Metabolic profiling identifies Qrich2 as a novel glutamine sensor that regulates microtubule glutamylation and mitochondrial function in mouse sperm.

In our prior investigation, we discerned loss-of-function variants within the gene encoding glutamine-rich protein 2 (QRICH2) in two consanguineous families, leading to various morphological abnormalities in sperm flagella and male infertility. The Qrich2 knockout (KO) in mice also exhibits multiple morphological abnormalities of the flagella (MMAF) phenotype with a significantly decreased sperm motility. However, how ORICH2 regulates the formation of sperm flagella remains unclear. Abnormal glutamylation levels of tubulin cause dysplastic microtubules and flagella, eventually resulting in the decline of sperm motility and male infertility. In the current study, by further analyzing the Qrich2 KO mouse sperm, we found a reduced glutamylation level and instability of tubulin in Qrich2 KO mouse sperm flagella. In addition, we found that the amino acid metabolism was dysregulated in both testes and sperm, leading to the accumulated glutamine (Gln) and reduced glutamate (Glu) concentrations, and disorderly expressed genes responsible for Gln/Glu metabolism. Interestingly, mice fed with diets devoid of Gln/Glu phenocopied the Qrich2 KO mice. Furthermore, we identified several mitochondrial marker proteins that could not be correctly localized in sperm flagella, which might be responsible for the reduced mitochondrial function contributing to the reduced sperm motility in Qrich2 KO mice. Our study reveals a crucial role of a normal Gln/Glu metabolism in maintaining the structural stability of the microtubules in sperm flagella by regulating the glutamylation levels of the tubulin and identifies Qrich2 as a possible novel Gln sensor that regulates microtubule glutamylation and mitochondrial function in mouse sperm.

Redox-dependent Cd2+ inhibition of BK-type Ca2+-activated K+ channels.

Large-conductance Ca2+-activated K+ channels (BK channels) are formed by Slo1 subunits as a homotetramer. Besides Ca2+, other divalent cations, such as Cd2+, also activate BK channels when applied intracellularly by shifting the conductance-voltage relation to more negative voltages. However, we found that if the inside-out patch containing BK channels was treated with solution containing reducing agents such as dithiothreitol (DTT), then subsequent Cd2+ application completely inhibited BK currents. The DTT-dependent Cd2+ inhibition could be reversed by treating the patch with solutions containing H2O2, suggesting that a redox reaction regulates the Cd2+ inhibition of BK channels. Similar DTT-dependent Cd2+ inhibition was also observed in a mutant BK channel, Core-MT, in which the cytosolic domain of the channel is deleted, and in the proton-activated Slo3 channels but not observed in the voltage-gated Shaker K+ channels. A possible mechanism for the DTT-dependent Cd2+ inhibition is that DTT treatment breaks one or more disulfide bonds between cysteine pairs in the BK channel protein and the freed thiol groups coordinate with Cd2+ to form an ion bridge that blocks the channel or locks the channel at the closed state. However, surprisingly, none of the mutations of all cysteine residues in Slo1 affect the DTT-dependent Cd2+ inhibition. These results are puzzling, with an apparent contradiction: on one hand, a redox reaction seems to regulate Cd2+ inhibition of the channel, but on the other hand, no cysteine residue in the Slo1 subunit seems to be involved in such inhibition.

A loss-of-function variant in ZCWPW1 causes human male infertility with sperm head defect and high DNA fragmentation.

BACKGROUND: Male infertility is a global health issue. The more causative genes related to human male infertility should be further explored. The essential role of Zcwpw1 in male mouse fertility has been established and the role of ZCWPW1 in human reproduction needs further investigation to verify. METHODS: An infertile man with oligoasthenoteratozoospermia phenotype and his parents were recruited from West China Second University Hospital, Sichuan University. A total of 200 healthy Han Chinese volunteers without any evidence of infertility were recruited as normal controls, while an additional 150 infertile individuals were included to assess the prevalence of ZCWPW1 variants in a sporadic male sterile population. The causative gene variant was identified by Whole-exome sequencing and Sanger sequencing. The phenotype of the oligoasthenoteratozoospermia was determined by Papanicolaou staining, immunofluorescence staining and electron microscope. In-vitro experiments, western blot and in-silicon analysis were applied to assess the pathogenicity of the identified variant. Additionally, we examined the influence of the variant on the DNA fragmentation and DNA repair capability by Sperm Chromatin Dispersion and Neutral Comet Assay. RESULTS: The proband exhibits a phenotype of oligoasthenoteratozoospermia, his spermatozoa show head defects by semen examination, Papanicolaou staining and electron microscope assays. Whole-exome sequencing and Sanger sequencing found the proband carries a homozygous ZCWPW1 variant (c.1064C > T, p. P355L). Immunofluorescence analysis shows a significant decrease in ZCWPW1 expression in the proband's sperm. By exogenous expression with ZCWPW1 mutant plasmid in vitro, the obvious declined expression of ZCWPW1 with the mutation is validated in HEK293T. After being treated by hydroxyurea, MUT-ZCWPW1 transfected cells and empty vector transfected cells have a higher level of γ-H2AX, increased tail DNA and reduced H3K9ac level than WT-ZCWPW1 transfected cells. Furthermore, the Sperm Chromatin Dispersion assay revealed the proband's spermatozoa have high DNA fragmentation. CONCLUSIONS: It is the first report that a novel homozygous missense mutation in ZCWPW1 caused human male infertility with sperm head defects and high DNA fragmentation. This finding enriches the gene variant spectrum and etiology of oligoasthenoteratozoospermia.

Oxidized SOD1 accelerates cellular senescence in neural stem cells.

BACKGROUND: Neural stem cells (NSCs), especially human NSCs, undergo cellular senescence characterized by an irreversible proliferation arrest and loss of stemness after prolonged culture. While compelling correlative data have been generated to support the oxidative stress theory as one of the primary determinants of cellular senescence of NSCs, a direct cause-and-effect relationship between the accumulation of oxidation-mediated damage and cellular senescence of NSCs has yet to be firmly established. Human SOD1 (hSOD1) is susceptible to oxidation. Once oxidized, it undergoes aberrant misfolding and gains toxic properties associated with age-related neurodegenerative disorders. The present study aims to examine the role of oxidized hSOD1 in the senescence of NSCs. METHODS: NSCs prepared from transgenic mice expressing the wild-type hSOD1 gene were maintained in culture through repeated passages. Extracellular vesicles (EVs) were isolated from culture media at each passage. To selectively knock down oxidized SOD1 in NSCs and EVs, we used a peptide-directed chaperone-mediated protein degradation system named CT4 that we developed recently. RESULTS: In NSCs expressing the hSOD1 from passage 5, we detected a significant increase of oxidized hSOD1 and an increased expression of biomarkers of cellular senescence, including upregulation of P53 and SA-ß-Gal and cytoplasmic translocation of HMGB1. The removal of oxidized SOD1 remarkably increased the proliferation and stemness of the NSCs. Meanwhile, EVs derived from senescent NSCs carrying the wild-type hSOD1 contained high levels of oxidized hSOD1, which could accelerate the senescence of young NSCs and induce the death of cultured neurons. The removal of oxidized hSOD1 from the EVs abolished their senescence-inducing activity. Blocking oxidized SOD1 on EVs with the SOD1 binding domain of the CT4 peptide mitigated its toxicity to neurons. CONCLUSION: Oxidized hSOD1 is a causal factor in the cellular senescence of NSCs. The removal of oxidized hSOD1 is a strategy to rejuvenate NSCs and to improve the quality of EVs derived from senescent cells.

Application research of novel peptide mitochondrial-targeted antioxidant SS-31 in mitigating mitochondrial dysfunction.

Due to the pivotal role of mitochondria in the generation of adenosine triphosphate (ATP) and the regulation of cellular homeostasis, mitochondrial dysfunction may exert a profound impact on various physiological systems, potentially precipitating a spectrum of distinct diseases. Consequently, research pertaining to mitochondrial therapeutics has assumed increasing significance, warranting heightened scrutiny. In recent years, the field of mitochondrial therapy has witnessed noteworthy advancements, with active exploration into diverse pharmacological agents aimed at ameliorating mitochondrial function. Elamipretide (SS-31), a novel synthetic mitochondrial-targeted antioxidant, has emerged as a promising candidate with extensive therapeutic potential. Its notable attributes encompass the mitigation of oxidative stress, the suppression of inflammatory processes, the maintenance of mitochondrial dynamics, and the prevention of cellular apoptosis. As such, SS-31 may emerge as a viable choice for the treatment of mitochondrial dysfunction-related ailments in the foreseeable future. This article extensively expounds upon the superiority of SS-31 over natural antioxidants and traditional mitochondrial-targeted antioxidants, delves into its mechanisms of modulating mitochondrial function, and comprehensively summarizes its applications in alleviating mitochondrial dysfunction-associated disorders. Furthermore, we offer a comprehensive outlook on the expansive prospects of SS-31's future development and application.

Molecular and functional characterization of an antenna-enriched glutathione S-transferase BminGSTd3 involved in undecanol degradation in the citrus fruit fly, Bactrocera minax (Enderlein) (Diptera Tephritidae).

Bactrocera minax is a disastrous pest of citrus crops in China. Numerous studies focused on the molecular mechanism of odorant perception of B. minax, but the molecular mechanism of odorant degradation remains unclear. Glutathione S-transferases (GSTs) are considered as a class of odorant-degrading enzymes involved in degrading odorant molecules in insects' olfactory system. Here, we identified a delta-class GST gene, BminGSTd3, from B. minax. It was predominantly expressed in adult's olfactory organ antennae. The bacterially expressed recombinant BminGSTd3 was able to catalyze the conjugation of glutathione (GSH) with 2, 4-dinitrochlorobenzene (CDNB). Spectrophotometric analysis showed that undecanol can inhibit catalytic activities of BminGSTd3. Metabolic assays exhibited that undecanol can be depleted by BminGSTd3. Undecanol is believed to be an important B. minax sex pheromone component. The other components of the pheromone remain unclear. To understand how BminGSTd3 specifically recognizes undecanol, a 3D model of BminGSTd3 was constructed by homology modeling. Molecular docking based on this model revealed that E64 and S65 are the key amino acids recognizing undecanol, and this was proven by site-directed mutagenesis and intrinsic fluorescence assays. We suggest that BminGSTd3 is an undecanol metabolizing GST in B.minax, and E64 and S65 may serve as the key binding sites.

Fatty Acid Metabolism-Related lncRNAs are Potential Biomarkers for Predicting Prognoses and Immune Responses in Patients with Skin Cutaneous Melanoma.

Introduction: Skin cutaneous melanoma is becoming more dangerous since it has a poor prognosis and is resistant to treatment. Previous research has shown that lncRNAs and fatty acid metabolism are essential for numerous biological activities. There are no studies on the relationship between fatty acid metabolism-Related lncRNAs and skin cutaneous melanoma. Methods and Results: In order to better understand the prognosis and survival of SKCM patients, we investigated the significance of lncRNAs related to fatty acid metabolism. In this work, we looked at the fatty acid metabolism genes and lncRNAs expression patterns. On the basis of lncRNAs associated with fatty acid metabolism, a nomogram and a prognosis prediction model were created. Based on the profile of lncRNAs associated with fatty acid metabolism, functional and pharmacological sensitivity investigations were also carried out. We also looked at the connection between immunotherapy and the immune response. The findings demonstrated that a risk score model based on 11 essential lncRNAs for fatty acid metabolism may discriminate between the clinical condition of SKCM and more accurately predict prognosis and survival. We conducted quantitative reverse transcription polymerase-chain reaction (RT-PCR) to verify the model. Conclusion: These important lncRNAs further showed a strong association with the tumor immune system, and these important lncRNAs also showed a connection between SKCM and chemotherapeutic treatment sensitivity. Our research strives to provide fresh viewpoints and innovative approaches to the treatment and administration of SKCM.

Early Warning Effect of CHR, NLR and U-HBP on SIRS in Patients with Upper Urinary Tract Calculus After Flexible Ureteroscopic Lithotripsy.

Objective: Rising upper urinary tract calculus (UUTC) cases demand effective treatment. FUL, while efficient, poses infection risks and SIRS. This study explores CHR, NLR, and U-HBP as potential SIRS predictors post-FUL in UUTC patients, aiming to improve early detection and enhance SIRS management. Methods: A retrospective analysis was conducted on data from 216 UUTC patients who underwent FUL between April 2020 and April 2023. Occurrence of SIRS post-FUL was studied. Patients were categorized into SIRS and non-SIRS groups. CHR, NLR, and U-HBP levels were compared. Predictive value of CHR, NLR, and U-HBP for SIRS was assessed. Univariate and multivariate logistic regression analyses identified SIRS influencing factors. Results: In a study involving 216 patients undergoing Flexible Ureteroscopic Holmium Laser Lithotripsy (FUL), Systemic Inflammatory Response Syndrome (SIRS) occurred in 20.83% of cases. Patients with SIRS exhibited significantly elevated levels of C-reactive protein to High-density lipoprotein cholesterol ratio (CHR) (9.26 ± 2.17 vs. 3.89 ± 0.92), Neutrophil to Lymphocyte Ratio (NLR) (5.21 ± 0.98 vs. 2.62 ± 0.49), and Urinary Heparin Binding Protein (U-HBP) (3.01 ± 0.51 ng/L vs. 1.22 ± 0.19 ng/L) compared to the non-SIRS group. Multivariate analysis identified factors such as infected stones (OR = 3.294), stone size ≥ 30 mm (OR = 2.034), CHR ≥ 8.76 (OR = 4.554), NLR ≥ 3.74 (OR = 3.951), and U-HBP ≥ 1.55 ng/L (OR = 4.884) as significant predictors for SIRS. These findings emphasize the pivotal role of these biomarkers and stone characteristics in predicting inflammatory responses post-FUL surgery. Conclusion: This study establishes the predictive power of elevated C-reactive protein to High-density lipoprotein cholesterol ratio (CHR), Neutrophil to Lymphocyte Ratio (NLR), and Urinary Heparin Binding Protein (U-HBP) levels for Systemic Inflammatory Response Syndrome (SIRS) post Flexible Ureteroscopic Holmium Laser Lithotripsy (FUL) in upper urinary tract calculi patients. Stone characteristics, including infected stones and stone size ≥ 30 mm, are also key indicators of SIRS. These findings offer crucial insights for effective post-operative management, enhancing outcomes in urinary calculi treatment.

Separation and flow cytometry analysis of microplastics and nanoplastics.

In recent years, the utilization of flow cytometry for quantitative microplastic analysis has gained prominence. However, the current methods have some drawbacks that need to be improved. The present study aims to enhance the flow cytometry detection protocols for Nile red (NR) stained microplastics, facilitating distinct microplastic and nanoplastic enumeration. By elevating dimethyl sulfoxide (DMSO) concentration to 20%-30% within the solution, NR solubility improved and agglomeration reduced. The analysis of 26 replicates of polystyrene (PS) liquid samples through four distinct dot plots highlighted the superior accuracy of dot plots integrating yellow fluorescence. Through systematic staining of varying NR concentrations across three microplastic liquid samples (polyethylene terephthalate, polyethylene, and polypropylene), the optimal staining concentration was determined to be 15-20 µg/mL. The distributions of agglomerated NR and NR stained PS under two scenarios-dissolved NR and partially agglomerated NR-were compared. Results showed their distinct distributions within the side scatter versus yellow fluorescence dot plot. Counting results from gradient-diluted PS liquid samples revealed a microplastic detection lower limit of 104 particles/mL, with an optimal concentration range of 105-106 particles/mL. Flow cytometric assessment of PS microspheres spanning 150 nm to 40 µm indicated a 150 nm particle size detection minimum. Our investigation validated the efficacy of NR staining and subsequent flow cytometry analysis across eleven types of microplastics. Separation and concentration of microplastics (1.0-50.0 µm) and nanoplastics (0.2-1.0 µm) were achieved via sequential sieving through 50, 1.0, and 0.2 µm filter membranes. We used a combination of multiple filtration steps and flow cytometry to analyze microplastics and nanoplastics in nine simulated water samples. Our results showed that the combined amount of microplastics (1.0-50.0 µm) and nanoplastics (0.2-1.0 µm) after filtration had a ratio of 0.80-1.19 compared to the total microplastic concentration before filtration. This result confirms the practicality of our approach. By enhancing flow cytometry-based microplastic and nanoplastic detection protocols, our study provides pivotal technical support for research concerning quantitative toxicity assessment of microplastic and nanoplastic pollution.

Multi-view fusion-based local-global dynamic pyramid convolutional cross-tansformer network for density classification in mammography.

Object.Breast density is an important indicator of breast cancer risk. However, existing methods for breast density classification do not fully utilise the multi-view information produced by mammography and thus have limited classification accuracy.Method.In this paper, we propose a multi-view fusion network, denoted local-global dynamic pyramidal-convolution transformer network (LG-DPTNet), for breast density classification in mammography. First, for single-view feature extraction, we develop a dynamic pyramid convolutional network to enable the network to adaptively learn global and local features. Second, we address the problem exhibited by traditional multi-view fusion methods, this is based on a cross-transformer that integrates fine-grained information and global contextual information from different views and thereby provides accurate predictions for the network. Finally, we use an asymmetric focal loss function instead of traditional cross-entropy loss during network training to solve the problem of class imbalance in public datasets, thereby further improving the performance of the model.Results.We evaluated the effectiveness of our method on two publicly available mammography datasets, CBIS-DDSM and INbreast, and achieved areas under the curve (AUC) of 96.73% and 91.12%, respectively.Conclusion.Our experiments demonstrated that the devised fusion model can more effectively utilise the information contained in multiple views than existing models and exhibits classification performance that is superior to that of baseline and state-of-the-art methods.

Advances in the mechanisms related to follicle loss after frozen-thawed ovarian tissue transplantation.

Ovaries are important reproductive and endocrine organs in women. Ovarian tissue cryopreservation and transplantation technology can not only solve the fertility problems of patients, but also may improve female endocrine problems. This is particularly important for patients in urgent need of radiotherapy and chemotherapy, and for women with prepubertal malignant tumors. However, follicle loss after freeze-thawing is a key challenge for effective ovarian tissue transplantation and leads to poor transplant outcomes. Therefore, it is crucial to elucidate the mechanisms underlying follicle loss after transplantation. This paper reviews current research on the mechanisms of follicle loss after frozen-thawed ovarian tissue transplantation, including the activation, apoptosis, and pyroptosis mechanisms of primordialfollicles. Further, it highlights the requirement of more experimental studies for improving ovarian tissue transplantation methods.

Long-term effect of transurethral partial cystectomy with a 2-micrometer continuous-wave laser for non-muscle-invasive bladder cancer.

Purpose: We have reported the efficacy and safety of 2-micrometer continuous-wave laser cystectomy of non-muscle invasive bladder tumor (NMIBC) (J Urol. 2009;182:66-9). In this study, we evaluated the long-term outcomes of patients with NMIBC who underwent transurethral partial cystectomy with a 2-micrometer continuous-wave laser, and explored the risk factors for tumor recurrence. Methods: This was a retrospective study of patients with NMIBC planned to undergo transurethral partial cystectomy with a 2-micrometer continuous-wave laser at the Fourth Medical Center of the PLA General Hospital between January 2012 and December 2014. The primary outcome was bladder cancer recurrence. Results: A total of 75 patients were enrolled. Sixty-two (82.7%) were male. The patients were 59.8 ± 12.9 years of age. The mean operation time was 38.7 ± 20.4 min. No Clavien grade >2 complications occurred. The duration of catheter indwelling was 3.6 ± 1.8 days. The hospital stay was 6.0 ± 2.3 days. The median follow-up was 80 months. A total of 17 patients had a recurrence during follow-up, and the recurrence-free survival (RFS) rate was 77.3%. In the multivariable analysis, the tumor risk group were independently associated with the recurrence of NMIBC (p = 0.026). Conclusions: After TURBT with a 2-micrometer continuous-wave laser, RFS was 77.3% at the median follow-up of 80 months. All complications were mild. Only tumor risk group was independently associated with the recurrence of NMIBC.

MED27 plays a tumor-promoting role in breast cancer progression by targeting KLF4.

The mediator complex usually cooperates with transcription factors to be involved in RNA polymerase II-mediated gene transcription. As one component of this complex, MED27 has been reported in our previous studies to promote thyroid cancer and melanoma progression. However, the precise function of MED27 in breast cancer development remains poorly understood. Here, we found that MED27 was more highly expressed in breast cancer samples than in normal tissues, especially in triple-negative breast cancer, and its expression level was elevated with the increase in pathological stage. MED27 knockdown in triple-negative breast cancer cells inhibited cancer cell metastasis and stemness maintenance, which was accompanied by downregulation of the expression of EMT- and stem traits-associated proteins, and vice versa in non-triple-negative breast cancer. Furthermore, MED27 knockdown sensitized breast cancer cells to epirubicin treatment by inducing cellular apoptosis and reducing tumorsphere-forming ability. Based on RNA-seq, we identified KLF4 as the possible downstream target of MED27. KLF4 overexpression reversed the MED27 silencing-mediated arrest of cellular metastasis and stemness maintenance capacity in breast cancer in vitro and in vivo. Mechanistically, MED27 transcriptionally regulated KLF4 by binding to its promoter region at positions -156 to +177. Collectively, our study not only demonstrated the tumor-promoting role of MED27 in breast cancer progression by transcriptionally targeting KLF4, but also suggested the possibility of developing the MED27/KLF4 signaling axis as a potential therapeutic target in breast cancer.

Deficiency of cancer/testis antigen gene CT55 causes male infertility in humans and mice.

The Cancer/Testis Antigen (CTA) genes comprise a group of genes whose expression under physiological conditions is restricted to the testis but is activated in many human cancers. Depending on the particular expression pattern, the CTA genes are speculated to play a role in spermatogenesis, but evidence is limited thus far. Here, we reported patients with a hemizygous nonsense mutation in cancer-testis antigen 55 (CT55) suffering from male infertility with extreme disruption in sperm production, morphology, and locomotion. Specifically, the insufficiency of sperm individualization, excessive residue of unnecessary cytoplasm, and defects in acrosome development were evident in the spermatozoa of the patients. Furthermore, mouse models with depletion of Ct55 showed accelerated infertility with age, mimicking the defects in sperm individualization, unnecessary cytoplasm removal, and meanwhile exhibiting the disrupted cumulus-oocyte complex penetration. Mechanistically, our functional experiments uncovered CT55 as a new autophagic manipulator to regulate spermatogenesis via selectively interacting with LAMP2 and GABARAP (which are key regulators in the autophagy process) and further fine-tuning their expression. Therefore, our findings revealed CT55 as a novel CTA gene involved in spermatogenesis due to its unprecedented autophagy activity.

Cerebral Ischemic Preconditioning Aggravates Death of Oligodendrocytes.

Neurodegeneration can benefit from ischemic preconditioning, a natural adaptive reaction to sublethal noxious stimuli. Although there is growing interest in advancing preconditioning to preserve brain function, preconditioning is not yet considered readily achievable in clinical settings. One of the most challenging issues is that there is no fine line between preconditioning stimuli and lethal stimuli. Here, we show deleterious effect of preconditioning on oligodendrocyte precursor cells (OPCs). We identified Bcl-2/adenovirus E1B 19-kDa interacting protein 3 (BNIP3), a mitochondrial BH3-only protein specifically involved in OPCs loss after preconditioning. Repeated ischemia stabilized BNIP3 and increased the vulnerability of OPCs to subsequent ischemic events. BNIP3 became mitochondrial-bound and was concurrent with the dysfunction of monocarboxylate transporter 1 (MCT1). Inhibition of BNIP3 by RNAi or necrostatin-1 (Nec-1) and knocking out of BNIP3 almost completely prevented OPCs loss and preserved white matter integrity. Together, our results suggest that the unfavorable effect of BNIP3 on OPCs should be noted for safe development of ischemic tolerance. BNIP3 inhibition appears to be a complementary approach to improve the efficacy of preconditioning for ischemic stroke.

Manganese induces tumor cell ferroptosis through type-I IFN dependent inhibition of mitochondrial dihydroorotate dehydrogenase.

Ferroptosis is a novel form of regulated cell death characterized by the iron-dependent accumulation of lipid peroxides to lethal levels, which is morphologically, biochemically, and genetically distinct from apoptosis, necroptosis, autophagy, and pyroptosis. Manganese play an important role in innate immunity and antitumor immunity. Many manganese-based nanomaterials induce tumor cell death by catalyzing the production of reactive oxygen species (ROS) within the tumor. However, the exact underlying mechanisms remain unclear. As research on ferroptosis advances and its regulatory mechanisms in tumors continue to be refined, more evidence has suggested that triggering ferroptosis in tumor cells is an effective strategy for tumor treatment. In this study, we found that administration of MnCl2 to tumor cells resulted in lipid peroxidation and increased the levels of mitochondrial ROS, consequently leading to ferroptosis. Dihydroorotate dehydrogenase (DHODH)-mediated ferroptosis defence is a targetable vulnerability in cancer. We show that MnCl2 downregulated DHODH expression in tumor cells, resulting in increased mitochondrial ROS and lipid peroxidation to induce ferroptosis. In addition, MnCl2 enhanced the phosphorylation levels of STING, TBK1, and IRF3 and upregulated the expression of type-I interferon (IFN), produced by the cGAS-STING signaling pathway. When inhibiting the cGAS-STING signaling pathway or type-I IFN, DHODH expression was restored, reversing lipid peroxidation and ROS production and rescuing MnCl2-induced ferroptosis.. Knockout of IFNAR1 or overexpression of DHODH weakens the antitumor effect of MnCl2. Mechanistically, these results revealed that Manganese treatment-activated cGAS-STING signaling promote mitochondrial lipid peroxidation and ROS production by releasing type-I IFNs that reduce DHODH function and thereby inducing ferroptosis in tumor cells. This may provide a new strategy to complement existing antitumor treatment regimens.

Cardiac myxoma shedding leads to lower extremity arterial embolism: A case report.

BACKGROUND: Left cardiac myxoma (CM) is the most common benign tumor of primary cardiac tumors, but because of its special position caused by pathological physiology change, caused by the complications of the heavier, the surface is often accompanied by blood clots, once fall out, it causes peripheral vascular embolization, such as acute lower limb artery embolization, harmfulness is large, high morbidity, and easy to occur repeatedly. CASE SUMMARY: A 67-year-old male patient suddenly appeared numbness and weakness of the left lower limb and could not walk without obvious incentive. The patient was finally diagnosed as left CM complicated with acute lower limb arterial embolism after completing cardiac ultrasound, computer tomography angiography, and histopathological analysis, such as hematoxylin-eosin stain staining, immunohistochemistry and special staining including alcian blue staining and periodic acid schiff staining. Arterial thrombosis was removed successfully by femoral artery thrombectomy, postoperative numbness and weakness of the patient's left lower limb disappeared, skin temperature became warm, and dorsal foot artery pulsation was accessible. The patient was readmitted to the hospital 8 mo after discharge for left atrial mass resection, and was diagnosed as CM by postoperative histopathological examination. CONCLUSION: Although CM is rare, it may be considered as the source of embolism in patients with acute limb ischemia. Repeated loss of thrombus on the tumor and its surface may lead to repeated embolism of peripheral vessels. Cardiac ultrasound is helpful for early diagnosis. Here, we use this case report to highlight left CM as an important cause of acute limb ischemia and to report our experience in the diagnosis and treatment of lower limb arterial embolism caused by CM detachment.

BPTF inhibition antagonizes colorectal cancer progression by transcriptionally inactivating Cdc25A.

As the largest subunit of the nuclear remodeling factor complex, Bromodomain PHD Finger Transcription Factor (BPTF) has been reported to be involved in tumorigenesis and development in several cancers. However, to date, its functions and related molecular mechanisms in colorectal cancer (CRC) are still poorly defined and deserve to be revealed. In this study, we uncovered that, under the expression regulation of c-Myc, BPTF promoted CRC progression by targeting Cdc25A. BPTF was found to be highly expressed in CRC and promoted the proliferation and metastasis of CRC cells through BPTF specific siRNAs, shRNAs or inhibitors. Based on RNA-seq, combined with DNA-pulldown, ChIP and luciferase reporter assay, we proved that, by binding to -178/+107 region within Cdc25A promoter, BPTF transcriptionally activated Cdc25A, thus accelerating the cell cycle process of CRC cells. Meanwhile, BPTF itself was found to be transcriptionally regulated by c-Myc. Moreover, BPTF knockdown or inactivation was verified to sensitize CRC cells to chemotherapeutics, 5-Fluorouracil (5FU) and Oxaliplatin (Oxa), c-Myc inhibitor and cell cycle inhibitor not just at the cellular level in vitro, but in subcutaneous xenografts or AOM/DSS-induced in situ models of CRC in mice, while Cdc25A overexpression partially reversed BPTF silencing-caused tumor growth inhibition. Clinically, BPTF, c-Myc and Cdc25A were highly expressed in CRC tissues simultaneously, the expression of any two of the three was positively correlated, and their expressions were highly relevant to tumor differentiation, TNM staging and poor prognosis of CRC patients. Thus, our study indicated that the targeted inhibition of BPTF alone, or together with chemotherapy and/or cell cycle-targeted therapy, might act as a promising new strategy for CRC treatment, while c-Myc/BPTF/Cdc25A signaling axis is expected to be developed as an associated set of candidate biomarkers for CRC diagnosis and prognosis prediction.

PRSS55 is a novel potential causative gene for human male infertility.

RESEARCH QUESTION: Testis-specific PRSS55 is a chymotrypsin-like serine protease that is highly conserved among mammalian species. The essential role of Prss55 in mouse male fertility has been established. What is the role of PRSS55 in human reproduction? DESIGN: Whole exome sequencing was used to identify the genetic cause in an infertile male with teratozoospermia. Papanicolaou staining, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to explore morphological defects in the patient's spermatozoa. Immunofluorescence staining and western blot analysis were conducted to assess the pathogenicity of the identified variant. Intracytoplasmic sperm injection (ICSI) was used to assist the patient with fertilization. RESULTS: Sanger sequencing of the pedigree demonstrated that the infertile man carried a novel homozygous mutation in PRSS55 (c.575C>T [p.A192V]). Morphological defects in the sperm head, neck, midpiece and tail were demonstrated by Papanicolaou staining, SEM and TEM. Immunofluorescence staining and western blotting of the patient's spermatozoa showed that the point mutation changed the conformation of PRSS55 and caused a sharp decrease in the PRSS55 protein concentration. The expression and subcellular localization of PRSS55 in the testis and spermatozoa of mice and humans showed that PRSS55 was expressed in the head and flagella of spermatids and epididymal spermatozoa. Moreover, ICSI treatment for this kind of infertile patient was shown to be effective. CONCLUSIONS: These findings revealed a novel mutation in PRSS55 in an infertile patient, suggesting for the first time the crucial role of PRSS55 in human fertility. This study provides new insight into genetic counselling diagnoses and subsequent treatment for male infertility.