Preparation of Controlled Multicompartmental Gel Microcarriers Based on Aqueous Two-Phase Emulsions for 3D Partitioned Cell Coculture In Vitro.

A facile method was proposed for preparing controllable multicompartment gel microcarriers using an aqueous two-phase emulsion system. By leveraging the density difference between the upper polyethylene glycol solution and the lower dextran-calcium chloride (CaCl2) solution in the collection solution and the high viscosity of the lower solution, controllable fusion of core-shell droplets made by coextrusion devices was achieved at the water/water (w/w) interface to fabricate microcarriers with separated core compartments. By adjusting the sodium alginate concentration, collected solution composition, and number of fused liquid droplets, the pore size, shape, and number of compartments could be controlled. Caco-2 and HepG2 cells were encapsulated in different compartments to establish gut-liver coculture models, exhibiting higher viability and proliferation compared to monoculture models. Notably, significant differences in cytokine expression and functional proteins were observed between the coculture and monoculture models. This method provides new possibilities for preparing complex and functional three-dimensional coculture materials.

Association of lifestyle and occupational exposure factors with human semen quality: a cross-sectional study of 1060 participants.

The incidence of male infertility (MI) is rising annually. However, the lifestyle and occupational exposure factors contributing to MI remain incompletely understood. This study explored the effects of self-reported lifestyle and occupational exposure factors on semen quality. Among 1060 subjects invited to participate, 826 were eligible. The participants' general characteristics, lifestyle, and occupational exposure factors were collected immediately before or after semen evaluation through an online questionnaire. Initially, univariate analysis was used to investigate the relationship between the abovementioned factors and semen quality. The results indicated significant associations between low semen quality and various factors, including age, BMI, infertility type and duration, abstinence time, semen and sperm parameters, smoking, alcohol consumption, irregular sleep habits, and frequent exposure to high temperatures and chemicals at work (p < 0.05). Then, multivariate analysis was conducted to identify factors independently associated with low semen quality. Adjustment for relevant confounders was achieved by including factors with a p-value < 0.25 from univariate analyses as covariates in the binomial and ordered logistic regression models. The results suggested that alcohol consumption was a positive factor for sperm concentration (odds ratio [OR] = 0.60; 95% confidence interval [CI] = 0.36-0.99; p = 0.045). The groups with a BMI ≥ 24 and <28 kg/m2 showed a significant decrease in sperm progressive motility when compared to the reference group (BMI < 24 kg/m2) (OR = 0.63; 95% CI = 0.46-0.87, p = 0.005). In addition, the groups that drank green tea <1 time/week (OR = 1.52, 95% CI = 1.05-2.2) and 1-4 times/week (OR = 1.61, 95% CI = 1.02-2.54) exhibited significantly increased sperm DFI values compared with the group that drank green tea 5-7 times/week. In conclusion, these findings underscore the importance of maintaining a normal weight and regularly consuming green tea for men.

Construction of Dome-Shaped 3D Corneal Epithelial Tissue Models Based on Eyeball-Shaped Gel Microspheres.

By overcoming interspecies differences and mimicking the in vivo microenvironment, three-dimensional (3D) in vitro corneal models have become a significant novel tool in contemporary ophthalmic disease research. However, existing 3D corneal models struggle to replicate the actual human corneal environment, especially the dome-shaped physiological structure with adjustable curvature. Addressing these challenges, this study introduces a straightforward method for fabricating collagen/chitosan-alginate eyeball-shaped gel microspheres with a Janus structure via a two-phase aqueous system, used subsequently to construct in vitro 3D corneal epithelial tissue models. By adjusting the diameter ratio of collagen/chitosan to alginate droplets, we can create eyeball-shaped gel microspheres with varying curvatures. Human corneal epithelial cells were seeded on the surfaces of these microspheres, leading to the formation of in vitro 3D corneal epithelial tissues characterized by dome-like multilayers and tight junctions. Additionally, the model demonstrated responsiveness to UVB exposure through the secretion of reactive oxygen species (ROS) and proinflammatory factors. Therefore, we believe that in vitro 3D corneal epithelial tissue models with dome-shaped structures hold significant potential for advancing ophthalmic research.

Adenylate kinase phosphate energy shuttle underlies energetic communication in flagellar axonemes.

The complexities of energy transfer mechanisms in the flagella of mammalian sperm flagella have been intensively investigated and demonstrate significant diversity across species. Enzymatic shuttles, particularly adenylate kinase (AK) and creatine kinase (CK), are pivotal in the efficient transfer of intracellular ATP, showing distinct tissue- and species-specificity. Here, the expression profiles of AK and CK were investigated in mice and found to fall into four subgroups, of which Subgroup III AKs were observed to be unique to the male reproductive system and conserved across chordates. Both AK8 and AK9 were found to be indispensable to male reproduction after analysis of an infertile male cohort. Knockout mouse models showed that AK8 and AK9 were central to promoting sperm motility. Immunoprecipitation combined with mass spectrometry revealed that AK8 and AK9 interact with the radial spoke (RS) of the axoneme. Examination of various human and mouse sperm samples with substructural damage, including the presence of multiple RS subunits, showed that the head of radial spoke 3 acts as an adapter for AK9 in the flagellar axoneme. Using an ATP probe together with metabolomic analysis, it was found that AK8 and AK9 cooperatively regulated ATP transfer in the axoneme, and were concentrated at sites associated with energy consumption in the flagellum. These findings indicate a novel function for RS beyond its structural role, namely, the regulation of ATP transfer. In conclusion, the results expand the functional spectrum of AK proteins and suggest a fresh model regarding ATP transfer within mammalian flagella.

All-aqueous droplets-templated tailorable core-shell alginate microspheres for constructing vascularized intestinal mucosain vitromodels.

Recently,in vitromodels of intestinal mucosa have become important tools for drug screening and studying the physiology and pathology of the intestine. These models enable the examination of cellular behavior in diseased states or in reaction to alterations in the microenvironment, potentially serving as alternatives to animal models. One of the major challenges in constructing physiologically relevantin vitromodels of intestinal mucosa is the creation of three-dimensional microstructures that accurately mimic the integration of intestinal epithelium and vascularized stroma. Here, core-shell alginate (Alg) microspheres were generated to create the compartmentalized extracellular matrix microenvironment needed to simulate the epithelial and vascularized stromal compartments of the intestinal mucosa. We demonstrated that NIH-3T3 and human umbilical vein endothelial cells embedded in the core of the microspheres can proliferate and develop a vascular network, while human colorectal adenocarcinoma cells (Caco-2) can form an epithelial monolayer in the shell. Compared to Caco-2 monolayer encapsulated within the shell, the presence of the vascularized stroma enhances their proliferation and functionality. As such, our core-shell Alg microspheres provide a valuable method for generatingin vitromodels of vascularized intestinal mucosa with epithelial and vascularized stroma arranged in a spatially relevant manner and demonstrating near-physiological functionality.

MRE11A: a novel negative regulator of human DNA mismatch repair.

BACKGROUND: DNA mismatch repair (MMR) is a highly conserved pathway that corrects DNA replication errors, the loss of which is attributed to the development of various types of cancers. Although well characterized, MMR factors remain to be identified. As a 3'-5' exonuclease and endonuclease, meiotic recombination 11 homolog A (MRE11A) is implicated in multiple DNA repair pathways. However, the role of MRE11A in MMR is unclear. METHODS: Initially, short-term and long-term survival assays were used to measure the cells' sensitivity to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Meanwhile, the level of apoptosis was also determined by flow cytometry after MNNG treatment. Western blotting and immunofluorescence assays were used to evaluate the DNA damage within one cell cycle after MNNG treatment. Next, a GFP-heteroduplex repair assay and microsatellite stability test were used to measure the MMR activities in cells. To investigate the mechanisms, western blotting, the GFP-heteroduplex repair assay, and chromatin immunoprecipitation were used. RESULTS: We show that knockdown of MRE11A increased the sensitivity of HeLa cells to MNNG treatment, as well as the MNNG-induced DNA damage and apoptosis, implying a potential role of MRE11 in MMR. Moreover, we found that MRE11A was largely recruited to chromatin and negatively regulated the DNA damage signals within the first cell cycle after MNNG treatment. We also showed that knockdown of MRE11A increased, while overexpressing MRE11A decreased, MMR activity in HeLa cells, suggesting that MRE11A negatively regulates MMR activity. Furthermore, we show that recruitment of MRE11A to chromatin requires MLH1 and that MRE11A competes with PMS2 for binding to MLH1. This decreases PMS2 levels in whole cells and on chromatin, and consequently comprises MMR activity. CONCLUSIONS: Our findings reveal that MRE11A is a negative regulator of human MMR.

Bi-allelic variants in chromatoid body protein TDRD6 cause spermiogenesis defects and severe oligoasthenoteratozoospermia in humans.

BACKGROUND: The association between the TDRD6 variants and human infertility remains unclear, as only one homozygous missense variant of TDRD6 was found to be associated with oligoasthenoteratozoospermia (OAT). METHODS: Whole-exome sequencing and Sanger sequencing were employed to identify potential pathogenic variants of TDRD6 in infertile men. Histology, immunofluorescence, immunoblotting and ultrastructural analyses were conducted to clarify the structural and functional abnormalities of sperm in mutated patients. Tdrd6-knockout mice were generated using the CRISPR-Cas9 system. Total RNA-seq and single-cell RNA-seq (scRNA-seq) analyses were used to elucidate the underlying molecular mechanisms, followed by validation through quantitative RT-PCR and immunostaining. Intracytoplasmic sperm injection (ICSI) was also used to assess the efficacy of clinical treatment. RESULTS: Bi-allelic TDRD6 variants were identified in five unrelated Chinese individuals with OAT, including homozygous loss-of-function variants in two consanguineous families. Notably, besides reduced concentrations and impaired motility, a significant occurrence of acrosomal hypoplasia was detected in multiple spermatozoa among five patients. Using the Tdrd6-deficient mice, we further elucidate the pivotal role of TDRD6 in spermiogenesis and acrosome identified. In addition, the mislocalisation of crucial chromatoid body components DDX4 (MVH) and UPF1 was also observed in round spermatids from patients harbouring TDRD6 variants. ScRNA-seq analysis of germ cells from a patient with TDRD6 variants revealed that TDRD6 regulates mRNA metabolism processes involved in spermatid differentiation and cytoplasmic translation. CONCLUSION: Our findings strongly suggest that TDRD6 plays a conserved role in spermiogenesis and confirms the causal relationship between TDRD6 variants and human OAT. Additionally, this study highlights the unfavourable ICSI outcomes in individuals with bi-allelic TDRD6 variants, providing insights for potential clinical treatment strategies.

Activating Lobule VI PCTH+-Med Pathway in Cerebellum Blocks the Acquisition of Methamphetamine Conditioned Place Preference in Mice.

Cerebellum has been implicated in drug addiction; however, its underlying cellular populations and neuronal circuitry remain largely unknown. In the current study, we identified a neural pathway from tyrosine hydroxylase (TH)-positive Purkinje cells (PCTH+) in cerebellar lobule VI to calcium/calmodulin-dependent protein kinase II (CaMKII)-positive glutamatergic neurons in the medial cerebellar nucleus (MedCaMKII), forming the lobule VI PCTH+-MedCaMKII pathway in male mice. In naive male mice, inhibition of PCTH+ neurons activated Med neurons. During conditioned place preference (CPP) training, exposure to methamphetamine (METH) inhibited lobule VI PCTH+ neurons while excited MedCaMKII neurons in mice. Silencing MedCaMKII using a tetanus toxin light chain (tettox) suppressed the acquisition of METH CPP in mice but resulted in motor coordination deficits in naive mice. In contrast, activating lobule VI PCTH+ terminals within Med inhibited the activity of Med neurons and subsequently blocked the acquisition of METH CPP in mice without affecting motor coordination, locomotor activity, and sucrose reinforcements in naive mice. Our findings identified a novel lobule VI PCTH+-MedCaMKII pathway within the cerebellum and explored its role in mediating the acquisition of METH-preferred behaviors.

METH exposure alters sperm DNA methylation in F0 mice and mPFC transcriptome in male F1 mice.

RATIONALE: Methamphetamine (METH) exposure has toxicity in sperm epigenetic phenotype and increases the risk for developing addiction in their offspring. However, the underlying transgenerational mechanism remains unclear. OBJECTIVES: The current study aims to investigate the profiles of sperm epigenetic modifications in male METH-exposed mice (F0) and medial prefrontal cortex (mPFC) transcriptome in their male first-generation offspring (F1). METHODS: METH-related male F0 and F1 mice model was established to investigate the effects of paternal METH exposure on reproductive functions and sperm DNA methylation in F0 and mPFC transcriptomic profile in F1. During adulthood, F1 was subjected to a conditioned place preference (CPP) test to evaluate sensitivity to METH. The gene levels were verified with qPCR. RESULTS: METH exposure obviously altered F0 sperms DNA methylated profile and male F1 mPFC transcriptomic profile, many of which being related to neuronal system and brain development. In METH-sired male F1, subthreshold dose of METH administration effectively elicited CPP, along with more mPFC activation. After qPCR verification, Sort1 and Shank2 were at higher levels in F0 sperm and F1 mPFC. CONCLUSIONS: Our findings put new insights into paternal METH exposure-altered profiles of F0 sperm DNA methylation and male F1 mPFC transcriptomics. Several genes, such as Sort1 and Shank2, might be used as potential molecules for further research on the transgenerational vulnerability to drug addiction in offspring by paternal drug exposure.

Recent Progress in Using Mesoporous Carbon Materials as Catalyst Support for Proton Exchange Membrane Fuel Cells.

Developing durable oxygen reduction reaction (ORR) electrocatalysts is essential to step up the large-scale applications of proton exchange membrane fuel cells (PEMFCs). Traditional ORR electrocatalysts provide satisfactory activity, yet their poor durability limits the long-term applications of PEMFCs. Porous carbon used as catalyst support in Pt/C is vulnerable to oxidation under high potential conditions, leading to Pt nanoparticle dissolution and carbon corrosion. Thus, integrating Pt nanoparticles into highly graphitic mesoporous carbons could provide long-term stability. This Perspective seeks to reframe the existing approaches to employing Pt alloys and mesoporous carbon-integrated ORR electrocatalysts to improve the activity and stability of PEMFCs. The unusual porous structure of mesoporous carbons promotes oxygen transport, and graphitization provides balanced stability. Furthermore, the synergistic effect between Pt alloys and heteroatom doping in mesoporous carbons not only provides a great anchoring surface for catalyst nanoparticles but also improves the intrinsic activity. Furthermore, the addition of Pt alloys into mesoporous carbon optimizes the available surface area and creates an effective electron transfer channel, reducing the mass transport resistance. The long-term goals for fuel-cell-powered cars, especially those designed for heavy-duty use, are well aligned with the results shown when this hybrid material is used in PEMFCs to improve performance and durability.

Ultrafast charge transfer in metal-free H2O2 photoproduction by anhydride modified g-C3N4.

As a low-cost, low toxicity and metal-free catalyst with strong light absorption, graphitic carbon nitride (g-C3N4)-based materials have gained wide attention for efficient H2O2 photocatalysis. However, further investigation regarding the charge transfer process and reaction mechanism of H2O2 photoproduction remains to be completed. In this work, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTDA) modified g-C3N4 is synthesized through a facile one-step dehydration process, and the H2O2 photoproduction could reach 22.5 µmol within 8 hours. The proposed structure of g-BTDA is confirmed by FTIR, XPS and SEM studies. The transient absorption reveals a 20.88 ps charge transfer process caused by the electron withdrawing ability of the CO group, and a 2-electron oxygen reduction pathway is proposed. Our work represents a new strategy for efficient H2O2 photoproduction using easily acquired materials with future application potential.

Elucidating the Mass Transportation Behavior of Gas Diffusion Layers via a H2 Limiting Current Test.

The gas diffusion layer (GDL), as a key component of proton exchange membrane fuel cells (PEMFCs), plays a crucial role in PEMFC's polarization performance, particularly in mass transport properties at high current densities. To elucidate the correlation between GDLs' structure and their mass transport properties, a limiting current test with the H2 molecular probe was established and employed to investigate three representative GDLs with and without the microporous layer (MPL). By varying humidity and back pressure, the mass transport resistance of three GDLs was measured in an operating fuel cell, and an elaborate analysis of H2 transport was conducted. The results showed that the transport resistance (RDM) of GDLs was affected by the thickness and pore size distribution of the macroporous substrate (MPS) and the MPL. In the process of gas transport, the smaller pore size and thicker MPL increase the force of gas on the pore wall, resulting in an increase in transmission resistance. Through further calculation and analysis, the total transport resistance can be divided into pressure-related resistance (RP) and pressure-independent resistance (RNP). RP mainly originates from the transport resistance in both MPLs and the substrate layers of GDLs, exhibiting a linear relationship to the pressure; RNP mainly originates from the transport resistance in the MPLs. 29BC with thick MPL shows the largest RNP, and T060 without MPL shows the RNP = 0. This methodology enables in situ measurements of mass transport resistances for gas diffusion media, which can be easily applied for developing and deploying PEMFCs.

Nitrogen-doped hierarchical porous carbons derived from biomass for oxygen reduction reaction.

Nowadays biomass has become important sources for the synthesis of different carbon nanomaterials due to their low cost, easy accessibility, large quantity, and rapid regeneration properties. Although researchers have made great effort to convert different biomass into carbons for oxygen reduction reaction (ORR), few of these materials demonstrated good electrocatalytical performance in acidic medium. In this work, fresh daikon was selected as the precursor to synthesize three dimensional (3D) nitrogen doped carbons with hierarchical porous architecture by simple annealing treatment and NH3 activation. The daikon-derived material Daikon-NH3-900 exhibits excellent electrocatalytical performance towards oxygen reduction reaction in both alkaline and acidic medium. Besides, it also shows good durability, CO and methanol tolerance in different electrolytes. Daikon-NH3-900 was further applied as the cathode catalyst for proton exchange membrane (PEM) fuel cell and shows promising performance with a peak power density up to 245 W/g.

[Genetic analysis of a patient with familial hypercholesterolemia due to variant of LDLR gene].

OBJECTIVE: To analyze variant of LDLR gene in a patient with familial hypercholesterolemia (FH) in order to provide a basis for the clinical diagnosis and genetic counseling. METHODS: A patient who had visited the Reproductive Medicine Center of the First Affiliated Hospital of Anhui Medical University in June 2020 was selected as the study subject. Clinical data of the patient was collected. Whole exome sequencing (WES) was applied to the patient. Candidate variant was verified by Sanger sequencing. Conservation of the variant site was analyzed by searching the UCSC database. RESULTS: The total cholesterol level of the patient was increased, especially low density lipoprotein cholesterol. A heterozygous c.2344A>T (p.Lys782*) variant was detected in the LDLR gene. Sanger sequencing confirmed that the variant was inherited from the father. CONCLUSION: The heterozygous c.2344A>T (p.Lys782*) variant of the LDLR gene probably underlay the FH in this patient. Above finding has provided a basis for genetic counseling and prenatal diagnosis for this family.

Novel FSIP2 Variants Induce Super-Length Mitochondrial Sheath and Asthenoteratozoospermia in Humans.

Asthenoteratozoospermia is one of the major factors for male infertility, whereas the causes of large numbers of cases are still unknown. We identified compound heterozygous variants of FSIP2 in three unrelated individuals from a cohort of 105 patients with asthenoteratozoospermia by exome sequencing. Deleterious FSIP2 variations caused severe disassembly of the fibrous sheath and axonemal defects. Intriguingly, spermatozoa in our study manifested "super-length" mitochondrial sheaths, increased levels of the mitochondrial sheath outer membrane protein TOMM20 and decreased mitochondrial ATP consumption. Dislocation or deletion of the annulus and reduction or dislocation of the annulus protein SEPT4 were also observed. While the lengthened mitochondrial sheaths were not presented in men harboring SEPT4 variants. Furthermore, female partners of two of three men achieved successful pregnancies following intracytoplasmic sperm injection (ICSI). Overall, we presume that FSIP2 may not only serve as a structural protein of the fibrous sheath but also as an intra-flagellar transporter involving in the axonemal assembly, mitochondrial selection and the termination of mitochondrial sheath extension during spermatogenesis, and ICSI is an effective treatment for individuals with FSIP2-associated asthenoteratozoospermia.

Maximum thickness of non-buffer limited electro-active biofilms decreases at higher anode potentials.

The accumulation of protons in electro-active biofilms (EABfs) has been reported as a critical parameter determining produced currents at the anode since the very beginning of the studies on Bio-electrochemical systems (BESs). Even though the knowledge gained on the influence of this parameter on the produced currents, its influence on EABfs growth is frequently overlooked. In this study, we quantified EABfs thicknesses in real-time and related them to the produced current at three buffer concentrations, two anode potentials and two acetate concentrations. The thickest EABfs (80 µm) and higher produced currents (2.5 A.m-2) were measured when a 50 mM buffer concentration was used. By combining the measured EABfs thicknesses with the pH in the anolyte, a simple model was developed to identify buffer limitations. Buffer limited EABfs with thicknesses of 15 and 42 µm were identified at -0.3 V vs Ag/AgCl when 10 and 50 mM buffer concentrations were used, respectively. At -0.2 V vs Ag/AgCl, the thicknesses of buffer limited EABfs decreased to 13 and 20 µm, respectively. The model also estimated buffer and acetate diffusion rates in EABfs and allowed to determine the boundary between a buffer and acetate limited EABfs. The diffusion rates reported in this study and the definition of the boundary between buffer and acetate limited EABfs provide a powerful tool to avoid limitations, leading to higher produced currents at the anode.

Exploration of molecular features of PCOS with different androgen levels and immune-related prognostic biomarkers associated with implantation failure.

Background: Polycystic ovary syndrome (PCOS), the most common heterogeneous reproductive disease afflicting women of childbearing age, has been recognized as a chronic inflammatory disease recently. Most PCOS patients have hyperandrogenism, indicating a poor prognosis and poor pregnancy outcomes. The molecular mechanism underlying PCOS development is still unknown. In the present study, we investigated the gene expression profiling characteristics of PCOS with hyperandrogenism (HA) or without hyperandrogenism (NHA) and identified immune-related factors that correlated with embryo implantation failure. Methods: PCOS and recurrent implantation failure (RIF) microarray datasets were obtained from the Gene Expression Omnibus (GEO) database. ClueGO software was used to perform enrichment analysis of differentially expressed genes (DEGs) in PCOS with varying androgen levels. The Weighted Co-Expression Network Analysis (WGCNA) was used to identify co-expressed modules and shared gene signatures between HA PCOS and RIF. Moreover, the upregulated DEGs of HA PCOS and RIF were intersected with shared gene signatures screening by WGCNA to excavate further key prognostic biomarkers related to implantation failure of HA PCOS. The selected biomarker was verified by qRT-PCR. Results: A total of 271 DEGs were found in HA PCOS granulosa cell samples, and 720 DEGs were found in NHA PCOS. According to CuleGO enrichment analysis, DEGs in HA PCOS are enriched in immune activation and inflammatory response. In contrast, DEGs in NHA PCOS are enriched in mesenchymal cell development and extracellular space. Using WGCNA analysis, we discovered 26 shared gene signatures between HA PCOS and RIF, which were involved in corticosteroid metabolism, bone maturation and immune regulation. DAPK2 was furtherly screened out and verified to be closely related with the development of HA PCOS, acting as an independent predictor biomarker of the embryo implantation failure. DAPK2 expression was negatively correlated to the embryo implantation rate (r=-0.474, P=0.003). The immune infiltration results suggested that upregulated DAPK2 expression was closely related with NK cell infiltration and macrophage M2, playing an essential role in the pathogenesis of implantation failure in HA PCOS. Conclusion: Our research revealed the expression profiling of PCOS with different androgen levels and identified DAPK2 as a critical prognostic biomarker for implantation failure in PCOS.

Biallelic loss-of-function mutations in SEPTIN4 (C17ORF47), encoding a conserved annulus protein, cause thin midpiece spermatozoa and male infertility in humans.

Asthenoteratozoospermia is the primary cause of infertility in humans. However, the genetic etiology remains largely unknown for those suffering from severe asthenoteratozoospermia caused by thin midpiece defects. In this study, we identified two biallelic loss-of-function variants of SEPTIN4 (previously SEPT4) (Patient 1: c.A721T, p.R241* and Patient 2: c.C205T, p.R69*) in two unrelated individuals from two consanguineous Chinese families. SEPT4 is a conserved annulus protein that is critical for male fertility and the structural integrity of the sperm midpiece in mice. SEPT4 mutations disrupted the formation of SEPT-based annulus and localization of SEPTIN subunits in sperms from patients. The ultrastructural analysis demonstrated striking thin midpiece spermatozoa defects owing to annulus loss and disorganized mitochondrial sheath. Immunofluorescence and immunoblotting analyses of the mitochondrial sheath proteins TOMM20 and HSP60 further indicated that the distribution and abundance of mitochondria were impaired in men harboring biallelic SEPT4 variants. Additionally, we found that the precise localization of SLC26A8, a testis-specific anion transporter that colocalizes with SEPT4 at the sperm annulus, was missing without SEPT4. Moreover, the patient achieved a good pregnancy outcome following intracytoplasmic sperm injection. Overall, our study demonstrated for the first time that SEPT4 variants that induced thin midpiece spermatozoa defects were directly associated with human asthenoteratozoospermia.

Biallelic Variants in CCDC39 Gene Lead to Primary Ciliary Dyskinesia and Kartagener Syndrome.

Background: Primary ciliary dyskinesia (PCD) is a clinical syndrome characterized by cilia with an abnormal structure or function. Its main clinical manifestations comprise chronic bronchitis, cough, recurrent respiratory infections, situs inversus, and male infertility. Single-gene variants are widely assumed to be the main cause of this rare disease, and more than 40 genes have been described to be associated with its onset. CCDC39 is essential for assembling the inner dynein arms and dynein regulatory complex and is important in cilia motility. CCDC39 variants were reported as a monogenic etiology of PCD. Methods: This study investigated two unrelated Chinese patients diagnosed as PCD. The chest computed tomography scan was performed to identify PCD phenotypes of the two probands. Considering the effect of PCD on male fertility, routine semen analysis, sperm morphology examination, and scanning electron microscopy were performed to assess the semen characteristics of male proband in family 2 (F2 II-1), who had a history of infertility. Subsequently, the peripheral blood samples of probands were collected to perform whole-exome sequencing (WES) to explore the possible genetic causes of this disease. Results: Whole-exome sequencing revealed a homozygous CCDC39 variant in the female proband of family 1 (F1 II-1: c.286C>T:p.Arg96Ter) and two compound heterozygous CCDC39 variants in the male proband of family 2 (F2 II-1: c.732_733del: p.Ala245PhefsTer18; c.2800_2802dup:p.Val934dup). The two probands showed the typical PCD phenotypes, including chronic bronchitis, recurrent respiratory infections, and situs inversus. The male proband also showed oligoasthenoteratospermia with multiple morphological abnormalities of the sperm flagella. Additionally, CCDC39 protein level was significantly lower in the sperm of male proband than in the sperm from normal controls. Conclusion: We identified a homozygous variant reported previously and two compound heterozygous variants of CCDC39 possibly responsible for PCD pathogenesis, expanding the variant spectrum of Chinese PCD, Kartagener syndrome, and morphological abnormalities of the sperm flagella involving CCDC39.