Mesenchymal Stem-Cell Derived Exosome Therapy as a Potential Future Approach for Treatment of Male Infertility Caused by Chlamydia Infection

Some microbial sexually transmitted infections (STIs) have adverse effects on the reproductive tract, sperm function, and male fertility. Given that STIs are often asymptomatic and cause major complications such as urogenital inflammation, fibrosis, and scarring, optimal treatments should be performed to prevent the noxious effect of STIs on male fertility. Among STIs, Chlamydia trachomatis is the most common asymptomatic preventable bacterial STI. C. trachomatis can affect both sperm and the male reproductive tract. Recently, mesenchymal stem cells (MSCs) derived exosomes have been considered as a new therapeutic medicine due to their immunomodulatory, anti-inflammatory, anti-oxidant, and regenerative effects without consequences through the stem cell transplantation based therapies. Inflammation of the genital tract and sperm dysfunction are the consequences of the microbial infections, especially Chlamydia trachomatis. Exosome therapy as a noninvasive approach has shown promising results on the ability to regenerate the damaged sperm and treating asthenozoospermia. Recent experimental methods may be helpful in the novel treatments of male infertility. Thus, it is demonstrated that exosomes play an important role in preventing the consequences of infection, and thereby preventing inflammation, reducing cell damage, inhibiting fibrogenesis, and reducing scar formation. This review aimed to overview the studies about the potential therapeutic roles of MSCs-derived exosomes on sperm abnormalities and male infertility caused by STIs.

First Detection of Chlamydia trachomatis 'Swedish' Variant (nvCT) in a Russian Couple with Infertility

BACKGROUND

Chronic asymptomatic chlamydial genital infection caused by the wild-type of Chlamydia trachomatis (wtCT) is the most common bacterial infection causing human infertility. The novel 'Swedish' variant of С.trachomatis (nvCT) which contains a 377 bp deletion in a region that is specifically targeted in some nucleic acid amplification tests may impede diagnosis.

OBJECTIVE

The study aimed to investigate whether nvCT may be a possible cause of infertility in a couple undergoing in vitro fertilization (IVF).

METHOD

Clinical specimens from both genital (urethra and cervix) and extra-genital sites (pharynx, conjunctive, blood) of a couple who experienced multiple unsuccessful attempts at pregnancy by natural fertilization and IVF procedures were analyzed before and after antibiotic therapy. Both partners had neither somatic nor endocrinal abnormality nor any clinically apparent genital manifestations of Chlamydia or other STIs.

RESULTS

Before antibiotic therapy all the samples of the Female Partner (FP) contained DNA of only the nvCT. After antibiotic therapy, additionally, DNA of wtCT of genovars E and D was detected in specimens from her conjunctiva and oropharynx. All samples of the Male Partner (MP) revealed co-infection of nvCT and wtCT. Identical SNP within the variable region 4 (VD4) of the ompA gene confirmed the identity of the wtCT strains found in both partners. The FP had a positive anti-chlamydial IgG titer. The sperm characteristics of the MP, motility (immotile spermatozoa was 51.1% versus 21.6%) and vitality (46% versus 68%) declined progressively, and the MP anti-chlamydial IgG titer was negative.

CONCLUSION

Infertility in this couple may have been caused by chronic asymptomatic and persistent nvCT-associated infection that was complicated by re-infection later with wtCT. This study illustrates the importance of including detection methods for nvCT strains in the investigation of infertility cases.

Is there a role for Serratia marcescens in male infertility: An experimental study?

OBJECTIVE

Establishment of a male BALB/c mouse model to study the role of sperm impairing S. marcescens on mouse reproductive potential. The current study can add to use of reliable animal models to provide a noteworthy evidence for the microbial cause of infertility.

METHODS

The mice in the test groups II, III, IV were intraperitoneally administered with different doses (10⁴, 10⁶ or 10⁸ cfu) of S. marcescens whereas, group I serving as control, received PBS, for 10 consecutive days. The groups were evaluated for any change in body weight, tissue somatic index (%), seminal parameters and histology. Confirmation of S. marcescens from reproductive organs was done by reisolating the same by cultural characteristics and biochemical tests.

RESULTS

The results showed that weight gain was evident only in mice receiving PBS (group I), whereas a decrease was recorded in the test groups (group II, III and IV). Only testes of test groups showed significant changes in TSI values whereas, no change in TSI was observed in any reproductive organ of any test group. Seminal parameters viz. sperm count, motility and viability were found to decrease in test groups II, III and IV as compared to control group I. Interestingly, the number of pus cells and percent decapitation was more prominent in test groups which received higher doses (i.e. group III and group IV). The histopathological examination revealed mild to dense inflammation in vas deferens and caudal epididymis in all test groups except hypospermatogenesis which was observed only in test group III and IV. However, in group I, neither adverse changes nor any sign of inflammation were observed.

CONCLUSION

Intraperitoneal inoculation of S. marcescens could lead to alteration of semen parameters, induction of decapitation in spermatozoa and histopathological changes, thereby decreasing the reproductive potential of male mice.

miR-424/322 is downregulated in the semen of patients with severe DNA damage and may regulate sperm DNA damage

Sperm DNA integrity is an essential factor for accurate transmission of genetic information. Human sperm DNA damage is a common cause of male infertility but the exact mechanism remains poorly understood. Considering the vital role of microRNA (miRNA) in multiple pathophysiological processes, we hypothesised that testicular miRNA is involved in sperm DNA damage during spermatogenesis. Infertile patients with high sperm DNA fragment index (DFI; n=94) were selected from 1090 infertile men and a total of 18 testis-specific seminal miRNAs previously identified from human seminal plasma were chosen and tested. miR-29c and miR-424 were downregulated in men with high DFI. The inhibition of these two miRNAs in mice confirmed the role of miR-424 (murine homologue miR-322) in sperm DNA damage during spermatogenesis; by contrast, miR-29c exhibited a negative result. Thus, miR-424/322 is involved in sperm DNA damage. Furthermore, the dysregulation of this miRNA can induce DNA double-strand breaks during spermatogenesis.

Molecular detection of Chlamydia trachomatis and other sexually transmitted bacteria in semen of male partners of infertile couples in Tunisia: the effect on semen parameters and spermatozoa apoptosis markers

This study was undertaken to determine the prevalence of Chlamydia trachomatis, Mycoplasmas, and Ureaplasmas in semen samples of the male partners of infertile couples and to investigate whether Chlamydia trachomatis could initiate apoptosis in human spermatozoa. A total of 85 males partners of infertile couples undergoing routine semen analysis according to World Health Organization guidelines were included. Specimens were examined for the presence of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum and Ureaplasma parvum by Real time PCR (qPCR). Semen specimens were analysed for the appearance of apoptotic markers (sperm DNA fragmentation, activated caspase 3 levels, mitochondrial membrane potential (ΔΨm)) using flow cytometry. C. trachomatis, N. gonorrhoeae, U. urealyticum, M genitalium were detected in semen samples of 13 (15.2%), 5 (5.8%), 5 (5.8%) and 3 (3.5%) male partners of infertile couples, respectively. M. hominis and U. parvum were detected in semen sample of only one patient (1.1%). The semen of infertile men positive for C. trachomatis showed lower mean of semen count and lower rapid progressive motility (category [a]) of spermatozoa compared to uninfected men with statistically significances (p = 0.02 and p = 0.04, respectively). Flow cytometry analyses demonstrated a significant increase of the mean rate of semen with low ΔΨm and caspase 3 activation of infertile men positive for C. trachomatis compared to uninfected men (p = 0.006 and p = 0.001, respectively). DNA fragmentation was also increased in sperm of infertile men positive for C. trachomatis compared to uninfected men but without statistical significances (p = 0.62). Chlamydial infection was associated to loss of ΔΨm and caspase 3activation. Thus, C. trachomatis infection could be incriminated in apoptosis induction of spermatozoa. These effects may explain the negative direct impact of C. trachomatis infection on sperm fertilizing ability.

Male rat genital tract infection with Chlamydia muridarum has no significant consequence on male fertility

PURPOSE

Chlamydia trachomatis infection of the male genital tract was proposed to alter male fertility. We studied the putative consequences of chlamydial male genital tract infection on semen quality and male fertility in an experimental rat model of infection.

MATERIALS AND METHODS

We used 36 male and 40 female Wistar rats. Male genital infection was created by inoculating Chlamydia muridarum in the meatal urethra. The presence of C. muridarum was evaluated by polymerase chain reaction in semen and male genital tract organs early (15 days) and late (80 days) after infection. Sperm quality parameters were assayed in seminal and epididymal sperm from sham infected and infected rats. Mating studies with sexually mature females were performed and fertility parameters were assayed, including potency, fecundity and fertility indexes, fetal size, and pre-implantation and post-implantation embryo loss.

RESULTS

Male rats showed ascending, disseminated infection 15 days after infection. Bacteria persisted in the prostate and seminal vesicles 80 days after infection. C. muridarum was detected in semen in most rats regardless of acute or chronic infection. Seminal or epididymal sperm quality did not differ in infected and sham infected rats 15 or 80 days after infection. Sperm apoptosis was also minimal in infected rats. No differences were observed in fertility parameters between infected and sham infected rats.

CONCLUSIONS

C. muridarum infects the rat male genital tract and persists mainly in the prostate. Although C. muridarum was detected in semen during acute and chronic infection, no alterations in sperm quality were observed. C. muridarum infection does not impair male fertility.