Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
2.
Elife ; 132024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38573307

RESUMEN

The perinuclear theca (PT) is a dense cytoplasmic web encapsulating the sperm nucleus. The physiological roles of PT in sperm biology and the clinical relevance of variants of PT proteins to male infertility are still largely unknown. We reveal that cylicin-1, a major constituent of the PT, is vital for male fertility in both mice and humans. Loss of cylicin-1 in mice leads to a high incidence of malformed sperm heads with acrosome detachment from the nucleus. Cylicin-1 interacts with itself, several other PT proteins, the inner acrosomal membrane (IAM) protein SPACA1, and the nuclear envelope (NE) protein FAM209 to form an 'IAM-cylicins-NE' sandwich structure, anchoring the acrosome to the nucleus. WES (whole exome sequencing) of more than 500 Chinese infertile men with sperm head deformities was performed and a CYLC1 variant was identified in 19 patients. Cylc1-mutant mice carrying this variant also exhibited sperm acrosome/head deformities and reduced fertility, indicating that this CYLC1 variant most likely affects human male reproduction. Furthermore, the outcomes of assisted reproduction were reported for patients harbouring the CYLC1 variant. Our findings demonstrate a critical role of cylicin-1 in the sperm acrosome-nucleus connection and suggest CYLC1 variants as potential risk factors for human male fertility.


Asunto(s)
Acrosoma , Infertilidad Masculina , Animales , Humanos , Masculino , Ratones , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Infertilidad Masculina/genética , Proteínas de la Membrana/genética , Semen , Cabeza del Espermatozoide , Espermatozoides
3.
Cell Mol Life Sci ; 81(1): 118, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38448737

RESUMEN

Tektins are microtubule inner proteins (MIPs) and localize at the inside lumen of doublet microtubules (DMTs) of cilia/flagella. TEKTIP1, a newly identified protein by cryo-electron microscopy (cryo-EM), is proposed to be localized at the center of the tektin bundle and hypothesized to recruit tektins or stabilize the bundle. However, the physiological role of TEKTIP1 is unknown. In this study, we generated Tektip1-knockout (Tektip1-/-) mice and showed that they were male subfertile primarily due to reduced sperm motility. A high percentage of sperm from Tektip1-/- mice showed moderately disorganized axoneme structures and abnormal flagellar waveforms. TEKTIP1 predominately interacted with TEKT3 among tektins. Loss of TEKTIP1 partially disturbed the organization of tektin bundle by mainly affecting the native status of TEKT3 and its interaction with other tektins. Collectively, our study reveals the physiological role and potential molecular mechanism of TEKTIP1 in axonemal structure and sperm motility, highlights the importance of MIPs in stabilizing DMTs, and suggests a potential relevance of TEKTIP1 deficiency to human asthenospermia. Tektip1-/- mice will be an excellent animal model to study the DMT organization of sperm flagella using cryo-EM in future.


Asunto(s)
Axonema , Proteínas de Microtúbulos , Semen , Humanos , Masculino , Animales , Ratones , Femenino , Microscopía por Crioelectrón , Motilidad Espermática , Espermatozoides , Flagelos
4.
Hum Reprod ; 39(5): 880-891, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38414365

RESUMEN

STUDY QUESTION: Could actin-related protein T1 (ACTRT1) deficiency be a potential pathogenic factor of human male infertility? SUMMARY ANSWER: A 110-kb microdeletion of the X chromosome, only including the ACTRT1 gene, was identified as responsible for infertility in two Chinese males with sperm showing acrosomal ultrastructural defects and fertilization failure. WHAT IS KNOWN ALREADY: The actin-related proteins (e.g. ACTRT1, ACTRT2, ACTL7A, and ACTL9) interact with each other to form a multimeric complex in the subacrosomal region of spermatids, which is crucial for the acrosome-nucleus junction. Actrt1-knockout (KO) mice are severely subfertile owing to malformed sperm heads with detached acrosomes and partial fertilization failure. There are currently no reports on the association between ACTRT1 deletion and male infertility in humans. STUDY DESIGN, SIZE, DURATION: We recruited a cohort of 120 infertile males with sperm head deformations at a large tertiary hospital from August 2019 to August 2023. Genomic DNA extracted from the affected individuals underwent whole exome sequencing (WES), and in silico analyses were performed to identify genetic variants. Morphological analysis, functional assays, and ART were performed in 2022 and 2023. PARTICIPANTS/MATERIALS, SETTING, METHODS: The ACTRT1 deficiency was identified by WES and confirmed by whole genome sequencing, PCR, and quantitative PCR. Genomic DNA of all family members was collected to define the hereditary mode. Papanicolaou staining and electronic microscopy were performed to reveal sperm morphological changes. Western blotting and immunostaining were performed to explore the pathological mechanism of ACTRT1 deficiency. ICSI combined with artificial oocyte activation (AOA) was applied for one proband. MAIN RESULTS AND THE ROLE OF CHANCE: We identified a whole-gene deletion variant of ACTRT1 in two infertile males, which was inherited from their mothers, respectively. The probands exhibited sperm head deformations owing to acrosomal detachment, which is consistent with our previous observations on Actrt1-KO mice. Decreased expression and ectopic distribution of ACTL7A and phospholipase C zeta were observed in sperm samples from the probands. ICSI combined with AOA effectively solved the fertilization problem in Actrt1-KO mice and in one of the two probands. LIMITATIONS, REASONS FOR CAUTION: Additional cases are needed to further confirm the genetic contribution of ACTRT1 variants to male infertility. WIDER IMPLICATIONS OF THE FINDINGS: Our results reveal a gene-disease relation between the ACTRT1 deletion described here and human male infertility owing to acrosomal detachment and fertilization failure. This report also describes a good reproductive outcome of ART with ICSI-AOA for a proband. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Chongqing medical scientific research project (Joint project of Chongqing Health Commission and Science and Technology Bureau, 2023MSXM008 and 2023MSXM054). There are no competing interests to declare. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Acrosoma , Infertilidad Masculina , Proteínas de Microfilamentos , Adulto , Humanos , Masculino , Acrosoma/patología , Acrosoma/ultraestructura , Actinas/metabolismo , Actinas/genética , Secuenciación del Exoma , Fertilización/genética , Eliminación de Gen , Infertilidad Masculina/genética , Cabeza del Espermatozoide/ultraestructura , Cabeza del Espermatozoide/patología , Inyecciones de Esperma Intracitoplasmáticas , Espermatozoides/ultraestructura , Espermatozoides/anomalías , Proteínas de Microfilamentos/genética
5.
Accid Anal Prev ; 195: 107391, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38007876

RESUMEN

Road vehicles are highly susceptible to single-vehicle crashes (SVCs) under complex road geometry and inclement weather, which can significantly threaten traffic safety and mobility of the whole traffic system. Most existing studies involve various simplifications and approximations to assess the associated SVC risks promptly, and therefore the assessment accuracy is often compromised. A novel multi-fidelity approach is developed for the reliability-based risk assessment of SVCs to balance the simulation accuracy and efficiency. Specifically, a high-fidelity transient dynamic vehicle model is introduced for a robust estimation of the vehicle dynamics under various driving environments, assisted by a low-fidelity simplified physics-based vehicle model to improve the computational efficiency. Based on the simulations of the two models, a new multi-fidelity improved cross entropy-based importance sampling (MFICE) algorithm is proposed for integrating multi-fidelity information and facilitating accurate and efficient reliability analysis. Five demonstrative cases are studied to evaluate the performance of the proposed approach, including the comparison with existing representative approaches. The results show that the proposed innovative multi-fidelity approach can provide a reliability evaluation of SVCs both accurately and efficiently, with obviously superior performance over typical state-of-the-art counterparts. Therefore, the proposed approach bears great potential on developing proactive and near real-time intelligent traffic operation and management strategies against SVCs in both normal and hazardous conditions.


Asunto(s)
Accidentes de Tránsito , Conducción de Automóvil , Humanos , Accidentes de Tránsito/prevención & control , Seguridad , Reproducibilidad de los Resultados , Medición de Riesgo
7.
Elife ; 122023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-38126872

RESUMEN

Male infertility is a worldwide population health concern. Asthenoteratozoospermia is a common cause of male infertility, but its etiology remains incompletely understood. No evidence indicates the relevance of CFAP52 mutations to human male infertility. Our whole-exome sequencing identified compound heterozygous mutations in CFAP52 recessively cosegregating with male infertility status in a non-consanguineous Chinese family. Spermatozoa of CFAP52-mutant patient mainly exhibited abnormal head-tail connection and deformed flagella. Cfap52-knockout mice resembled the human infertile phenotype, showing a mixed acephalic spermatozoa syndrome (ASS) and multiple morphological abnormalities of the sperm flagella (MMAF) phenotype. The ultrastructural analyses further revealed a failure of connecting piece formation and a serious disorder of '9+2' axoneme structure. CFAP52 interacts with a head-tail coupling regulator SPATA6 and is essential for its stability. Expression of microtubule inner proteins and radial spoke proteins were reduced after the CFAP52 deficiency. Moreover, CFAP52-associated male infertility in humans and mice could be overcome by intracytoplasmic sperm injection (ICSI). The study reveals a prominent role for CFAP52 in sperm development, suggesting that CFAP52 might be a novel diagnostic target for male infertility with defects of sperm head-tail connection and flagella development.


Asunto(s)
Infertilidad Masculina , Semen , Animales , Humanos , Masculino , Ratones , Proteínas del Citoesqueleto , Flagelos , Infertilidad Masculina/diagnóstico , Infertilidad Masculina/genética , Ratones Noqueados , Proteínas de Microtúbulos , Cabeza del Espermatozoide , Cola del Espermatozoide
8.
EBioMedicine ; 93: 104675, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37352829

RESUMEN

BACKGROUND: Male infertility is a worldwide population health concern, but its aetiology remains largely understood. Although CFAP70 variants have already been reported in two oligo-astheno-teratozoospermia (OAT) individuals by sequencing, animal evidence to support CFAP70 as a credible OAT-pathogenic gene is lacking. METHOD: Cfap70-KO mice were generated to explore the physiological role of CFAP70. CFAP70 variants were detected in infertile men with OAT by whole exome sequencing and Sanger sequencing confirmation. Cfap70-truncated mice were further generated to explore the pathogenicity of the nonsense variant of CFAP70 identified in the proband. FINDINGS: Here, we demonstrate that Cfap70-KO mice are sterile mainly due to OAT and further identify a Chinese infertile man carrying a homozygous nonsense variant (c.2962C > T/p.R988X) of CFAP70. Cfap70-truncated mice lacking 5-8 tetratricopeptide repeats (TPRs) mimic the patient's symptoms. CFAP70 is required for the biogenesis of spermatid flagella partially by regulating the expression of OAT-associated proteins (e.g., QRICH2), assisting the cytoplasmic preassembly of the calmodulin- and radial spoke-associated complex (CSC), and controlling the manchette localization of axoneme-related proteins. Moreover, we suggest that CFAP70-associated male infertility could be overcome by intracytoplasmic sperm injection (ICSI) treatment. INTERPRETATION: Overall, we demonstrate that CFAP70 is necessary to assemble spermatid flagella and that CFAP70 gene could be used as a diagnostic target for male infertility with OAT in the clinic. FUNDING: This study was supported by the National Key Research and Development Project (2019YFA0802101 to S.C), Open Fund of Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education (to S.C), Central Government to Guide Local Scientific and Technological Development (ZY21195023 to B.W), and Basic Research Projects of Central Scientific Research Institutes (to B.W).


Asunto(s)
Infertilidad Masculina , Semen , Humanos , Masculino , Animales , Ratones , Infertilidad Masculina/diagnóstico , Infertilidad Masculina/genética , Infertilidad Masculina/patología
9.
Sci Adv ; 8(40): eabn0968, 2022 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-36206347

RESUMEN

Centrosomal protein dysfunction might cause ciliopathies. However, the role of centrosomal proteins in male infertility remains poorly defined. Here, we identified a pathogenic splicing mutation in CEP78 in male infertile patients with severely reduced sperm number and motility, and the typical multiple morphological abnormalities of the sperm flagella phenotype. We further created Cep78 knockout mice, which showed an extremely low sperm count, completely aberrant sperm morphology, and approximately null sperm motility. The infertility of the patients and knockout mice could not be rescued by an intracytoplasmic sperm injection treatment. Mechanistically, CEP78 might regulate USP16 expression, which further stabilizes Tektin levels via the ubiquitination pathway. Cep78 knockout mice also exhibited impairments in retina and outer hair cells of the cochlea. Collectively, our findings identified nonfunctional CEP78 as an indispensable factor contributing to male infertility and revealed a role for this gene in regulating retinal and outer hair cell function in mice.


Asunto(s)
Infertilidad Masculina , Motilidad Espermática , Animales , Humanos , Masculino , Ratones , Proteínas de Ciclo Celular/genética , Infertilidad Masculina/genética , Ratones Noqueados , Mutación , Semen , Motilidad Espermática/genética , Cola del Espermatozoide/patología , Espermatozoides/fisiología
10.
Cell Rep ; 40(1): 111049, 2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35793634

RESUMEN

The perinuclear theca (PT) is a cytoskeletal element encapsulating the sperm nucleus; however, our understanding of the physiological roles of PT in sperm is very limited. We show that Calicin interacts with itself and many other PT components, indicating it may serve as an organizing center of the PT assembly. Calicin is detectable first when surrounding the acrosome, then detected around the entire nucleus, and finally translocated to the postacrosomal region of spermatid heads. Intriguingly, loss of Calicin specifically causes surface subsidence of sperm heads in the nuclear condensation stage. Calicin interacts with inner acrosomal membrane (IAM) protein Spaca1 and nuclear envelope (NE) components to form an "IAM-PT-NE" structure. Intriguingly, Ccin-knockout sperm also exhibit DNA damage and failure of fertilization. Our study provides solid animal evidence to suggest that the PT encapsulating sperm nucleus helps shape the sperm head and maintain the nuclear structure.


Asunto(s)
Proteínas del Citoesqueleto , Semen , Cabeza del Espermatozoide , Animales , Proteínas del Citoesqueleto/metabolismo , Citoesqueleto/fisiología , Masculino , Ratones , Semen/metabolismo , Cabeza del Espermatozoide/metabolismo , Cabeza del Espermatozoide/fisiología
11.
Development ; 149(12)2022 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-35616329

RESUMEN

The perinuclear theca (PT) is a cytoskeletal element encapsulating the sperm nucleus; however, the physiological roles of the PT in sperm are largely uncertain. Here, we reveal that ACTRT1, ACTRT2, ACTL7A and ACTL9 proteins interact to form a multimeric complex and localize to the subacrosomal region of spermatids. Furthermore, we engineered Actrt1-knockout (KO) mice to define the functions of ACTRT1. Despite normal sperm count and motility, Actrt1-KO males were severely subfertile owing to a deficiency in fertilization. Loss of ACTRT1 caused a high incidence of malformed heads and detachment of acrosomes from sperm nuclei, caused by loosened acroplaxome structure during spermiogenesis. Furthermore, Actrt1-KO sperm showed reduced ACTL7A and PLCζ protein content as a potential cause of fertilization defects. Moreover, we reveal that ACTRT1 anchors developing acrosomes to the nucleus, likely by interacting with the inner acrosomal membrane protein SPACA1 and the nuclear envelope proteins PARP11 and SPATA46. Loss of ACTRT1 weakened the interaction between ACTL7A and SPACA1. Our study and recent findings of ACTL7A/ACTL9-deficient sperm together reveal that the sperm PT-specific ARP complex mediates the acrosome-nucleus connection.


Asunto(s)
Acrosoma , Infertilidad Masculina , Acrosoma/metabolismo , Animales , Humanos , Infertilidad Masculina/genética , Infertilidad Masculina/metabolismo , Masculino , Proteínas de la Membrana/metabolismo , Ratones , Ratones Noqueados , Proteínas de Microfilamentos/metabolismo , Espermátides/metabolismo , Espermatogénesis/genética , Espermatozoides/metabolismo
12.
Hum Mol Genet ; 31(7): 1013-1021, 2022 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-34448846

RESUMEN

Non-obstructive azoospermia (NOA) is an important cause of male infertility, and the genetic pathogenesis is still incompletely understood. The previous study reported that heterozygous mutation of c.346-1G > A in spermatogenesis and oogenesis specific basic helix-loop-helix 1 (SOHLH1) was identified in two NOA patients and suggested it is the pathogenic factor for NOA. However, in our research, this heterozygous mutation was confirmed in three Chinese infertile patients who suffered from teratozoospermia, but they had normal sperm number. Intriguingly, a homozygous mutation of c.346-1G > A in SOHLH1 was detected in a severe oligozoospermia (SOZ) patient, characterized with severely decreased sperm count. Notably, we unprecedently revealed that this homozygous mutation of c.346-1G > A in SOHLH1 leads to the sharp decrease in various germ cells and spermatogenesis dysfunction, which is similar to the phenotype of SOHLH1 knockout male mice. Moreover, western blotting confirmed that the homozygous mutation declined SOHLH1 protein expression. Additionally, we correlated the good prognosis of intracytoplasmic sperm injection (ICSI) in the patients carrying the mutation of c.346-1G > A in SOHLH1. Thus, we suggested that the heterozygous mutation of c.346-1G > A in SOHLH1 is responsible for teratozoospermia, and this homozygous mutation in SOHLH1 impairs spermatogenesis and further leads to the reduced sperm count, eventually causing male infertility, which unveils a new recessive-inheritance pattern of SOHLH1-associated male infertility initially.


Asunto(s)
Azoospermia , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Animales , Azoospermia/genética , Homocigoto , Humanos , Masculino , Ratones , Mutación , Espermatogénesis/genética , Espermatozoides
13.
Hum Reprod Update ; 27(1): 154-189, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-33118031

RESUMEN

BACKGROUND: Infertility is a major issue in human reproductive health, affecting an estimated 15% of couples worldwide. Infertility can result from disorders of sex development (DSD) or from reproductive endocrine disorders (REDs) with onset in infancy, early childhood or adolescence. Male infertility, accounting for roughly half of all infertility cases, generally manifests as decreased sperm count (azoospermia or oligozoospermia), attenuated sperm motility (asthenozoospermia) or a higher proportion of morphologically abnormal sperm (teratozoospermia). Female infertility can be divided into several classical types, including, but not limited to, oocyte maturation arrest, premature ovarian insufficiency (POI), fertilization failure and early embryonic arrest. An estimated one half of infertility cases have a genetic component; however, most genetic causes of human infertility are currently uncharacterized. The advent of high-throughput sequencing technologies has greatly facilitated the identification of infertility-associated gene mutations in patients over the past 20 years. OBJECTIVE AND RATIONALE: This review aims to conduct a narrative review of the genetic causes of human infertility. Loss-of-function mutation discoveries related to human infertility are summarized and further illustrated in tables. Corresponding knockout/mutated animal models of causative genes for infertility are also introduced. SEARCH METHODS: A search of the PubMed database was performed to identify relevant studies published in English. The term 'mutation' was combined with a range of search terms related to the core focus of the review: infertility, DSD, REDs, azoospermia or oligozoospermia, asthenozoospermia, multiple morphological abnormalities of the sperm flagella (MMAF), primary ciliary dyskinesia (PCD), acephalic spermatozoa syndrome (ASS), globozoospermia, teratozoospermia, acrosome, oocyte maturation arrest, POI, zona pellucida, fertilization defects and early embryonic arrest. OUTCOMES: Our search generated ∼2000 records. Overall, 350 articles were included in the final review. For genetic investigation of human infertility, the traditional candidate gene approach is proceeding slowly, whereas high-throughput sequencing technologies in larger cohorts of individuals is identifying an increasing number of causative genes linked to human infertility. This review provides a wide panel of gene mutations in several typical forms of human infertility, including DSD, REDs, male infertility (oligozoospermia, MMAF, PCD, ASS and globozoospermia) and female infertility (oocyte maturation arrest, POI, fertilization failure and early embryonic arrest). The causative genes, their identified mutations, mutation rate, studied population and their corresponding knockout/mutated mice of non-obstructive azoospermia, MMAF, ASS, globozoospermia, oocyte maturation arrest, POI, fertilization failure and early embryonic arrest are further illustrated by tables. In this review, we suggest that (i) our current knowledge of infertility is largely obtained from knockout mouse models; (ii) larger cohorts of clinical cases with distinct clinical characteristics need to be recruited in future studies; (iii) the whole picture of genetic causes of human infertility relies on both the identification of more mutations for distinct types of infertility and the integration of known mutation information; (iv) knockout/mutated animal models are needed to show whether the phenotypes of genetically altered animals are consistent with findings in human infertile patients carrying a deleterious mutation of the homologous gene; and (v) the molecular mechanisms underlying human infertility caused by pathogenic mutations are largely unclear in most current studies. WILDER IMPLICATIONS: It is important to use our current understanding to identify avenues and priorities for future research in the field of genetic causes of infertility as well as to apply mutation knowledge to risk prediction, genetic diagnosis and potential treatment for human infertility.


Asunto(s)
Infertilidad Femenina/genética , Infertilidad Masculina , Animales , Femenino , Humanos , Infertilidad Masculina/genética , Mutación con Pérdida de Función , Masculino , Ratones , Ratones Noqueados , Motilidad Espermática , Espermatozoides
14.
Cancers (Basel) ; 12(8)2020 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-32823589

RESUMEN

Ovarian cancer is a leading cause of death from gynecologic malignancies worldwide. Although CD83 is widely described as a solid marker for mature dendritic cells, emerging pieces of evidence indicate the expression of membrane protein CD83 by various tumor cells, including ovarian cancer cells. However, the potential role of CD83 in ovarian cancer cell properties and development remains absolutely unknown. By using human CD83 stable overexpression and knockdown sublines of several ovarian cancer cells, we observed that CD83 advanced the growth proliferation, colony formation ability, spheroid formation, and in vivo tumorigenicity of ovarian cancer cells; surprisingly, CD83 limited their migration and invasion potentials. Positive regulation of proliferation/stemness factors (e.g., cyclin-CDKs and KIT/CD44) but negative regulation of matrix metallopeptidases (e.g., MMP1 and 7) by CD83 were revealed by the integrated analysis of transcriptome and proteome. Furthermore, immunoprecipitation-mass spectrometry (IP-MS) and co-immunoprecipitation (Co-IP) first identified the association of CD83 with MAP3K7 (also known as TAK1) and MAP3K7-binding protein TAB1 on the cell membrane. Moreover, CD83 functions through the activation of MAP3K7-MEK1/2-ERK1/2 cascades to further regulate downstream FOXO1/p21/CDK2/CCNB1 and STAT3/DKK1 signaling pathways, thus activating proliferation and spheroid formation of ovarian cancer cells, respectively. Collectively, our findings define a CD83-MAPK pathway in the regulation of proliferation and stemness in ovarian cancer cells, with potential therapeutic applications in blocking their progression.

15.
Accid Anal Prev ; 145: 105698, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32763507

RESUMEN

Work zone traffic safety under adverse weather conditions has been a serious concern for drivers and transportation agencies. Existing studies on work zone traffic safety with statistical approaches are limited by the availability of data from historical crashes. To date, there is no comprehensive simulation framework to assess work zone traffic safety under adverse driving environments by considering both multi-vehicle and single-vehicle crashes. To fill this gap, this paper presents an integrated framework to evaluate traffic safety in work zone under adverse driving conditions by considering specific work zone configuration, weather and road surface conditions. A new risk index is introduced to assess the traffic safety risk of work zones by integrating the risks of multi-vehicle crashes and single-vehicle crashes. Traffic safety of a typical work zone under different weather conditions is studied to demonstrate the proposed framework. The impacts of the differential speed limits (DSL) and truck proportion on the work zone traffic safety are also investigated. Results show that adverse weather may increase the crash risk in work zones. The effect of DSL on the work zone traffic safety is found to be insignificant while the truck ratio influences the work zone safety in the rainy and snowy weather by primarily affecting the multi-vehicle crash risks.


Asunto(s)
Accidentes de Tránsito/clasificación , Tiempo (Meteorología) , Lugar de Trabajo , Conducción de Automóvil , Simulación por Computador , Humanos , Vehículos a Motor , Medición de Riesgo , Seguridad
16.
Cancers (Basel) ; 12(5)2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32429086

RESUMEN

Long non-coding RNA (lncRNA), which is a kind of noncoding RNA, is generally characterized as being more than 200 nucleotide transcripts in length. LncRNAs exhibit many biological activities, including, but not limited to, cancer development. In this review, a search of the PubMed database was performed to identify relevant studies published in English. The term "lncRNA or long non-coding RNA" was combined with a range of search terms related to the core focus of the review: mechanism, structure, regulation, and cancer. The eligibility of the retrieved studies was mainly based on the abstract. The decision as to whether or not the study was included in this review was made after a careful assessment of its content. The reference lists were also checked to identify any other study that could be relevant to this review. We first summarized the molecular mechanisms of lncRNAs in tumorigenesis, including competing endogenous RNA (ceRNA) mechanisms, epigenetic regulation, decoy and scaffold mechanisms, mRNA and protein stability regulation, transcriptional and translational regulation, miRNA processing regulation, and the architectural role of lncRNAs, which will help a broad audience better understand how lncRNAs work in cancer. Second, we introduced recent studies to elucidate the structure of lncRNAs, as there is a link between lncRNA structure and function and visualizing the architectural domains of lncRNAs is vital to understanding their function. Third, we explored emerging evidence for regulators of lncRNA expression, lncRNA turnover, and lncRNA modifications (including 5-methylcytidine, N6-methyladenosine, and adenosine to inosine editing), highlighting the dynamics of lncRNAs. Finally, we used autophagy in cancer as an example to interpret the diverse mechanisms of lncRNAs and introduced clinical trials of lncRNA-based cancer therapies.

17.
Mol Reprod Dev ; 87(2): 223-230, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32011766

RESUMEN

Sertoli cells (SCs) are presumed to be the center of testis differentiation because they provide both structural support and biological regulation for spermatogenesis. Previous studies suggest that SCs control germ cell (GC) count and Leydig cell (LC) development in mouse testes. However, the regulatory role of SCs on peritubular myoid (PTM) cell fate in fetal testis has not been clearly reported. Here, we employed Amh-Cre; diphtheria toxin fragment A (DTA) mouse model to selectively ablate SCs from embryonic day (E) 14.5. Results found that SC ablation in the fetal stage caused the disruption of testis cords and the massive loss of GCs. Furthermore, the number of α-smooth muscle actin-labeled PTM cells was gradually decreased from E14.5 and almost lost at E18.5 in SC ablation testis. Interestingly, some Ki67 and 3ß-HSD double-positive fetal LCs could be observed in Amh-Cre; DTA testes at E16.5 and E18.5. Consistent with this phenomenon, the messenger RNA levels of Hsd3b1, Cyp11a1, Lhr, Star and the protein levels of 3ß-HSD and P450Scc were significantly elevated by SC ablation. SC ablation appears to induce ectopic proliferation of fetal LCs although the total LC number appeared reduced. Together, these findings bring us a better understanding of SCs' central role in fetal testis development.


Asunto(s)
Diferenciación Celular/genética , Toxina Diftérica/genética , Madurez de los Órganos Fetales , Integrasas/genética , Fragmentos de Péptidos/genética , Túbulos Seminíferos/embriología , Células de Sertoli/metabolismo , Animales , Proliferación Celular/genética , Toxina Diftérica/metabolismo , Células Germinativas/metabolismo , Integrasas/metabolismo , Células Intersticiales del Testículo/metabolismo , Masculino , Ratones , Modelos Animales , Fragmentos de Péptidos/metabolismo , Ratas Transgénicas , Espermatogénesis
18.
Oxid Med Cell Longev ; 2019: 8030697, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31583044

RESUMEN

The interaction between germ cell and somatic cell plays important roles in germ cell development. However, the exact function of gonad somatic cell in germ cell differentiation is unclear. In the present study, the function of gonad somatic cell in germ cell meiosis was examined by using mouse models with aberrant somatic cell differentiation. In Wt1R394W/R394W mice, the genital ridge is absent due to the apoptosis of coelomic epithelial cells. Interestingly, in both male and female Wt1R394W/R394W germ cells, STRA8 was detected at E12.5 and the scattered SYCP3 foci were observed at E13.5 which was consistent with control females. In Wt1-/flox; Cre-ERTM mice, Wt1 was inactivated by the injection of tamoxifen at E9.5 and the differentiation of Sertoli and granulosa cells was completely blocked. We found that most germ cells were located outside of genital ridge after Wt1 inactivation. STRA8, SYCP3, and γH2AX proteins were detected in germ cells of both male and female Wt1-/flox; Cre-ERTM gonads, whereas no thread-like SYCP3 signal was observed. Our study demonstrates that aberrant development of gonad somatic cells leads to ectopic expression of meiosis-associated genes in germ cells, but meiosis was arrested before prophase I. These results suggest that the proper differentiation of gonad somatic cells is essential for germ cell meiosis.


Asunto(s)
Células Germinativas/metabolismo , Animales , Diferenciación Celular , Femenino , Gónadas , Células Híbridas , Masculino , Meiosis , Ratones
19.
Front Biosci (Landmark Ed) ; 24(8): 1401-1425, 2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-31136987

RESUMEN

Currently, there are few male contraceptive methods that are purely based on prevention of the entry of the sperm into the female reproductive tract. An alternative approach for designing reversible male contraceptive is achieved by transient testicular heating (TTH). This treatment, through massive germ cell apoptosis, causes reversible oligospermia or azoospermia. Here, we describe as how TTH causes DNA damage, oxidative stress, apoptosis, autophagy, sperm protein expression, and alters the biochemical components of seminal plasma. Further understanding of TTH will help design safe and reversible male contraception.


Asunto(s)
Calefacción/métodos , Calor , Oligospermia/fisiopatología , Semen/fisiología , Espermatozoides/fisiología , Testículo/fisiopatología , Anticoncepción/métodos , Daño del ADN , Humanos , Masculino , Oligospermia/metabolismo , Semen/metabolismo , Espermatozoides/metabolismo , Testículo/metabolismo , Testículo/patología
20.
J Proteome Res ; 18(4): 1819-1826, 2019 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-30835130

RESUMEN

Seminoma and embryonal carcinoma (EC), two typical types of testicular germ cell tumors (TGCTs), present significant differences in growth behavior, expression characteristics, differentiation potential, clinical features, therapy, and prognosis. The purpose of this study was to compare the distinctive or preference metabolic pathways between seminoma and EC. The Cancer Genome Atlas revealed that many genes encoding metabolic enzymes could distinguish between seminoma and EC. Using well-characterized cell line models for seminoma (Tcam-2 cells) and EC (NT2 cells), we characterized their metabolite profiles using ultraperformance liquid chromatography coupled to Q-TOF mass spectrometry (UPLC/Q-TOF MS). In general, the integrated results from transcriptome and metabolite profiling revealed that seminoma and EC exhibited distinctive characteristics in the metabolisms of amino acids, glucose, fatty acids, sphingolipids, nucleotides, and drugs. Notably, an attenuation of citric acid cycle/mitochondrial oxidative phosphorylation and sphingolipid biosynthesis as well as an increase in arachidonic acid metabolism and (very) long-chain fatty acid abundance occurred in seminoma as compared with EC. Our study suggests histologic subtype-dependent metabolic reprogramming in TGCTs and will lead to a better understanding of the metabolic signatures and biology of TGCT subtypes.


Asunto(s)
Carcinoma Embrionario/metabolismo , Metaboloma/genética , Neoplasias de Células Germinales y Embrionarias/metabolismo , Seminoma/metabolismo , Neoplasias Testiculares/metabolismo , Transcriptoma/genética , Carcinoma Embrionario/genética , Línea Celular Tumoral , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Masculino , Espectrometría de Masas , Neoplasias de Células Germinales y Embrionarias/genética , Seminoma/genética , Neoplasias Testiculares/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...