CD147 is required for matrix metalloproteinases-2 production and germ cell migration during spermatogenesis

SARS-CoV-2-associated lymphopenia: possible mechanisms and the role of CD147

T lymphocytes play a primary role in the adaptive antiviral immunity. Both lymphocytosis and lymphopenia were found to be associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While lymphocytosis indicates an active anti-viral response, lymphopenia is a sign of poor prognosis. T-cells, in essence, rarely express ACE2 receptors, making the cause of cell depletion enigmatic. Moreover, emerging strains posed an immunological challenge, potentially alarming for the next pandemic. Herein, we review how possible indirect and direct key mechanisms could contribute to SARS-CoV-2-associated-lymphopenia. The fundamental mechanism is the inflammatory cytokine storm elicited by viral infection, which alters the host cell metabolism into a more acidic state. This "hyperlactic acidemia" together with the cytokine storm suppresses T-cell proliferation and triggers intrinsic/extrinsic apoptosis. SARS-CoV-2 infection also results in a shift from steady-state hematopoiesis to stress hematopoiesis. Even with low ACE2 expression, the presence of cholesterol-rich lipid rafts on activated T-cells may enhance viral entry and syncytia formation. Finally, direct viral infection of lymphocytes may indicate the participation of other receptors or auxiliary proteins on T-cells, that can work alone or in concert with other mechanisms. Therefore, we address the role of CD147-a novel route-for SARS-CoV-2 and its new variants. CD147 is not only expressed on T-cells, but it also interacts with other co-partners to orchestrate various biological processes. Given these features, CD147 is an appealing candidate for viral pathogenicity. Understanding the molecular and cellular mechanisms behind SARS-CoV-2-associated-lymphopenia will aid in the discovery of potential therapeutic targets to improve the resilience of our immune system against this rapidly evolving virus.

CD147 mediates S protein pseudovirus of SARS-CoV-2 infection and its induction of spermatogonia apoptosis

Male cases diagnosed COVID-19 with more complications and higher mortality compared with females, and the overall consequences of male sex hormones and semen parameters deterioration were observed in COVID-19 patients, whereas the involvement and mechanism for spermatogenic cell remains unclear. The study was aimed to investigate the infection mode of S protein (D614G) pseudovirus (pseu-S-D614G) to spermatogenic cells, as well as the influence on cell growth. Both mouse spermatogonia (GC-1 cell, immortalized spermatogonia) and spermatocyte (GC-2 cell, immortalized spermatocytes) were used to detect the infection of pseu-S-D614G of SARS-CoV-2, and further explored the effect of SARS-CoV-2-spike protein (S-protein) and SARS-CoV-2-spike protein (omicron) (O-protein) on GC-1 cell apoptosis and proliferation. The data showed that the pseu-S-D614G invaded into GC-1 cells through either human ACE2 (hACE2) or human CD147 (hCD147), whereas GC-2 cells were insensitive to viral infection. In addition, the apoptosis and proliferation suppression inflicted by S-protein and O-protein on GC-1 cells was through Bax-Caspase3 signaling rather than arresting cell cycle progression. These findings suggest that CD147, apart from ACE2, may be a potential receptor for SARS-CoV-2 infection in testicular tissues, and that the apoptotic effect was induced in spermatogonia cells by S-protein or O-protein, eventually resulted in the damage to male fertility.

In vivo CRISPR screening directly targeting testicular cells

CRISPR-Cas9 short guide RNA (sgRNA) library screening is a powerful approach to understand the molecular mechanisms of biological phenomena. However, its in vivo application is currently limited. Here, we developed our previously established in vitro revival screening method into an in vivo one to identify factors involved in spermatogenesis integrity by utilizing sperm capacitation as an indicator. By introducing an sgRNA library into testicular cells, we successfully pinpointed the retinal degeneration 3 (Rd3) gene as a significant factor in spermatogenesis. Single-cell RNA sequencing (scRNA-seq) analysis highlighted the high expression of Rd3 in round spermatids, and proteomics analysis indicated that Rd3 interacts with mitochondria. To search for cell-type-specific signaling pathways based on scRNA-seq and proteomics analyses, we developed a computational tool, Hub-Explorer. Through this, we discovered that Rd3 modulates oxidative stress by regulating mitochondrial distribution upon ciliogenesis induction. Collectively, our screening system provides a valuable in vivo approach to decipher molecular mechanisms in biological processes.

Genomic evolution of island birds from the view of the Swinhoe's pheasant (Lophura swinhoii)

Island endemic birds account for the majority of extinct vertebrates in the past few centuries. To date, the evolutionary characteristics of island endemic bird's is poorly known. In this research, we de novo assembled a high-quality chromosome-level reference genome for the Swinhoe's pheasant, which is a typical endemic island bird. Results of collinearity tests suggest rapid ancient chromosome rearrangement that may have contributed to the initial species radiation within Phasianidae, and a role for the insertions of CR1 transposable elements in rearranging chromosomes in Phasianidae. During the evolution of the Swinhoe's pheasant, natural selection positively selected genes involved in fecundity and body size functions, at both the species and population levels, which reflect genetic variation associated with island adaptation. We further tested for variation in population genomic traits between the Swinhoe's pheasant and its phylogenetically closely related mainland relative the silver pheasant, and found higher levels of genetic drift and inbreeding in the Swinhoe's pheasant genome. Divergent demographic histories of insular and mainland bird species during the last glacial period may reflect the differing impact of insular and continental climates on the evolution of species. Our research interprets the natural history and population genetic characteristics of the insular endemic bird the Swinhoe's pheasant, at a genome-wide scale, provides a broader perspective on insular speciation, and adaptive evolution and contributes to the genetic conservation of island endemic birds.

Eif2s3y alleviated LPS-induced damage to mouse testis and maintained spermatogenesis by negatively regulating Adamts5

Eif2s3y (eukaryotic translation initiation factor 2, subunit 3, structural gene Y-linked, Eif2s3y) is an essential gene for spermatogenesis. Early studies have shown that Eif2s3y can promote the proliferation of spermatogonial stem cells (SSCs) and can replace the Y chromosome together with sex-determining region Y (Sry) to transform SSCs into round spermatozoa. We injected lentiviral particles into the seminiferous tubules of mouse testes by sterile surgery surgically to establish overexpressing Eif2s3y testes. And then the mice were intraperitoneally injected with LPS to established the model of testis inflammation. Through RNA sequencing, qRT-PCR analysis, Western blot, co-culture etc., we found that Eif2s3y alleviated LPS-induced damage in mouse testes and maintained spermatogenesis. In testes with Eif2s3y overexpression, the seminiferous tubules were more regularly organized after exposure to LPS compared with the control. Eif2s3y performs its function by negatively regulating Adamts5 (a disintegrin and metalloproteinase containing a thrombospondin-1 motif), an extracellular matrix-degrading enzyme. ADAMTS5 shows a disruptive effect when the testis is exposed to LPS. Overexpression of Eif2s3y inhibited the TLR4/NFκB signaling pathway in the testis in response to LPS. Generally, our research shows that Eif2s3y protects the testis from LPS and maintains spermatogenesis by negatively regulating Adamts5.

SARS-CoV-2 and male infertility: from short- to long-term impacts

PURPOSE

The coronavirus 2019 (COVID-19) pandemic-caused by a new type of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-has posed severe impacts on public health worldwide and has resulted in a total of > 6 million deaths. Notably, male patients developed more complications and had mortality rates ~ 77% higher than those of female patients. The extensive expression of the SARS-CoV-2 receptor and related proteins in the male reproductive tract and the association of serum testosterone levels with viral entry and infection have brought attention to COVID-19's effects on male fertility.

METHODS

The peer-reviewed articles and reviews were obtained by searching for the keywords SARS-CoV-2, COVID-19, endocrine, spermatogenesis, epididymis, prostate, and vaccine in the databases of PubMed, Web of Science and Google Scholar from 2020-2022.

RESULTS

This review summarizes the effects of COVID-19 on the male reproductive system and investigates the impact of various types of SARS-CoV-2 vaccines on male reproductive health. We also present the underlying mechanisms by which SARS-CoV-2 affects male reproduction and discuss the potentially harmful effects of asymptomatic infections, as well as the long-term impact of COVID-19 on male reproductive health.

CONCLUSION

COVID-19 disrupted the HPG axis, which had negative impacts on spermatogenesis and the epididymis, albeit further investigations need to be performed. The development of vaccines against various SARS-CoV-2 variations is important to lower infection rates and long-term COVID risks.

CD147 Facilitates the Pathogenesis of Psoriasis through Glycolysis and H3K9me3 Modification in Keratinocytes

Psoriasis is a chronic inflammatory skin disease featuring rapid proliferation of epidermal cells. Although elevated glycolysis flux has been reported in psoriasis, the molecular mechanisms underlying its pathogenesis remain unclear. We investigated the role of the integral membrane protein CD147 in psoriasis pathogenesis, observing its high expression in psoriatic skin lesions of humans and imiquimod (IMQ)-induced mouse models. In mouse models, genomic deletion of epidermal CD147 markedly attenuated IMQ-induced psoriatic inflammation. We found that CD147 interacted with glucose transporter 1 (Glut1). Depletion of CD147 in the epidermis blocked glucose uptake and glycolysis in vitro and in vivo. In CD147-knockout mice and keratinocytes, oxidative phosphorylation was increased in the epidermis, indicating CD147's pivotal role in glycolysis reprogramming during pathogenesis of psoriasis. Using non-targeted and targeted metabolic techniques, we found that epidermal deletion of CD147 significantly increased the production of carnitine and α-ketoglutaric acid (α-KG). Depletion of CD147 also increased transcriptional expression and activity of γ-butyrobetaine hydroxylase (γ-BBD/BBOX1), a crucial molecule for carnitine metabolism, by inhibiting histone trimethylations of H3K9. Our findings demonstrate that CD147 is critical in metabolic reprogramming through the α-KG-H3K9me3-BBOX1 axis in the pathogenesis of psoriasis, indicating that epidermal CD147 is a promising target for psoriasis treatment.

MMPs, ADAMs and ADAMTSs are associated with mammalian sperm fate

Metalloproteinases include matrix metalloproteinases and disintegrin metalloproteinases. They are important members of the ECM degradation and reconstruction process and are associated with tissue development and disease. The ECM is a three-dimensional network of large molecules consisting of a variety of proteins. It is a physical scaffold for organs, and all types of cells can be found within the ECM. The testicle, where sperm are produced, is an organ that is constantly in dynamic flux. Metalloproteinases can regulate testicular tissue development and the maturation of sperm by affecting the ECM. Metalloproteinase disorders can lead to cryptorchidism, azoospermia, poor semen quality and other diseases. As a member of the metalloproteinase family, ADAMTS plays an important role in testicular slippage to the scrotum. ADAM is involved in the fertilization process, and excessive MMP can damage the BTB. In the testis, metalloproteinase stability represents the stability of the extracellular microenvironment in which germ cells are located and is associated with reproductive function. Metalloproteinases have a definite relationship with male reproduction, but the underlying mechanism is still unclear. This paper summarizes the literature on various metalloproteinases in testicular tissue physiology and pathology to elucidate their role in reproductive function and male reproductive mechanisms.

Regulation of Traction Force through the Direct Binding of Basigin and Calpain 4

Traction force and mechanosensing (the ability to sense mechanical attributes of the environment) are two important factors used by a cell to modify behavior during migration. Previously it was determined that the calpain small subunit, calpain 4, regulates the production of traction force independent of its proteolytic holoenzyme. A proteolytic enzyme is formed by calpain4 binding to either of its catalytic partners, calpain 1 and 2. To further understand how calpain 4 regulates traction force, we used two-hybrid analysis to identify more components of the traction pathway. We discovered that basigin, an integral membrane protein and a documented matrix-metalloprotease (MMP) inducer binds to calpain 4 in two-hybrid and pull-down assays. Traction force was deficient when basigin was silenced in MEF cells, and defective in substrate adhesion strength. Consistent with Capn4 ^-/- MEF cells, the cells deficient in basigin responded to localized stimuli. Together these results implicate basigin in the pathway in which calpain 4 regulates traction force independent of the catalytic large subunits.

CD147 and MMPs as key factors in physiological and pathological processes

Cluster of differentiation 147 (CD147) or extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that induces the synthesis of matrix metalloproteinases (MMPs). MMPs, as zinc-dependent proteases and versatile enzymes, play critical roles in the degradation of the extracellular matrix (ECM) components, cleaving of the receptors of cellular surfaces, signaling molecules, and other precursor proteins, which may lead to attenuation or activation of such targets. CD147 and MMPs play essential roles in physiological and pathological conditions and any disorder in the expression, synthesis, or function of CD147 and MMPs may be associated with various types of disease. In this review, we have focused on the roles of CD147 and MMPs in some major physiological and pathological processes.

Defb19 regulates the migration of germ cell and is involved in male fertility

β-defensins are small antimicrobial peptides that play essential roles in male fertility. Although several members of the β-defensin family are preferentially expressed in the testis, their involvement in spermatogenesis remains elusive. In this study, we have characterized the expression and function of Defb19 in mouse testis. Our results showed that Defb19 is expressed in both Sertoli cells and germ cells. Overexpression of Defb19 in the 15P-1 Sertoli cell line decreases the expression of cell junction molecules and promotes the matrix adhesion and migration of Sertoli cells. Recombinant DEFB19 and conditioned medium of Defb19-overexpressed 15P-1 cells promote the migration of GC2-spd spermatocyte cell line. Knockout of Defb19 in mouse by CRISPR/Cas9 resulted in male subfertility with testicular and epididymal atrophy. A marked increase in apoptosis and a significant decrease in the sperm count were observed in the KO mice. Together, our study has uncovered an important role of Defb19 in male fertility by regulating the migration of both the Sertoli cells and the germ cells. Our study has shed new light on the functions of β-defensins in the testis.

CD147 deficiency is associated with impairedsperm motility/acrosome reaction and offersa therapeutic target for asthenozoospermia

Patients with asthenozoospermia often present multiple defects in sperm functions apart from a decrease in sperm motility. However, the etiological factors underlying these multifaceted defects remain mostly unexplored, which may lead to unnecessary treatment and unsatisfactory assisted reproductive technologies (ART) outcome. Here, we show that the protein levels of CD147 were lowered in sperm obtained from asthenozoospermic infertile patients exhibiting defects in both sperm motility and the acrosome reaction. Whereas CD147 maintained sperm motility before capacitation, female tract-derived soluble CD147 interacted with sperm-bound CD147 to induce an acrosome reaction in capacitated sperm. Soluble CD147 treatment restored the acrosome reaction and improved the fertility of sperm from patients with asthenozoospermia. Mechanistically, CD147 promotes sperm motility and acrosome reaction (AR) by eliciting Ca²⁺ influx through soluble CD147 binding to sperm-bound CD147. Notably, the level of soluble CD147 in seminal plasma was positively correlated with the fertilization rate and pregnancy outcome in infertile couples undergoing in vitro fertilization. Our study has identified a marker for the diagnosis and a therapeutic target for the defective AR capability in asthenozoospermia and a candidate for the prediction of in vitro fertilization outcomes for male infertile patients that facilitates the development of precision medicine in ART.

The probable mechanism of reduced androgen level in COVID-19 patients

COVID-19, caused by the SARS-CoV-2, has challenged the health care systems of the world. Although the pulmonary complications of the infection have received extensive attention, addressing the other complications (e.g., changes in androgen levels) could further provide a more efficient understanding of the disease, which might aid in combating it. Since the association between androgens and the expression and activity of SARS-CoV-2 receptors has been proven and anti-androgen-based therapies have been considered in this regard, addressing various aspects of androgen level changes can be constructive. The present paper examines the possible mechanisms of changes in androgen levels by the virus. It seems that the infection of the gonads by the SARS-CoV-2 could reduce the androgen levels by affecting different cellular pathways.

Alterations of mRNA and lncRNA profiles associated with the extracellular matrix and spermatogenesis in goats

Objective

Spermatozoa are produced within the seminiferous tubules after sexual maturity. The expression levels of mRNAs and lncRNAs in testicular tissues are different at each stage of testicular development and are closely related to formation of the extracellular matrix (ECM) and spermatogenesis. Therefore, we set out to study the expression of lncRNAs and mRNAs during the different developmental stages of the goat testis.

Methods

We constructed 12 RNA libraries using testicular tissues from goats aged 3, 6, and 12 months, and studied the functions of mRNAs and lncRNAs using the gene ontogeny (GO) and Kyoto encyclopedia of genes and genomes (KEGG) databases. Relationships between differentially expressed genes (DEGs) were analyzed by lncRNA-mRNA co-expression network and protein-protein interaction network (PPI). Finally, the protein expression levels of matrix metalloproteinase 2 (MMP2), insulin-like growth factor 2 (IGF2), and insulin-like growth factor-binding protein 6 (IGFBP6) were detected by western blotting.

Results

We found 23, 8, and 135 differentially expressed lncRNAs and 161, 12, and 665 differentially expressed mRNAs that were identified between 3 vs 6, 6 vs 12, and 3 vs 12 months, respectively. GO, KEGG, and PPI analyses showed that the differential genes were mainly related to the ECM. Moreover, MMP2 was a hub gene and co-expressed with the lncRNA TCONS-0002139 and TCONS-00093342. The results of quantitative reverse-transcription polymerase chain reaction verification were consistent with those of RNA-seq sequencing. The expression trends of MMP2, IGF2, and IGFBP6 protein were the same as that of mRNA, which all decreased with age. IGF2 and MMP2 were significantly different in the 3 vs 6-month-old group (p<0.05).

Conclusion

These results improve our understanding of the molecular mechanisms involved in sexual maturation of the goat testis.

Matrix metalloproteinase (MMP)-2, MMP-9, semen quality and sperm longevity in fractionated stallion semen

Matrix metalloproteinase (MMP)-2 and MMP-9 are gelatinases that take part in several reproductive processes. The aim of this study was to measure levels of MMP-2 and MMP-9 in fractionated stallion ejaculates, and to evaluate the association between these components and semen quality, and sperm longevity during cooled storage. Semen quality were assessed separately for sperm-rich fractions (HIGH), sperm-poor fractions (LOW), and whole ejaculate samples (WE) from 33 stallions. After cooled storage with SP either present or removed, sperm motility and DFI were determined. The relative activity of the pro-form of MMP-2, active MMP-2 and total MMP-9 were evaluated using gelatin zymography, and all were present in all fractions of the stallion's ejaculate, with higher relative activity of the latent than active forms and the highest relative activity in the HIGH fraction. The relative activities of MMP-2 and MMP-9 were positively correlated to sperm concentration and total sperm count, but only in the HIGH fraction and not in LOW or WE. The relative activities of MMPs were not related to differences in sperm longevity during cooled storage, measured as sperm motility and DFI. There was a harmful effect of SP on DFI during storage, but this effect was not associated with differences in the relative activities of MMPs. In conclusion, the relative activities of MMPs are not useful as markers for semen quality (other than sperm concentration), or sperm survival during storage in horses.

miR-4319 inhibited retinoblastoma cells proliferation, migration, invasion and EMT progress via suppressing CD147 mediated MMPs expression

Tumor migration is the critical step that lead to the migration in retinoblastoma (RB), in which microRNAs (miRNAs) play important roles. This study aimed to investigate the role of microRNA-4319 (miR-4319) in the development of retinoblastoma by identifying its targets, as well as its underlying regulatory mechanisms. Our data shown that miR-4319 was downregulated in RB tissues and RB cell lines. Enhanced miR-4319 suppressed cell proliferation, migration, invasion and EMT progress, promoted cell apoptosis in SO-RB50 and RB-Y79 cells. Of note, extracellular matrix metalloproteinase inducer (EMMPRI/CD147) was identified as a direct target gene for miR-4319. MMPs were regulated by CD147 and participated in the miR-4319 regulatory network in SO-RB50 cells. In addition, overexpression of CD147 abrogated the inhibitory effect of miR-4319 on RB cells. In summary, miR-4319 overexpression suppressed cell proliferation, migration and invasion may through suppressing the CD147 mediated MMPs expression, suggesting that miR-4319 may serve as a potential diagnostic biomarker and treatment target for RB.

COVID-19 Mediated by Basigin Can Affect Male and Female Fertility

Coronavirus disease 2019 (COVID-19) prevalence has caused many problems in society and disrupted many regular aspects of life. COVID-19 contains major structural proteins that among them, S protein can promote fusion of the viral and cellular membranes and facilitate the entry of coronavirus into the host cells. Basigin (BSG) is one of the most important receptors for COVID-19 that mediates its entry to host cells. Also, Basigin has an important role in male and female reproduction. Basigin is expressed in the uterus and plays an important role during embryo implantation and needed for successful implantation. Therefore, disruption or inhibition of Basigin causes to a weakness in embryo implantation. Therefore, if a woman or a man is infected with COVID-19, it is recommended that they do not attempt to conception until their treatment is complete. It is also recommended tests for COVID-19 be performed on infertile couples before using assisted reproductive technology (ART).

Long-term exposure to 4G smartphone radiofrequency electromagnetic radiation diminished male reproductive potential by directly disrupting Spock3-MMP2-BTB axis in the testes of adult rats

The correlation between long-term exposure to SRF-EMR and the decline in male fertility is gradually receiving increasing attention from the medical society. While male reproductive organs are often exposed to SRF-EMR, little is currently known about the direct effects of long-term SRF-EMR exposure on the testes and its involvement in the suppression of male reproductive potential. The present study was designed to investigate this issue by using 4G SRF-EMR in rats. A unique exposure model using a 4G smartphone achieved localized exposure to the scrotum of the rats for 6 h each day (the smartphone was kept on active talk mode and received an external call for 1 min over 10 min intervals). Results showed that SRF-EMR exposure for 150 days decreased sperm quality and pup weight, accompanied by testicular injury. However, these adverse effects were not evident in rats exposed to SRF-EMR for 50 days or 100 days. Sequencing analysis and western blotting suggested Spock3 overexpression in the testes of rats exposed to SRF-EMR for 150 days. Inhibition of Spock3 overexpression improved sperm quality decline and alleviated testicular injury and BTB disorder in the exposed rats. Additionally, SRF-EMR exposure suppressed MMP2 activity, while increasing the activity of the MMP14-Spock3 complexes and decreasing MMP14-MMP2 complexes; these results were reversed by Spock3 inhibition. Thus, long-term exposure to 4G SRF-EMR diminished male fertility by directly disrupting the Spock3-MMP2-BTB axis in the testes of adult rats. To our knowledge, this is the first study to show direct toxicity of SRF-EMR on the testes emerging after long-term exposure.

Association between the FAS/FASL Variants and Risk of Male Infertility in Asian Populations; A Systematic Review and Meta-Analysis

Background and Objectives: Studies suggest that FAS/FASL polymorphisms are associated with male infertility; however, their results are still inconclusive. Therefore, this systematic review and meta-analysis aimed to summarize and clarify the overall association of FAS/FASL polymorphisms and risk of male infertility. Materials and Methods: Our search was conducted on the databases of Science Direct, PubMed and Google Scholar. For performing the meta-analysis, pooled odds ratio (OR) values with 95% confidence interval (CI) was applied in order to analyze the strength of association between the FAS/FASL polymorphisms and risk of male infertility. A total of seven relevant studies published up to September 2018 were considered. Results: FASL-844C/T genotype results of 559 patients and 623 healthy individuals were included in our study. For FAS-670A/G genotype effect, 751 patients and 821 healthy individuals were explored. Results showed that all analysis models including dominant, recessive and allelic models of FASL-844C/T and FAS-670A/G polymorphism had no significant effect on infertility in men (p > 0.05 and p > 0.05, respectively). According to sensitivity analysis, our results were stable. Conclusion: We demonstrated that FAS/FASL polymorphisms might not be an effective factor on male reproductive health. For precise determination of FAS/FASL polymorphisms effects on male infertility, large-scale case-control studies should be performed.

Collagenolytic Enzymes and their Applications in Biomedicine

Nowadays, enzymatic therapy is a very promising line of treatment for many different diseases. There is a group of disorders and conditions, caused by fibrotic and scar processes and associated with the excessive accumulation of collagen that needs to be catabolized to normalize the connective tissue content. The human body normally synthesizes special extracellular enzymes, matrix metalloproteases (MMPs) by itself. These enzymes can cleave components of extracellular matrix (ECM) and different types of collagen and thus maintain the balance of the connective tissue components. MMPs are multifunctional enzymes and are involved in a variety of organism processes. However, under pathological conditions, the function of MMPs is not sufficient, and these enzymes fail to deal with disease. Thus, medical intervention is required. Enzymatic therapy is a very effective way of treating such collagen-associated conditions. It involves the application of exogenous collagenolytic enzymes that catabolize excessive collagen at the affected site and lead to the successful elimination of disease. Such collagenolytic enzymes are synthesized by many organisms: bacteria, animals (especially marine organisms), plants and fungi. The most studied and commercially available are collagenases from Clostridium histolyticum and from the pancreas of the crab Paralithodes camtschatica, due to their ability to effectively hydrolyse human collagen without affecting other tissues, and their wide pH ranges of collagenolytic activity. In the present review, we summarize not only the data concerning existing collagenase-based medications and their applications in different collagen-related diseases and conditions, but we also propose collagenases from different sources for their potential application in enzymatic therapy.

CD147 as an apoptosis regulator in spermatogenesis: deciphering its association with matrix metalloproteinases' pathway

CD147 plays an important role in germ cells migration and survival/apoptosis during the spermatogenesis process. However, to best of our knowledge, there is no report on the exact role of CD147 gene in the regulation of germ cells apoptosis through matrix metalloproteinases (MMPs). So, the current study aims to evaluate the role of CD147 gene expression in the regulation of germ cells apoptosis in conjunction with MMPs. Real-Time PCR was applied to investigate the expression of CD147, MMP2, MMP7, and MMP9 genes in the azoospermic patients and fertile males. Receiver-operating characteristic curve was used to interpret gene expression data. According to our results, a significant decrease in the expression of CD147 gene and an increase in MMPs genes expression were observed in infertile patients compared to fertile males. These results proved this fact that the CD147 gene has an important role in the regulation of germ cells apoptosis via a MMPs-dependent pathway.

Synergistic effects of TIMP2-418G/C and MMP9-1562C/T variants on the male infertility risk

Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) involve in the degradation of the extracellular matrix (ECM) that imbalances their activity and may lead to various diseases. The present study aims to evaluate the association between MMP9-1562C/T and TIMP2-418G/C variants and synergistic effects of both variants on male infertility in an Iranian population. We analyzed these polymorphisms in 101 infertile men and 106 fertile men as a control group using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Based on the obtained results, no considerable association was observed in MMP9-1562C/T polymorphism frequency between infertile men and controls while frequencies of TIMP2-418G/C variant were significantly different in infertile and control groups (P = 0.028). Men with CC, GC and CC + GC genotypes for TIMP2-418G/C polymorphism had an increased risk of infertility compared to men with GG genotype [OR = 1.85, 95% CI (0.917-3.734, P = 0.086), OR = 1.94, 95% CI (1.098-3.437, P = 0.023) and OR = 2.053 95% CI (1.179-3.577, P = 0.011), respectively]. Also, in the presence of both TIMP2-418C and MMP9-1562T alleles the male infertility risk was significantly increased (P = 0.032). The current study suggests that the variation of TIMP2 gene and its interaction with MMP9 gene might be associated with male infertility. However, to confirm these findings, further studies are required in different ethnicities and with a larger sample size.

Expression of transcriptional factor EB (TFEB) in differentiating spermatogonia potentially promotes cell migration in mouse seminiferous epithelium

BACKGROUND

Spermatogenesis is a complex process involving the self-renewal and differentiation of spermatogonia into mature spermatids in the seminiferous tubules. During spermatogenesis, germ cells migrate from the basement membrane to cross the blood-testis barrier (BTB) and finally reach the luminal side of the seminiferous epithelium. However, the mechanism for regulating the migration of germ cells remains unclear. In this study, we focused on the expression and function of transcriptional factor EB (TFEB), a master regulator of lysosomal biogenesis, autophagy and endocytosis, in spermatogenesis.

METHODS

The expression pattern of the TFEB in mouse testes were investigated by Western blotting and immunohistochemistry analyses. Either undifferentiated spermatogonia or differentiating spermatogonia were isolated from testes using magnetic-activated cell sorting based on specific cell surface markers. Differentiation of spermatogonia was induced with 100 nM retinoic acid (RA). shRNA was used to knock down TFEB in cells. TFEB expression was detected by immunofluorescence, qRT-PCR, and Western blotting. Cell migration was determined by both transwell migration assay and wound healing assay applied to a cell line of immortalized spermatogonia, GC-1 cells.

RESULTS

During testicular development, TFEB expression was rapidly increased in the testes at the period of 7 days post-partum (dpp) to 14 dpp, whereas in adult testis, it was predominantly localized in the nucleus of spermatogonia at stages VI to VIII of the seminiferous epithelial cycle. Accordingly, TFEB was observed to be mainly expressed in differentiating spermatogonia and was activated for nuclear translocation by RA treatment. Moreover, knockdown of TFEB expression by RNAi did not affect spermatogonial differentiation, but significantly reduced cell migration in GC-1 cells.

CONCLUSION

These findings imply that regionally distinct expression and activation of TFEB was strongly associated with RA signaling, and therefore may promote cell migration across the BTB and transport along the seminiferous epithelium.

Activin A target genes are differentially expressed between normal and neoplastic adult human testes: clues to gonocyte fate choice

BACKGROUND

Human testicular germ cell tumours (TGCT) arise from germ cell neoplasia in situ (GCNIS) cells that originate from foetal germ cell precursors. Activin A is central to normal foetal testis development, and its dysregulation may contribute to TGCT aetiology.

OBJECTIVE

(i) To test whether the expression profiles of activin A targets in normal and neoplastic human testes indicates functional links with TGCT progression. (ii) To investigate whether activin A levels influence MMP activity in a neoplastic germ cell line.

MATERIALS AND METHODS

(1) Bouin's fixed, paraffin-embedded human testes were utilized for PCR-based transcript analysis and immunohistochemistry. Samples (n = 5 per group) contained the following: (i) normal spermatogenesis, (ii) GCNIS or (iii) seminoma. CXCL12, CCL17, MMP2 and MMP9 were investigated. (2) The human seminoma-derived TCam-2 cell line was exposed to activin A (24 h), and target transcripts were measured by qRT-PCR (n = 4). ELISA (n = 4) and gelatin zymography (n = 3) showed changes in protein level and enzyme activity, respectively.

RESULTS

(i) Cytoplasmic CXCL12 was detected in Sertoli and other somatic cells, including those surrounding seminoma cells. Anti-CCL17 labelled only the cytoplasm of Sertoli cells surrounding GCNIS, while anti-MMP2 and anti-MMP9 labelled germline and epithelial-like cells in normal and neoplastic testes. (ii) Exposing TCam-2 cells to activin A (50 ng/mL) elevated MMP2 and MMP9 transcripts (fourfold and 30-fold), while only MMP2 protein levels were significantly higher after activin A (5 ng/mL and 50 ng/mL) exposure. Importantly, gelatin zymography revealed activin A increased production of activated MMP2.

DISCUSSION

Detection of CCL17 only in GCNIS tumours may reflect a change in Sertoli cell phenotype to a less mature state. Stimulation of MMP2 activity by activin A in TCam-2 cells suggests activin influences TGCT by modulating the tumour niche.

CONCLUSION

This knowledge provides a basis for understanding how physiological changes that influence activin/TGF-β superfamily signalling may alter germ cell fate.

ADAMTS1 and ADAMTS5 metalloproteases produced by Sertoli cells: a potential diagnostic marker in azoospermia

In this study, our aim was to detect protein levels of A Disintegrin and Metalloproteinase with Thrombospondin Motifs 1 and 5 (ADAMTS1 and ADAMTS5) proteases and to examine the effect of in vitro FSH supplementation on protease production in cultured Sertoli cells. The expression of metalloproteases, ADAMTS1, and ADAMTS5 were investigated in Sertoli cell cultures as well as in ejaculate of azoospermic men which then were compared with ejaculates of the fertile control group. A total of 15 azoospermic men, diagnosed as obstructive (OA, n = 5) and nonobstructive (NOA, n = 10) azoospermia were included in the study. ADAMTS1, ADAMTS5 and FSH receptors (FSHR) were found to be expressed 2.56, 2.10, and 2.66-fold less in Sertoli cells of NOA patients, than those of OA (p < 0.05). After rFSH was added onto Sertoli cell cultures of NOA patients, their expression did not increase significantly and did not reach to levels of control group. Evaluation of ejaculates revealed that the expression of ADAMTS1 and ADAMTS5 were insignificantly 1.03 and 1.1-fold higher in OA group (p > 0.05), respectively; however, in the NOA group, their expression were 1.70 and 1.96-fold lower, respectively, when compared with the fertile control group (p < 0.05) which was statistically significant. As a conclusion, the present study has revealed that insufficiency of ADAMTS1 and ADAMTS5 expression in Sertoli cells may have an important role in the etiology of male infertility. As expected due to low FSHR expression, rFSH response is impaired in NOA patients with relatively low ADAMTS expression response; therefore, such patients might hardly benefit from rFSH treatment. Further studies with larger cohorts may reveal ADAMTSs' potential use as a predictive marker for positive sperm retrieval in azoospermic patients who are scheduled to undergo testicular sperm extraction. Abbreviations: ADAM: A Disintegrin and Metalloproteinase; ADAMTS1 and ADAMTS5: A Disintegrin and Metalloproteinase with 10 Thrombospondin Motifs 1 and 5; ADAMTS: A Disintegrin and Metalloproteinase with Thrombospondin; ABP: androgen binding protein; CAMs: cell adhesion molecules; ECM: extracellular matrix; FSH: follicle stimulating hormone; FSHR: FSH receptors; HRP: horseradish peroxidase; MMP: matrix metalloproteinases; MP: metalloproteinases; NOA: nonobstructive azoospermia; OA: obstructive azoospermia; TIMP-1: tissue inhibitor of metalloproteinase-1.

CD147 Induces Epithelial-to-Mesenchymal Transition by Disassembling Cellular Apoptosis Susceptibility Protein/E-Cadherin/β-Catenin Complex in Human Endometriosis

Epithelial-to-mesenchymal transition (EMT) is postulated to be a prerequisite for the establishment of endometriosis (EMS), a common reproductive disorder in women. Our previous studies have demonstrated the elevated expression of transmembrane glycoprotein CD147 and its prosurvival effect on abnormal cells in endometriosis. Intriguingly, CD147 is known to promote EMT in cancers. However, the involvement of CD147 in EMT during the establishment of endometriosis remains incompletely understood. We found that CD147 promotes EMT in human endometrial adenocarcinoma cell line Ishikawa. We identified a novel CD147-interacting partner, cellular apoptosis susceptibility protein (CAS), which stabilized the interaction between E-cadherin (E-cad) and β-catenin (β-cat) by forming the CAS/E-cad/β-cat complex. Down-regulation of CAS led to the release and nuclear translocation of β-cat from E-cad, resulting in the overexpression of the EMT-promoting gene SNAIL. Interestingly, overexpression of CD147 impaired the interaction between CAS and E-cad and triggered the release of β-cat from the CAS/E-cad/β-cat complex, which in turn led to EMT. Furthermore, CAS was down-regulated in EMS, with elevated levels of CD147 and nuclear β-cat. These findings suggest a previously undefined role of CAS in regulating EMT and reveal the involvement of a CD147-induced EMT signaling pathway in pathogenic progression of EMS.

Gene Polymorphism of Matrix Metalloproteinase 9 in Asthenozoospermic Male Subjects

Background:

Matrix metalloproteinase (MMPs) play important roles in the structural and functional properties of reproductive organs. The aim of this study is to determine the prevalence of C-1562T MMP-9 (rs3918242) gene polymorphism in fertile and infertile men. In addition, we aim to determine the association between C-1562T MMP-9 and G-1575A MMP-2 gene polymorphisms.

Materials and Methods:

A total of 400 subjects, including 200 fertile and 200 infertile men, were recruited for this casecontrol study. The allele frequencies and genotype distributions of single nucleotide polymorphism in the promoter regions of MMP-9 (C-1562T) were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The chi-square (χ2) test was used to assess the distribution of genotype frequencies.

Results:

There were no significant differences found in the genotype distributions or allele frequencies between fertile and infertile men for the C-1562T MMP-9 gene polymorphism. The percent of immotile sperm in infertile men with the CC and CT genotypes of C-1562T MMP-9 gene polymorphism significantly differed compared with that of subjects with the TT genotype. The frequency of CC/GA-combined genotypes of C-1562T MMP-9 and G-1575A MMP-2 gene polymorphisms significantly differed in fertile and infertile men (P=0.031).

Conclusion:

Our results suggest that genetic polymorphisms in MMP may impact male fertility.

Epidermal CD147 expression plays a key role in IL-22-induced psoriatic dermatitis

Psoriasis is a chronic inflammatory skin disease characterized by abnormal keratinocyte proliferation and terminal differentiation. Interleukin-22 (IL-22) and the transcription factor Stat3 play pivotal roles in the pathogenesis of psoriasis. CD147 is a transmembrane glycosylation protein that belongs to the immunoglobulin superfamily. Our previous studies have shown that CD147 is a marker of high keratinocyte proliferation and poor keratinocyte differentiation as well as a psoriasis susceptibility gene. The current study demonstrates that CD147 is highly expressed in psoriatic skin lesions. Specific CD147 over-expression in the epidermis of K5-promoter transgenic mice promotes imiquimod (IMQ)-induced psoriasis-like inflammation characterized by acanthosis, granular layer loss and inflammatory cell infiltration. We also found that IL-22 increases CD147 transcription in vitro and in vivo and that Stat3 binds directly to the CD147 promoter between positions -854 and -440, suggesting that CD147 expression is up-regulated in patients with psoriasis through Stat3 activation. In addition, CD147 knockdown dramatically blocks IL-22-mediated Stat3 activation as well as IL-22-induced cytokine, chemokine and antimicrobial factor expression. Together, these findings show that CD147 is a novel and key mediator of IL-22-induced psoriatic alterations in the epidermis and might be a therapeutic target in patients with psoriasis.

Up-regulation of Bcl-2 by CD147 Through ERK Activation Results in Abnormal Cell Survival in Human Endometriosis

CONTEXT

Human endometriosis (EMS) is characterized by insufficient apoptosis. Our previous studies have shown elevated CD147 expression in human endometriotic tissues and its involvement in endometrial cell apoptosis. However, the exact underlying mechanism remains elusive.

OBJECTIVE

The objective was to examine the correlation of the highly expressed CD147 with anti-apoptotic factor Bcl-2 in human endometriotic tissues and to determine the CD147-regulated apoptotic pathway in human endometrial epithelial cell line (HES).

DESIGN

This was a laboratory study using human tissue analysis and HES cell culture.

SETTING

The setting was an academic research center and hospital.

PATIENTS

Patients were 30 women with ovarian EMS and 12 women without EMS.

INTERVENTIONS

mRNA levels of CD147 and Bcl-2 were evaluated in endometriotic tissues by quantitative real-time PCR. HES cells were transfected with pcDNA3.0-CD147 overexpressing plasmid or immune-depleted by CD147 antibody.

MAIN OUTCOME MEASURES

Main outcome measures were reverse transcription, quantitative real-time PCR, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, and Western blotting.

RESULTS

In human endometriotic tissues, Bcl-2 was up-regulated and positively correlated with CD147 expression, accompanied by activated ERK signaling. In HES cells, overexpression of CD147 increased viable cells and up-regulated Bcl-2 expression by activation of ERK signaling. Interference with CD147 function suppressed ERK signaling and decreased Bcl-2 expression, followed by accumulation of apoptotic factors, including cleaved caspase-9, cleaved caspase-3, and cleaved poly ADP-ribose polymerase.

CONCLUSIONS

The presently found strong correlations between Bcl-2 and CD147, ERK, and CD147 in human endometriotic lesions and the demonstrated reduced cell apoptosis through CD147-ERK-Bcl-2 intrinsic apoptosis signaling axis suggest that this CD147-regulated signaling may contribute to the enhanced cell survival in the progression of human EMS.

Expression of matrix metalloproteinases (MMP-2, MMP-9) and their inhibitors (TIMP-1, TIMP-2) in canine testis, epididymis and semen

This study aims to investigate the role of matrix metalloproteinases (MMPs) in determining semen quality and to evaluate the expression and cellular localization of MMP-2, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 in the testes, epididymis and ejaculated spermatozoa. Gelatinase activities between normal (n = 21) and abnormal (n = 25) semen samples showed a significant, sixfold increase in proMMP-2 and MMP-2 activity in high than low sperm concentration samples (p < 0.001). ProMMP-9 and MMP-9 levels were significantly elevated in samples with low sperm counts compared to those with high sperm density (p < 0.001). High levels of proMMP-2 and MMP-2 were associated with high sperm motility (≥70%, p < 0.001). Sperm-rich fraction showed significantly (eight-fold) higher proMMP-9 enzymatic activity compared with prostatic fraction. The mRNA expressions of MMP-2, MMP-9, TIMP-1 and TIMP-2 were confirmed in testicular and epididymal tissues. Immunohistochemical staining illustrated the MMP-2-specific strong immunoreactivity in the head of mature spermatids during spermatogenesis, whereas MMP-9, TIMP-1 and TIMP-2 were absent in these cells. Matrix metalloproteinase-9 immunoreactivity was observed in the spermatocyte and round spermatid, whereas TIMP-1 was only exhibited in the residual bodies. Immunolabeling of epididymal and ejaculated sperm demonstrated MMP-2 localization along acrosomal region of sperm, while MMP-9, TIMP-1 and TIMP-2 localization was merely limited to the flagella. In conclusion, spermatozoa initially acquire MMP-2 during their formation at testicular level, and the presence of this protein persists through the epididymal transit and up to ejaculate. The enzymatic activity of MMP-2 and MMP-9 may serve as an alternative biomarker in determining semen quality.

New insights into germ cell migration and survival/apoptosis in spermatogenesis: Lessons from CD147

CD147, also named basigin (Bsg) or extracellular matrix (ECM) metalloproteinase inducer (EMMPRIN), is a highly glycosylated protein first identified as a tumor cell surface molecule. In cancer, it is well established that CD147 promotes metastasis by stimulating the production of MMPs. Recent studies have also suggested that it may be associated with tumor growth and angiogenesis. Interestingly, CD147 is expressed in germ cells of different development stages in the testis and its knockout mice are infertile, indicating an essential role of CD147 in spermatogenesis. While the detailed involvement of CD147 in spermatogenesis remains elusive, our recent findings have revealed a dual role of CD147 in germ cell development. On the one hand, it regulates the migration of spermatogonia and spermatocytes via the induction of MMP-2 production; on the other hand, it specifically regulates the survival/apoptosis of spermatocytes but not spermatogonia through a p53-independent pathway. In this review, we aim to provide an overview on the functions of CD147, comparing its roles in cancer and the testis, thereby providing new insights into the regulatory mechanisms underlying the process of spermatogenesis.

The biological function and clinical utilization of CD147 in human diseases: a review of the current scientific literature

CD147 or EMMPRIN is a member of the immunoglobulin superfamily in humans. It is widely expressed in human tumors and plays a central role in the progression of many cancers by stimulating the secretion of matrix metalloproteinases (MMPs) and cytokines. CD147 regulates cell proliferation, apoptosis, and tumor cell migration, metastasis and differentiation, especially under hypoxic conditions. CD147 is also important to many organ systems. This review will provide a detailed overview of the discovery, characterization, molecular structure, diverse biological functions and regulatory mechanisms of CD147 in human physiological and pathological processes. In particular, recent studies have demonstrated the potential application of CD147 not only as a phenotypic marker of activated regulatory T cells but also as a potential diagnostic marker for early-stage disease. Moreover, CD147 is recognized as an effective therapeutic target for hepatocellular carcinoma (HCC) and other cancers, and exciting clinical progress has been made in HCC treatment using CD147-directed monoclonal antibodies.

Novel regulators of spermatogenesis

Spermatogenesis is a multistep process that supports the production of millions of sperm daily. Understanding of the molecular mechanisms that regulate spermatogenesis has been a major focus for decades. Yet, the regulators involved in different cellular processes of spermatogenesis remain largely unknown. Human diseases that result in defective spermatogenesis have provided hints on the molecular mechanisms regulating this process. In this review, we have summarized recent findings on the function and signaling mechanisms of several genes that are known to be associated with disease or pathological processes, including CFTR, CD147, YWK-II and CT genes, and discuss their potential roles in regulating different processes of spermatogenesis.

Expression of matrix metalloproteinase-13 (MMP-13) in the testes of growing and adult chicken

Although several matrix metalloproteinases (MMPs) have been implicated in testis development, the presence of MMP-13 protein has not been directly substantiated in the male avian gonads. In this study, we examined the expression patterns of MMP-13 and MMP inhibitors, TIMP-1 and TIMP-2, in immature (4weeks), pre-pubertal (16weeks), and mature (1year) chicken testes. Using RT-PCR analysis, we observed that MMP-13 mRNA was expressed in immature testis. In Western blot analysis, the expression level of MMP-13 protein peaked in the immature testes during marked tissue remodeling, whereas it gradually decreased during testis maturation. High expression levels of TIMP-1 (34-kDa) and TIMP-2 (55-kDa) were detected only in immature and pre-pubertal testes and not in adult testis. Four different forms of TIMP-2 protein were differentially detected in the testes of growing and adult chicken. Using immunohistochemistry we localized both secreted and intracellular forms of MMP-13, TIMP-1, and TIMP-2 proteins. These proteins were temporally and spatially distributed in growing and adult testes, and all their expression levels were similar to the expression profile of Western blot results. These findings suggest that age-related changes of MMP-13 with balance of TIMPs act in concert to effect the controlled testicular remodeling and maturation.

Intercellular adhesion molecules (ICAMs) and spermatogenesis

BACKGROUND

During the seminiferous epithelial cycle, restructuring takes places at the Sertoli-Sertoli and Sertoli-germ cell interface to accommodate spermatogonia/spermatogonial stem cell renewal via mitosis, cell cycle progression and meiosis, spermiogenesis and spermiation since developing germ cells, in particular spermatids, move 'up and down' the seminiferous epithelium. Furthermore, preleptotene spermatocytes differentiated from type B spermatogonia residing at the basal compartment must traverse the blood-testis barrier (BTB) to enter the adluminal compartment to prepare for meiosis at Stage VIII of the epithelial cycle, a process also accompanied by the release of sperm at spermiation. These cellular events that take place at the opposite ends of the epithelium are co-ordinated by a functional axis designated the apical ectoplasmic specialization (ES)-BTB-basement membrane. However, the regulatory molecules that co-ordinate cellular events in this axis are not known.

METHODS

Literature was searched at http://www.pubmed.org and http://scholar.google.com to identify published findings regarding intercellular adhesion molecules (ICAMs) and the regulation of this axis.

RESULTS

Members of the ICAM family, namely ICAM-1 and ICAM-2, and the biologically active soluble ICAM-1 (sICAM-1) are the likely regulatory molecules that co-ordinate these events. sICAM-1 and ICAM-1 have antagonistic effects on the Sertoli cell tight junction-permeability barrier, involved in Sertoli cell BTB restructuring, whereas ICAM-2 is restricted to the apical ES, regulating spermatid adhesion during the epithelial cycle. Studies in other epithelia/endothelia on the role of the ICAM family in regulating cell movement are discussed and this information has been evaluated and integrated into studies of these proteins in the testis to create a hypothetical model, depicting how ICAMs regulate junction restructuring events during spermatogenesis.

CONCLUSIONS

ICAMs are crucial regulatory molecules of spermatogenesis. The proposed hypothetical model serves as a framework in designing functional experiments for future studies.

CPU86017-RS attenuate hypoxia-induced testicular dysfunction in mice by normalizing androgen biosynthesis genes and pro-inflammatory cytokines

AIM

Downregulation of androgen biosynthesis genes StAR (steroidogenic acute regulatory) and 3β-HSD (3β-hydroxysteroid dehydrogenase) contributes to low testosterone levels in hypoxic mice and is possibly related to increased expression of pro-inflammatory cytokines in the testis. The aim of this study is to investigate the effects of CPU86017-RS that block Ca(2+) influx on hypoxia-induced testis insult in mice.

METHODS

Male ICR mice were divided into 5 groups: control group, hypoxia group, hypoxia group treated with nifedipine (10 mg/kg), hypoxia groups treated with CPU86017-RS (60 or 80 mg/kg). Hypoxia was induced by placing the mice in a chamber under 10%±0.5% O2 for 28 d (8 h per day). The mice were orally administered with drug in the last 14 d. At the end of experiment the testes of the mice were harvested. The mRNA and protein levels of StAR, 3β-HSD, connexin 43 (Cx43), matrix metalloprotease 9 (MMP9), endothelin receptor A (ET(A)R) and leptin receptor (OBRb) were analyzed using RT-PCR and Western blotting, respectively. The malondialdehyde (MDA), lactate dehydrogenase (LDH), succinate dehydrogenase (SDH) and acid phosphatase (ACP) levels were measured using biochemical kits. Serum testosterone concentration was measured with radioimmunoassay.

RESULTS

Hypoxia significantly increased the MDA level, and decreased the LDH, ACP and SDH activities in testes. Meanwhile, hypoxia induced significant downregulation of StAR and 3β-HSD in testes responsible for reduced testosterone biosynthesis. It decreased the expression of Cx43, and increased the expression of MMP9, ETAR and OBRb, leading to abnormal testis function and structure. These changes were effectively diminished by CPU86017-RS (80 mg/kg) or nifedipine (10 mg/kg).

CONCLUSION

Low plasma testosterone level caused by hypoxia was due to downregulation of StAR and 3β-HSD genes, in association with an increased expression of pro-inflammatory cytokines. These changes can be alleviated by CPU86017-RS or nifedipine.