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The Journal of Biological Chemistry Feb 2023DNA resection-the nucleolytic processing of broken DNA ends-is the first step of homologous recombination. Resection is catalyzed by the resectosome, a multienzyme...
DNA resection-the nucleolytic processing of broken DNA ends-is the first step of homologous recombination. Resection is catalyzed by the resectosome, a multienzyme complex that includes bloom syndrome helicase (BLM), DNA2 or exonuclease 1 nucleases, and additional DNA-binding proteins. Although the molecular players have been known for over a decade, how the individual proteins work together to regulate DNA resection remains unknown. Using single-molecule imaging, we characterized the roles of the MRE11-RAD50-NBS1 complex (MRN) and topoisomerase IIIa (TOP3A)-RMI1/2 during long-range DNA resection. BLM partners with TOP3A-RMI1/2 to form the BTRR (BLM-TOP3A-RMI1/2) complex (or BLM dissolvasome). We determined that TOP3A-RMI1/2 aids BLM in initiating DNA unwinding, and along with MRN, stimulates DNA2-mediated resection. Furthermore, we found that MRN promotes the association between BTRR and DNA and synchronizes BLM and DNA2 translocation to prevent BLM from pausing during resection. Together, this work provides direct observation of how MRN and DNA2 harness the BTRR complex to resect DNA efficiently and how TOP3A-RMI1/2 regulates the helicase activity of BLM to promote efficient DNA repair.
Topics: Humans; DNA; DNA Breaks, Double-Stranded; DNA Repair; DNA Topoisomerases, Type I; Multienzyme Complexes; Single Molecule Imaging
PubMed: 36529288
DOI: 10.1016/j.jbc.2022.102802 -
International Journal of Molecular... Nov 2022Prostate cancer (PCa) is a common cancer and a major cause of cancer-related death worldwide in men, necessitating novel targets for cancer therapy. High expression of...
Prostate cancer (PCa) is a common cancer and a major cause of cancer-related death worldwide in men, necessitating novel targets for cancer therapy. High expression of Bloom's syndrome protein (BLM) helicase is associated with the occurrence and development of PCa. Therefore, the identification and development of new BLM inhibitors may be a new direction for the treatment of PCa. Here, we identified a novel inhibitor by molecular docking and put it to systematic evaluation via various experiments, AO/854, which acted as a competitive inhibitor that blocked the BLM-DNA interaction. Cellular evaluation indicated that AO/854-suppressed tumor growth and metastasis in PC3 cells by enhancing DNA damage, phosphorylating Chk1/Chk2, and altering the p53 signaling pathway. Collectively, the study highlights the potential of BLM as a therapeutic target in PCa and reveals a distinct mechanism by which AO/854 competitively inhibits the function of BLM.
Topics: Humans; Male; Bloom Syndrome; Molecular Docking Simulation; RecQ Helicases; DNA; DNA Damage; Prostatic Neoplasms
PubMed: 36499126
DOI: 10.3390/ijms232314798 -
International Journal of Oncology Jan 2023Prostate cancer (PCa) is one of the most fundamental causes of cancer‑related mortality and morbidity among males. However, the underlying mechanisms have not yet been...
Prostate cancer (PCa) is one of the most fundamental causes of cancer‑related mortality and morbidity among males. However, the underlying mechanisms have not yet been fully clarified. The present study aimed to investigate the effects of plasmacytoma variant translocation 1 (PVT1) on the malignant behaviors of PCa cells and to explore the possible molecular mechanisms involved. The expression levels of PVT1 and microRNA (miRNA/miR)‑27b‑3p in PCa tissues and cell lines were measured using reverse‑transcritpion‑quantitative polymerase chain reaction. Methyltransferase 3 (METTL3)‑mediated PVT1 N‑methyladenosine (mA) modifications were detected using RNA immunoprecipitation (RIP) and RNA pull‑down assays. Bioinformatics analysis was used to predict the interactions of miR‑27b‑3p with PVT1 and bloom syndrome protein (BLM), and these interactions were validated using RIP, dual‑luciferase reporter and biotin pull‑down assays. The functional importance of miR‑27b‑3p, PVT1 and BLM within PCa cells was assessed through the utilization of Cell Counting Kit‑8, Transwell, wound healing and colony formation assays, and the use of a mouse xenograft model. The results revealed the high expression level of PVT1 in PCa tissues and cells, and epigenetic analyses revealed the upregulation of PVT1 expression following METTL3‑mediated mA modification. PVT1 overexpression induced PCa cells to become more proliferative, migratory and invasive, whereas PVT1 knockdown led to the opposite phenotype. Furthermore, miR‑27b‑3p was found to target both PVT1 and BLM, and PVT1 functioned to sequester miR‑27b‑3p within cells, thereby indirectly promoting the BLM expression level. BLM overexpression reversed the adverse effects of PVT1 knockdown on the migratory, proliferative and invasive capabilities of PCa cells and . The overexpression of PVT1 contributed to the aggressive phenotype of PCa cells by regulating the miR‑27b‑3p/BLM axis. On the whole, the findings of the present study may provide novel potential targets for the treatment of PCa.
Topics: Humans; Mice; Animals; Male; RNA, Long Noncoding; Prostatic Neoplasms; MicroRNAs; Methyltransferases
PubMed: 36484368
DOI: 10.3892/ijo.2022.5464 -
Clinical and Experimental Emergency... Sep 2023
PubMed: 36475354
DOI: 10.15441/ceem.22.390 -
Journal of Human Reproductive Sciences 2022Infertility is a world-wide problem and one third females. Over the years, anti-mullerian hormone (AMH) has emerged as a major marker of ovarian reserve. There is also...
BACKGROUND
Infertility is a world-wide problem and one third females. Over the years, anti-mullerian hormone (AMH) has emerged as a major marker of ovarian reserve. There is also increasing interest in determining the factors which can impact AMH levels.
AIMS
To correlate the association of reproductive and lifestyle factors on AMH levels in women of Indian origin.
SETTINGS AND DESIGN
Multicentric cross sectional study.
MATERIALS AND METHODS
The study was conducted using data extracted from the patient records of seven private fertility practices located in North India. Women who were attending these clinics for fertility treatment were requested to fill the questionnaire related to reproductive and lifestyle factors.
STATISTICAL ANALYSIS USED
Our outcome variable was level of AMH measured in the past 3 months, and was assessed as normal or low. All analyses were conducted using STATA 17.
RESULTS
We found a direct association of low AMH with increasing age, short cycles, amenorrhea and women with family history of premature menopause. We found a direct correlation of high AMH and women with polycystic ovary syndrome and those whose partners had Oligoasthenoteratozoospermia (OATS) or azoospermia. There was no correlation with smoking, sleep, diet, body mass index, cell phone or laptop use in our study.
CONCLUSION
Reproductive and lifestyle factors may affect ovarian reserve and but there was a dearth of human studies in this area. To the best of our knowledge this is the first human study on the effect of AMH on Laptop and Cell phone use. We urgently need more studies to confirm or refute our findings so that we can counsel our patients well.
PubMed: 36341011
DOI: 10.4103/jhrs.jhrs_79_22 -
The Journal of Clinical Investigation Dec 2022Axon loss contributes to many common neurodegenerative disorders. In healthy axons, the axon survival factor NMNAT2 inhibits SARM1, the central executioner of programmed...
Axon loss contributes to many common neurodegenerative disorders. In healthy axons, the axon survival factor NMNAT2 inhibits SARM1, the central executioner of programmed axon degeneration. We identified 2 rare NMNAT2 missense variants in 2 brothers afflicted with a progressive neuropathy syndrome. The polymorphisms resulted in amino acid substitutions V98M and R232Q, which reduced NMNAT2 NAD+-synthetase activity. We generated a mouse model to mirror the human syndrome and found that Nmnat2V98M/R232Q compound-heterozygous CRISPR mice survived to adulthood but developed progressive motor dysfunction, peripheral axon loss, and macrophage infiltration. These disease phenotypes were all SARM1-dependent. Remarkably, macrophage depletion therapy blocked and reversed neuropathic phenotypes in Nmnat2V98M/R232Q mice, identifying a SARM1-dependent neuroimmune mechanism as a key driver of disease pathogenesis. These findings demonstrate that SARM1 induced inflammatory neuropathy and highlight the potential of immune therapy as a treatment for this rare syndrome and other neurodegenerative conditions associated with NMNAT2 loss and SARM1 activation.
Topics: Male; Animals; Mice; Humans; Adult; Armadillo Domain Proteins; Nicotinamide-Nucleotide Adenylyltransferase; Nerve Degeneration; Cytoskeletal Proteins; Axons; Peripheral Nervous System Diseases; Macrophages
PubMed: 36287209
DOI: 10.1172/JCI159800 -
Open Forum Infectious Diseases Oct 2022Reported adverse reactions to the mRNA-1273 vaccine (Spikevax, Moderna Inc) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) range from mild, local...
Reported adverse reactions to the mRNA-1273 vaccine (Spikevax, Moderna Inc) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) range from mild, local delayed cutaneous reactions to rarer, more serious reactions such as myocarditis. Here, we describe the presentation and successful treatment of delayed, localized necrotizing inflammatory myositis following a third dose of the mRNA-1273 SARS-CoV-2 vaccine. To our knowledge, this is the first report of biopsy-confirmed, delayed inflammatory myositis after administration of an mRNA-1273 SARS-CoV-2 vaccine booster.
PubMed: 36267257
DOI: 10.1093/ofid/ofac499 -
Frontiers in Public Health 2022The human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (HIV/AIDS) are worldwide public health issues. Since Saudi Arabia is growing more...
Knowledge of HIV/AIDS transmission modes and attitudes toward HIV/AIDS infected people and the level of HIV/AIDS awareness among the general population in the kingdom of Saudi Arabia: A cross-sectional study.
INTRODUCTION
The human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (HIV/AIDS) are worldwide public health issues. Since Saudi Arabia is growing more accessible to the outside world, it is critical to analyze the general population's knowledge of HIV/AIDS transmission modes and attitudes toward HIV/AIDS infected people, and the level of HIV/AIDS awareness. Therefore, this study aimed to assess the knowledge of HIV/AIDS transmission modes and attitudes toward HIV/AIDS infected people, as well as the level of HIV/AIDS awareness among the general population in the Kingdom of Saudi Arabia.
METHODS
The current online community-based cross-sectional descriptive study was conducted among the general population of the Kingdom of Saudi Arabia using a self-administrated electronic questionnaire between October 2017 and February 2018. A score <3 was considered a negative response. In contrast, scores of 3 and 4 were considered positive responses. The sum score of each outcome was evaluated according to Bloom's cutoff point. The scores for knowledge and attitude were transformed into mean percentage scores by dividing the sum scores obtained by the respondents by the number of items multiplied by 100. Consequently, the overall mean percentage of scores for each category of knowledge and attitude at 60% and above was considered a good level, whereas <60% was deemed a poor level.
RESULTS
A total of 2,081 subjects residing in the Kingdom of Saudi Arabia participated in this survey. The mean score of the participant's responses to knowledge items on HIV/AIDS transmission modes was 84.2 ± 15.8%. The mean score of the participant's responses to attitude items toward HIV/AIDS infected people was 50.1 ± 49.9%. The mean score of the participant's responses to attitude items toward the level of HIV/AIDS awareness in Saudi Arabia was 55.7 ± 3.6%. Many socio-demographic variables were significantly associated with mean scores of knowledge of HIV/AIDS transmission modes, mean scores of attitude toward HIV/AIDS infected people, and mean scores of attitude toward the level of HIV/AIDS awareness (value ≤ 0.05). The Spearman rank correlation explained significant negative linear correlations between knowledge of HIV/AIDS transmission modes-attitudes toward HIV/AIDS infected people and knowledge of HIV/AIDS transmission modes-attitudes toward the level of HIV/AIDS awareness of r = -0.040 and r = -0.070, respectively (-value ≤ 0.05). Otherwise, there was a positive linear correlation between attitudes toward HIV/AIDS infected people-attitudes toward the level of HIV/AIDS awareness (r = 0.080, -value = 0.072).
CONCLUSIONS
The study showed that a high percentage of the respondents had good knowledge of HIV/AIDS transmission modes. However, a low rate of the study respondents had positive attitudes toward HIV/AIDS infected people and the level of HIV/AIDS awareness among the general population in Saudi Arabia. Therefore, there is a dire need for advocacy campaigns and policies to help reduce HIV stigmatization levels.
Topics: Acquired Immunodeficiency Syndrome; Cross-Sectional Studies; HIV Infections; Health Knowledge, Attitudes, Practice; Humans; Saudi Arabia
PubMed: 36238245
DOI: 10.3389/fpubh.2022.955458 -
Translational Psychiatry Sep 2022Mood disorders are an important public health issue and recent advances in genomic studies have indicated that molecules involved in neurodevelopment are causally...
Mood disorders are an important public health issue and recent advances in genomic studies have indicated that molecules involved in neurodevelopment are causally related to mood disorders. BLM-s (BCL-2-like molecule, small transcript isoform), a BH3-only proapoptotic BCL-2 family member, mediates apoptosis of postmitotic immature neurons during embryonic cortical development, but its role in the adult brain is unknown. To better understand the physiological role of Blm-s gene in vivo, we generated a Blm-s-knockout (Blm-s) mouse. The Blm-s mice breed normally and exhibit grossly normal development. However, global depletion of Blm-s is highly associated with depression- and anxiety-related behaviors in adult mutant mice with intact learning and memory capacity. Functional magnetic resonance imaging of adult Blm-s mice reveals reduced connectivity mainly in the ventral dentate gyrus (vDG) of the hippocampus with no alteration in the dorsal DG connectivity and in total hippocampal volume. At the cellular level, BLM-s is expressed in DG granule cells (GCs), and Blm-s mice show reduced dendritic complexity and decreased spine density in mature GCs. Electrophysiology study uncovers that mature vGCs in adult Blm-s DG are intrinsically more excitable. Interestingly, certain genetic variants of the human Blm homologue gene (VPS50) are significantly associated with depression traits from publicly resourced UK Biobank data. Taken together, BLM-s is required for the hippocampal mood control function. Loss of BLM-s causes abnormality in the electrophysiology and morphology of GCs and a disrupted vDG neural network, which could underlie Blm-s-null-associated anxiety and depression.
Topics: Adult; Animals; Apoptosis; Dentate Gyrus; Hippocampus; Humans; Mice; Neurogenesis; Neurons; Proto-Oncogene Proteins c-bcl-2; RecQ Helicases
PubMed: 36163151
DOI: 10.1038/s41398-022-02184-6 -
Nutrients Sep 2022Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease in Australia and is recognised to play a role in the development of hepatocellular...
BACKGROUND
Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease in Australia and is recognised to play a role in the development of hepatocellular carcinoma (HCC). There are no clear guidelines regarding screening for HCC in NAFLD. The aim of this retrospective study was to compare the characteristics and survival rates of NAFLD-HCC to patients with non-NAFLD-HCC to help guide future research in this area.
METHODS
A total of 152 HCC patients with either NAFLD ( = 36) or non-NAFLD ( = 116) were retrospectively analysed from the HCC database and medical records. Chi-square and independent t-test were used to compare baseline characteristics and Kaplan-Meier curves and Cox models were used for survival analysis.
RESULTS
Patients with NAFLD-HCC were more likely to be diagnosed due to symptoms rather than through screening, and at an older age, compared with non-NAFLD HCC. The median survival rates were lower in NAFLD-HCC (17.2 months) than in those with non-NAFLD-HCC (23.5 months).
CONCLUSION
There is a rise in the number of HCC cases in patients with NAFLD, and this has significant implications for hepatologists as they are presented with more advanced diseases and have poorer outcomes. Future studies on HCC will need to identify this group earlier in order to have an impact on the HCC survival rate.
Topics: Carcinoma, Hepatocellular; Humans; Liver Cirrhosis; Liver Neoplasms; Non-alcoholic Fatty Liver Disease; Retrospective Studies; Risk Factors
PubMed: 36145251
DOI: 10.3390/nu14183875