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Abstract Background Learning to perform strabismus surgery is an essential aspect of ophthalmologists’ surgical training. Automated classification strategy for surgical steps can improve the effectiveness of training curricula and the efficient evaluation of residents’ performance. To this end, we aimed to develop and validate a deep learning (DL) model for automated detecting strabismus surgery steps in the videos. Methods In this study, we gathered 479 strabismus surgery videos from Shanghai Children’s Hospital, affiliated to Shanghai Jiao Tong University School of Medicine, spanning July 2017 to October 2021. The videos were manually cut into 3345 clips of the eight strabismus surgical steps based on the International Council of Ophthalmology’s Ophthalmology Surgical Competency Assessment Rubrics (ICO-OSCAR: strabismus). The videos dataset was randomly split by eye-level into a training (60%), validation (20%) and testing dataset (20%). We evaluated two hybrid DL algorithms: a Recurrent Neural Network (RNN) based and a Transformer-based model. The evaluation metrics included: accuracy, area under the receiver operating characteristic curve, precision, recall and F1-score. Results DL models identified the steps in video clips of strabismus surgery achieved macro-average AUC of 1.00 (95% CI 1.00–1.00) with Transformer-based model and 0.98 (95% CI 0.97-1.00) with RNN-based model, respectively. The Transformer-based model yielded a higher accuracy compared with RNN-based models (0.96 vs. 0.83, p

ABSTRACT: Fowl adenovirus serotype 4 (FAdV-4) is the causative agent of hydropericardium hepatitis syndrome in chickens, which causes severe economic impact to the poultry industry. A simple, swift and reliable detection is crucial for timely identification of FAdV-4 infection, promoting effective viral prevention and control measures. Herein, the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 12a (Cas12a) system detection platform based on loop-mediated isothermal amplification (LAMP) was studied. The CRISPR RNA (crRNA) and LAMP primers were designed and screened based on the highly conserved region of the FAdV-4 hexon gene. The parameters were then optimized individually to achieve the ideal reaction performance. The platform could lead visual detection of FAdV-4 to achieve as low as 1 copy in less than 40 min without the need for specialized instrumentation or complex equipment. Moreover, it was greatly specific, and did not cross-react with other common avian viruses. Following the validation of 30 clinical samples of suspected FAdV-4 infection, the results LAMP-CRISPR/Cas12a method generated showed fully concordance with which of the gold standard quantitative real-time PCR. To summarize, this study presented a novel, swift, expedient and inexpensive detection platform for FAdV-4, which is beneficial to viral inchoate diagnosis and point-of-care testing.

Abstract Forest carbon sequestration capacity in China remains uncertain due to underrepresented tree demographic dynamics and overlooked of harvest impacts. In this study, we employ a process-based biogeochemical model to make projections by using national forest inventories, covering approximately 415,000 permanent plots, revealing an expansion in biomass carbon stock by 13.6 ± 1.5 Pg C from 2020 to 2100, with additional sink through augmentation of wood product pool (0.6-2.0 Pg C) and spatiotemporal optimization of forest management (2.3 ± 0.03 Pg C). We find that statistical model might cause large bias in long-term projection due to underrepresentation or neglect of wood harvest and forest demographic changes. Remarkably, disregarding the repercussions of harvesting on forest age can result in a premature shift in the timing of the carbon sink peak by 1–3 decades. Our findings emphasize the pressing necessity for the swift implementation of optimal forest management strategies for carbon sequestration enhancement.

Abstract The voltage-gated calcium channel CaV1.2 is essential for cardiac and vessel smooth muscle contractility and brain function. Accumulating evidence demonstrates that malfunctions of CaV1.2 are involved in brain and heart diseases. Pharmacological inhibition of CaV1.2 is therefore of therapeutic value. Here, we report cryo-EM structures of CaV1.2 in the absence or presence of the antirheumatic drug tetrandrine or antihypertensive drug benidipine. Tetrandrine acts as a pore blocker in a pocket composed of S6II, S6III, and S6IV helices and forms extensive hydrophobic interactions with CaV1.2. Our structure elucidates that benidipine is located in the DIII-DIV fenestration site. Its hydrophobic sidechain, phenylpiperidine, is positioned at the exterior of the pore domain and cradled within a hydrophobic pocket formed by S5DIII, S6DIII, and S6DIV helices, providing additional interactions to exert inhibitory effects on both L-type and T-type voltage gated calcium channels. These findings provide the structural foundation for the rational design and optimization of therapeutic inhibitors of voltage-gated calcium channels.

ABSTRACT: Since 2015, an outbreak of an infectious disease in broilers caused by fowl adenovirus serotype 4 (FAdV-4) has occurred in China, resulting in substantial economic losses. Rapid, accurate, and specific detection are significant in the prevention and control of FAdV-4. In this study, an FAdV-4 detection method combining loop-mediated isothermal amplification (LAMP) and Pyrococcus furiosus Argonaute (PfAgo) was established. Specific primers, guide DNAs (gDNAs), and molecular beacons were designed to target a conserved region of the FAdV-4 hexon gene. After optimizing the reaction conditions, the minimum detection of this assay could reach 5 copies. It only amplified FAdV-4, and there was no cross-reactivity with other pathogens. The assay took about only 50 min, and the results could be visualized with the naked eye under ultraviolet or blue light, getting rid of specialized instruments. This novel LAMP-PfAgo assay was validated by using 20 clinical samples and the results were identical to gold-standard real-time polymerase chain reaction method. In summary, the LAMP-PfAgo assay established in the paper provides a rapid, reliable, convenient, ultra-sensitive and highly specific tool for the on-site detection and clinical diagnosis of FAdV-4.

Background Oligospermia is one of the most common reasons for male infertility which is troubling numerous couples of child-bearing age. This investigation scrutinizes the implications and mechanistic underpinnings of ursolic acid’s effect on busulfan-induced oligospermia in mouse models. Methods A singular intraperitoneal injection of busulfan at a dosage of 30 mg/kg induced oligospermia. Two weeks subsequent to this induction, mice were subjected to various dosages of ursolic acid (10, 30, and 50 mg/kg body weight, respectively) on a daily basis for four consecutive weeks. Following this treatment period, a meticulous analysis of epididymal sperm parameters, encompassing concentration and motility, was conducted using a computer-assisted sperm analysis system. The histopathology of the mice testes was performed utilizing hematoxylin and eosin staining, and the cytoskeleton regeneration of the testicular tissues was analyzed via immunofluorescent staining. Serum hormone levels, including testosterone, luteinizing hormone, and follicle-stimulating hormone, as well as reactive oxygen species levels (inclusive of reactive oxygen species and malondialdehyde), were gauged employing specific enzyme-linked immunosorbent assay kits. Differentially expressed genes of testicular mRNA between the oligospermia-induced group and the various ursolic acid treatment groups were identified through RNA sequencing analysis. Results The results revealed that a dosage of 50 mg/kg ursolic acid treatment could increase the concentration of epididymal sperm in oligospermia mice, promote the recovery of testicular morphology, regulate hormone levels and ameliorate oxidative damage. The mechanism research results indicated that ursolic acid increased the expression level of genes related to motor proteins in oligospermia mice.

Abstract Salt-overly-sensitive 1 (SOS1) is a unique electroneutral Na+/H+ antiporter at the plasma membrane of higher plants and plays a central role in resisting salt stress. SOS1 is kept in a resting state with basal activity and activated upon phosphorylation. Here, we report the structures of SOS1. SOS1 forms a homodimer, with each monomer composed of transmembrane and intracellular domains. We find that SOS1 is locked in an occluded state by shifting of the lateral-gate TM5b toward the dimerization domain, thus shielding the Na+/H+ binding site. We speculate that the dimerization of the intracellular domain is crucial to stabilize the transporter in this specific conformation. Moreover, two discrete fragments and a residue W1013 are important to prevent the transition of SOS1 to an alternative conformational state, as validated by functional complementation assays. Our study enriches understanding of the alternate access model of eukaryotic Na+/H+ exchangers.

The aim of this study was to establish a new method for the determination of homoisoflavanones (Ⅲ, Ⅳ, V) in polygonatum odoratum(POD) by combination of thin layer chromatography (TLC) and chemical derivative resonance Raman spectroscopy (RRS). The twice chromatography method of TLC was used to improve the specificity of the component to be tested; the method of the relative Rf was used to reduce the use of the reference substance of the component to be tested; the chemical derivatization method was used to improve the signal intensity of Raman spectrum for the component to be tested in POD, so as to obtain a trace amount fingerprint structure information of the measured component. The method exhibits robust specificity, high sensitivity, and reliable stability, there by offering a novel reference approach for the identification and evaluation of homoisoflavanones (Ⅲ, Ⅳ, V) in POD.

The CaV2.3 channel is involved in synaptic plasticity and neurological disorders. Here, authors resolve the human CaV2.3 structure to explore functional heterogeneity of VSDs and elucidated the closed- and open-state inactivation mechanisms of the channel.

Excitatory amino acid transporter 2 (EAAT2) mediates glutamate uptake in the synapse. Here, authors report cryo-EM structures of the human EAAT2 in complexes with glutamate or selective inhibitor WAY-213613, revealing important insights into substrate recognition and selective inhibition.

T-type calcium channels are implicated in many diseases. Here, multiple structures of CaV3.3 channel elucidate molecular mechanisms of T-type CaV channels activation at low voltage and interaction with different clinically used channel blockers.

NaV1.3 is involved in neuronal development, hormone secretion and pain perception. Here, the authors elucidate the molecular mechanism for modulation of NaV1.3 by a site-2 neurotoxin bulleyaconitine A and a subtype selective antagonist ICA121431.

Abstract Dorzagliatin is a novel allosteric glucokinase activator targeting both pancreatic and hepatic glucokinase currently under clinical investigation for treatment of type 2 diabetes (T2D). This study aimed to investigate the effect of renal impairment (RI) on dorzagliatin’s pharmacokinetics (PKs) and safety, and to guide appropriate clinical dosing in patients with diabetic kidney disease, including end‐stage renal disease (ESRD). Based on the results from physiologically‐based pharmacokinetic modeling, the predicted outcome of RI on dorzagliatin PK property would be minimum that the plasma exposure area under concentration (AUC) of dorzagliatin in patients with ESRD would increase at about 30% with minimal change in peak concentration (Cmax) comparing to those in healthy volunteers (HVs). To definitively confirm the prediction, a two‐part RI study was designed and conducted based on regulatory guidance starting with the patients with ESRD matched with HVs. Results of the RI study showed minimum difference between patients with ESRD and HVs with respect to dorzagliatin exposure with geometric mean ratio of ESRD to HV at 0.81 for Cmax and 1.11 for AUC. The elimination half‐life, volume of distribution, and systemic clearance for dorzagliatin were similar between the two groups. Dorzagliatin was well‐tolerated in patients with ESRD during the study. Therefore, RI showed no significant impact on dorzagliatin PK, suggesting that dorzagliatin can be readily used in patients with T2D at all stages of RI without need for dose adjustment.

Background: Tree demography is an essential indicator of various forest ecosystem services, and understanding its changes is critical for the sustainable management of forests. During the past four decades, China implemented unprecedented forest restoration projects, which altered tree demography by increasing the number of trees and introducing new species. However, it remains unclear how species composition has changed in China in response to the past forest restoration and demographical processes. Methods: We applied Forest Stability Index (FSI) and the relative change of FSI (%FSI) to describe the population dynamics of tree species and structure in China since 1998, using field-survey data collected from over 200,000 plot-records from the 6th to 9th National Forest Inventories (NFIs). Results: The overall populations of both natural and planted forests have grown rapidly from 1998 to 2018, while the range of changes in the relative tree density was more variable for natural forests (ranging from −8.53% to 42.46%) than for planted forests (ranging from −1.01% to 13.31%). The populations declined only in some of the tree species, including Betula platyphylla, Ulmus pumila, and Robinia pseudoacacia. In contrast, the populations of trees in the largest size-class either remained stable or expanded. Conclusions: Tree density of China's forests (both natural and planted forests) generally expanded and the overall populations increased in most size classes, with greater increases occurred in planted forests. In contrasting to the global decline trends of large diameter trees, here we found no apparent decline for trees in the largest size-class in China, highlighting China's success in improving forest health and forest adaptations to climate change. We advocate for more studies to reveal the mechanisms of the changes in tree demography, which will help to improve forest ecosystem services such as the carbon sequestration capacity.

Purpose: To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of SHR2285, the first oral coagulation factor XIa (FXIa) inhibitor developed in China in combination with aspirin, clopidogrel or ticagrelor in healthy subjects.Methods: This study was a single-center, randomized, double-blind, placebo-controlled (only SHR2285) design (NCT04945616). A total of 52 healthy subjects, 29 male and 23 female, were completed in this study. The subjects were divided into three groups: A, B and C, 16 subjects in group A [aspirin + clopidogrel + placebo or SHR2285 200 mg bid (1:3, 4 received placebo and 12 received SHR2285)] 16 subjects in group B [aspirin + clopidogrel + placebo or SHR2285 300 mg bid (1:3, 3 received placebo and 13 received SHR2285)] and 20 subjects in group C (aspirin + ticagrelor + placebo or SHR2285 300 mg bid (2:3, 8 received placebo and 12 received SHR2285)), respectively. All groups were administered orally for six consecutive days. Safety, tolerability, pharmacokinetics and pharmacodynamics parameters were assessed.Results: 1) SHR2285 was well tolerated, and all adverse events were mild. There was no evidence of an increased risk of bleeding. 2) After 6 days of twice-daily administration, SHR2285 could reach a steady state. The mean half-life of SHR2285 in group A, group B and group C was 13.9 h, 14.5 h and 13.8 h, respectively. 3) SHR2285 markedly inhibited FXI activity and prolonged activated partial thromboplastin time (APTT). In group A, group B and group C, the mean maximum inhibition rate of FXI activity was 84.8%, 89.3% and 92.2% and the mean maximum prolongation of APTT was 2.08-fold, 2.36-fold and 2.26-fold, respectively.Conclusion: These data suggest that SHR2285, a potential oral FXIa inhibitor, is expected to become a novel, safe and effective anticoagulant when combined with aspirin, clopidogrel or ticagrelor.

Sodium/proton exchanger 1 (NHE1) and its obligate binding partner Calcineurin B-homologous protein 1 (CHP1) regulate intracellular pH and volume homeostasis. Structures of the human NHE1-CHP1 complex offer insight into the regulation of NHE1 pH-sensitivity by CHP1 and into the interactions with NHE1 inhibitors.

Abstract Retinal degeneration diseases (RDDs) are common and devastating eye diseases characterized by the degeneration of photoreceptors, which are highly associated with oxidative stress. Previous studies reported that mitochondrial dysfunction is associated with various neurodegenerative diseases. However, the role of mitochondrial proteostasis mainly regulated by mitophagy and mitochondrial unfolded protein response (mtUPR) in RDDs is unclear. We hypothesized that the mitochondrial proteostasis is neuroprotective against oxidative injury in RDDs. In this study, the data from our hydrogen peroxide (H2O2)-treated mouse retinal cone cell line (661w) model of RDDs showed that nicotinamide riboside (NR)-activated mitophagy increased the expression of LC3B II and PINK1, and promoted the co-localization of LC3 and mitochondria, as well as PINK1 and Parkin in the H2O2-treated 661w cells. However, the NR-induced mitophagy was remarkably reversed by chloroquine (CQ) and cyclosporine A (CsA), mitophagic inhibitors. In addition, doxycycline (DOX), an inducer of mtUPR, up-regulated the expression of HSP60 and CHOP, the key proteins of mtUPR. Activation of both mitophagy and mtUPR increased the cell viability and reduced the level of apoptosis and oxidative damage in the H2O2-treated 661w cells. Furthermore, both mitophagy and mtUPR played a protective effect on mitochondria by increasing mitochondrial membrane potential and maintaining mitochondrial mass. By contrast, the inhibition of mitophagy by CQ or CsA reversed the beneficial effect of mitophagy in the H2O2-treated 661w cells. Together, our study suggests that the mitophagy and mtUPR pathways may serve as new therapeutic targets to delay the progression of RDDs through enhancing mitochondrial proteostasis.

The widespread application of fuel cells is hampered by the sluggish kinetics of the oxygen reduction reaction (ORR), which traditionally necessitates the use of high-cost platinum group metal catalysts. The indispensability of these metal catalysts stems from their ability to overcome kinetic barriers, but their high cost and scarcity necessitate alternative strategies. In this context, porous organic polymers (POPs), which are built up from the molecular level, are emerging as promising precursors to produce carbonaceous catalysts owning to their cost-effectiveness, high electrical conductivity, abundant active sites and extensive surface area accessibility. To enhance the intrinsic ORR activity and optimize the performance of these electrocatalysts, recognizing, designing, and increasing the density of active sites are identified as three crucial steps. These steps, which form the core of our review, serve to elucidate the link between the material structure design and ORR performance evaluation, thereby providing valuable insights for ongoing research in the field. Leveraging the precision of polymer skeletons based on molecular units, POP-derived carbonaceous catalysts provide an excellent platform for in-depth exploration of the role and working mechanism for the specific active site during the ORR process. In this review, the recent advances pertaining to the synthesis techniques and electrochemical functions of various types of active sites, pinpointed from POPs, are systematically summarized, including heteroatoms, surficial substituents and edge/defects. Notably, the structure–property relationship, between these active sites and ORR performance, are discussed and emphasized, which creates guidelines to shed light on the design of high-performance ORR electrocatalysts.

Background: Targeting factor XI (FXI) is a promising therapeutic strategy for the treatment and prevention of thrombosis without increasing the risk of bleeding. Here, we assessed the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of SHR2285, a novel FXIa inhibitor, in healthy subjects.Methods: In this randomized, double-blinded, placebo-controlled, dose-ascending single-dosing trial (NCT03769831), eligible volunteer subjects receive either SHR2285 or placebo in a 3:1 ratio. Subjects assigned to the SHR2285 group received a single oral dose of SHR2285 at 50 mg, which was subsequently escalated to 100 mg, 200 mg, and 400 mg. Safety, pharmacokinetics, and pharmacodynamics parameters were assessed. All subjects were followed for 6 days.Results: SHR2285 was well tolerated. All adverse events were grade 1, and there was no evidence of bleeding events. The PK results revealed a rapid onset of action of SHR2285 (median time to maximum plasma concentration [Tmax] in different dose groups ranged 3.0–4.0 h) and the mean half-life ranged from 7.6 to 15.8 h. The metabolite SHR164471 had a slightly longer Tmax than the parent SHR2285, reaching a peak at a median of 6.0–7.0 h, and its mean half-life were 10.1–14.7 h in different dose groups. The sums of the area under the concentration–time curve from zero to time infinity of SHR2285 and SHR164471 in the 200 and 400 mg groups were similar, indicating the sum pharmacological activity of SHR2285 and SHR164471 showed a saturation trend between 200 and 400 mg. PD analysis showed that the inhibition of FXI activity was synchronized with prolonged activated partial thromboplastin time after SHR2285 administration, but the serum prothrombin time and international normalized ratio levels were not affected by SHR2285.Conclusion: SHR2285 demonstrated favorable safety, PK, and PD profiles in the dose range of 50 mg–400 mg. This first-in-human study supports the further development of SHR2285 for indications requiring anticoagulation.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03769831, identifier [NCT03769831].

Summary: N-type voltage-gated calcium (CaV) channels mediate Ca2+ influx at presynaptic terminals in response to action potentials and play vital roles in synaptogenesis, release of neurotransmitters, and nociceptive transmission. Here, we elucidate a cryo-electron microscopy (cryo-EM) structure of the human CaV2.2 complex in apo, ziconotide-bound, and two CaV2.2-specific pore blockers-bound states. The second voltage-sensing domain (VSD) is captured in a resting-state conformation, trapped by a phosphatidylinositol 4,5-bisphosphate (PIP2) molecule, which is distinct from the other three VSDs of CaV2.2, as well as activated VSDs observed in previous structures of CaV channels. This structure reveals the molecular basis for the unique inactivation process of CaV2.2 channels, in which the intracellular gate formed by S6 helices is closed and a W-helix from the domain II–III linker stabilizes closed-state inactivation. The structures of this inactivated, drug-bound complex lay a solid foundation for developing new state-dependent blockers for treatment of chronic pain.

For the first time, multiple parallel microchannels in a single microgroove have been fabricated by the heating-assisted micromolding in capillaries technique (HAMIMIC). Microchannel development, cross-sectional shape, and length were all explored in depth. The factors affecting the cross-sectional shape and length of the double-microchannel were also discussed. Finally, a special-shaped PDMS guiding mold was designed to control the cross-sectional shape and length of multiple parallel microchannels for controlled growth. The HAMIMIC technique provides a low-cost, straightforward, and repeatable way to create multiple parallel microchannels in a single microgroove, and will promote the progress of bifurcated vessels and thrombus vessels preparation technology.

Liposomes are attractive carriers for targeted and controlled drug delivery receiving increasing attention in cancer photothermal therapy. However, the field of creating near-infrared nanomaterial-liposome hybrid nanocarriers (NIRN-Lips) is relatively little understood. The hybrid nanocarriers combine the dual superiority of nanomaterials and liposomes, with more stable particles, enhanced photoluminescence, higher tumor permeability, better tumor-targeted drug delivery, stimulus-responsive drug release, and thus exhibiting better anti-tumor efficacy. Herein, this review covers the liposomes supported various types of near-infrared nanomaterials, including gold-based nanomaterials, carbon-based nanomaterials, and semiconductor quantum dots. Specifically, the NIRN-Lips are described in terms of their feature, synthesis, and drug-release mechanism. The design considerations of NIRN-Lips are highlighted. Further, we briefly introduced the photothermal conversion mechanism of NIRNs and the cell death mechanism induced by photothermal therapy. Subsequently, we provided a brief conclusion of NIRNs-Lips applied in cancer photothermal therapy. Finally, we discussed a synopsis of associated challenges and future perspectives for the applications of NIRN-Lips in cancer photothermal therapy.

Despite the importance of testosterone as a metabolic hormone, its effects on myocardial metabolism in the ischemic heart remain unclear. Myocardial ischemia leads to metabolic remodeling, ultimately resulting in ATP deficiency and cardiac dysfunction. In the present study, the effects of testosterone replacement on the ischemic heart were assessed in a castrated rat myocardial infarction model established by ligating the left anterior descending coronary artery 2 weeks after castration. The results of real-time PCR and Western blot analyses showed that peroxisome proliferator-activated receptor α (PPARα) decreased in the ischemic myocardium of castrated rats, compared with the sham-castration group, and the mRNA expression of genes involved in fatty acid metabolism (the fatty acid translocase CD36, carnitine palmitoyltransferase I, and medium-chain acyl-CoA dehydrogenase) and glucose transporter-4 also decreased. A decline in ATP levels in the castrated rats was accompanied by increased cardiomyocyte apoptosis and fibrosis and impaired cardiac function, compared with the sham-castration group, and these detrimental effects were reversed by testosterone replacement. Taken together, our findings suggest that testosterone can modulate myocardial metabolic remodeling by upregulating PPARα after myocardial infarction, exerting a protective effect on cardiac function.

Objective: Hydroxytyrosol (HT), a polyphenolic component identified in olive oil and leaves, represents one of the most extensively investigated natural phenol due to its diverse beneficial biological properties. Recent studies have shown that HT exhibits protective effects on reproductive function and can improve sperm quality. However, the precise effect and underlying mechanism of HT on oligozoospermia remain unclear. This study aims to investigate the effect and mechanism of HT across varying concentrations on oligozoospermia. Methods: Oligozoospermia was induced in ICR male mice via intraperitoneal injection of busulfan (BUS, 30 mg/ kg). The mice were randomly categorized into five groups as Normal, BUS, HT 10 mg/kg, HT 30 mg/kg and HT 50 mg/kg. The efficacy of HTon oligozoospermia was assessed through sperm concentration and motility using a computer-assisted sperm analysis system. Testicular and epididymal histology was examined via hematoxylin-eosin staining, while cytoskeletal integrity was evaluated by immunofluorescence. Hormone levels, along with reactive oxygen species (ROS) and malondialdehyde (MDA) were examined by ELISA kits. Differentially expressed genes were identified through RNA sequencing, and the expression levels of key genes were validated by qPCR. Results: The results indicated that HT (50 mg/kg) significantly increased sperm concentration, promoted morphological recovery of testicular tissue, heightened the levels of serum testosterone, follicle-stimulating hormone, luteinizing hormone, as well as decreased the accumulation of ROS and MDA in mice with oligozoospermia. RNA sequencing analysis and RT-qPCR results revealed that HT could restore spermatogenesis and ameliorate oligozoospermia by up-regulating genes related to cilium organization, microtubule-based movement, and spermatid differentiation and development. Conclusions: HT demonstrates therapeutic efficacy against busulfan-induced oligozoospermia. The mechanism of HT on oligozoospermia may be related to its influence on cilium and microtubule-based movement, along with the differentiation and development of spermatids. HT shows potential as a prospective therapeutic intervention for the treatment of oligozoospermia. [ABSTRACT FROM AUTHOR]

The voltage-gated calcium channel CaV1.2 is essential for cardiac and vessel smooth muscle contractility and brain function. Accumulating evidence demonstrates that malfunctions of CaV1.2 are involved in brain and heart diseases. Pharmacological inhibition of CaV1.2 is therefore of therapeutic value. Here, we report cryo-EM structures of CaV1.2 in the absence or presence of the antirheumatic drug tetrandrine or antihypertensive drug benidipine. Tetrandrine acts as a pore blocker in a pocket composed of S6II, S6III, and S6IV helices and forms extensive hydrophobic interactions with CaV1.2. Our structure elucidates that benidipine is located in the DIII-DIV fenestration site. Its hydrophobic sidechain, phenylpiperidine, is positioned at the exterior of the pore domain and cradled within a hydrophobic pocket formed by S5DIII, S6DIII, and S6DIV helices, providing additional interactions to exert inhibitory effects on both L-type and T-type voltage gated calcium channels. These findings provide the structural foundation for the rational design and optimization of therapeutic inhibitors of voltage-gated calcium channels. [ABSTRACT FROM AUTHOR]

Sodium-calcium exchanger proteins influence calcium homeostasis in many cell types and participate in a wide range of physiological and pathological processes. Here, we elucidate the cryo-EM structure of the human Na+/Ca2+ exchanger NCX1.3 in the presence of a specific inhibitor, SEA0400. Conserved ion-coordinating residues are exposed on the cytoplasmic face of NCX1.3, indicating that the observed structure is stabilized in an inward-facing conformation. We show how regulatory calcium-binding domains (CBDs) assemble with the ion-translocation transmembrane domain (TMD). The exchanger-inhibitory peptide (XIP) is trapped within a groove between the TMD and CBD2 and predicted to clash with gating helices TMs1/6 at the outward-facing state, thus hindering conformational transition and promoting inactivation of the transporter. A bound SEA0400 molecule stiffens helix TM2ab and affects conformational rearrangements of TM2ab that are associated with the ion-exchange reaction, thus allosterically attenuating Ca2+-uptake activity of NCX1.3. [ABSTRACT FROM AUTHOR]