Mendelian randomization analysis does not reveal a causal influence of mental diseases on osteoporosis

A-485 alleviates postmenopausal osteoporosis by activating GLUD1 deacetylation through the SENP1-Sirt3 signal pathway

OBJECTIVE

Postmenopausal osteoporosis (OP) is a bone disease caused by estrogen deficiency. A-485 is a selective inhibitor of p300/CBP histone acetyltransferase (HAT) with potential regulatory effects on bone remodeling. This study aims to investigate the effects of A-485 on postmenopausal OP and its underlying mechanisms.

METHODS

For animal experiments, 61 female Wistar rats were used to establish an OP model through ovariectomy (OVX). The rats were administered with A-485 (100 mg/kg/day) via intraperitoneal injection for six weeks. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA). Histopathological changes were observed using HE and Masson's trichrome staining. ELISA was used to measure bone resorption markers (CTX-1, DPD) and the bone formation marker (P1NP) in rats. Osteoblast differentiation markers (Runx2, OCN), SENP1, Sirt3 expression levels, and GLUD1 acetylation were assessed via Western blot (WB) and RT-qPCR. In vitro, MC3T3-E1 osteogenic progenitor cells were cultured in osteogenic differentiation medium supplemented with ascorbic acid, β-glycerophosphate, dexamethasone, and fulvestrant. CCK-8 was performed to evaluate cell proliferation. Flow cytometry was selected to measure apoptosis and mitochondrial membrane potential. WB and RT-qPCR were employed to analyze ERα, ERβ, Runx2, Sirt3, and GLUD1 acetylation. Additionally, Alizarin red staining was applied to monitor osteoblast mineralization. ATP levels were detected using a commercial kit, and ROS levels were measured by MitoSOX Red.

RESULTS

In vivo, ovariectomized rats exhibited lower BMD, impaired bone trabeculae, increased CTX-1 and DPD, and altered expression of Runx2 and OCN, all of which were reversed by A-485 treatment. In vitro, A-485 activated GLUD1 deacetylation, enhanced osteogenic differentiation, and improved mitochondrial function. Regarding the mechanism, A-485 activated the SENP1-Sirt3 signal pathway, with SENP1 knockdown negating the effects of A-485. In vivo, A-485 reduced GLUD1 acetylation and promoted improvement of OP, which were reversed by SENP1 knockdown.

CONCLUSION

A-485 ameliorates postmenopausal OP by activating GLUD1 deacetylation via the SENP1-Sirt3 signal pathway, thus improving mitochondrial function, and promoting osteogenic differentiation and mineralization.

Causal link between mental disorders and gastrointestinal diseases: a Mendelian randomization study

Background

Observational research suggests that mental diseases may increase the risk of gastrointestinal diseases. However, the causal link between these conditions remains unclear. In this study, we conducted a two-sample Mendelian randomization (MR) analysis to investigate the causal associations between common mental diseases and the risk of gastrointestinal diseases.

Methods

First, a series of parameters were set to select single-nucleotide polymorphisms (SNPs) from genome-wide association studies (GWAS). Second, A two-sample Mendelian randomization analysis was conducted to investigate the causal link between mental diseases (Alzheimer's disease, depression, major depressive disorder, Parkinson's disease, schizophrenia) and gastrointestinal diseases (gastritis and duodenitis, gastric cancer) while removing outliers using MR-PRESSO. Finally, eight methods of MR analysis were used to generate forest plots, including inverse variance weighted (IVW), inverse variance weighted (fixed effects) (IVW fixed effects), maximum likelihood (ML), MR-Egger, weighted median, penalized weighted median, simple mode, and weighted mode, with IVW considered the primary method.

Results

The result demonstrated that most MDs have no evidence of a causal link between gastrointestinal diseases except Parkinson's disease and gastric cancer based on the IVW method (OR = 0.929 [95% CI = 0.869-0.992], p = 0.029). Subsequently, we performed a robustness analysis to ensure consistency.

Conclusions

Our method provided evidence supporting a causal link between Parkinson's disease and the risk of gastric cancer. However, no evidence was found for other mental diseases influencing the risk of gastrointestinal diseases. Further research is warranted to explore how mental diseases affect the development of gastrointestinal diseases.

Evaluating the Bidirectional Causal Effects of Alzheimer's Disease Across Multiple Conditions: A Systematic Review and Meta-Analysis of Mendelian Randomization Studies

This study systematically evaluates and meta-analyzes Mendelian randomization studies on the bidirectional causal relationship between Alzheimer's disease (AD) and systemic diseases. We searched five databases, assessed study quality, and extracted data. Diseases were classified using ICD-11, and the meta-analysis was performed with RevMan 5.4. A total of 56 studies identified genetic links between AD susceptibility and systemic diseases. Notably, genetic proxies for hip osteoarthritis (OR = 0.80; p = 0.007) and rheumatoid arthritis (OR = 0.97; p = 0.004) were inversely associated with AD risk, while gout (OR = 1.02; p = 0.049) showed a positive association. Genetic liability to depression (OR = 1.03; p = 0.001) elevated AD risk, and AD genetic risk increased susceptibility to delirium (OR = 1.32; p = 0.0005). Cardiovascular traits, including coronary artery disease (OR = 1.07; p = 0.021) and hypertension (OR = 4.30; p = 0.044), were causally linked to a higher AD risk. Other conditions, such as insomnia, chronic periodontitis, migraine, and certain cancers, exhibited significant genetic correlations. Intriguingly, herpes zoster (OR = 0.87; p = 0.005) and cataracts (OR = 0.96; p = 0.012) demonstrated inverse genetic associations with AD. These findings suggest potential therapeutic targets and preventive strategies, emphasizing the need to address comorbid systemic diseases to reduce AD risk and progression.

The impact of remnant lipids on keloid formation: a causal analysis using mendelian randomization

Keloids are pathological scars that remain a significant clinical challenge due to their persistence and high recurrence rates. Lipid metabolism disturbances are believed to contribute to keloid formation. However, the causal effect of lipids on keloids has not been established. We employed two-sample Mendelian randomization (TSMR) analyses to explore the causality between 25 lipid parameters and keloid using genome-wide association study data. The inverse variance weighting method was the primary analytical approach for estimating causality. We also conducted sensitivity analyses to validate the stability of TSMR results. Our study provides evidence suggesting a genetic association between remnant lipids and keloid formation, with triglyceride-rich remnant lipoproteins, particularly triglycerides to total lipids ratio in very large VLDL(XL.VLDL.TG), potentially promoting keloid formation and cholesterol-rich remnant lipoproteins possibly offering a protective effect. These findings highlight the potential role of remnant lipid parameters, especially XL.VLDL.TG, in modulating keloid development through inflammatory processes. While these findings provide valuable new insights into lipid metabolism and keloid pathogenesis, further experimental studies are required to clarify the mechanisms and confirm the relevance of these lipid parameters in keloid formation. The identification of remnant lipid parameters as potential biomarkers for keloid risk opens new avenues for diagnostic and therapeutic strategies, but further research is required to apply these findings in clinical practice.

Mendelian randomization studies of risk and protective factors for osteoporosis: a systematic review and meta-analysis

Background

Mendelian randomization is believed to attenuate the biases inherent in observational studies, yet a meta-analysis of Mendelian randomization studies in osteoporosis has not been conducted thus far. This study aims to evaluate the connection between potential causal factors and the risk of osteoporosis by synthesizing evidence from Mendelian randomization studies.

Methods

The databases PubMed, Web of Science, and Embase were systematically searched for Mendelian randomization studies investigating factors influencing osteoporosis up to May 2024. Meta-analyses were conducted to assess the associations between various potential pathogenic factors and osteoporosis using Mendelian Randomization studies. The quality of the study was evaluated according to the Strengthening the Reporting of Observational Studies in Epidemiology via Mendelian Randomization (STROBE-MR) guidelines.

Results

A total of 706 potentially relevant articles were screened, resulting in the inclusion of 53 studies in the systematic review, of which 30 were eligible for the meta-analysis. The combined findings from these 30 studies revealed that rheumatoid arthritis, inflammatory bowel disease, sex hormone binding globulin, depression, non-alcoholic fatty liver disease, primary biliary cholangitis and asthma are associated with increased risk of osteoporosis, while basal metabolic rate and gut microbiota (NB1n) serves as a protective factor. However, the association between obesity, type 2 diabetes mellitus, metformin, ulcerative colitis, leisure sedentary behaviors, systemic lupus erythematosus, serum iron and osteoporosis was found to be nonsignificant.

Conclusion

In summary, our meta-analysis indicates that significant causal relationships with osteoporosis's onset and progression have been established for rheumatoid arthritis, inflammatory bowel disease, primary biliary cholangitis, non-alcoholic fatty liver disease, depression, sex hormone binding globulin, basal metabolic rate, gut microbiota (NB1n), and asthma.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier PROSPERO CRD42024540504.

The Association Between Antipsychotics and Bone Fragility: An Updated Comprehensive Review

BACKGROUND

Antipsychotic drugs appear to be related to reduced bone mineral density (BMD). We conducted a narrative review to collect the available literature investigating the relationship between antipsychotic use and bone fragility.

METHODS

A review of the published literature was conducted and reported through PubMed/Scopus/Cochrane libraries. We included studies using any antipsychotic treatment where the bone metabolism, osteoporosis, and/or risk of fractures has been assessed.

RESULTS

After screening 1707 items, we finally included 15 papers. A total of 3245 initial patients were identified, of whom 1357 patients with a mean age of 43.8 years underwent antipsychotic treatment and were analyzed. The mean antipsychotic treatment duration of the treated group was 15.8 ± 13.9 years. Among the included studies, two reported a statistically significant difference in lumbar BMD reduction between the antipsychotic exposed group and the control group. Femoral neck BMD levels had been reported in four of the case-control studies; two reported a statistically significant difference in femoral neck BMD reduction between the antipsychotic exposed group and the control group.

CONCLUSIONS

Prolonged use of antipsychotic treatment seems to be associated with an increased risk of reduced BMD, and, consequentially, with an augmented risk of bone fragility and fractures. This effect is not limited to vulnerable groups, such as those with significant medical comorbidities, the elderly, and postmenopausal women, but may also apply to anyone using antipsychotics in the long-term. Clinicians' awareness of antipsychotic prescriptions should optimize their potential while reducing this risk.

Causal relationship between thyroid function and multiple sclerosis: A bidirectional Mendelian randomization study

An association between thyroid function and multiple sclerosis (MS) has been reported in several observational studies, but the causal relationship between them is still unclear. Thus, this study used a bidirectional Mendelian randomization (MR) to investigate the associations between thyroid function and MS. Bidirectional MR was used to explore the causal relationship between thyroid function (thyroid-stimulating hormone [TSH], free thyroxine [FT4], hyperthyroidism, and hypothyroidism) and MS. Genome-wide association study (GWAS) data of thyroid function and MS were obtained from the ThyroidOmics Consortium and the FinnGen Consortium, respectively. Inverse-variance weighted method (IVW) was the primary analysis method to assess causality with Weighted median, MR-Egger regression, weighted mode, and simple mode as auxiliary methods. Sensitivity analyses were performed using heterogeneity tests, horizontal pleiotropy tests and leave-one-out method. There was a positive causal relationship between TSH and MS (IVW: OR = 1.202, 95% CI: 1.040-1.389, P = .013), and no strong evidence was found for an effect of FT4 (IVW: OR = 1.286, 95% CI: 0.990-1.671, P = .059), hypothyroidism (IVW: OR = 1.247, 95% CI: 0.961-1.617, P = .096), and hyperthyroidism (IVW: OR = 0.966, 95% CI: 0.907-1.030, P = .291) on the risk of MS. In the reverse MR results, there was no causal relationship between MS and TSH (IVW: β = -0.009, P = .184), FT4 (IVW: β = -0.011, P = .286), hypothyroidism (IVW: OR = 0.992, 95% CI: 0.944-1.042, P = .745), and hyperthyroidism (IVW: OR = 1.026, 95% CI: 0.943-1.117, P = .549). Cochran's Q test, MR-Egger intercept test, MR-PRESSO global test, and Leave-one-out did not observe horizontal pleiotropy and heterogeneity. In conclusion, MR analysis supported a positive causal relationship between TSH and MS.

Association of cancer and schizophrenia, major depression and bipolar disorder: A Mendelian randomization study

BACKGROUND

Schizophrenia, bipolar disorder and major depression have been reported to be associated with some cancers. However, the magnitude of the causal relationship between them remains unclear. This study aims to explore the potential association between three major mental diseases and the risk of some cancers.

METHODS

We performed the two-sample Mendelian randomization(MR) analysis using publicly available genome-wide association studies (GWAS) statistics to investigate the causal relationship between these three mental diseases and some common types of cancers, including breast cancer, ovarian cancer, lung cancer, colorectal cancer, bladder cancer, prostate cancer, thyroid cancer, pancreatic cancer, malignant melanoma and glioma. We obtained genetic association estimates for schizophrenia, bipolar disorder and depression from the Psychiatric Genomics Consortium.The genetic association estimates for cancers were obtained from the UK Biobank, the MRC-IEU consortium and the GliomaScan consortium.

RESULTS

After correction for heterogeneity and horizontal pleiotropy, we detected suggestive evidence for the association between thyroid cancer and genetically predicted schizophrenia (OR = 1.543, 95% CI: 1.023-2.328, P = 0.039), and thyroid cancer and major depression (OR = 3.573, 95% CI: 1.068-11.953, P = 0.039). No evidence of causal effects of schizophrenia, major depression and bipolar disorder on other types of cancers.

CONCLUSIONS

Our findings suggest the association of schizophrenia and major depression and the development of thyroid cancer.

Causal relationships of mental diseases and thyroid diseases based on a Mendelian randomization study

Evidence from observational researches have suggested that mental diseases are able to affect thyroid diseases. However, the causal relationship between mental diseases and the risk of thyroid diseases still remains unclear. Herein, we conducted a two-sample Mendelian randomization (MR) statistical analysis method to assess the causality between mental diseases and thyroid diseases. Initially, publicly available genome-wide association studies summary data were leveraged to obtain single-nucleotide polymorphisms based on set parameters. Subsequently, a two-sample MR was utilized to analyze causal relationships between mental diseases (Alzheimer disease, bipolar disorder, major depressive disorder, Parkinson disease, schizophrenia) and thyroid diseases (hyperthyroidism/thyrotoxicosis, hypothyroidism) with removing outliers based on MR-PRESSO method. Finally, 8 regression MR methods (inverse variance weighted [IVW], IVW fixed effects, c, MR Egger, weighted median, penalized weighted median, simple mode, weighted mode) were performed to evaluate bias and effectiveness, of which IVW was considered as the primary method. Our results demonstrated that most of mental diseases have no causal relationships with thyroid diseases except bipolar disorder and hyperthyroidism/thyrotoxicosis based on IVW method [odds ratio: 0.999, 95% confidence interval: 0.998-1.000, P = .028], and bipolar disorder and hypothyroidism based on IVW method [odds ratio: 0.997, 95% confidence interval: 0.995-0.999, P = .002]. Then we subsequently conducted a consistent robustness analysis to assess heterogeneity and horizontal pleiotropy. Our method reports causal relationships exist mental diseases and the risk of thyroid diseases. Subsequent researches are still warranted to determine how mental diseases influence the development of thyroid diseases.

Identification of heel bone mineral density as a risk factor of Alzheimer's disease by analyzing large-scale genome-wide association studies datasets

Introduction: Both low bone mineral density (BMD) and Alzheimer's disease (AD) commonly co_occur in the older adult. Until now, the association between AD and BMD has been widely reported by observational studies. However, Mendelian randomization (MR) studies did not support the causal association between BMD and AD. We think that the lack of significant causal association between AD and BMD identified by recent MR studies may be caused by small number of potential instrumental variables. Methods: We conduct a MR study to evaluate the causal effect of heel BMD on the risk of AD using 1,362 genome-wide significant and independent (p < 5.00E-08) heel BMD genetic variants as the potential instrumental variables, which are identified by a large-scale genome wide association study (GWAS) of heel BMD in 394,929 UK Biobank individuals. Using these 1,362 genome-wide significant and independent heel BMD genetic variants, we extracted their corresponding AD GWAS summary results in IGAP AD GWAS dataset (n = 63,926) and FinnGen AD GWAS dataset (n = 377,277). Five methods including inverse-variance weighted meta-analysis (IVW), weighted median, MR-Egger, MR-PRESSO, and MRlap were selected to perform the MR analysis. 951 of these 1,362 genetic variants are available in AD GWAS dataset. Results: We observed statistically significant causal effect of heel BMD on the risk of AD using IVW in IGAP AD GWAS dataset (OR = 1.048, 95%CI: 1.002-1.095, p = 0.04) and FinnGen AD GWAS dataset (OR = 1.053, 95% CI:1.011-1.098, p = 0.011). Importantly, meta-analysis of IVW estimates from IGAP and FinnGen further supported the causal effect of heel BMD on the risk of AD (OR = 1.051, 95% CI: 1.02-1.083, p = 0.0013). Discussion: Collectively, our current MR study supports heel BMD to be a risk factor of AD by analyzing the large-scale heel BMD and AD GWAS datasets. The potential mechanisms underlying the association between heel BMD and AD should be further evaluated in future.