models. We found that Fut1 mRNA and Fut4 mRNA were upregulated, while Fut2 mRNA and Fut9 mRNA were downregulated by androgen in the caput epididymis. However, in the vas deferens and prostate, only Fut4 mRNA and Fut2 mRNA were respectively upregulated following exposure to androgen. In the seminal vesicle, all fucosyltransferases, with the exception of Fut9, were upregulated. We identified the androgen receptor binding sites (ARBSs) of Fut2, Fut4 and Fut9 in the caput epididymis. Luciferase assay for these ARBSs is able to provide an indication as to why Fut4 and Fut9 are differently expressed and regulated by androgen, although they catalyze the same α-(1,3) fucose linkage. Our study showed that androgen could differentially regulate the expression of these fucosyltransferases and provided an insight into the characteristic distribution of each fucosyltransferase responsible for LeX/LeY biosynthesis in the male reproductive tract.

Identification of microRNAs and application of RNA interference for gene targeting in vivo in the rat epididymis.

Identification, detection, and use of small-ribonucleic acid (RNA) molecules have been paid increasing attention in the past decades. Here we show studies of two interrelated lines of this research in a sperm maturation-related organ, the epididymis. First, by using microarray and small-RNA library screening systems, a series of spatially and temporally regulated known and novel small regulatory RNA molecules, referred to as microRNAs, has been identified and characterized. Second, small double-stranded RNAs, called small interfering RNAs, emerged as a powerful tool to knock down gene expression by a pathway known as RNA interference. It has been successfully used to silence epididymal gene expression in vivo to elucidate the function of several sperm motility- and capacitation-related proteins in the rat epididymis.

Dual effects of daidzein on chicken hepatic vitellogenin II expression and estrogen receptor-mediated transactivation in vitro.

Two in vitro systems were employed to delineate the estrogenic activity of daidzein (Da), alone or in combination with high or low concentrations of estrogen in two cell types possessing different estrogen-receptor (ER) isoforms, ERalpha and/or ERbeta: (1) vitellogenin II (VTG), the egg yolk precursor protein and the endpoint biomarker for estrogenicity, in chicken primary hepatocytes, and (2) CHO-K1 cells transiently co-transfected with ERalpha or ERbeta and estrogen-response elements (ERE) linked to a luciferase reporter gene. Da (100 microM) alone induced VTG mRNA expression in chicken hepatocytes, albeit with much less potency compared to estradiol (E(2)). Da exhibited different effects in the presence of 1 microM and 10 microM E(2). At a concentration of 100 microM, Da enhanced 1 microM E(2)-induced VTG transcription by 2.4-fold, but significantly inhibited 10 microM E(2)-induced VTG mRNA expression in a dose-dependent fashion from 1 to 100 microM. Tamoxifen completely blocked the estrogenic effect of daidzein, alone or in combination with 1 microM of E(2), but did not influence its anti-estrogenic effect on 10 microM E(2)-induced VTG mRNA expression. Furthermore, neither E(2) nor daidzein, alone or in combination, affected ERalpha mRNA expression, yet all the treatments significantly up-regulated ERbeta mRNA expression in chicken hepatocytes. E(2) effectively triggered estrogen-response elements (ERE)-driven reporter gene transactivation in CHO-K1 cells expressing ERalpha or ERbeta and showed much greater potency with ERalpha than with ERbeta. In contrast, daidzein was 1000 times more powerful in stimulating ERbeta- over ERalpha-mediated transactivation. Daidzein, in concentrations ranging from 5 nM to 50 microM, did not affect ERbeta-mediated transactivation induced by 1 nM E(2), but it significantly inhibited ERbeta-mediated transactivation induced by 10 nM E(2) at 500 nM. Despite the tremendous difference in sensitivity between the two in vitro systems, daidzein exhibited greater potency as an estrogen-antagonist for ERbeta-mediated activity.

[Isolation and expression of novel expressed sequence tags (ESTs) from ovarian follicles of Shaoxing ducks].

Three expressed sequence tags ( ESTs), SXDF0201 (271 bp), SXDF0202 (200 bp) and SXDF0203 (173 bp), were isolated from ovarian follicles of Shaoxing ducks by using silver staining mRNA differential display. GenBank/BLAST analysis revealed that SXDF0201 was not homologous to any of the published sequences from all species, indicating that it was a novel EST and was then registered in GenBank (GenBank Accession No.: CB072629), while SXDF0202 and SXDF0203 were found to be highly homologous to seven known chicken ESTs and chicken mRNA for gizzard smooth muscle myosin heavy chain. 5'-RACE was employed to extend the SXDF0201 to 544 bp which was confirmed as novel in BLAST search. The temporal and spatial expression of SXDF0201 and SXDF0202 were also investigated with semi-quantitative RT-PCR. The result showed that: both SXDF0201 and SXDF0202 were found to be expressed in hypothalamus, pituitary, muscle, liver, and fat tissues of Shaoxing ducks; SXDF0201 was expressed significantly higher in ovaries of 30-day-old Shaoxing ducks compared with that of 60-day-old (P < 0.05) and 90-day-old (P = 0.015), but the expression of SXDF0202 showed no difference throughout the ovarian development; granulose layers expressed higher SXDF0201 than theca layers in almost all hierarchical follicles, the expression of SXDF0202 in granulose layers increased along with follicular maturation (P < 0.01) from Fw to F3 follicles, but decreased dramatically to the lowest in F1 follicles (P < 0.01). In theca layers, the highest expression of SXDF0202 was found in Fw follicles (P < 0.01).

[Expression of mRNAs for GHR, IGF-IR, FSHR and LHR in granulosa and theca layers of ovarian follicles of Shaoxing ducks].

Expression of genes encoding growth hormone receptor (GHR), type I insulin-like growth factor receptor (IGF-IR), follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) was measured in granulosa and theca layers of the largest (F1), third largest (F3), fifth largest (F5) preovulatory follicles and large white follicles (LWF) in the ovary of Shaoxing ducks, with relative quantitative reverse transcription-polymerase chain reaction (RT-PCR) using beta-actin as an internal standard. The results showed that GHR mRNA was more abundant in theca layer than in granulosa layer in all the follicles investigated, in theca layer, the LWF follicle expressed highest the level of GHR mRNA, while no differences in granulosa layer were observed among follicles at different stages of development. In contrast, the expression of IGF-IR mRNA in theca layer was evidently lower than that in granulosa layer, but no significant changes were found among different stages of follicles in either layers, except that LWF trended to express higher IGF-IR mRNA in the theca layer compared to other preovulatory follicles. Similar to IGF-IR mRNA, FSHR mRNA was more abundant in granulosa layer and no significant differences were found among different stages of follicles in either layers. In contrast, the expression of LHR mRNA followed a different pattern. In the theca layer, the expression level maintained consistent, while in the granulosa layer, a significant stepwise increase was observed as the follicles matured, resulting in higher mRNA level of LHR in the granulosa layer of largest follicles (F1), but lower mRNA level of LHR in the granulosa layer of smaller follicles (F5 and LWF). These results suggest that GH and IGF-I regulate ovary function by respective dominant sites in the follicles, and they cooperate with LH and FSH to regulate the follicle development via their respective receptors. The high expression of LHR mRNA in granulosa layer of large follicles might be related to the establishment of the follicle hierarchy and ovulation.