The novel SARS-coronavirus 2 (SARS-CoV-2) poses a global challenge on healthcare and society. For understanding the susceptibility for SARS-CoV-2 infection, the cell type-specific expression of the host cell surface receptor is necessary. The key protein suggested to be involved in host cell entry is angiotensin I converting enzyme 2 (ACE2). Here, we report the expression pattern of ACE2 across > 150 different cell types corresponding to all major human tissues and organs based on stringent immunohistochemical analysis. The results were compared with several datasets both on the mRNA and protein level. ACE2 expression was mainly observed in enterocytes, renal tubules, gallbladder, cardiomyocytes, male reproductive cells, placental trophoblasts, ductal cells, eye, and vasculature. In the respiratory system, the expression was limited, with no or only low expression in a subset of cells in a few individuals, observed by one antibody only. Our data constitute an important resource for further studies on SARS-CoV-2 host cell entry, in order to understand the biology of the disease and to aid in the development of effective treatments to the viral infection.

https://www.embopress.org/doi/pdf/10.15252/msb.20209610

The protein expression profile of ACE2 in human tissues.

The novel SARS-coronavirus 2 (SARS-CoV-2) poses a global challenge on healthcare and society. For understanding the susceptibility for SARS-CoV-2 infection, the cell type-specific expression of the host cell surface receptor is necessary. The key protein suggested to be involved in host cell entry is Angiotensin I converting enzyme 2 (ACE2). Here, we report the expression pattern of ACE2 across >150 different cell types corresponding to all major human tissues and organs based on stringent immunohistochemical analysis. The results were compared with several datasets both on the mRNA and protein level. ACE2 expression was mainly observed in enterocytes, renal tubules, gallbladder, cardiomyocytes, male reproductive cells, placental trophoblasts, ductal cells, eye and vasculature. In the respiratory system, the expression was limited, with no or only low expression in a subset of cells in a few individuals, observed by one antibody only. Our data constitutes an important resource for further studies on SARS-CoV-2 host cell entry, in order to understand the biology of the disease and to aid in the development of effective treatments to the viral infection.

https://biorxiv.org/content/10.1101/2020.03.31.016048v1.full.pdf

The protein expression profile of ACE2 in human tissues

AGA Institute Rapid Review of the Gastrointestinal and Liver Manifestations of COVID-19, Meta-Analysis of International Data, and Recommendations for the Consultative Management of Patients with COVID-19.

A Single-Cell RNA Expression Map of Human Coronavirus Entry Factors

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) disease (COVID-19) appears to have a higher mortality rate in presence of comorbidities and in men. The latter suggests the presence of a possible sex-dependent susceptibility. An enzymatic system involved in this different predisposition could be represented by angiotensin converting enzyme 2 (ACE2). ACE2 is activated and down-regulated by the spike protein of the virus and allows the penetration of SARS-CoV-2 into epithelial cells and myocardium. Data on the experimental animal have shown that 17s-estradiol increases the expression and activity of ACE2 in both adipose tissue and kidney. Spontaneously hypertensive male mice have a higher myocardial ACE2 expression than females and its levels decrease after orchiectomy. In addition to this first aspect, the recent evidence of an increased frequency of venous thromboembolism in patients with COVID-19 (a clinical element associated with a worse prognosis) calls the attention on the safety of treatment with testosterone, in particular in hypogonadal men with greater genetic predisposition. Evidence that sex hormones are able to modulate the expression of ACE2 could help in interpreting epidemiological results and in designing more appropriate intervention strategies. Moreover, the vitamin D deficiency in elderly men may be worthy of further study regarding the epidemiological aspects of this different susceptibility and lethality between sexes.

https://www.mdpi.com/1422-0067/21/8/2948/pdf

Sex-Specific SARS-CoV-2 Mortality: Among Hormone-Modulated ACE2 Expression, Risk of Venous Thromboembolism and Hypovitaminosis D.

Since SARS-CoV-2 infection was first identified in December 2019, it spread rapidly and a global pandemic of COVID-19 has occurred. ACE2, the receptor for entry into the target cells by SARS-CoV-2, was found to abundantly express in testes, including spermatogonia, Leydig and Sertoli cells. However, there is no clinical evidence about whether SARS-CoV-2 infection can affect male gonadal function so far. In this study, we compared the sex-related hormones between 81 reproductive-aged men with SARS-CoV-2 infection and 100 age-matched healthy men, and found that serum luteinizing hormone (LH) was significantly increased, but the ratio of testosterone (T) to LH and the ratio of follicle stimulating hormone (FSH) to LH were dramatically decreased in males with COVID-19. Besides, multivariable regression analysis indicated that c-reactive protein (CRP) level was significantly associated with serum T:LH ratio in COVID-19 patients. This study provides the first direct evidence about the influence of medical condition of COVID-19 on male sex hormones, alerting more attention to gonadal function evaluation among patients recovered from SARS-CoV-2 infection, especially the reproductive-aged men.

/pdf/effect-of-sars-cov-2-infection-upon-male-gonadal-function-a-1c8pqib3oo.pdf

Effect of SARS-CoV-2 infection upon male gonadal function: A single center-based study

This study examined the impact of 935MHz phone-simulating electromagnetic radiation on embryo implantation of pregnant mice. Each 7-week-old Kunming (KM) female white mouse was set up with a KM male mouse in a single cage for mating overnight after induction of ovulation. In the first three days of pregnancy, the pregnant mice was exposed to electromagnetic radiation at low-intensity (150 μW/cm(2), ranging from 130 to 200 μW/cm(2), for 2- or 4-h exposure every day), mid-intensity (570 μW/cm(2), ranging from 400 to 700 μW/cm(2), for 2- or 4-h exposure every day) or high-intensity (1400 μW/cm(2), ranging from 1200 to 1500 μW/cm(2), for 2- or 4-h exposure every day), respectively. On the day 4 after gestation (known as the window of murine embryo implantation), the endometrium was collected and the suspension of endometrial glandular cells was made. Laser scanning microscopy was employed to detect the mitochondrial membrane potential and intracellular calcium ion concentration. In high-intensity, 2- and 4-h groups, mitochondrial membrane potential of endometrial glandular cells was significantly lower than that in the normal control group (P<0.05). The calcium ion concentration was increased in low-intensity 2-h group but decreased in high-intensity 4-h group as compared with the normal control group (P<0.05). However, no significant difference was found in mitochondrial membrane potential of endometrial glandular cells between low- or mid-intensity groups and the normal control group, indicating stronger intensity of the electromagnetic radiation and longer length of the radiation are required to inflict a remarkable functional and structural damage to mitochondrial membrane. Our data demonstrated that electromagnetic radiation with a 935-MHz phone for 4 h conspicuously decreased mitochondrial membrane potential and lowered the calcium ion concentration of endometrial glandular cells. It is suggested that high-intensity electromagnetic radiation is very likely to induce the death of embryonic cells and decrease the chance of their implantation, thereby posing a high risk to pregnancy.

Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation

The endometrial basal layer is essential for endometrial regeneration, whose disruption leads to thin endometrium or intrauterine adhesion (IUA) with an unsatisfactory prognosis. Emerging data indicate that platelet-rich plasma (PRP) can promote endometrial proliferation, but the mechanism by which PRP regulates endometrial regeneration remains unclear. Herein, we investigated the therapeutic effects and possible mechanisms of PRP on endometrial regeneration. IUA animal model was generated by sham, mechanically damaging endometrium with or without PRP for 10 days. The uterine section in the model group showed degenerative changes with a narrow endometrial lumen, atrophic columnar epithelium, decreased number of endometrial glands, decreased endometrial thickness, and increased collagen deposition. The above disruption could be ameliorated by the PRP. Transcriptome sequencing analysis displayed that the retinol metabolism pathway and extracellular matrix (ECM) receptor interaction pathway were up-regulated and enriched in differential expression genes (DEGs). Melanotransferrin (MELTF) was the key up-regulated gene in PRP-induced endometrial regeneration, which was verified in vivo and in vitro. Ferroptosis, autophagy, and pyroptosis were down-regulated in PRP-treated Ishikawa cells. Conclusively, PRP promotes endometrium regeneration by up-regulating the retinol metabolism and ECM receptor interaction pathway with MELTF. Meanwhile, PRP could also inhibit endometrial epithelial cell death by regulating ferroptosis, autophagy, and pyroptosis. 

/pdf/meltf-might-regulate-ferroptosis-pyroptosis-and-autophagy-in-vfo78ees.pdf

MELTF Might Regulate Ferroptosis, Pyroptosis, and Autophagy in Platelet-Rich Plasma-Mediated Endometrial Epithelium Regeneration

This study evaluated the effect of intrauterine perfusion of autologous platelet-rich plasma (PRP) on pregnancy outcomes in women with recurrent implantation failure (RIF). Key biomedical databases were searched to identify relevant clinical trials and observational studies. Outcomes included clinical pregnancy rate, chemical pregnancy rate, implantation rate, live birth rate, and abortion rate. Data was extracted from ten studies (six randomised controlled trials, four cohort studies) involving 1555 patients. Pregnancy outcomes were improved in women treated with PRP compared to controls: clinical pregnancy rate (RR = 1.96, 95% CI [1.67, 2.31], p < 0.00001, I2 = 46%), chemical pregnancy rate (RR = 1.79, 95% CI [1.54, 2.08], p < 0.00001, I2 = 29%), implantation rate (RR = 1.90, CI [1.50, 2.41], p < 0.00001, I2 = 0%), live birth rate (RR = 2.83, CI [1.45, 5.52], p = 0.0007, I2 = 83%), abortion rate (RR = 0.40, 95% CI [0.18, 0.90], p = 0.03, I2 = 59%). These data imply PRP has potential to improve pregnancy outcomes in women with RIF, suggesting a promising role in assisted reproductive technology.IMPACT STATEMENTWhat is already known on this subject? Platelet-rich plasma (PRP) is an autologous blood product that contains platelets, various growth factors, and cytokines at concentrations above the normal baseline level. Recent studies have shown that intrauterine infusion of autologous PRP can improve pregnancy outcomes in infertile women.What do the results of this study add? This systematic review and meta-analysis of data from ten studies (n = 1555; 775 cases and 780 controls) investigated the effect of intrauterine perfusion of autologous PRP on pregnancy outcomes in women with recurrent implantation failure (RIF). Findings suggest that pregnancy outcomes, including clinical pregnancy rate, chemical pregnancy rate, implantation rate, live birth rate and abortion rate were improved in women treated with PRP compared to controls.What are the implications of these findings for clinical practice and/or further research? RIF remains a challenge for researchers, clinicians, and patients. Our study identified PRP as a potential intervention in assisted reproduction. As an autologous blood preparation, PRP eliminates the risk of an immune response and transmission of disease. PRP is low cost and effective and may represent a new approach to the treatment of patients with RIF.

Effect of intrauterine infusion of platelet-rich plasma for women with recurrent implantation failure: a systematic review and meta-analysis.

Abstract Background As a member of RNA-binding protein, CDKN2AIP has been shown to play a critical role in stem cell pluripotency and somatic differentiation. Recent studies indicate that Cdkn2aip is essential for spermatogonial self-renewal and proliferation through the activating Wnt-signaling pathway. However, the mechanisms of how Cdkn2aip regulate spermatogenesis is poorly characterized. Results We discovered that the CDKN2AIP was expressed in spermatocyte as well as spermatids and participated in spermiogenesis. Cdkn2aip −/− mice exhibited multiple sperm head defects accompanied by age dependent germ cell loss that might be result of protamine replacement failure and impaired SUN1 expression. Loss of Cdkn2aip expression in male mice resulted in synapsis failure in 19% of all spermatocytes and increased apoptosis due to damaged DNA double-strand break (DSB) repair and crossover formation. In vitro, knockdown of Cdkn2aip was associated with extended S phase, increased DNA damage and apoptosis. Conclusions Our findings not only identified the importance of CDKN2AIP in spermiogenesis and germ cell development, but also provided insight upon the driving mechanism. 

/pdf/cdkn2aip-is-critical-for-spermiogenesis-and-germ-cell-m2vjv3i7.pdf

Ling Ma

Papers

Effect of SARS-CoV-2 infection upon male gonadal function: A single center-based study

Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation

MELTF Might Regulate Ferroptosis, Pyroptosis, and Autophagy in Platelet-Rich Plasma-Mediated Endometrial Epithelium Regeneration

Effect of intrauterine infusion of platelet-rich plasma for women with recurrent implantation failure: a systematic review and meta-analysis.

CDKN2AIP is critical for spermiogenesis and germ cell development