Homozygous CCDC146 mutation causes oligoasthenoteratozoospermia in humans and mice

Infertility represents a significant health concern,with sperm quantity and quality being crucial determinants of male fertility.Oligoasthenoteratozoospermia(OAT)is characterized by reduced sperm motility,lower sperm concentration,and morphological abnormalities in sperm heads and flagella.Although variants in several genes have been implicated in OAT,its genetic etiologies and pathogenetic mechanisms remain inadequately understood.In this study,we identified a homozygous nonsense mutation(c.916C>T,p.Arg306*)in the coiled-coil domain containing 146(CCDC146)gene in an infertile male patient with OAT.This mutation resulted in the production of a truncated CCDC146 protein(amino acids 1-305),retaining only two out of five coiled-coil domains.To validate the pathogenicity of the CCDC146 mutation,we generated a mouse model(Ccdc146^(mut/mut))with a similar mutation to that of the patient.Consistently,the Ccdc146mut/mut mice exhibited infertility,characterized by significantly reduced sperm counts,diminished motility,and multiple defects in sperm heads and flagella.Furthermore,the levels of axonemal proteins,including DNAH17,DNAH1,and SPAG6,were significantly reduced in the sperm of Ccdc146^(mut/mut) mice.Additionally,both human and mouse CCDC146 interacted with intraflagellar transport protein 20(IFT20),but this interaction was lost in the mutated versions,leading to the degradation of IFT20.This study identified a novel deleterious homozygous nonsense mutation in CCDC146 that causes male infertility,potentially by disrupting axonemal protein transportation.These findings offer valuable insights for genetic counseling and understanding the mechanisms underlying CCDC146 mutant-associated infertility in human males.

Vertical transmission of the Yq AZFc microdeletion from father to son over two or three generations in infertile Han Chinese families

This study was carried out to analyze the vertical transmission of Yq AZFc microdeletions from father to son in infertile Han Chinese families to investigate genetic factors and family background affecting fertility status.The peripheral blood of infertile males in 19 Han families was extracted and screened with modified multiplex polymerase chain reaction （PCR）. Family trees were drawn according to fertility status and clinical characteristics of the subjects. The vertical transmission of Yq AZFc microdeletions was detected in six cases of 19 investigated families （31.6%,6/19）. Although both fathers and sons showed a similar type of Yq AZFc deletion,the fathers were fertile,whereas the sons were infertile and showed severe oligozoospermia. The vertical transmission of Yq AZFc microdeletion from fertile fathers to infertile sons over generations is not rare. This has different effects on fertility status in fathers and sons in Han Chinese families. Both genetic factors and family background affect spermatogenetic phenotypes.

"Micro-deletions" of the human Y chromosome and their relationship with male infertility

The Y chromosome evolves from an autochromosome and accumulates male-related genes including sex-determining region of Y-chromosome （SRY） and several spermatogenesis-related genes. The human Y chromosome （60 Mb long） is largely composed of repetitive sequences that give it a heterochromatic appearance, and it consists of pseudoautosomal, euchromatic, and heterochromatic regions. Located on the two extremities of the Y chromosome, pseudoautosomal regions 1 and 2 （PAR1 and PAR2, 2.6 Mb and 320 bp long, respectively） are homologs with the termini of the X chromosome. The euchromatic region and some of the repeat-rich heterochromatic parts of the Y chromosome are called ＂male-specific Y＂ （MSY）, which occupy more than 95% of the whole Y chromosome. After evolution, the Y chromosome becomes the smallest in size with the least number of genes but with the most number of copies of genes that are mostly spermatogenesis-related. The Y chromosome is characterized by highly repetitive sequences （including direct repeats, inverted repeats, and palindromes） and high polymorphism. Several gene rearrangements on the Y chromosome occur during evolution owing to its specific gene structure. The consequences of such rearrangements are not only loss but also gain of specific genes. One hundred and fifty three haplotypes have been discovered in the human Y chromosome. The structure of the Y chromosome in the GenBank belongs to haplotype R1. There are 220 genes （104 coding genes, 111 pseudogenes, and 5 other uncategorized genes） according to the most recent count. The 104 coding genes encode a total of about 48 proteins/protein families （including putative proteins/protein families）. Among them, 16 gene products have been discovered in the azoospermia factor region （AZF） and are related to spermatogenesis. It has been discovered that one subset of gene rearrangements on the Y chromosome, ＂micro-deletions＂, is a major cause of male infertility in some populations. However, controversies exist about different Y chromosome haplotypes. Six AZFs of the Y chromosome have been discovered including AZFa, AZFb, AZFc, and their combinations AZFbc, AZFabc, and partial AZFc called AZFc/gr/gr. Different deletions in AZF lead to different content spermatogenesis loss from teratozoospermia to infertility in different populations depending on their Y haplotypes. This article describes the structure of the human Y chromosome and investigates the causes of micro-deletions and their relationship with male infertility from the view of chromosome evolution. After analysis of the relationship between AZFc and male infertility, we concluded that spermatogenesis is controlled by a network of genes, which may locate on the Y chromosome, the autochromosomes, or even on the X chromosome. Further investigation of the molecular mechanisms underlying male fertility/infertility will facilitate our knowledge of functional genomics.

Clinical features and therapeutic strategies of obstructive azoospermia in patients treated by bilateral inguinal hernia repair in childhood

Childhood inguinal herniorrhaphy is one common cause of seminal tract obstruction. Vasovasostomy （VV） can reconstruct seminal deferens and result in appearance of sperm and natural pregnancy in some patients. Secondary epididymal obstruction caused by a relatively long-term vasal obstruction is a common cause of lower patency compared with VV due to vasectomy in adults. From July 2007 to June 2012, a total of 62 patients, with history of childhood inguinal herniorrhaphy and diagnosed as obstructive azoospermia were treated in our center. The overall patency rate and natural pregnancy rate were 56.5% （35/62） and 25.8% （16/62）, respectively. 48.4% （30/62） of the patients underwent bilateral VV in the inguinal region, with a patency rate of 76.7% （23/30） and a natural pregnancy rate of 36.7% （11/30）, respectively. 30.6% （19/62） of the patients underwent bilateral VV and unilateral or bilateral vasoepididymostomies due to ipsilateral epididymal obstruction with the patency and natural pregnancy rate decreasing to 63.2% （12/19） and 26.3% （5/19）. 21.0% （13/62） of the patients merely underwent vasal exploration without reconstruction due to failure to find distal vasal stump, etc. Our study indicate that microsurgical reanastomosis is an effective treatment for some patients with seminal tract obstruction caused by childhood inguinal herniorrhaphy.

Sexual and reproductive health service needs of university/ college students： updates from a survey in Shanghai, China

Aim： To promote the provision of reproductive health services to young people by exploring the attitudes and perceptions of university students in Shanghai, China, toward reproductive health. Methods： From July 2004 to May 2006, 5 243 students from 14 universities in Shanghai took part in our survey. Topics covered the demands of reproductive health-care services, attitudes towards and experience with sex, exposure to pornographic material, and knowledge on sexual health and sexually transmitted infections （STIs）/AIDS. Results： Of the 5 067 students who provided valid answer sheets, 50.05% were female and 49.95% were male, 14.86% were medical students, and 85.14% had non-medical backgrounds. A total of 38.4% of respondents had received reproductive health education previously. The majority of students supported school-based reproductive health education, and also acquired information about sex predominantly from books, schoolmates, and the Internet. Premarital sexual behavior was opposed by 17.7% of survey participants, and 37.5% could identify all the three types of STIs listed in the questionnaire. Although 83.7% knew how HIV is transmitted, only 55.7% knew when to use a condom and 57.8% knew that the use of condoms could reduce the risk of HIV infection. Conclusion： The reproductive health service is lagging behind current attitudes and demands of university students. Although students＇ attitudes towards sexual matters are liberal, their knowledge about reproductive health and STIs/AIDS is still limited. It is therefore necessary to provide effective and confidential reproductive health services to young people.

Generation of male germ cells from induced pluripotent stem cells （iPS cells）： an in vitro and in vivo study

Recent studies have reported that induced pluripotent stem （iPS） cells from mice and humans can differentiate into primordial germ cells. However, whether iPS cells are capable of producing male germ cells is not known. The objective of this study was to investigate the differentiation potential of mouse iPS cells into spermatogonial stem cells and late-stage male germ cells. We used an approach that combines in vitrodifferentiation and in vivotransplantation. Embryoid bodies （EBs） were obtained from iPS cells using leukaemia inhibitor factor （LIF）-free medium. Quantitative PCR revealed a decrease in Oct4 expression and an increase in StraSand Vasa mRNA in the EBs derived from iPS cells, iPS cell-derived EBs were induced by retinoic acid to differentiate into spermatogonial stem cells （SSCs）, as evidenced by their expression of VASA, as well as CDH1 and GFRal, which are markers of SSCs. Furthermore, these germ cells derived from iPS cells were transplanted into recipient testes of mice that had been pre-treated with busulfan. Notably, iPS cell-derived SSCs were able to differentiate into male germ cells ranging from spermatogonia to round spermatids, as shown by VASA and SCP3 expression. This study demonstrates that iPS cells have the potential to differentiate into late-stage male germ cells. The derivation of male germ cells from iPS cells has potential applications in the treatment of male infertility and provides a model for uncovering the molecular mechanisms underlying male germ cell development.

Fertility outcome of patients with testicular tumor： before and after treatment

Testicular cancer （TC） is the most curable type of cancer, with a survival rate of more than 95%. Oncologists are faced with the challenge that gonadotoxic cancer treatments can compromise future fertility, either temporarily or permanently. Our aim was to investigate the long-term effects of TC treatments on male fertility and on the offspring of patients who had received these treatments. Between January 1996 and December 2010, 125 eligible patients, ranging from 18 to 54 years （median age 36.3 _＋ 15.7）, with unilateral TC underwent surgery, chemotherapy or radiotherapy at our center. Some of these patients had their semen samples cryopreserved in the Shanghai Human Sperm Bank. The clinical data were evaluated, and questionnaire and telephone follow-up surveys were given to all patients. The data were analyzed to determine the patients＇ fertility status pre- and posttreatment. Of the 125 eligible patients, 93.6% （117/125） were accessible and were evaluated. Among 81 men who were married before diagnosis, 21 had conceived successfully before diagnosis and six reported azoospermia. Posttreatment conception was attempted by 73 men; of these, 16 conceived naturally and 19 conceived by artificial reproductive techniques, resulting in 37 healthy babies with no congenital malformations. Of the patients who had not conceived before treatment, 21.9% （21/96） banked their sperm and 23.8% of these patients （5/21） subsequently used the banked sperm. Retroperitoneal lymph node dissection, chemotherapy and radiotherapy were the most highly correlated with lack of conception to TC patients with the desire for biological conception. There is no birth defects or childhood malignancies. post-TC treatment. Sperm banking should be recommended evidence to suggest that TC treatments are associated with

Prevalent false positives of azoospermia factor a （AZFa） microdeletions caused by single-nucleotide polymorphism rs72609647 in the sY84 screening of male infertility

Multiplex polymerase chain reaction （PCR） has been widely used to detect Y-chromosome micredeletions, which is one of the major causes of male infertility. Both the European Academy of Andrology （EAA） and the European Molecular Genetics Quality Network （EMQN） have recommended the use of sY84 and sY86 markers for the detection of azoospermia factor a （AZFa） microdeletion during DNA testing for male infertility. In this study, a large-scale analysis of AZF microdeletion in a total of 630 Chinese males, including healthy semen donors （n=200）, infertile males with normal sperm count （n=226） and patients with either nonobstructive azoospermia or severe oligozoospermia （n=204）, was performed. A series of nine sequence-tagged site （STS） markers from the AZF region of the Y chromosome was used to detect microdeletions. All primers were designed based on the recommendations of the National Center for Biotechnology Information. An unusually high incidence （73/630, 11.6%） of sY84-absent but sY86-present genotypes was observed in the AZFa microdeletion screening. Sequencing the sY84-flanking region revealed a total of 73 patients with sY84-absent but sY86-present genotypes have a T-to-G transversion at the fifth base from the 5＇ end of the reverse sY84 primer. These prevalent false positives, which were not only observed in infertile men, but also observed in donors, resulted from a single-nucleotide polymorphism （SNP） named rs72609647 in the targeting sequence of the reverse sY84 primer. Our study suggests that a pre-screening of existence of rs72609647 polymorphism can prevent the frequent false positive results of AZFa microdeletions detection in the infertile Chinese males. Given the SNP rs72609647 was recently found in a deep sequencing of a Chinese individual, the current EAA and EMQN standards may need to be scrutinized among different populations to avoid the potential genetic variations in the primer binding sequences.

Ex vivo relaxation effect of Cuscuta chinensis extract on rabbit corpus cavernosum

The effect of Cuscuta chinensis extract on the rabbit penile corpus cavernosum （PCC） was evaluated in the present study. Penises obtained from healthy male New Zealand white rabbits （2.5-3.0 kg） were precontracted with phenylephrine （Phe, 10 pmol I^-1） and then treated with various concentrations of Cuscuta chinensis extract （1, 2, 3, 4 and 5 mg ml^-1）. The change in penile tension was recorded, and cyclic nucleotides in the PCC were measured by radioimmunoassay （RIA）. The interaction between Cuscuta chinensis and sildenafil was also evaluated. The result indicated that the PCC relaxation induced by Cuscuta chinensis extract was concentration-dependent. Pre-treatment with an nitric oxide synthase （NOS） inhibitor （No〉 nitro-L-arginine-methyl ester, L-NAME）, a guanylyl cyclase inhibitor （1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-l-one, ODQ）, or a protein kinase A inhibitor （KT 5720） did not completely inhibit the relaxation. Incubation of penile cavernous tissue with the Cuscuta chinensis extract significantly increased cyclic guanosine monophosphate （cGMP） and cyclic adenosine monophosphate （cAMP） in the PCC. Moreover, the Cuscuta chinensis extract significantly enhanced sildenafil-induced PCC relaxation. In conclusion, the Cuscuta chinensis extract exerts a relaxing effect on penile cavernous tissue in part by activating the NO-cGMP pathway, and it may improve erectile dysfunction （ED）, which does not completely respond to sildenafil citrate.

Development and clinical application of a new testicular prosthesis

A new type of testicular prosthesis made of silastic with an elliptical shape to mimic a normal testis was developed by our team and submitted for patenting in China. The prosthesis was produced in different sizes to imitate the normal testis of the patient. To investigate the effects and safety of the testicular prosthesis, 20 patients receiving testicular prosthesis implantation were recruited for this study. Follow-up after 6 months revealed no complications in the patients. All the patients answered that they were satisfied with their body image and the position of the implants, 19 patients were satisfied with the size and 16 patients were satisfied with the weight. These results show that the testicular prosthesis used in this study can meet patient＇s expectations. Patients undergoing orchiectomy should be offered the option to receive a testicular prosthesis implantation. The dimensions and weight of the available prosthetic implants should be further addressed to improve patient satisfaction.

Xeno-free culture of human spermatogonial stem cells supported by human embryonic stem cell-derived fibroblast-like cells

Spermatogonial stem cells （SSCs） divide continuously to support spermatogenesis throughout postnatal life and transmit genetic information to the next generation. Here, we report the successful establishment of the method for the isolation and identification of human SSCs from testicular tissue, and to determine the culture conditions required to expand SSCs on human embryonic stem cell-derived fibroblast-like cells （hdFs）. Large-scale cultures of SSCs were maintained on hdF feeder layers and expanded in the presence of a combination of cytokines and glial cell line-derived neurotrophic factor for at least 2 months. Cell surface marker analysis showed that SSCs retained high levels of alkaline phosphatase activity and stained strongly for anti-stage-specific embryonic antigen （SSEA）-1, OCT4 and CD49f. They also expressed the genes OCT4, SOX3 and STRA8 as detected by reverse transcription polymerase chain reaction （RT-PCR） analysis. These data clearly illustrate a novel approach for the growth of human SSCs using hdFs as feeder cells, potentially eliminating xenogeneic contaminants. This system provides a new opportunity for the study of the regulatory mechanism of the ‘niche＇ that governs SSC self-renewal, and will be a valuable source of SSCs for potential clinical applications.

Effect of rhTNF-α on Mitochondrial Transmembrane Potential and Motility of Human Sperm in vitro by Flow Cytometry and Computer Aided of Semen Analysis

To evaluate effect of recombined human tumor necrosis factor （rhTNF- α） on mitochondrial transmembrane potential and motility of human sperm in vitro Methods Semen samples for study were obtained from 40 health men （average age 26 ± 1.2 years） with normal semen analysis. Sperm suspension with computer aided of semen analysis （CASA） technique; 2） were stained in the presence of 10 μg/ml Rh123 and PI, mitochondrial transmembrane potential of those was analyzed by flow cytometry （FCM）. Results Significant differences were found between experimental groups and control groups on viability, straight line velocity, curvilinear velocity, average path velocity, progressive motility of human sperm and number of sperm with normal mitochondrial transmembrane potential （P〈0.01） expect final concentration 30 pg/ml group （P〉0. 05）. Sperm motility lowed with increasing rhTNF-α concentration and incubating time （P〈0. 01）. Number of sperm with normal mitochondrial transmembrane potential decreased with increasing rhTNF-α concentration and incubating time （P〈0.01）. Conclusion rh TNF-α can decrease human sperm motility function in vitro, which can interfere the function of human sperm mitochondrial transmembrane potential and may inhibit sperm mitochondrial enzymatic activities.

Sperm banking for male reproductive preservation： a 6-year retrospective multi-centre study in China

Sperm banking can preserve male fertility effectively, but the current conditions of sperm cryopreservation in China have not been investigated. This retrospective investigation was based on data collected at multiple centres in China from January 2003 to December 2008. The collected data included urogenital history, indication for cryopreservation, semen parameters, use rate, type of assisted reproductive technique （ART） treatment and pregnancy outcome. The study population included 1 548 males who had banked their semen during the study period at one of the clinics indicated above. Approximately 1.9% （30/1 548） of the cryopreserved semen samples were collected from cancer patients; about 88.8% （1 374/1 548） of the patients had banked their semen for ART and 8.6% （134/1 548） had a male infertility disease （such as anejaculation, severe oligozoospermia and obstructive azoospermia）. The total use rate of cryopreserved semen was 22.7% （352/1 548）, with 119 live births. The cancer group use rate was 6.7% （2/30）, with one live birth by intracytoplasmic single sperm injection （ICSI）. The ART group use rate was 23.2% （319/1 374）, with 106 live births. The reproductive disease group use rate was 23.1% （31/134）, with 12 live births. The semen parameters in each category varied; the cancer patient and infertility disease groups had poor semen quality. In vitro fertilization （IVF） and ICSI were the most common ART treatments for cryopreserved sperm. Semen cryopreservation as a salvage method is effective, but in many conditions it is underutilized, especially in cancer patients. Lack of awareness, urgency of cancer treatment and financial constraints are the main causes of the low access rate. The concept of fertility preservation should be popularized to make better use of this medical service in China.

An overview on ethical issues about sperm donation

Beyond the scientific progress in assisted reproductive technologies （ART）, it is necessary to discuss the ethical considerations behind these advances. Ethical issues concerning sperm donation have been considered and discussed by government and non-governmental agencies, the public, media and academic institutions in many countries. Recommendations and guidelines concerning sperm donation issues vary from country to country and between professional groups within countries. This paper attempts to present an overview of findings and reports from various agencies concerning the ethics of sperm donation. The following topics are considered： limiting the number of donor offspring; minimizing risk of infection and genetics from sperm donors; age requirements for sperm donors; and anonymity versus non-anonymity of sperm donors. The diversity of policies shows that each country has its unique set of guidelines tailored toward its own specific needs. Similarly, countries designing their own procedures and guidelines concerning reproductive medicine must tailor them toward their own needs and practical considerations. In China's Mainland, the anonymous policy for sperm donation should still be carried out, and the number of donor offspring should be revaluated. ART procedures must be conducted in a way that is respectful of those involved. Ethical principles must respect the interests and welfare of persons who will be born as well as the health and psychosocial welfare of all participants, including sperm donors.

Advances in penile-sparing surgical approaches

Objective:Penile cancer(PeCa)is a rare disease with a global incidence of 36068 new cases in 2020.This accounts for 0.4%of all male malignancies.The surgical management of PeCa depends on the location of the tumour and depth of invasion.Here,we review the oncological and functional outcomes of penile-preserving surgery(PPS).Methods:A PubMed search until July 2021 on PPS for PeCa was conducted;a narrative review on different penile-sparing approaches and outcomes was performed.Results:PPS is now the standard of care in specialist centres for distal tumours not involving the corpus cavernosa.Laser therapy,glans resurfacing,and wide local excision are options for superficial lesions,whilst glansectomy is required for lesions invading into the corpus spongiosum.Conclusion:PPS aims to preserve urinary and sexual function without compromising oncological outcomes.

A prospective randomized controlled study on scheduled PDE5i and vacuum erectile devices in the treatment of erectile dysfunction after nerve sparing prostatectomy

Cavernous nerve injury is an important cause of erectile dysfunction(ED).Although protective nerve technology has been widely used in nerve-sparing radical prostatectomy(nsRP),the incidence of ED is still very high after surgery.The purpose of our study was to evaluate erectile function(EF)and penile length in the non-erectile state(PLNES)following scheduled phosphodiesterase 5 inhibitor(PDE5i),vacuum erectile device(VED)treatment,and combination therapy after nsRP.One hundred patients with localized prostate cancer and normal EF were randomized to scheduled PDE5i group,VED treatment group,a combined treatment group,and the control group without any intervention.The International Index of Erectile Function-5(IIEF-5)scores and PLNES were evaluated after 6 months and 12 months of treatment.Sexual Encounter Profile(SEP-Question 2 and SEP-Question 3)were evaluated after 12 months of treatment.Ninety-one of the 100 randomized patients completed the study.We found that the 5 mg tadalafil once a day(OaD)combined with VED can help improve IIEF-5 scores in nsRP patients after both 6 months and 12 months.VED alone or combined with tadalafil OaD can help patients maintain PLNES.VED combined with tadalafil OaD can improve the rate of successful penetration(SEP-Question 2)after 12 months.There were no significant differences in the return to target EF after 12 months among the groups.No significant correlation was noted between the variables and return to target EF(IIEF≥17),and between the variables and effective shortening of the patient’s penis(shortening≥1 cm)after 12 months of intervention.

NODAL secreted by male germ cells regulates the proliferation and function of human Sertoli cells from obstructive azoospermia and nonobstructive azoospermia patients

This study was designed to explore the regulatory effects of male germ cell secreting factor NODAL on Sertoli cell fate decisions from obstructive azoospermia （OA） and nonobstructive azoospermia （NOA） patients. Human Sertoli cells and male germ cells were isolated using two-step enzymatic digestion and SATPUT from testes of azoospermia patients. Expression of NODAL and its multiple receptors in human Sertoli cells and male germ cells were characterized by reverse transcription-polymerase chain reaction （RT-PCRI and immunochemistry. Human recombinant NODAL and its receptor inhibitor SB431542 were employed to probe their effect on the proliferation of Sertoli cells using the CCK-8 assay. Quantitative PCR and Western blots were utilized to assess the expression of Sertoli cell functional genes and proteins. NODAL was found to be expressed in male germ cells but not in Sertoli cells, whereas its receptors ALK4, ALK7, and ACTR-IIB were detected in Sertoli cells and germ cells, suggesting that NODAL plays a regulatory role in Sertoli cells and germ cells via a paracrine and autocrine pathway, respectively. Human recombinant NODAL could promote the proliferation of human Sertoli cells. The expression of cell cycle regulators, including CYCLIN A, CYCLIN D1 and CYCLIN E, was not remarkably affected by NODAL signaling. NODAL enhanced the expression of essential growth factors, including GDNF, SCF, and BMP4, whereas SB431542 decreased their levels. There was not homogeneity of genes changes by NODAL treatment in Sertoli cells from OA and Sertoli cell-only syndrome （SCO） patients. Collectively, this study demonstrates that NODAL produced by human male germ cells regulates proliferation and numerous gene expression of Sertoli cells.

Plasticity of male germline stem cells and their applications in reproductive and regenerative medicine

Spermatogonial stem cells （SSCs）, also known as male germline stem cells, are a small subpopulation of type A spermatogonia with the potential of self-renewal to maintain stem cell pool and differentiation into spermatids in mammalian testis. SSCs are previously regarded as the unipotent stem cells since they can only give rise to sperm within the seminiferous tubules. However, this concept has recently been challenged because numerous studies have demonstrated that SSCs cultured with growth factors can acquire pluripotency to become embryonic stem-like cells. The in vivo and in vitro studies from peers and us have clearly revealed that SSCs can directly transdifferentiate into morphologic, phenotypic, and functional cells of other lineages. Direct conversion to the cells of other tissues has important significance for regenerative medicine. SSCs from azoospermia patients could be induced to differentiate into spermatids with fertilization and developmental potentials. As such, SSCs could have significant applications in both reproductive and regenerative medicine due to their unique and great potentials. In this review, we address the important plasticity of SSCs, with focuses on their self-renewal, differentiation, dedifferentiation, transdifferentiation, and translational medicine studies.

Modulation of SIRT1 expression improves erectile function in aged rats

Silent information regulator 2-related enzyme 1(SIRT1)is an aging-related protein activated with aging.Herein,we evaluated the role of SIRT1 in aging-related erectile dysfunction.The expression of SIRT1 was modulated in aged Sprague-Dawley rats following intragastric administration of resveratrol(Res;5 mg kg^(-1)),niacinamide(NAM;500 mg kg^(-1))or Res(5 mg kg^(-1))+tadalafil(Tad;phosphodiesterase-5[PDE5]inhibitor;5 mg kg^(-1))for 8 weeks.Then,we determined erectile function by the ratio of intracavernosal pressure(IcP)/mean systemic arterial pressure(MAP).Cavernosal tissues were extracted to evaluate histological changes,cell apoptosis,nitric oxide(NO)/cyclic guanosine monophosphate(cGMP),the superoxide dismutase(SOD)/3,4-methylenedioxyamphetamine(MDA)level,and the expression of SIRT1,p53,and forkhead box O3(FOX03a)using immunohistochemistry,terminal deoxynucleotidyl transferase(TdT)-mediated 2'-deoxyuridine 5'-triphosphate(dUTP)nick-end labeling(TUNEL),enzyme-linked immunosorbent assays,and western blot analysis.Compared with the control,Res treatment significantly improved erectile function,reflected by an increased content of smooth muscle and endothelium,NO/cGMP and SOD activity,and reduced cell apoptosis and MDA levels.The effect of Res was improved by adding Tad.In addition,the protein expression of SIRT1 was increased in the Res group,accompanied by decreased p53 and FOxO3a levels.In addition,inhibition of SIRT1 by NAM treatment resulted in adverse results compared with Res treatment.SIRT1 activation ameliorated aging-related erectile dysfunction,supporting the potential of SIRT1 as a target for erectile dysfunction treatment.

Genetic characterization and protein stability analysis of a Chinese family with Von Hippel-Lindau disease

Background Von HippeI-Lindau disease （VHL）,a heritable autosomal dominant disease characterized by neoplasia in multiple organ systems,has rarely been reported in Asia.We genetically investigated a unique Chinese family with VHL disease and performed an analysis of the VHL protein stability.Methods Genomic deoxyribonucleic acid （DNA） extracted from peripheral blood was amplified by polymerase chain reaction （PCR） to three exons of the VHL gene in 9 members of the Chinese family with VHL disease.PCR products were directly sequenced.We estimated the effects of VHL gene mutation on the stability of pVHL,which is indicated by the free energy difference between the wild-type and the mutant protein （△△G）.Results The Chinese family was classified as VHL type 1.Three family members,including two patients and a carrier,had a T to G heterozygotic missense mutation at nucleotide 515 of the VHL gene exon 1.This missense mutation resulted in the transition from leucine to arginine in amino acid 101 of the VHL protein.There was low stability of the VHL protein （the △△G was 12.71 kcal/mol） caused by this missense mutation.Conclusions We first reported a family with this VHL gene mutation in Asia.This missense mutation is predicted to significantly reduce the stability of the VHL protein and contribute to the development of the renal cell carcinoma （RCC） phenotype displayed by this family.The genetic characterization and protein stability analysis of families with VHL disease are important for early diagnosis and prevention of the disease being passed on to their offspring.