CDK5-cyclin B1 regulates mitotic fidelity.

CDK1 has been known to be the sole cyclin-dependent kinase (CDK) partner of cyclin B1 to drive mitotic progression1. Here we demonstrate that CDK5 is active during mitosis and is necessary for maintaining mitotic fidelity. CDK5 is an atypical CDK owing to its high expression in post-mitotic neurons and activation by non-cyclin proteins p35 and p392. Here, using independent chemical genetic approaches, we specifically abrogated CDK5 activity during mitosis, and observed mitotic defects, nuclear atypia and substantial alterations in the mitotic phosphoproteome. Notably, cyclin B1 is a mitotic co-factor of CDK5. Computational modelling, comparison with experimentally derived structures of CDK-cyclin complexes and validation with mutational analysis indicate that CDK5-cyclin B1 can form a functional complex. Disruption of the CDK5-cyclin B1 complex phenocopies CDK5 abrogation in mitosis. Together, our results demonstrate that cyclin B1 partners with both CDK5 and CDK1, and CDK5-cyclin B1 functions as a canonical CDK-cyclin complex to ensure mitotic fidelity.

Relationship between postpartum psychological disorders and emotion regulation strategies: A cross-sectional study.

To explore the relationship between postpartum psychological disorders and emotion regulation strategies and analyze the influencing factors of postpartum psychological disorders. This study was conducted using a cross-sectional design. A total of 230 postpartum women hospitalized in the Second Affiliated Hospital of Xuzhou Medical University from October 2022 to March 2023 were selected as the investigation objects. A general data questionnaire, Hamilton Anxiety Scale, Hamilton Depression Scale, Pittsburgh Sleep Quality Index, and Emotion Regulation Questionnaire were administered to the enrolled women. Pearson correlation analysis was used to assess the association between the Hamilton Anxiety Scale, Hamilton Depression Scale, Pittsburgh Sleep Quality Index, and Emotion Regulation Questionnaire. Furthermore, logistic regression was employed to assess the influencing factors of postpartum psychological disorders. Pearson correlation analysis showed that cognitive reappraisal was negatively correlated and expression inhibition was positively associated with anxiety, depression, and sleep quality symptoms (all P < .05). Logistic regression results demonstrated that the mode of delivery, number of births, feeding method, and pressure to breastfeed were risk factors affecting postpartum psychological disorders (P < .05). Cognitive reappraisal is an effective emotion regulation strategy that can relieve postpartum psycho-neurological symptoms by reducing the symptoms of anxiety, depression, and sleep disorders. Along with encouraging pregnant women to adopt positive emotional regulation strategies, medical personnel should focus on the stress associated with cesarean section, artificial feeding, and pressure to breastfeed and adopt required intervention measures to decrease the occurrence of postpartum psychological and neurological symptoms.

A new flavonostilbene glycoside and four new stilbene derivatives from the roots of Polygonum multiflorum.

One new flavonostilbene glycoside, polygonflavanol C (1), two new dimeric stilbene glycosides, multiflorumiside M and multiflorumiside N (2-3), one new diphenyl ethanol glycoside, (R)-2,3,5,4'-tetrahydroxy-diphenylethanol 2-O-ß-D-glucopyranoside (4), and one new deoxybenzoin glycoside, 2,4,3',5'-tetrahydroxy-6-methyl-deoxybenzoin 2-O-ß-D-glucopyranoside (5), together with six known ones (6-11), were isolated from the roots of Polygonum multiflorum. Their structures were elucidated by the comprehensive spectroscopic analyses. In addition, compounds 1 and 7 showed significantly in vitro anti-inflammatory activity.

Effect of endoscopic therapy and drug therapy on prognosis and rebleeding in patients with esophagogastric variceal bleeding.

Esophagogastric variceal bleeding (EVB) is one of the common digestive system emergencies with poor prognosis and high rate of rebleeding after treatment. To explore the effects of endoscopic therapy and drug therapy on the prognosis and rebleeding of patients with EVB, and then select better treatment methods to effectively improve the prognosis. From January 2013 to December 2022, 965 patients with EVB who were hospitalized in gastroenterology Department of the 940 Hospital of Joint Logistic Support Forces of PLA were retrospectively analyzed. Patients were divided into endoscopic treatment group (ET, n = 586) and drug treatment group (DT, n = 379). Propensity score matching (PSM) analysis was performed in both groups, and the general information, efficacy and length of hospital stay were recorded. The patients were followed up for 3 months after bleeding control to determine whether rebleeding occurred. There were 286 cases in each group after PSM. Compared with DT group, ET had higher treatment success rate (P < 0.001), lower rebleeding rate (P < 0.001), lower mortality rate within 3 months, and no significant difference in total hospital stay (P > 0.05). Compared with drug therapy, endoscopic treatment of EVB has short-term efficacy advantages, and can effectively reduce the incidence of rebleeding and mortality within 3 months.

Association of urinary and seminal plasma vanadium concentrations with semen quality: A repeated-measures study of 1135 healthy men.

Although animal studies have shown the reproductive toxicity of vanadium, less is known about its effects on semen quality in humans. Among 1135 healthy men who were screened as potential semen donors, we investigated the relationships of semen quality with urinary and seminal plasma vanadium levels via inductively coupled plasma-mass spectrometry (ICP-MS). Spearman rank correlation tests and linear regression models were used to assess the correlations between average urinary and within-individual pooled seminal plasma vanadium concentrations (n = 1135). We utilized linear mixed-effects models to evaluate the associations of urinary and seminal plasma vanadium levels (n = 1135) with repeated sperm quality parameters (n = 5576). Seminal plasma vanadium concentrations were not significantly correlated with urinary vanadium concentrations (r = 0.03). After adjusting for possible confounders, we observed inverse relationships of within-individual pooled seminal plasma vanadium levels with total count, semen volume, and sperm concentration (all P values for trend < 0.05). Specifically, subjects in the highest (vs. lowest) tertile of seminal plasma vanadium concentrations had - 11.3% (-16.4%, -5.9%), - 11.1% (-19.1%, -2.4%), and - 20.9% (-29.0%, -11.8%) lower sperm volume, concentration, and total count, respectively; moreover, urinary vanadium levels appeared to be negatively associated with sperm motility. These relationships showed monotonically decreasing dose-response patterns in the restricted cubic spline analyses. Our results demonstrated a poor correlation between urinary and seminal plasma levels of vanadium, and elevated vanadium concentrations in urine and seminal plasma may be adversely related to male semen quality.

The association between serum magnesium and chronic kidney disease in Chinese adults: a cross-sectional study.

BACKGROUND: Magnesium (Mg) is both an essential macro-element and a known catalyst, and it plays a vital role in various physiological activities and mechanisms in relation to chronic kidney disease (CKD). However, epidemiological evidence involving this is limited and not entirely consistent. This study aims to explore the association of serum Mg concentrations with the risk of CKD among general Chinese adults. METHODS: A total of 8,277 Chinese adults were included in the wave of 2009 from the China Health and Nutrition Survey (CHNS). The primary outcome was the risk of CKD, which was defined as the estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2. Multivariable logistic regression model was used to examine the relationship of serum Mg concentrations with the risk of CKD. RESULTS: Included were 8,277 individuals, with an overall CKD prevalence of 11.8% (n = 977). Compared with the first quartile of serum Mg, the multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for participants in the second, third, and fourth quartiles of serum Mg were 0.74 (0.58, 0.93), 0.87 (0.69, 1.11) and 1.29 (1.03, 1.61), respectively. Similar results were observed in our several sensitivity analyses. Restricted cubic spline analysis demonstrated a nonlinear (similar "J"-shaped) association between serum Mg concentrations and the risk of CKD (Pnonlinearity <0.001), with a threshold at around a serum Mg value of 2.2 mg/dL. CONCLUSIONS: Our results suggested a similar "J"-shaped association between serum Mg concentration and the risk of CKD among Chinese adults. Further large prospective studies are needed to verify these findings.

Risk factors of infection among close contacts of COVID-19: A systematic review and meta-analysis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) was first detected in December 2019, and declared as a pandemic by the World Health Organization (WHO) on March 11, 2020. The current management of COVID-19 is based generally on supportive therapy and treatment to prevent respiratory failure. METHODS: PubMed, Web of Science, Embase, CNKI, and other databases were searched by computer, and relevant literature published from December 2019 to November 2022 on the influencing factors of infection in close contacts with novel coronavirus pneumonia was collected. Meta-analysis was carried out after literature screening, quality assessment, and data extraction. RESULTS: A total of 425 articles were retrieved and 11 were included. Meta-analysis showed that there were 6 risk factors, and the combined OR value and 95% CI of each influencing factor were 5.23 (3.20, 8.57) for family members, 1.63 (0.56, 4.77) for regular contact, 2.14 (0.62, 7.32) for the elderly, 0.58 (0.001569.89) for cohabitation, 1.97 (1.02, 3.82) for women and 0.75 (0.01, 54.07) for others. The Deeks' funnel diagram indicates that there is no potential publication bias among the included studies. CONCLUSION: Family members and gender differences are the risk factors of infection among close contacts, and it cannot be proved that there are differences in infection among frequent contact, advanced age, and living together.

A high-resolution mass spectrometric approach to a qualitative and quantitative comparative metabolism of the humantenine-type alkaloid rankinidine.

RATIONALE: Rankinidine belongs to the humantenine-type alkaloids isolated from Gelsemium. Currently, the mechanism behind the toxicity differences of rankinidine has not been explained. In this study, our purpose was to elucidate the major in vitro metabolic pathways of rankinidine and to compare the formation of metabolites of rankinidine in human (HLMs), rat (RLMs), goat (GLMs) and pig (PLMs) liver microsomes. METHODS: This is the first study to compare the in vitro metabolism of rankinidine with high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/QTOF). The MS/MS data and LC/MS peak area acquired in positive ion mode were used to analyze metabolite structures and compare metabolism. RESULTS: We identified 11 metabolites (M1-M11) in total and found five main metabolic pathways, consisting of demethylation (M1), reduction (M2), oxidation at different positions (M3-M5), oxidation and reduction (M6-M10) and demethylation and oxidation (M11). The metabolism of rankinidine has qualitative and quantitative species-specific differences in vitro. In PLMs and GLMs, the main metabolic pathway of rankinidine was oxidation. Notably, among the four species, the oxidation ability of rankinidine was highest in pigs and goats, and the demethylation and reduction abilities of rankinidine were highest in humans and rats. CONCLUSIONS: The interspecific metabolic differences of rankinidine in HLMs, PLMs, GLMs and RLMs were compared and studied for the first time using LC/QTOF. These findings will certainly support future studies of rankinidine metabolism in vivo and will contribute to elucidating the cause of species-specific differences behind Gelsemium toxicity.

Suppressive Effects of Gelsemine on Anxiety-like Behaviors Induced by Chronic Unpredictable Mild Stress in Mice.

Gelsemine is an active principle and a major alkaloid found in Gelsemium genus of plants belonging to the Loganiaceae family. The aim of the present study was to explore whether gelsemine exerts anxiolytic effects on a mouse model of chronic-unpredictable-mild-stress (CUMS)-induced anxiety-like behaviors. NOD-like receptor protein 3 (NLRP3) inflammasome, downregulated cAMP-response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) were also evaluated as potential mechanisms. First, gelsemine reversed a CUMS-induced decrease in body-weight gain in mice. Next, gelsemine alleviated CUMS-induced anxiety-like behaviors, as evidenced by the increased distance traveled in the central zone of the open-field test, both the increased percentage of time spent and distance traveled in the light compartment, the increased number of transitions between compartments in the light/dark-transition test, and the increased percentage of entries and time spent in the open arm of the elevated plus-maze. In addition, gelsemine decreased the levels of pro-inflammatory cytokines, including interleukin (IL)-1ß and IL-6, in the hypothalamus and hippocampus of CUMS mice. Interestingly, further investigations revealed that gelsemine inhibited the CUMS-induced activation of NLRP3-inflammasome pathways and downregulated CREB and BDNF overexpression in the hypothalamus. In summary, gelsemine alleviated anxiety-like behaviors in the CUMS-induced mouse model. Gelsemine exerted its anxiolytic effects by modulating the NLRP3 and CREB/BDNF pathways.

CHK1 Inhibitor Blocks Phosphorylation of FAM122A and Promotes Replication Stress.

While effective anti-cancer drugs targeting the CHK1 kinase are advancing in the clinic, drug resistance is rapidly emerging. Here, we demonstrate that CRISPR-mediated knockout of the little-known gene FAM122A/PABIR1 confers cellular resistance to CHK1 inhibitors (CHK1is) and cross-resistance to ATR inhibitors. Knockout of FAM122A results in activation of PP2A-B55α, a phosphatase that dephosphorylates the WEE1 protein and rescues WEE1 from ubiquitin-mediated degradation. The resulting increase in WEE1 protein expression reduces replication stress, activates the G2/M checkpoint, and confers cellular resistance to CHK1is. Interestingly, in tumor cells with oncogene-driven replication stress, CHK1 can directly phosphorylate FAM122A, leading to activation of the PP2A-B55α phosphatase and increased WEE1 expression. A combination of a CHK1i plus a WEE1 inhibitor can overcome CHK1i resistance of these tumor cells, thereby enhancing anti-cancer activity. The FAM122A expression level in a tumor cell can serve as a useful biomarker for predicting CHK1i sensitivity or resistance.

CDK phosphorylation of TRF2 controls t-loop dynamics during the cell cycle.

The protection of telomere ends by the shelterin complex prevents DNA damage signalling and promiscuous repair at chromosome ends. Evidence suggests that the 3' single-stranded telomere end can assemble into a lasso-like t-loop configuration1,2, which has been proposed to safeguard chromosome ends from being recognized as DNA double-strand breaks2. Mechanisms must also exist to transiently disassemble t-loops to allow accurate telomere replication and to permit telomerase access to the 3' end to solve the end-replication problem. However, the regulation and physiological importance of t-loops in the protection of telomere ends remains unknown. Here we identify a CDK phosphorylation site in the shelterin subunit at Ser365 of TRF2, whose dephosphorylation in S phase by the PP6R3 phosphatase provides a narrow window during which the RTEL1 helicase can transiently access and unwind t-loops to facilitate telomere replication. Re-phosphorylation of TRF2 at Ser365 outside of S phase is required to release RTEL1 from telomeres, which not only protects t-loops from promiscuous unwinding and inappropriate activation of ATM, but also counteracts replication conflicts at DNA secondary structures that arise within telomeres and across the genome. Hence, a phospho-switch in TRF2 coordinates the assembly and disassembly of t-loops during the cell cycle, which protects telomeres from replication stress and an unscheduled DNA damage response.

A mitotic CDK5-PP4 phospho-signaling cascade primes 53BP1 for DNA repair in G1.

Mitotic cells attenuate the DNA damage response (DDR) by phosphorylating 53BP1, a critical DDR mediator, to prevent its localization to damaged chromatin. Timely dephosphorylation of 53BP1 is critical for genome integrity, as premature recruitment of 53BP1 to DNA lesions impairs mitotic fidelity. Protein phosphatase 4 (PP4) dephosphorylates 53BP1 in late mitosis to allow its recruitment to DNA lesions in G1. How cells appropriately dephosphorylate 53BP1, thereby restoring DDR, is unclear. Here, we elucidate the underlying mechanism of kinetic control of 53BP1 dephosphorylation in mitosis. We demonstrate that CDK5, a kinase primarily functional in post-mitotic neurons, is active in late mitotic phases in non-neuronal cells and directly phosphorylates PP4R3ß, the PP4 regulatory subunit that recognizes 53BP1. Specific inhibition of CDK5 in mitosis abrogates PP4R3ß phosphorylation and abolishes its recognition and dephosphorylation of 53BP1, ultimately preventing the localization of 53BP1 to damaged chromatin. Our results establish CDK5 as a regulator of 53BP1 recruitment.

Ca2+-PKCα-ERK1/2 signaling pathway is involved in the suppressive effect of propofol on proliferation of neural stem cells from the neonatal rat hippocampus.

Neonatal exposure to propofol induces persistent behavioral abnormalities in adulthood. In addition to triggering the apoptosis of neurons in the developing brain, anesthetics may contribute to the development of cognitive deficits by interfering neurogenesis. Given the importance of neural stem cell (NSC) proliferation in neurogenesis, the effect of propofol on NSC proliferation and the mechanisms underlying this effect were investigated. Hippocampal NSC proliferation from neonatal rats was examined using 5-bromo-2'-deoxyuridine incorporation assays in vitro. The [Ca2+]i was analyzed using flow cytometry. The activations of protein kinase C (PKC)-α and extracellular signal-regulated kinases 1/2 (ERK1/2) were measured by western blot. Our results showed that propofol significantly inhibited NSC proliferation in vitro. [Ca2+]i and activations of PKCα and ERK1/2 in NSCs were markedly suppressed by propofol (5, 10, 20, 40 and 80 µM). Ca2+ channel blocker verapamil, PKCα inhibitor chelerythrine and ERK1/2 kinase inhibitor PD98059 exerted their maximal effects on NSC function at concentrations of 20, 10 and 20 µM, respectively. Propofol (20 µM) could not produce further additional suppression effects when used in combination with verapamil (20 µM), chelerythrine (10 µM) or PD98059 (20 µM). In addition, phorbol-12-myristate-13-acetate (PMA, a activator of PKC) markedly attenuated the suppressive effects of propofol on ERK1/2 phosphorylation and NSC proliferation. The inhibition effects on PKCα activation, ERK1/2 phosphorylation and NSC proliferation induced by propofol were significantly improved by BayK8644 (a calcium channel agonist). These results indicate that propofol can inhibits hippocampal NSC proliferation by suppressing the Ca2+-PKCα-ERK1/2 signaling pathway.

TIRR regulates 53BP1 by masking its histone methyl-lysine binding function.

P53-binding protein 1 (53BP1) is a multi-functional double-strand break repair protein that is essential for class switch recombination in B lymphocytes and for sensitizing BRCA1-deficient tumours to poly-ADP-ribose polymerase-1 (PARP) inhibitors. Central to all 53BP1 activities is its recruitment to double-strand breaks via the interaction of the tandem Tudor domain with dimethylated lysine 20 of histone H4 (H4K20me2). Here we identify an uncharacterized protein, Tudor interacting repair regulator (TIRR), that directly binds the tandem Tudor domain and masks its H4K20me2 binding motif. Upon DNA damage, the protein kinase ataxia-telangiectasia mutated (ATM) phosphorylates 53BP1 and recruits RAP1-interacting factor 1 (RIF1) to dissociate the 53BP1-TIRR complex. However, overexpression of TIRR impedes 53BP1 function by blocking its localization to double-strand breaks. Depletion of TIRR destabilizes 53BP1 in the nuclear-soluble fraction and alters the double-strand break-induced protein complex centring 53BP1. These findings identify TIRR as a new factor that influences double-strand break repair using a unique mechanism of masking the histone methyl-lysine binding function of 53BP1.

Laparoscopic surgery assisted by colonoscopy for a submucosal cecal fecalith presenting as acute appendicitis: A case report.

RATIONALE: A cecal submucosal fecalith is extremely rare and is likely to be misdiagnosed as appendicitis with an incarcerated fecalith. PATIENT CONCERNS: This review presents the case of a female patient complaining of recurrent abdominal pain in the right lower quadrant, similar to the clinical symptoms of appendicitis. Physical examination revealed an abdominal tenderness in the right lower quadrant without rebound tenderness or muscular tension. An ultrasound examination found a mass located in the right lower abdomen. Computed tomography showed a high-density shadow in the cecal cavity. DIAGNOSES: A fecalith was detected in the submucosal cecal wall. The postoperative pathologic examination showed that the fecalith was located in the submucosa. INTERVENTIONS: A partial cecal excision was performed under laparoscopic surgery assisted by colonoscopy. OUTCOMES: The patient was discharged 1 week after surgery without postoperative complications. LESSONS: Fecaliths should be considered in the differential diagnosis of submucosal occupying lesions of the cecum.

MicroRNA-711 is a prognostic factor for poor overall survival and has an oncogenic role in breast cancer.

MicroRNAs are important in cancer development and progression. In the present study, the clinical significance and function of microRNA-711 (miR-711) expression in breast cancer were investigated. The expression level of miR-711 was analyzed in breast cancer tissue samples using reverse transcription-quantitative polymerase chain reaction. Cell proliferation, colony formation, apoptosis and Transwell assays were performed in breast cancer cell lines transfected with miR-711 mimics or inhibitors, or control sequence. miR-711 was found to be upregulated in 30 formalin-fixed paraffin-embedded breast cancer tissue samples compared with paired non-cancerous breast tissues (P<0.05). Furthermore, a higher miR-711 expression was demonstrated to be associated with poor overall and disease-free survival times in 161 breast cancer patients, and miR-711 was identified as an independent prognostic factor using multivariate Cox regression analysis. In vitro, overexpression of miR-711 resulted in a significant increase in proliferation, colony formation, migration and invasion of breast cancer cells. By contrast, downregulating miR-711 inhibited cell proliferation, colony formation, migration and invasion and enhanced the rate of apoptosis of breast cancer cells. To the best of our knowledge, the present study is the first to demonstrate that miR-711 is an independent prognostic factor and serves an important oncogenic function in breast cancer, suggesting that miR-711 is a potential biomarker of prognosis and a molecular therapeutic target in breast cancer.