Cell-specific expression and immunolocalization of nitric oxide synthase isoforms and soluble guanylyl cyclase α and β subunits in postnatal porcine uteri

Gasotransmitters in pregnancy: from conception to uterine involution

Gasotransmitters are endogenous small gaseous messengers exemplified by nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S or sulfide). Gasotransmitters are implicated in myriad physiologic functions including many aspects of reproduction. Our objective was to comprehensively review basic mechanisms and functions of gasotransmitters during pregnancy from conception to uterine involution and highlight future research opportunities. We searched PubMed and Web of Science databases using combinations of keywords nitric oxide, carbon monoxide, sulfide, placenta, uterus, labor, and pregnancy. We included English language publications on human and animal studies from any date through August 2018 and retained basic and translational articles with relevant original findings. All gasotransmitters activate cGMP signaling. NO and sulfide also covalently modify target protein cysteines. Protein kinases and ion channels transduce gasotransmitter signals, and co-expressed gasotransmitters can be synergistic or antagonistic depending on cell type. Gasotransmitters influence tubal transit, placentation, cervical remodeling, and myometrial contractility. NO, CO, and sulfide dilate resistance vessels, suppress inflammation, and relax myometrium to promote uterine quiescence and normal placentation. Cervical remodeling and rupture of fetal membranes coincide with enhanced oxidation and altered gasotransmitter metabolism. Mechanisms mediating cellular and organismal changes in pregnancy due to gasotransmitters are largely unknown. Altered gasotransmitter signaling has been reported for preeclampsia, intrauterine growth restriction, premature rupture of membranes, and preterm labor. However, in most cases specific molecular changes are not yet characterized. Nonclassical signaling pathways and the crosstalk among gasotransmitters are emerging investigation topics.

Expression of bone morphogenetic protein 2, 4, and related components of the BMP signaling pathway in the mouse uterus during the estrous cycle

The objective was to investigate the expression of bone morphogenetic protein (BMP) family members in the mouse uterus during the estrous cycle by real-time polymerase chain reaction (PCR) and immunohistochemistry. Uterine samples from Swiss ICR mice were collected and dissected free of surrounding tissue. One uterine horn was snap frozen in liquid nitrogen immediately after collection and stored at -80 °C for RNA extraction, and the other was fixed in 40 mg/ml paraformaldehyde at room temperature for immunolocalization of BMP2 protein. Real-time PCR analysis showed that the expression level of Bmp2 was significantly higher at proestrus than at estrus and metestrus (P<0.05). The relative abundance of Bmp4 exhibited significant fluctuations, but there were no statistically significant differences between the expression levels of Bmp2 and Bmp4 (P>0.05). The expression levels of Bmpr1a and Bmpr2 remained unchanged during estrous cycles. However, the level of Bmpr1b mRNA decreased significantly at estrus (P<0.05), increasing subsequently at metestrus. Furthermore, the level of Bmpr1b mRNA was significantly lower than those of Bmpr1a and Bmpr2 mRNA at the corresponding stages (P<0.05). All three receptor-regulated Smads (R-Smads) detected were differentially expressed in the mouse uterus and the expression levels of Smad1 and Smad5 were significantly higher than that of Smad8 (P<0.05). In addition, the expression level of Smad4 did not change substantially throughout the estrous cycle. Immunohistochemical experiments revealed that BMP2 protein was differentially expressed and localized mainly in the uterine luminal and glandular epithelial cells throughout the estrous cycle. In conclusion, our results provide information about the variation in the mRNA levels of Bmp2 and Bmp4 and related components of the BMP signaling pathway. The data provide quantitative and useful information about the roles of endometrial BMP proposed and demonstrated by others, such as the degradation and remodeling of the endometrium.

Effects of thyroid hormones on the antioxidative status in the uterus of young adult rats

Thyroid hormones and oxidative stress play significant roles in the normal functioning of the female reproductive system. Nitric oxide (NO), a free radical synthesized by nitric oxide synthases (NOS), participates in the regulation of thyroid function and is also a good biomarker for assessment of the oxidative stress status. Therefore, the purpose of this study was to investigate effects of thyroid hormones on uterine antioxidative status in young adult rats. Thirty immature female Sprague-Dawley rats were randomly divided into three groups: control, hypothyroid (hypo-T) and hyperthyroid (hyper-T). The results showed the body weights decreased significantly in both the hypo-T and hyper-T groups and that uterine weights were decreased significantly in the hypo-T group. The serum concentrations of total triiodothyronine (T3) and thyroxine (T4), as well as estradiol (E2), were significantly decreased in the hypo-T group, but increased in the hyper-T group. The progesterone (P4) concentrations in the hypo- and hyperthyroid rats markedly decreased. Immunohistochemistry results provided evidence that thyroid hormone nuclear receptor α/β (TRα/β) and three NOS isoforms were located in different cell types of rat uteri. The NO content and total NOS and inducible NOS (iNOS) activities were markedly diminished in the hypo-T group but increased in the hyper-T group. Moreover, the activities of both glutathione peroxidase (GSH-Px) and catalase (CAT) exhibited significant decreases and increases in the hypo-T and hyper-T groups, respectively. The malondialdehyde (MDA) contents in both the hypo-T and hyper-T groups showed a significant increase. Total superoxide dismutase (T-SOD) activity in the hypo- and hyper-T rats markedly decreased. In conclusion, these results indicated that thyroid hormones have an important influence on the modulation of uterine antioxidative status.

Different approaches for interpretation and reporting of immunohistochemistry analysis results in the bone tissue - a review

BACKGROUND

Immunohistochemistry (IHC) is a well-established, widely accepted method in both clinical and experimental parts of medical science. It allows receiving valuable information about any process in any tissue, and especially in bone. Each year the amount of data, received by IHC, grows in geometric progression. But the lack of standardization, especially on the post-analytical stage (interpreting and reporting of results), makes the comparison of the results of different studies impossible.

METHODS

Comprehensive PubMED literature search with a combination of search words "immunohistochemistry" and "scoring system" was performed and 773 articles describing IHC results were identified. After further manual analysis 120 articles were selected for detailed evaluation of used approaches.

RESULTS

Six major approaches to the interpretation and presentation of IHC analysis results were identified, analyzed and described.

CONCLUSIONS

The overview of the existing approaches in evaluation and interpretation of IHC data, which are provided in the article, can be used in bone tissue research and for either better understanding of existing scoring systems or developing a new one. Standard multiparametric, semiquantitative IHC scoring systems should simplify and clarify the process of interpretation and reporting of received data.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_221.

Protective effects of Big-leaf mulberry and physiological roles of nitric oxide synthases in the testis of mice following water immersion and restraint stress

Big-leaf mulberry is a new hybrid plant from the application of cell engineering technology, but its effect in stress-induced testicular dysfunction is unknown. Nitric oxide (NO) is a tiny, highly reactive lipophilic molecule produced by nitric oxide synthases (NOS). Three isoforms of NOS (neuronal NOS, inducible NOS and endothelial NOS) have been identified. Our aim was to investigate the effect of water immersion and restraint stress (WIRS) on NOS in the testis, and the effect of Big-leaf mulberry to protect against WIRS. The activity and expression of NOS, and total antioxidant capacity (T-AOC) in the mouse testis of different treatment groups (non-WIRS, 3 h-WIRS, WIRS-recovery) were examined. Histological analysis of WIRS-induced testicular damage and immunohistochemical staining of NOS were also analyzed. Results demonstrated that WIRS-exposed mice produced several injuries and showed an increased iNOS and eNOS mRNA expression in testes, whereas pretreatment with Big-leaf mulberry down-regulated iNOS and eNOS mRNA expressions and up-regulated T-AOC activities. Immunohistochemical studies showed that both iNOS and eNOS were localized in germ cells, spermatozoa and blood vessels in addition to Leydig cells and Sertoli cells, but nNOS was not present in these areas. In conclusion, our results suggested that Big-leaf mulberry exerted a protective effect on WIRS-induced testicular dysfunction, and iNOS and eNOS appeared to exert an important action in mouse testes exposed to WIRS.