Design and synthesis of novel imidazole-chalcone derivatives as microtubule protein polymerization inhibitors to treat cervical cancer and reverse cisplatin resistance.

Using the licochalcone moiety as a lead compound scaffold, 16 novel imidazole-chalcone derivatives were designed and synthesized as microtubule protein polymerization inhibitors. The proliferation inhibitory activities of the derivatives against SiHa (human cervical squamous cell carcinoma), C-33A (human cervical cancer), HeLa (human cervical cancer), HeLa/DDP (cisplatin-resistant human cervical cancer), and H8 (human cervical epithelial immortalized) cells were evaluated. Compound 5a exhibited significant anticancer activity with IC50 values ranging from 2.28 to 7.77 µM and a resistance index (RI) of 1.63, while showing minimal toxicity to normal H8 cells. When compound 5a was coadministered with cisplatin, the RI of cisplatin to HeLa/DDP cells decreased from 6.04 to 2.01, while compound 5a enhanced the fluorescence intensity of rhodamine 123 in HeLa/DDP cells. Further studies demonstrated that compound 5a arrested cells at the G2/M phase, induced apoptosis, reduced colony formation, inhibited cell migration, and inhibited cell invasion. Preliminary mechanistic studies revealed that compound 5a decreased the immunofluorescence intensity of α-/ß-tubulin in cancer cells, reduced the expression of polymerized α-/ß-tubulin, and increased the expression of depolymerized α-/ß-tubulin. Additionally, the molecular docking results demonstrate that compound 5a can interact with the tubulin colchicine binding site and generate multiple types of interactions. These results suggested that compound 5a has anticancer effects and significantly reverses cervical cancer resistance to cisplatin, which may be related to its inhibition of microtubule and P-glycoprotein (P-gp) activity.

Mustn1 is a smooth muscle cell-secreted microprotein that modulates skeletal muscle extracellular matrix composition.

OBJECTIVE: Skeletal muscle plasticity and remodeling are critical for adapting tissue function to use, disuse, and regeneration. The aim of this study was to identify genes and molecular pathways that regulate the transition from atrophy to compensatory hypertrophy or recovery from injury. Here, we have used a mouse model of hindlimb unloading and reloading, which causes skeletal muscle atrophy, and compensatory regeneration and hypertrophy, respectively. METHODS: We analyzed mouse skeletal muscle at the transition from hindlimb unloading to reloading for changes in transcriptome and extracellular fluid proteome. We then used qRT-PCR, immunohistochemistry, and bulk and single-cell RNA sequencing data to determine Mustn1 gene and protein expression, including changes in gene expression in mouse and human skeletal muscle with different challenges such as exercise and muscle injury. We generated Mustn1-deficient genetic mouse models and characterized them in vivo and ex vivo with regard to muscle function and whole-body metabolism. We isolated smooth muscle cells and functionally characterized them, and performed transcriptomics and proteomics analysis of skeletal muscle and aorta of Mustn1-deficient mice. RESULTS: We show that Mustn1 (Musculoskeletal embryonic nuclear protein 1, also known as Mustang) is highly expressed in skeletal muscle during the early stages of hindlimb reloading. Mustn1 expression is transiently elevated in mouse and human skeletal muscle in response to intense exercise, resistance exercise, or injury. We find that Mustn1 expression is highest in smooth muscle-rich tissues, followed by skeletal muscle fibers. Muscle from heterozygous Mustn1-deficient mice exhibit differences in gene expression related to extracellular matrix and cell adhesion, compared to wild-type littermates. Mustn1-deficient mice have normal muscle and aorta function and whole-body glucose metabolism. We show that Mustn1 is secreted from smooth muscle cells, and that it is present in arterioles of the muscle microvasculature and in muscle extracellular fluid, particularly during the hindlimb reloading phase. Proteomics analysis of muscle from Mustn1-deficient mice confirms differences in extracellular matrix composition, and female mice display higher collagen content after chemically induced muscle injury compared to wild-type littermates. CONCLUSIONS: We show that, in addition to its previously reported intracellular localization, Mustn1 is a microprotein secreted from smooth muscle cells into the muscle extracellular space. We explore its role in muscle ECM deposition and remodeling in homeostasis and upon muscle injury. The role of Mustn1 in fibrosis and immune infiltration upon muscle injury and dystrophies remains to be investigated, as does its potential for therapeutic interventions.

Plasma campesterol and ABCG5/ABCG8 gene loci on the risk of cholelithiasis and cholecystitis: evidence from Mendelian randomization and colocalization analyses.

The causal relationships between plasma metabolites and cholelithiasis/cholecystitis risks remain elusive. Using two-sample Mendelian randomization, we found that genetic proxied plasma campesterol level showed negative correlation with the risk of both cholelithiasis and cholecystitis. Furthermore, the increased risk of cholelithiasis is correlating with the increased level of plasma campesterol. Lastly, genetic colocalization study showed that the leading SNP, rs4299376, which residing at the ABCG5/ABCG8 gene loci, was shared by plasma campesterol level and cholelithiasis, indicating that the aberrant transportation of plant sterol/cholesterol from the blood stream to the bile duct/gut lumen might be the key in preventing cholesterol gallstone formation.

Design, Synthesis, and In vitro Anti-cervical Cancer Activity of a Novel MDM2-p53 Inhibitor Based on a Chalcone Scaffold.

OBJECTIVE: Several novel fluorinated chalcone derivatives were synthesized, and their in vitro anticervical cancer activity and mechanism of action were investigated using the parent nucleus of licorice chalcone as the lead compound backbone and MDM2-p53 as the target. METHODS: In this study, 16 novel chalcone derivatives (3a-3r) were designed and synthesized by molecular docking technology based on the licorice chalcone parent nucleus as the lead compound scaffold and the cancer apoptosis regulatory target MDM2-p53. The structures of these compounds were confirmed by 1H-NMR, 13C-NMR, and HR-ESI-MS. The inhibitory effects of the compounds on the proliferation of three human cervical cancer cell lines (SiHa, HeLa, and C-33A) and two normal cell lines (H8 and HaCaT) were determined by MTT assay, and the initialstructure-activity relationship was analyzed. Transwell and flow cytometry were used to evaluate the effects of target compounds on the inhibition of cancer cell migration and invasion, apoptosis induction, and cell cycle arrest. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot (WB) were used to detect the effects of candidate compounds on mRNA, p53, and Murine double minute 2 (MDM2) protein expression. The binding characteristics of the target compounds to the MDM2 protein target in the p53-MDM2 pathway were evaluated by molecular docking technology. RESULTS: The target compounds had considerable inhibitory activity on the proliferation of three cervical cancer cell lines. Among them, compound 3k (E)-3-(4-(dimethylamino)phenyl)-2-methyl-1-(3- (trifluoromethyl)phenyl)prop-2-en-1-one) showed the highest activity against HeLa cells (IC50=1.08 µmol/L), which was better than that of the lead compound Licochalcone B, and 3k showed lower toxicity to both normal cells. Compound 3k strongly inhibited the migration and invasion of HeLa cells and induced apoptosis and cell cycle arrest at the G0/G1 phase. Furthermore, compound 3k upregulated the expression of p53 and BAX and downregulated the expression of MDM2, MDMX, and BCL2. Moreover, molecular docking results showed that compound 3k could effectively bind to the MDM2 protein (binding energy: -9.0 kcal/mol). These results suggest that the compounds may activate the p53 signaling pathway by inhibiting MDM2 protein, which prevents cancer cell proliferation, migration, and invasion and induces apoptosis and cell cycle arrest in cancer cells. CONCLUSION: This study provides a new effective and low-toxicity drug candidate from licochalcone derivatives for treating cervical cancer.

Design and Synthesis of Novel α-Methylchalcone Derivatives, Anti-Cervical Cancer Activity, and Reversal of Drug Resistance in HeLa/DDP Cells.

In this study, a collection of newly developed α-methylchalcone derivatives were synthesized and assessed for their inhibitory potential against human cervical cancer cell lines (HeLa, SiHa, and C33A) as well as normal human cervical epithelial cells (H8). Notably, compound 3k exhibited substantial inhibitory effects on both HeLa and HeLa/DDP cells while demonstrating lower toxicity toward H8 cells. Furthermore, the compound 3k was found to induce apoptosis in both HeLa and HeLa/DDP cells while also inhibiting the G2/M phase, resulting in a decrease in the invasion and migration capabilities of these cells. When administered alongside cisplatin, 3k demonstrated a significant reduction in the resistance of HeLa/DDP cells to cisplatin, as evidenced by a decrease in the resistance index (RI) value from 7.90 to 2.10. Initial investigations into the underlying mechanism revealed that 3k did not impact the expression of P-gp but instead facilitated the accumulation of rhodamine 123 in HeLa/DDP cells. The results obtained from CADD docking analysis demonstrated that 3k exhibits stable binding to microtubule proteins and P-gp targets, forming hydrogen bonding interaction forces. Immunofluorescence analysis further revealed that 3k effectively decreased the fluorescence intensity of α and ß microtubules in HeLa and HeLa/DDP cells, resulting in disruptions in cell morphology, reduction in cell numbers, nucleus coagulation, and cell rupture. Additionally, Western blot analysis indicated that 3k significantly reduced the levels of polymerized α and ß microtubule proteins in both HeLa and HeLa/DDP cell lines while concurrently increasing the expression of dissociated α and ß microtubule proteins. The aforementioned findings indicate a potential correlation between the inhibitory effects of 3k on HeLa and HeLa/DDP cells and its ability to inhibit tubulin and P-gp.

Zfp697 is an RNA-binding protein that regulates skeletal muscle inflammation and regeneration.

Muscular atrophy is a mortality risk factor that happens with disuse, chronic disease, and aging. Recovery from atrophy requires changes in several cell types including muscle fibers, and satellite and immune cells. Here we show that Zfp697/ZNF697 is a damage-induced regulator of muscle regeneration, during which its expression is transiently elevated. Conversely, sustained Zfp697 expression in mouse muscle leads to a gene expression signature of chemokine secretion, immune cell recruitment, and extracellular matrix remodeling. Myofiber-specific Zfp697 ablation hinders the inflammatory and regenerative response to muscle injury, compromising functional recovery. We uncover Zfp697 as an essential interferon gamma mediator in muscle cells, interacting primarily with ncRNAs such as the pro-regenerative miR-206. In sum, we identify Zfp697 as an integrator of cell-cell communication necessary for tissue regeneration.

Design, Synthesis, and Anti-Cervical Cancer and Reversal of Tumor Multidrug Resistance Activity of Novel Nitrogen-Containing Heterocyclic Chalcone Derivatives.

This study involved the design and synthesis of 21 new nitrogen-containing heterocyclic chalcone derivatives utilizing the active substructure splicing principle, with glycyrrhiza chalcone serving as the lead compound. The targets of these derivatives were VEGFR-2 and P-gp, and their efficacy against cervical cancer was evaluated. Following preliminary conformational analysis, compound 6f ((E)-1-(2-hydroxy-5-((4-hydroxypiperidin-1-yl)methyl)-4-methoxyphenyl)-3-(4-((4-methylpiperidin-1-yl)methyl)phenyl)prop-2-en-1-one) exhibited significant antiproliferative activity against human cervical cancer cells (HeLa and SiHa) with IC50 values of 6.52 ± 0.42 and 7.88 ± 0.52 µM, respectively, when compared to other compounds and positive control drugs. Additionally, this compound demonstrated lower toxicity towards human normal cervical epithelial cells (H8). Subsequent investigations have demonstrated that 6f exerts an inhibitory impact on VEGFR-2, as evidenced by its ability to impede the phosphorylation of p-VEGFR-2, p-PI3K, and p-Akt proteins in HeLa cells. This, in turn, results in the suppression of cell proliferation and the induction of both early and late apoptosis in a concentration-dependent manner. Furthermore, 6f significantly curtails the invasion and migration of HeLa cells. In addition, 6f had an IC50 of 7.74 ± 0.36 µM against human cervical cancer cisplatin-resistant HeLa/DDP cells and a resistance index (RI) of 1.19, compared to 7.36 for cisplatin HeLa cells. The combination of 6f and cisplatin resulted in a significant reduction in cisplatin resistance in HeLa/DDP cells. Molecular docking analyses revealed that 6f exhibited binding free energies of -9.074 and -9.823 kcal·mol-1 to VEGFR-2 and P-gp targets, respectively, and formed hydrogen bonding forces. These findings suggest that 6f has potential as an anti-cervical cancer agent and may reverse cisplatin-resistant activity in cervical cancer. The introduction of the 4-hydroxy piperidine and 4-methyl piperidine rings may contribute to its efficacy, and its mechanism of action may involve dual inhibition of VEGFR-2 and P-gp targets.

Relationships between circulating metabolites and facial skin aging: a Mendelian randomization study.

BACKGROUND: Blood metabolites are important to various aspects of our health. However, currently, there is little evidence about the role of circulating metabolites in the process of skin aging. OBJECTIVES: To examine the potential effects of circulating metabolites on the process of skin aging. METHOD: In the primary analyses, we applied several MR methods to study the associations between 249 metabolites and facial skin aging risk. In the secondary analyses, we replicated the analyses with another array of datasets including 123 metabolites. MR Bayesian model averaging (MR-BMA) method was further used to prioritize the metabolites for the identification of predominant metabolites that are associated with skin aging. RESULTS: In the primary analyses, only the unsaturation degree of fatty acids was found significantly associated with skin aging with the IVW method after multiple testing (odds ratio = 1.084, 95% confidence interval = 1.049-1.120, p = 1.737 × 10-06). Additionally, 11 out of 17 unsaturation-related biomarkers showed a significant or suggestively significant causal effect [p < 0.05 and > 2 × 10-4 (0.05/249 metabolites)]. In the secondary analyses, seven metabolic biomarkers were found significantly associated with skin aging [p < 4 × 10-4 (0.05/123)], while six of them were related to the unsaturation degree. MR-BMA method validated that the unsaturation degree of fatty acids plays a dominant role in facial skin aging. CONCLUSIONS: Our study used systemic MR analyses and provided a comprehensive atlas for the associations between circulating metabolites and the risk of facial skin aging. Genetically proxied unsaturation degree of fatty acids was highlighted as a dominant factor correlated with the risk of facial skin aging.

Mendelian randomization in blood metabolites identifies triglycerides and fatty acids saturation level as associated traits linked to pancreatitis risk.

Background: There is very limited evidence on the causal effects of blood metabolites on pancreatitis risks. To reveal the causal associations between plasma metabolites and pancreatitis risks, we performed two-sample Mendelian randomization (MR) and Bayesian model averaging (MR-BMA) analyses in European ancestry. Methods: The summary-level statistics from two genome-wide association studies with 249 and 123 metabolic traits derived from two separate cohorts involving ~115,000 (UK Biobank) and ~25,000 individuals from European ancestry were used for the analyses. The summary statistics of four pancreatitis datasets from FinnGen R5 and two pancreatitis datasets from UK Biobank were exploited as the outcome. We first performed univariable MR analysis with different metabolic GWAS data on multiple pancreatitis datasets to demonstrate the association pattern among different metabolites categories. Next, we exploited the MR-BMA method to pinpoint the dominating factors on the increased risk of pancreatitis. Results: In the primary analysis with 249 traits, we found that plasma triglycerides were positively associated with pancreatitis risk. Intriguingly, a large number of traits associated with saturation or unsaturation of fatty acids also demonstrated causal associations. The replication study analyzing 123 metabolic traits suggested that bisallylic groups levels and omega-3 fatty acids were inversely correlated with pancreatitis risk. MR-BMA analyses indicated that the ratio of triglycerides to total lipid in various HDL particles played leading roles in pancreatitis susceptibility. In addition, the degree of unsaturation, the ratio of polyunsaturated fatty acids to monounsaturated fatty acids and the level of monounsaturated fatty acids showed causal associations with either decreased or increased pancreatitis susceptibility. Conclusions: Our MR study provided an atlas of causal associations of genetically predicted blood metabolites on pancreatitis, and offered genetic insights showing intervention in triglycerides and the supplementation of unsaturated fatty acids are potential strategies in the primary prevention of pancreatitis.

Multi-transcriptome analysis following an acute skeletal muscle growth stimulus yields tools for discerning global and MYC regulatory networks.

Myc is a powerful transcription factor implicated in epigenetic reprogramming, cellular plasticity, and rapid growth as well as tumorigenesis. Cancer in skeletal muscle is extremely rare despite marked and sustained Myc induction during loading-induced hypertrophy. Here, we investigated global, actively transcribed, stable, and myonucleus-specific transcriptomes following an acute hypertrophic stimulus in mouse plantaris. With these datasets, we define global and Myc-specific dynamics at the onset of mechanical overload-induced muscle fiber growth. Data collation across analyses reveals an under-appreciated role for the muscle fiber in extracellular matrix remodeling during adaptation, along with the contribution of mRNA stability to epigenetic-related transcript levels in muscle. We also identify Runx1 and Ankrd1 (Marp1) as abundant myonucleus-enriched loading-induced genes. We observed that a strong induction of cell cycle regulators including Myc occurs with mechanical overload in myonuclei. Additionally, in vivo Myc-controlled gene expression in the plantaris was defined using a genetic muscle fiber-specific doxycycline-inducible Myc-overexpression model. We determined Myc is implicated in numerous aspects of gene expression during early-phase muscle fiber growth. Specifically, brief induction of Myc protein in muscle represses Reverbα, Reverbß, and Myh2 while increasing Rpl3, recapitulating gene expression in myonuclei during acute overload. Experimental, comparative, and in silico analyses place Myc at the center of a stable and actively transcribed, loading-responsive, muscle fiber-localized regulatory hub. Collectively, our experiments are a roadmap for understanding global and Myc-mediated transcriptional networks that regulate rapid remodeling in postmitotic cells. We provide open webtools for exploring the five RNA-seq datasets as a resource to the field.

Causal association of diet-derived circulating antioxidants with the risk of rheumatoid arthritis: A Mendelian randomization study.

BACKGROUND: Antioxidants, as scavengers of free radicals, have been proposed as potential targets for the prevention and treatment of rheumatoid arthritis (RA), however, the causal associations between antioxidants and RA are still in debate. OBJECTIVE: This study aims to evaluate this causal association with two-sample Mendelian randomization (MR) analysis. METHODS: Inverse-variance weighted was used as the major analysis method of MR. Genetic variants associated with dietary antioxidants including vitamin E (α- and γ-tocopherol), ß-carotene, lycopene, vitamin C (L-ascorbic acid or ascorbate), and retinol, and their circulating metabolites were used as instrumental variables. The causal effects of the antioxidants were assessed in genome-wide association study datasets of RA from a previous publication (Okada Y. et al.) and Finngen consortium and combined with meta-analysis. RESULTS: We observed that the levels of circulating retinol metabolite negatively correlates with the risk of overall RA in the dataset from Okada Y. et al. (odds ratio [OR]=0.952, 95% confidence interval [CI]=0.911-0.996, p = 0.031) and Finngen (OR=0.946, 95%CI=0.903-0.991, p = 0.020). The causal association remained consistent in the meta-analysis (OR=0.949, 95%CI=0.919-0.98, p = 0.002). Increased levels of circulating retinol metabolite also suggestively decreased the risk of seropositive RA (OR=0.936, 95%CI=0.884-0.992, p = 0.025) but not seronegative RA (OR=0.996, 95%CI=0.921-1.076, p = 0.913). No causal effects of other dietary antioxidants on RA were identified in our analyses. CONCLUSIONS: Our study suggested a protective effect of circulating retinol metabolites, but not other antioxidants, on overall RA and seropositive RA. Dietary supplementation of retinol may be an effective measure for the primary prevention of RA.

Mendelian randomization study for the roles of IL-18 and IL-1 receptor antagonist in the development of inflammatory bowel disease.

BACKGROUND AND AIMS: IL-1 and IL-18 play important roles in intestine barrier integrity maintenance and inflammatory response. However, their net effects on the risk of IBD are still inconclusive. Here, we used Mendelian randomization (MR) approaches to investigate the causal associations of IL-18 and IL-1Ra (receptor antagonist) on the risks of IBD and subtypes. METHODS: For IL-18, both three-sample and two-sample MR approaches were used for the causal inferences. In three-sample MR, three single nucleotide polymorphisms (SNPs) and the effect values were extracted from two quantitative trait loci (pQTL) datasets with non-overlapping populations. In two-sample MR, we extracted genetic instruments information from the same larger pQTL dataset. For IL-1Ra, we applied the two-sample MR method with summary-statistics from the larger pQTL dataset. Summary-level results of three large IBD/CD/UC genome-wide association studies in European ancestry were employed. Inverse-variance weighted method, various sensitivity analyses and meta-analysis were performed to give causal estimates, detect heterogeneity and correct for outliers. RESULTS: We observed consistent positive causal effects of IL-18 on all three major outcomes using three-sample MR, with meta-analyses odds ratios (ORs) equal to 1.240 (IBD), 1.199 (CD) and 1.274 (UC) respectively. The two-sample MR demonstrated similar results. Moreover, genetically predicted IL-1Ra is inversely associated with the risk of IBD/UC/CD with ORs equal to 0.915 (IBD), 0.902 (CD) and 0.899 (UC) respectively in meta-analyses. CONCLUSIONS: This study suggested genetically predicted IL-18 and IL-1Ra level are causally associated with an increased and decreased risk of IBD and subtypes.

Identification of blood metabolites linked to the risk of cholelithiasis: a comprehensive Mendelian randomization study.

BACKGROUND AND AIMS: Observational and Mendelian randomization (MR) studies have identified several modifiable risk factors of cholelithiasis. However, there is limited evidence about the causal effect of blood metabolites on the cholelithiasis risk. METHODS: To have a comprehensive understanding to causal relations between blood metabolites and cholelithiasis, for the primary discovery, we applied two MR methods to explore the associations between 249 circulating metabolites and cholelithiasis. For secondary validations, we replicated the examinations using another metabolic dataset with 123 metabolites. The summary statistics of cholelithiasis were retrieved from FinnGen Consortium Release 5 and UK Biobank. Inverse-variance weighted, weight median and MR-egger methods were used for calculating causal estimates. Furthermore, Bayesian model averaging MR (MR-BMA) method was employed to detect the dominant causal metabolic traits with adjustment for pleiotropy effects. RESULTS: In the primary analysis, sphingomyelin showed consistent protective causal associations with cholelithiasis; while plasma cholesterol-associated traits showed generally inverse correlation with cholelithiasis risk. Notably, large numbers of traits within the (un)saturated fatty acid category demonstrated significant causal effects. Secondary analyses demonstrated similar results, with traits related to the levels of bisallylic groups in fatty acids showing protective effects. Lastly, MR-BMA analyses discovered that the degree of unsaturation plays a predominant role in reducing the risk of cholelithiasis. CONCLUSION: Our MR study provides a complete atlas of associations between plasma metabolites on cholelithiasis risk. It highlighted that genetically predicted sphingomyelin and degree of unsaturation of fatty acid were causally associated with the reduced risk of cholelithiasis.

Serum Albumin and Circulating Metabolites and Risk of Venous Thromboembolism: A Two-Sample Mendelian Randomization Study.

Background and Aim: Previous observational studies indicated that the serum albumin levels and circulating metabolites are associated with a high risk of venous thromboembolism (VTE). However, whether these observations reflect causality remained unclear. Hence, we conducted a two-sample Mendelian randomization (MR) analysis to evaluate the causal associations of serum albumin and circulating metabolites with the risk of VTE. Methods and Results: Summary statistics of genetic instruments proxying serum albumin, total protein, and common circulating metabolites were extracted from genome-wide association studies in the European ancestry. Summary-level results of age- and sex-adjusted estimates for associations of the instruments with VTE were derived from the FinnGen consortium. We used the inverse-variance weighted (IVW) method as the primary analysis for univariable MR. Sensitivity analyses were performed to detect horizontal pleiotropy and outliers. Genetically proxied high-serum albumin and total protein levels were suggestive protective factor of VTE, with odds ratio (OR) = 0.69 (CI 0.54-0.89, p = 4.7 × 10-3) and 0.76 (CI 0.61-0.95, p = 0.015), respectively. Genetically proxied low-monounsaturated fatty acids and the ratio of monounsaturated fatty acid to total fatty acid are causally associated with increased risk of VTE, with ORs = 0.89 (CI 0.80-0.99, p = 0.031) and 0.85 (CI 0.78-0.94, p = 9.92 × 10-4), respectively. There is no indication of causal associations between other circulating metabolites and the risk of VTE. Conclusions: Genetically liability to low-serum albumin and total protein levels, low proxied monounsaturated fatty acids (MUFAs) and the ratio of MUFAs to total fatty acids are associated with the higher risk of VTE.

Causal Associations of Obesity With the Intervertebral Degeneration, Low Back Pain, and Sciatica: A Two-Sample Mendelian Randomization Study.

The role of obesity in the development of dorsopathies is still unclear. In this study, we assessed the associations between body mass index (BMI) and several dorsopathies including intervertebral disc degeneration (IVDD), low back pain (LBP), and sciatica by using the Mendelian randomization method. We also assessed the effect of several obesity-related traits on the same outcomes. Single-nucleotide polymorphisms associated with the exposures are extracted from summary-level datasets of previously published genome-wide association studies. Summary-level results of IVDD, LBP, and sciatica were from FinnGen. In our univariable Mendelian randomization analysis, BMI is significantly associated with increased risks of all dorsopathies including sciatica (OR = 1.33, 95% CI, 1.21-1.47, p = 5.19 × 10-9), LBP (OR = 1.28, 95% CI, 1.18-1.39, p = 6.60 × 10-9), and IVDD (OR = 1.23, 95% CI, 1.14-1.32, p = 2.48 × 10-8). Waist circumference, hip circumference, whole-body fat mass, fat-free mass, and fat percentage, but not waist-hip ratio, were causally associated with increased risks of IVDD and sciatica. Higher hip circumference, whole-body fat mass, fat-free mass, and fat percentage increased the risk of LBP. However, only whole-body fat-free mass remained to have a significant association with the risk of IVDD after adjusting for BMI with an odds ratio of 1.57 (95% CI, 1.32-1.86, p = 2.47 × 10-7). Proportions of BMI's effect on IVDD, sciatica, and LBP mediated by leisure sedentary behavior were 41.4% (95% CI, 21.8%, 64.8%), 33.8% (95% CI, 17.5%, 53.4%), and 49.7% (95% CI, 29.4%, 73.5%), respectively. This study provides evidence that high BMI has causal associations with risks of various dorsopathies. Weight control is a good measure to prevent the development of dorsopathies, especially in the obese population.

Mitochondrial NDUFA4L2 is a novel regulator of skeletal muscle mass and force.

The hypoxia-inducible nuclear-encoded mitochondrial protein NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2 (NDUFA4L2) has been demonstrated to decrease oxidative phosphorylation and production of reactive oxygen species in neonatal cardiomyocytes, brain tissue and hypoxic domains of cancer cells. Prolonged local hypoxia can negatively affect skeletal muscle size and tissue oxidative capacity. Although skeletal muscle is a mitochondrial rich, oxygen sensitive tissue, the role of NDUFA4L2 in skeletal muscle has not previously been investigated. Here we ectopically expressed NDUFA4L2 in mouse skeletal muscles using adenovirus-mediated expression and in vivo electroporation. Moreover, femoral artery ligation (FAL) was used as a model of peripheral vascular disease to induce hind limb ischemia and muscle damage. Ectopic NDUFA4L2 expression resulted in reduced mitochondrial respiration and reactive oxygen species followed by lowered AMP, ADP, ATP, and NAD+ levels without affecting the overall protein content of the mitochondrial electron transport chain. Furthermore, ectopically expressed NDUFA4L2 caused a ~20% reduction in muscle mass that resulted in weaker muscles. The loss of muscle mass was associated with increased gene expression of atrogenes MurF1 and Mul1, and apoptotic genes caspase 3 and Bax. Finally, we showed that NDUFA4L2 was induced by FAL and that the Ndufa4l2 mRNA expression correlated with the reduced capacity of the muscle to generate force after the ischemic insult. These results show, for the first time, that mitochondrial NDUFA4L2 is a novel regulator of skeletal muscle mass and force. Specifically, induced NDUFA4L2 reduces mitochondrial activity leading to lower levels of important intramuscular metabolites, including adenine nucleotides and NAD+ , which are hallmarks of mitochondrial dysfunction and hence shows that dysfunctional mitochondrial activity may drive muscle wasting.

Leisure Sedentary Behavior and Risk of Lung Cancer: A Two-Sample Mendelian Randomization Study and Mediation Analysis.

Leisure sedentary behavior, especially television watching, has been previously reported as associated with the risk of lung cancer in observational studies. This study aims to evaluate the causal association with two-sample Mendelian randomization (MR) analysis. Single nucleotide polymorphisms associated with leisure television watching, computer use, and driving were extracted from genome-wide association studies. Summary-level results of lung cancer overall and histological types were obtained from International Lung Cancer Consortium (ILCCO). In univariable MR using inverse-variance-weighted method, we observed causal effects of television watching on lung cancer [OR, 1.89, 95% confidence interval (CI), 1.41, 2.54; p = 2.33 × 10-5], and squamous cell lung cancer (OR, 2.37, 95% CI, 1.58, 3.55; p = 3.02 × 10-5), but not on lung adenocarcinoma (OR, 1.40, 95% CI, 0.94, 2.09; p = 0.100). No causal effects of computer use and driving on lung cancer were observed. Television watching significantly increased the exposure to several common risk factors of lung cancer. The associations of television watching with lung cancer and squamous cell lung cancer were compromised after adjusting for smoking quantity with multivariable MR. Our mediation analyses estimated indirect effects of television watching on lung cancer (beta, 0.31, 95% CI, 0.13, 0.52; p = 6.64 × 10-4) and squamous cell lung cancer (beta, 0.33, 95% CI, 0.14, 0.53, p = 4.76 × 10-4) mediated by smoking quantity. Our findings indicate that television watching is positively correlated with the risk of lung cancer, potentially mediated through affecting smoking quantity.

Disrupted circadian oscillations in type 2 diabetes are linked to altered rhythmic mitochondrial metabolism in skeletal muscle.

Circadian rhythms are generated by an autoregulatory feedback loop of transcriptional activators and repressors. Circadian rhythm disruption contributes to type 2 diabetes (T2D) pathogenesis. We elucidated whether altered circadian rhythmicity of clock genes is associated with metabolic dysfunction in T2D. Transcriptional cycling of core-clock genes BMAL1, CLOCK, and PER3 was altered in skeletal muscle from individuals with T2D, and this was coupled with reduced number and amplitude of cycling genes and disturbed circadian oxygen consumption. Inner mitochondria­associated genes were enriched for rhythmic peaks in normal glucose tolerance, but not T2D, and positively correlated with insulin sensitivity. Chromatin immunoprecipitation sequencing identified CLOCK and BMAL1 binding to inner-mitochondrial genes associated with insulin sensitivity, implicating regulation by the core clock. Inner-mitochondria disruption altered core-clock gene expression and free-radical production, phenomena that were restored by resveratrol treatment. We identify bidirectional communication between mitochondrial function and rhythmic gene expression, processes that are disturbed in diabetes.

Obesity, Type 2 Diabetes, and the Risk of Carpal Tunnel Syndrome: A Two-Sample Mendelian Randomization Study.

Some previous observational studies have reported an increased risk of carpal tunnel syndrome (CTS) in patients with obesity or type 2 diabetes (T2D), which was however, not observed in some other studies. In this study we performed a two-sample Mendelian randomization to assess the causal effect of obesity, T2D on the risk of CTS. Single nucleotide polymorphisms associated with the body mass index (BMI) and T2D were extracted from genome-wide association studies. Summary-level results of CTS were available through FinnGen repository. Univariable Mendelian randomization (MR) with inverse-variance-weighted method indicated a positive correlation of BMI with CTS risk [odds ratio (OR) 1.66, 95% confidence interval (CI), 1.39-1.97]. Genetically proxied T2D also significantly increased the risk of CTS [OR 1.17, 95% CI (1.07-1.29)]. The causal effect of BMI and T2D on CTS remained consistent after adjusting for each other with multivariable MR. Our mediation analysis indicated that 34.4% of BMI's effect of CTS was mediated by T2D. We also assessed the effects of several BMI and glycemic related traits on CTS. Waist circumference and arm fat-free mass were also causally associated with CTS. However, the associations disappeared after adjusting for the effect of BMI. Our findings indicate that obesity and T2D are independent risk factors of CTS.