N6-methyladenosine triggers renal fibrosis via enhancing translation and stability of ZEB2 mRNA.

In recent years, a surge in studies investigating N6-methyladenosine (m6A) modification in human diseases has occurred. However, the specific roles and mechanisms of m6A in kidney disease remain incompletely understood. This study revealed that m6A plays a positive role in regulating renal fibrosis (RF) by inducing epithelial-to-mesenchymal phenotypic transition (EMT) in renal tubular cells. Through comprehensive analyses, including m6A sequencing, RNA-seq, and functional studies, we confirmed the pivotal involvement of zinc finger E-box binding homeobox 2 (ZEB2) in m6A-mediated RF and EMT. Notably, the m6A-modified coding sequence of ZEB2 mRNA significantly enhances its translational elongation and mRNA stability by interacting with the YTHDF1/eEF-2 complex and IGF2BP3, respectively. Moreover, targeted demethylation of ZEB2 mRNA using the dm6ACRISPR system substantially decreases ZEB2 expression and disrupts the EMT process in renal tubular epithelial cells. In vivo and clinical data further support the positive influence of m6A/ZEB2 on RF progression. Our findings highlight the m6A-mediated regulation of RF through ZEB2, revealing a novel therapeutic target for RF treatment and enhancing our understanding of the impact of mRNA methylation on kidney disease.

RNA m1A methylation regulates glycolysis of cancer cells through modulating ATP5D.

Studies on biological functions of RNA modifications such as N6-methyladenosine (m6A) in mRNA have sprung up in recent years, while the roles of N1-methyladenosine (m1A) in cancer progression remain largely unknown. We find m1A demethylase ALKBH3 can regulate the glycolysis of cancer cells via a demethylation activity dependent manner. Specifically, sequencing and functional studies confirm that ATP5D, one of the most important subunit of adenosine 5'-triphosphate synthase, is involved in m1A demethylase ALKBH3-regulated glycolysis of cancer cells. The m1A modified A71 at the exon 1 of ATP5D negatively regulates its translation elongation via increasing the binding with YTHDF1/eRF1 complex, which facilitates the release of message RNA (mRNA) from ribosome complex. m1A also regulates mRNA stability of E2F1, which directly binds with ATP5D promoter to initiate its transcription. Targeted specific demethylation of ATP5D m1A by dm1ACRISPR system can significantly increase the expression of ATP5D and glycolysis of cancer cells. In vivo data confirm the roles of m1A/ATP5D in tumor growth and cancer progression. Our study reveals a crosstalk of mRNA m1A modification and cell metabolism, which expands the understanding of such interplays that are essential for cancer therapeutic application.

Recurrent RhoGAP gene fusion CLDN18-ARHGAP26 promotes RHOA activation and focal adhesion kinase and YAP-TEAD signalling in diffuse gastric cancer.

OBJECTIVE: Genomic studies of gastric cancer have identified highly recurrent genomic alterations impacting RHO signalling, especially in the diffuse gastric cancer (DGC) histological subtype. Among these alterations are interchromosomal translations leading to the fusion of the adhesion protein CLDN18 and RHO regulator ARHGAP26. It remains unclear how these fusion constructs impact the activity of the RHO pathway and what is their broader impact on gastric cancer development. Herein, we developed a model to allow us to study the function of this fusion protein in the pathogenesis of DGC and to identify potential therapeutic targets for DGC tumours with these alterations. DESIGN: We built a transgenic mouse model with LSL-CLDN18-ARHGAP26 fusion engineered into the Col1A1 locus where its expression can be induced by Cre recombinase. Using organoids generated from this model, we evaluated its oncogenic activity and the biochemical effects of the fusion protein on the RHOA pathway and its downstream cell biological effects in the pathogenesis of DGC. RESULTS: We demonstrated that induction of CLDN18-ARHGAP26 expression in gastric organoids induced the formation of signet ring cells, characteristic features of DGC and was able to cooperatively transform gastric cells when combined with the loss of the tumour suppressor geneTrp53. CLDN18-ARHGAP26 promotes the activation of RHOA and downstream effector signalling. Molecularly, the fusion promotes activation of the focal adhesion kinase (FAK) and induction of the YAP pathway. A combination of FAK and YAP/TEAD inhibition can significantly block tumour growth. CONCLUSION: These results indicate that the CLDN18-ARHGAP26 fusion is a gain-of-function DGC oncogene that leads to activation of RHOA and activation of FAK and YAP signalling. These results argue for further evaluation of emerging FAK and YAP-TEAD inhibitors for these deadly cancers.

[Magnetic induced phase shift detection system based on a novel sensor for cerebral hemorrhage].

The main magnetic field, generated by the excitation coil of the magnetic induction phase shift technology detection system, is mostly dispersed field with small field strength, and the offset effect needs to be further improved, which makes the detection signal weak and the detection system difficult to achieve quantitative detection, thus the technology is rarely used in vivo experiments and clinical trials. In order to improve problems mentioned above, a new Helmholtz birdcage sensor was designed. Stimulation experiment was carried out to analyze the main magnetic field in aspects of intensity and magnetic distribution, then different bleeding volume and bleeding rates experiments were conducted to compared with traditional sensors. The results showed that magnetic field intensity in detection region was 2.5 times than that of traditional sensors, cancellation effect of the main magnetic field was achieved, the mean value of phase difference of 10 mL rabbit blood was (-3.34 ± 0.21)°, and exponential fitting adjusted R 2 between phase difference and bleeding volumes and bleeding rates were both 0.99. The proposed Helmholtz birdcage sensor has a uniform magnetic field with a higher field strength, enable more accurate quantification of hemorrhage and monitored change of bleeding rates, providing significance in magnetic induced technology research for cerebral hemorrhage detection.

Critical thinking disposition of medical students in Anhui Province, China: a cross-sectional investigation.

OBJECTIVE: To investigate the critical thinking disposition of medical undergraduates. METHODS: This cross-sectional study was performed on 426 students from four majors, including preventive medicine, maternal and children's health care medicine, health inspection and quarantine, and food quality and safety. The survey was completed in May 2019 using the California Critical Thinking Dispositions Inventory-Chinese version (CTDI-CV). RESULTS: A total of 435 questionnaires were distributed and 426 valid questionnaires were collected, with an effective rate of 97.93%. The CTDI-CV overall average score was 262.02 ± 34.74 points indicating an ambivalent disposition in medical undergraduate students. Only one of the subscales (maturity in judgment) had mean scores of 43.35 ± 8.23 indicating the positive disposition of students. Among them, males scored 257.42 ± 35.06 lower than females' 264.82 ± 34.32, the difference was statistically significant. The target scores of preventive medicine, maternal and children's health medicine, health inspection and quarantine, and food quality and safety were 265.17 ± 30.10, 260.26 ± 37.05, 271.73 ± 33.55, and 252.11 ± 39.87, respectively. The difference was statistically significant. Among the three dimensions of seeking truth, open mind, and cognitive maturity, the scores of males were 38.26 ± 7.48, 38.78 ± 6.46 and 41.03 ± 8.69, which were lower than females' 39.97 ± 7.11, 40.48 ± 6.48 and 44.91 ± 7.60, respectively. The scores of food quality and safety students were 37.23 ± 7.08, 36.61 ± 7.41 and 40.57 ± 8.60, respectively, which were lower than the preventive medicine (39.98 ± 7.07, 40.60 ± 5.96 and 44.44 ± 6.97, respectively). CONCLUSION: Most medical students were found to have an ambivalent disposition which meant they were not disposed toward critical thinking. These findings suggested that more effective teaching methods should be taken to facilitate critical thinking disposition and problem-solving ability.

Targeting UPR branches, a potential strategy for enhancing efficacy of cancer chemotherapy.

Cancer cells are often exposed to cell intrinsic stresses and environmental perturbations that may lead to accumulation of unfolded and/or misfolded proteins in the lumen of endoplasmic reticulum (ER), a cellular condition known as ER stress. In response to ER stress, the cells elicit an adaptive process called unfolded protein response (UPR) to cope with the stress, supporting cellular homeostasis and survival. The ER stress sensors inositol requiring protein 1α (IRE1α), eukaryotic translation initiation factor 2 alpha kinase 3 (EIF2AK3, also called PERK), and activating transcription factor 6 (ATF6) constitute the three branches of UPR to resolve ER stress. IRE1α, PERK, and ATF6 play an important role in tumor cell growth and survival. They are also involved in chemotherapy resistance of cancers. These have generated widespread interest in targeting these UPR branches for cancer treatment. In this review, we provide an overview of the role of IRE1α, PERK, and ATF6 in cancer progression and drug resistance and we summarize the research advances in targeting these UPR branches to enhance the efficacy of chemotherapy of cancers.

Effect of deletion of gra17 and gra23 genes on the growth, virulence, and immunogenicity of type II Toxoplasma gondii.

The protozoan parasite Toxoplasma gondii secretes a number of dense granule proteins (GRAs) from the dense granule organelle to manipulate the host cell. Two of these effector proteins (GRA17 and GRA23) are involved in the trafficking of molecules between the parasitophorous vacuole (PV) and the host cell cytoplasm. However, their roles in establishing chronic infection remain obscured. In this study, CRISPR-Cas9 was used to delete gra17 or gra23 gene in T. gondii Pru strain (type II). The growth, the virulence, the ability to establish chronic infection, and the immunogenicity of the constructed mutant strains were investigated in Kunming mice. Pru:Δgra17 and Pru:Δgra23 mutants developed PVs with abnormal morphology and exhibited reduced growth rate, compared with the wild-type Pru strain. Deletion of gra17 abrogated acute infection and blocked cyst formation. Although the deletion of gra23 caused slight attenuation of the parasite virulence in mice, it caused a significant reduction in cyst formation. Immunization with Pru:Δgra17 induced high levels of IgG (IgG1 and IgG2a) antibodies and cytokines (interleukin-2 [IL-2], IL-10, IL-12, and interferon gamma [IFN-γ]), which conferred significant protection in mice challenged with virulent type I (RH), ToxoDB#9 (PYS) strains, or less virulent type II (Pru) strain of T. gondii. These findings show that GRA17 and GRA23 play important roles in T. gondii chronic infection and that irreversible deletion of gra17 in T. gondii type II Pru strain can be a viable option for stimulating protective immunity to T. gondii infection.

Angular random walk improvement of a fiber-optic gyroscope using an active fiber ring resonator.

High precision fiber-optic gyroscopes (FOGs) interrogated with broadband light have angular random walk (ARW) limited by the source relative intensity noise (RIN). A passive fiber ring resonator (passive FRR) reduces the RIN and improves the ARW, but the low power transmission results in a low signal-to-noise ratio at the detection. For a great ARW improvement, the fiber ring resonator should have not only a great RIN reduction but also a large power transmission. An erbium-doped fiber amplifier (EDFA) is inserted in the passive resonator to construct an active fiber ring resonator (active FRR). The EDFA compensates for the loss of the resonator and leads to a high finesse and a greater reduction in the RIN. The coupling ratios of the couplers in the active FRR are both 50%-50% tap. By adjusting the EDFA gain properly, a 17-dB decrease in the RIN is demonstrated, which reduces the standard deviation by 8.5 dB. Adding the active FRR between the Sagnac interferometer and the broadband light, the detected power reaches 150 µW with the FOG at rest and without modulation, which is about one hundred times of the detected power when using a passive FRR. The phase noise is reduced by 6 dB at the proper frequency. The ARW is improved by 4.9 dB from 1.40 to 0.45 mdeg/hour1/2.

Fiber optic gyroscope noise reduction with fiber ring resonator.

A method of improving the angular random walk (ARW) of a fiber optic gyroscope (FOG) using a fiber ring resonator (FRR) to reduce the relative intensity noise (RIN) is demonstrated. An FRR reduces the RIN near the proper frequency and improves the ARW. The analytical forms for the RIN transfer function and the power transmission of the FRR are derived when the free spectral range of the FRR is much narrower than the source bandwidth. Building the FRR using couplers and fiber with low excess loss enhances the RIN reduction. For the coupling ratios, there is a trade-off between the RIN reduction and the power transmission. The coupling ratios are 90%-10% tap in the experiment. When the FRR resonator length is shorter than the FOG coil length, the ARW improvement is further enhanced by adjusting the average window length in the signal processing. An experiment demonstrated a 7 dB decrease in the RIN at the loop proper frequency, which reduces the standard deviation by 3.5 dB. The ARW was reduced from 970 to 570 µdeg/h1/2, which amounts to a 2.3 dB reduction.

Enhancing the enzymatic saccharification of bamboo shoot shell by sequential biological pretreatment with Galactomyces sp. CCZU11-1 and deep eutectic solvent extraction.

In this study, sequential biological pretreatment (BP) with Galactomyces sp. CCZU11-1 at 30 °C for 3 days and deep eutectic solvent (DES) choline chloride: oxalic acid (ChCl:OA, 1 mol/2 mol) extraction at 120 °C for 1.5 h was used for pretreating BSS. It was found that combination pretreatment could effectively remove xylan and lignin for enhancing enzymatic saccharification. The reducing sugars and glucose from the hydrolysis of 100 g/L pretreated BSS with complexed cellulases of Galactomyces sp. CCZU11-1 were obtained in the yields of 81.0% and 74.1%, respectively. The BSS-hydrolyzates had no inhibitory effects on the lipid-accumulating microorganism Bacillus sp. CCZU11-1, and the cell mass and TAG accumulation were 4.8 g CDW/L and 2.2 g TAG/L, respectively. Fatty acids including palmitic acid (C16:0; 25.3%), palmitoleic acid (C16:1; 24.4%), stearic acid (C18:0; 15.1%), and oleic acid (C18:1; 21.6%) were accumulated in cells. Clearly, this combination pretreatment has high potential application in future.

The Endoplasmic Reticulum Stress Sensor IRE1α in Intestinal Epithelial Cells Is Essential for Protecting against Colitis.

Intestinal epithelial cells (IECs) have critical roles in maintaining homeostasis of intestinal epithelium. Endoplasmic reticulum (ER) stress is implicated in intestinal epithelium homeostasis and inflammatory bowel disease; however, it remains elusive whether IRE1α, a major sensor of ER stress, is directly involved in these processes. We demonstrate here that genetic ablation of Ire1α in IECs leads to spontaneous colitis in mice. Deletion of IRE1α in IECs results in loss of goblet cells and failure of intestinal epithelial barrier function. IRE1α deficiency induces cell apoptosis through induction of CHOP, the pro-apoptotic protein, and sensitizes cells to lipopolysaccharide, an endotoxin from bacteria. IRE1α deficiency confers upon mice higher susceptibility to chemical-induced colitis. These results suggest that IRE1α functions to maintain the intestinal epithelial homeostasis and plays an important role in defending against inflammation bowel diseases.

PHD3 Stabilizes the Tight Junction Protein Occludin and Protects Intestinal Epithelial Barrier Function.

Prolyl hydroxylase domain proteins (PHDs) control cellular adaptation to hypoxia. PHDs are found involved in inflammatory bowel disease (IBD); however, the exact role of PHD3, a member of the PHD family, in IBD remains unknown. We show here that PHD3 plays a critical role in maintaining intestinal epithelial barrier function. We found that genetic ablation of Phd3 in intestinal epithelial cells led to spontaneous colitis in mice. Deletion of PHD3 decreases the level of tight junction protein occludin, leading to a failure of intestinal epithelial barrier function. Further studies indicate that PHD3 stabilizes occludin by preventing the interaction between the E3 ligase Itch and occludin, in a hydroxylase-independent manner. Examination of biopsy of human ulcerative colitis patients indicates that PHD3 is decreased with disease severity, indicating that PHD3 down-regulation is associated with progression of this disease. We show that PHD3 protects intestinal epithelial barrier function and reveal a hydroxylase-independent function of PHD3 in stabilizing occludin. These findings may help open avenues for developing a therapeutic strategy for IBD.

miR-346 promotes migration and invasion of nasopharyngeal carcinoma cells via targeting BRMS1.

The aim of this study is to determine the expression and roles of miR-346 in nasopharyngeal carcinoma (NPC). We showed that miR-346 was upregulated in NPC tissues compared with adjacent non-tumorous nasopharyngeal tissues. Inhibition of miR-346 significantly attenuated the migration and invasion of NPC cells. Luciferase reporter assay showed that miR-346 targeted the 3'-untranslated region (3'-UTR) of breast cancer metastasis suppressor 1 (BRMS1). Overexpression of miR-346 suppressed the endogenous expression of BRMS1 in NPC cells. There was a significant negative correlation between miR-346 and BRMS1 protein expression in NPC tissues (r = -0.372, P = 0.008). Rescue experiments demonstrated that overexpression of BRMS1 lacking the 3'-UTR impaired the invasiveness of NPC cells transfected with miR-346 mimic. Taken together, miR-346 shows the ability to promote the migration and invasion of nasopharyngeal cancer cells via targeting BRMS1 and represents a potential therapeutic target for NPC.

The impacts of obstructive sleep apnea hypopnea syndrome severity and surgery intervention on psychological and behavioral abnormalities and postoperative recovery in pediatric patients.

BACKGROUND: The aim of this study was to investigate the degree of impact of obstructive sleep apnea hypopnea syndrome (OSAHS) severity on pediatric psychological and behavioral abnormalities. MATERIAL AND METHODS: Fifty-one children aged 5-12 years with a confirmed diagnosis of OSAHS were divided into 3 groups according to the severity of OSAHS. They underwent bilateral tonsillectomy plus adenoidectomy or adenoidectomy alone. Repeated polysomnography and integrated visual and auditory continuous performance testing (-IVA-CPT) was performed to assess full-scale response control quotient (FRCQ), full-scale attention quotient (FAQ), and hyperactivity (HYP) before surgery and 3 and 6 months after surgery. RESULTS: Mean FRCQ, FAQ, and HYP significantly improved over time in the 3 groups (FRCQ, F=292.05; FAQ, F=258.27; HYP, F=295.10, all P<0.001). FRCQ and HYP were not significantly different among the groups at the 3 time points. FAQ was significantly different among the groups (F=3.89, P<0.05). For FRCQ, FAQ, and HYP, there was no interaction between time and disease severity. Within groups, the effect of time on the apnea-hypopnea index (AHI) and lowest oxygen saturation (LaSO2) were significant for each group and they were significantly different among the 3 groups at each time point (all P<0.001). CONCLUSIONS: These results suggest that OSAHS may have a significant impact on self-control, attention, and hyperactivity in children, which is gradually alleviated after surgery. Disease severity was not closely related to preoperative mental and psychological function or postoperative recovery. Thus, we find it difficult to determine the impact degree of OSAHS severity on mental and psychological function or predict postoperative recovery by using OSAHS severity alone in children.

Correlation between 146S Antigen Content in Foot-and-Mouth Disease Inactivated Vaccines and Immunogenicity Level and Vaccine Potency Alternative Test Methods.

To investigate the association between 146S antigen contents in FMD inactivated vaccines and levels of antiviral immunity, this study vaccinated 30 kg pigs with three batches of FMD types O and A bivalent inactivated vaccines. Antibody titers and interferon-gamma (IFN-γ) secretion levels were measured on days 7, 14, 21, and 28 after primary immunization and on days 14 and 28 following booster immunization to assess associations between 146S contents and both antibody titers and IFN-γ secretion levels. Furthermore, 30 kg pigs were vaccinated with 46 batches of FMD type O inactivated vaccines and challenged on day 28, after which PD50 values were determined to evaluate the association between 146S content and PD50. The findings suggested that antibody titers and IFN-γ secretion levels at specific time points after immunization were positively associated with 146S contents. Additionally, 146S content showed a positive correlation with PD50, with greater PD50 values recorded for 146S contents ranging from 4.72 to 16.55 µg/dose. This investigation established a significant association between the 146S content in FMD inactivated vaccines and induced immune response against FMDV, thereby emphasizing its critical role in vaccine quality control. The determination of 146S content could serve as a new method for potency testing, offering an alternative to animal challenge tests.

The Impact of Recent Life Events, Internalizing Symptoms, and Emotion Regulation on the Severity of Non-Suicidal Self-Injury in Adolescents: A Mediation Analysis.

Background: Previous studies have demonstrated a strong association between recent stressful life events and non-suicidal self-injury (NSSI) among adolescents. Internalizing symptoms and difficulty in emotion regulation (DER) may mediate this relationship. This study aimed to investigate the relationship between recent stressful life events and NSSI severity in adolescents and the potential moderating role of internalizing symptoms and DER. Methods: A total of 224 adolescent inpatients (78.6% female) participated in the study, with an age range of 12-18 years old. Data on recent stressful life events, internalizing symptoms, DER, and NSSI behaviors were collected using a clinician-rated questionnaire. A structural equation model was used to test the hypothesized model. Results: The rate of NSSI reporting among adolescents in the past 12 months was 65.18%. Recent stressful life events were found to be directly associated with NSSI severity (ß = 0.128, P = 0.023). A chain-mediating effect between recent stressful life events and NSSI was also confirmed (ß = 0.034, P = 0.023), with DER and internalizing symptoms playing a chain-mediating role and DER having a significantly indirect association with NSSI through internalizing symptoms. Conclusion: Recent stressful life events appear to play a role in the etiology of NSSI, particularly punishment and interpersonal relationship events that warrant special attention. DER and internalizing symptoms play a chain-mediating role in the relationship between life events and NSSI. Reducing recent stressful life events, screening for internalizing symptoms, and improving emotion regulation may decrease NSSI behavior among adolescents.

Organic carbon cycling in the sediments of Prydz Bay, Eastern Antarctica: Implications for a high carbon sequestration potential.

Understanding the dynamics of sedimentary organic carbon (SOC) in the productive continental marginal sea surrounding Antarctica is crucial for elucidating the effect of this sea on the global carbon cycle. We analyzed 31 surface sediment samples and eight sediment cores collected from Prydz Bay (PB) and the adjacent basin area. The element and stable isotope compositions, grain size compositions, and biogenic silica and lithogenic minerals of these samples were used to evaluate the spatial variations in the sources, transport mechanisms, and preservation patterns of SOC, with a particular focus on the efficiency of the biological carbon pump (BCP). Our findings reveal that the SOC originated from mixed marine/terrestrial sources. The δ13C values were higher in the Prydz Bay Gyre (PBG) region than in the open sea area. Biogenic matter-rich debris, associated with fine-grained particles (silt and clay), was concentrated in the PBG, while abiotic ice-rafted debris and coarse-grained particles were preferentially deposited in the bank and ice shelf front regions. Lithogenic matter predominated in the basin sediments. The annual accumulation rate of SOC in PB ranged from 1.6 to 6.2 g·m-2·yr-1 (mean 4.2 ±â€¯1.9 g·m--2·yr-1), and the rates were higher in the PBG than in the ice shelf front region. Estimates based on our tentative box model suggest that the efficiency of the BCP, which refers to the proportion of surface-produced organic carbon successfully transferred to deep waters, is approximately 5.7 % in PB, surpassing the global average (~0.8 %) and the efficiencies reported for other polar environments. Furthermore, our calculations indicate that the SOC preservation efficiency (the ratio of preserved to initially deposited organic carbon in sediments) in PB is approximately 79 % ±â€¯20 %, underscoring the significant carbon sequestration potential within PB. The results of this study have important implications for the effects of sediment dynamics on the carbon cycle in the sea surrounding Antarctica.

Immunization with Live-Attenuated RHΔhad2a Strain Confers Partial Protective Immunity against Acute and Chronic Infection of Toxoplasma gondii in Mice.

Toxoplasmosis caused by Toxoplasma gondii is an important zoonosis of human and animal health significance. Current chemical therapeutics have side effects, and no commercially available vaccine is licensed for the prevention of toxoplasmosis in humans and most animals. Developing a safe and effective vaccine with long-term protection against T. gondii infection is necessary to control toxoplasmosis. HAD2a is a key member of the haloacid dehalogenase (HAD) phosphatase family, which is essential for T. gondii daughter budding. However, the role of HAD2a in T. gondii virulence remains unknown. In this study, we successfully constructed the had2a gene knockout strain in the T. gondii-type I RH strain (RHΔhad2a) and determined its role in virulence and vaccination. These results demonstrate that HAD2a played an important role in parasite daughter budding and in vitro replication. Knockout of the had2a gene attenuated the virulence of the T. gondii-type I RH strain. Vaccination with RHΔhad2a tachyzoites induced a Th1-biased immune response, provided partial protection against acute T. gondii infection in mice by highly virulent tachyzoites of RH and PYS (ToxoDB#9, Chinese I) strains, and conferred strong protection against challenge infection by cysts and oocysts of the less virulent type II Pru strain. These results demonstrate that T. gondii had2a is important for its in vitro proliferation and virulence in mice and that RHΔhad2a may be used as a candidate strain to generate a multiple gene knockout live-attenuated strain or be collaboratively applied with other live-attenuated strains to confer more effective protection against T. gondii infection.

Shared genetic architecture highlights the bidirectional association between major depressive disorder and fracture risk.

Background: There is limited evidence suggesting that osteoporosis might exacerbate depressive symptoms, while more studies demonstrate that depression negatively affects bone density and increases fracture risk. Aims: To explore the relationship between major depressive disorder (MDD) and fracture risk. Methods: We conducted a nested case-control analysis (32 670 patients with fracture and 397 017 individuals without fracture) and a matched cohort analysis (16 496 patients with MDD and 435 492 individuals without MDD) in the same prospective UK Biobank data set. Further, we investigated the shared genetic architecture between MDD and fracture with linkage disequilibrium score regression and the MiXeR statistical tools. We used the conditional/conjunctional false discovery rate approach to identify the specific shared loci. We calculated the weighted genetic risk score for individuals in the UK Biobank and logistic regression was used to confirm the association observed in the prospective study. Results: We found that MDD was associated with a 14% increase in fracture risk (hazard ratio (HR) 1.14, 95% CI 1.14 to 1.15, p<0.001) in the nested case-control analysis, while fracture was associated with a 72% increase in MDD risk (HR 1.72, 95% CI 1.64 to 1.79, p<0.001) in the matched cohort analysis, suggesting a longitudinal and bidirectional relationship. Further, genetic summary data suggested a genetic overlap between MDD and fracture. Specifically, we identified four shared genomic loci, with the top signal (rs7554101) near SGIP1. The protein encoded by SGIP1 is involved in cannabinoid receptor type 1 signalling. We found that genetically predicted MDD was associated with a higher risk of fracture and vice versa. In addition, we found that the higher expression level of SGIP1 in the spinal cord and muscle was associated with an increased risk of fracture and MDD. Conclusions: The genetic pleiotropy between MDD and fracture highlights the bidirectional association observed in the epidemiological analysis. The shared genetic components (such as SGIP1) between the diseases suggest that modulating the endocannabinoid system could be a potential therapeutic strategy for both MDD and bone loss.

N6-methyladenosine facilitates mitochondrial fusion of colorectal cancer cells via induction of GSH synthesis and stabilization of OPA1 mRNA.

Mitochondria undergo fission and fusion that are critical for cell survival and cancer development, while the regulatory factors for mitochondrial dynamics remain elusive. Herein we found that RNA m6A accelerated mitochondria fusion of colorectal cancer (CRC) cells. Metabolomics analysis and function studies indicated that m6A triggered the generation of glutathione (GSH) via the upregulation of RRM2B-a p53-inducible ribonucleotide reductase subunit with anti-reactive oxygen species potential. This in turn resulted in the mitochondria fusion of CRC cells. Mechanistically, m6A methylation of A1240 at 3'UTR of RRM2B increased its mRNA stability via binding with IGF2BP2. Similarly, m6A methylation of A2212 at the coding sequence (CDS) of OPA1-an essential GTPase protein for mitochondrial inner membrane fusion-also increased mRNA stability and triggered mitochondria fusion. Targeting m6A through the methyltransferase inhibitor STM2457 or the dm6ACRISPR system significantly suppressed mitochondria fusion. In vivo and clinical data confirmed the positive roles of the m6A/mitochondrial dynamics in tumor growth and CRC progression. Collectively, m6A promoted mitochondria fusion via induction of GSH synthesis and OPA1 expression, which facilitated cancer cell growth and CRC development.