Evaluating the causal effect of atherosclerosis on the risk of intervertebral disc degeneration.

Background: Intervertebral disc degeneration (IDD) and atherosclerosis are two common age-related conditions that can cause significant morbidity. While previous studies have suggested an association between the two conditions, the nature of this association remains unclear. Methods: We used Mendelian randomization (MR) to investigate the causal relationship between IDD and atherosclerosis. We identified genetic variants associated with IDD using summary statistics from a large genome-wide association study (GWAS). These variants were then used as instrumental variables to infer causal relationships with atherosclerosis in summary statistics from a separate GWAS. Results: Our MR analysis provided evidence for a causal relationship between IDD and atherosclerosis. We found that the genetic predisposition to atherosclerosis was associated with a higher risk of IDD (odds ratio [OR] = 3.55, 95% confidence interval [CI]: 1.07-11.74, p = 0.04). The IVW estimates were consistent with the observational findings and other robust MR methods. Sensitivity analyses suggested that our findings were robust to potential sources of bias. Conclusions: Our study provides evidence for a causal link between IDD and atherosclerosis, suggesting that interventions targeting atherosclerosis could have potential benefits for reducing the risk of IDD. Further research is needed to explore the underlying mechanisms that link these two conditions and to investigate potential therapeutic interventions.

Deep learning-based magnetic resonance imaging of the spine in the diagnosis and physiological evaluation of spinal metastases.

Background and objective: Spinal metastasis accounts for 70% of the bone metastases of tumors, so how to diagnose and predict spinal metastasis in time through effective methods is very important for the physiological evaluation of the therapy of patients. Methods: MRI scans of 941 patients with spinal metastases from the affiliated hospital of Guilin Medical University were collected, analyzed, and preprocessed, and the data were submitted to a deep learning model designed with our convolutional neural network. We also used the Softmax classifier to classify the results and compared them with the actual data to judge the accuracy of our model. Results: Our research showed that the practical model method could effectively predict spinal metastases. The accuracy was up to 96.45%, which could be used to diagnose the physiological evaluation of spinal metastases. Conclusion: The model obtained in the final experiment can capture the focal signs of patients with spinal metastases more accurately and can predict the disease in time, which has a good application prospect.

miR-4478 Accelerates Nucleus Pulposus Cells Apoptosis Induced by Oxidative Stress by Targeting MTH1.

OBJECTIVES: Low back pain is the leading cause of disability in the elderly population and is strongly associated with intervertebral disk degeneration (IVDD). However, the precise molecular mechanisms regulating IVDD remain elusive. This study aimed to investigate the role of differentially expressed miRNAs in the pathogenesis of IVDD. MATERIALS AND METHODS: We analyzed miRNA microarray datasets to identify differentially expressed miRNAs in IVDD progression and conducted quantitative real-time polymerase chain reaction and fluorescence in situ hybridization analysis to further confirm the differential expression of miR-4478 in nucleus pulposus (NP) tissues of patients diagnosed with IVDD. Using public databases of miRNA-mRNA interactions, we predicted the target genes of miR-4478, and subsequent flow cytometry and western blot analyses demonstrated the effect of MTH1 in H 2 O 2 -induced nucleus pulposus cells (NPCs) apoptosis. Finally, miR-4478 inhibitor was injected into NP tissues of the IVDD mouse model to explore the effect of miR-4478 in vivo. RESULTS: miR-4478 was upregulated in NP tissues from IVDD patients. Silencing of miR-4478 inhibits H 2 O 2 -induced NPCs apoptosis. MTH1 was identified as a target gene for miR-4478, and miR-4478 regulates H 2 O 2 -induced NPCs apoptosis by modulating MTH1. In addition, downregulation of miR-4478 alleviated IVDD in a mouse model. CONCLUSIONS: In summary, our study provides evidence that miR-4478 may aggravate IVDD through its target gene MTH1 by accelerating oxidative stress in NPCs and demonstrates that miR-4478 has therapeutic potential in IVDD treatment.

[Pulmonary Vascular Remodeling Characteristics of Pulmonary Arterial Hypertension Mouse Model Induced by Left Pneumonectomy and Jugular Vein Injection of Monocrotaline Pyrrole].

Objective: To compare and investigate the differences and characteristics of pulmonary vascular remodeling in three mouse models of pulmonary arterial hypertension (PAH) constructed by left pneumonectomy, jugular vein injection of monocrotaline pyrrole, and left pneumonectomy combined with jugular vein injection of monocrotaline pyrrole, to explore for a PAH animal model that approximates the clinical pathogenesis of PAH, and to create a model that will provide sound basis for thorough investigation into the pathogenesis of severe PAH. Methods: 59 male C57/BL mice (10-12 weeks, 24-30 g) were randomized into four groups, a control group ( n=9), a group that had left pneumonectomy (PE, n=15), a group that had jugular vein injection of monocrotaline pyrrole (MCTP, n=15), and the last group that had left pneumonectomy combined with jugular injection of monocrotaline pyrrole (P+M, n=20). To evaluate the effect of modeling and the characteristics of pulmonary vascular remodeling, hemodynamic and morphological parameters, including right ventricular systolic pressure (RVSP), right ventricle/(left ventricle plus septum) (RV/LV+S), percent of wall thickness in the pulmonary artery (WT%), muscularization of non-muscular arteries, neointima formation, and vascular obstruction score (VOS), were measured in each group. Results: 1) Compared with those of the control group, the RVSP, RV/LV+S, WT%, and the degree of small pulmonary arteries muscularization in the P+M group were significantly increased ( P<0.01). The MCTP group had just slightly higher findings for these indicators ( P<0.05), while no significant change in these indicators was observed in the PE group ( P>0.05). 2) Neointima formation in the acinus pulmonary arteries, which caused obvious stenosis of the lumen, was observed in the P+M group, the VOS being 1.25±0.80 points ( P<0.001). In contrast, neointima formation was not observed in the MCTP group or the PE groups, the VOS being 0 point ( P>0.05). Conclusion: Left pneumonectomy combined with jugular intravenous injection of MCTP could induce severe PAH formation in mouse. The model provides a good simulation of neointima formation, the characteristic pathological change of clinical severe PAH.

Grem1 accelerates nucleus pulposus cell apoptosis and intervertebral disc degeneration by inhibiting TGF-ß-mediated Smad2/3 phosphorylation.

Intervertebral disc degeneration (IVDD) is a main cause of low back pain, and inflammatory factors play key roles in its pathogenesis. Gremlin-1 (Grem1) was reported to induce an inflammatory response in other fields. This study aimed to investigate the mechanisms of Grem1 in the degenerative process of intervertebral discs. Dysregulated genes were determined by analyzing microarray profiles. The expression of Grem1 in 17 human disc samples (male:female = 9:8) and rat models (n = 5 each group) was measured by western blotting (WB), real-time quantitative PCR (RT-qPCR), and immunohistochemistry (IHC). The regulatory effects of Grem1 on apoptosis were examined using siRNAs, flow cytometry, immunofluorescence (IF), and WB. The therapeutic effect was evaluated by locally injecting specific Grem1 siRNA into IVDD rats. The expression of Grem1 was significantly increased in human degenerative intervertebral discs; furthermore, the expression of Grem1 positively correlated with the level of intervertebral disc degeneration. Grem1 was significantly overexpressed in tumor necrosis factor (TNF)-α-induced degenerative NP cells. Apoptosis in degenerative NP cells transfected with siRNA targeting Grem1 was significantly lower than that in the control group. Specific Grem1 siRNA markedly repressed the development of IVDD in surgery-induced IVDD rats. These results indicated that the expression of Grem1 was positively correlated with the severity of intervertebral disc degeneration, and Grem1 siRNA could inhibit Grem1-induced apoptosis and extracellular matrix alterations by mediating the TGF-ß/Smad signaling pathway. This study may provide a therapeutic strategy for alleviating inflammation-induced apoptosis associated with intervertebral disc degeneration.

Visfatin promotes intervertebral disc degeneration by inducing IL-6 expression through the ERK/JNK/p38 signalling pathways.

Visfatin reportedly induces the expression of proinflammatory cytokines. Severe grades of intervertebral disc disease (IVDD) exhibit higher expression of visfatin than mild ones. However, the direct relationship between visfatin and IVDD remains to be elucidated. This study aimed to clarify whether stimulation of visfatin in IVDD is mediated by IL-6. To investigate the role of visfatin in IVDD, a rat model of anterior disc puncture was established by injecting visfatin or PBS using a 27-gauge needle. Results revealed an obvious aggravation of the histological morphology of IVDD in the visfatin group. On treating human NP cellswith visfatin, the levels of collagenII and aggrecan decreased and those of matrix metallopeptidase 3 and IL-6 gradually increased. A rapid increase in ERK, JNK, and p38 phosphorylation was also noted after visfatin treatment. Compared to those treated with visfatin alone, NP cells pretreated with ERK1/2, JNK, and p38 inhibitors or siRNA targeting p38, ERK, and JNK exhibited a significant suppression of IL-6. Our data represent the first evidence that visfatin promotes IL-6 expression in NP cells via the JNK/ERK/p38-MAPK signalling pathways. Further, our findings suggest epidural fat and visfatin as potential therapeutic targets for controlling IVDD-associated inflammation.

[Association of age distribution with the expression of angiotensin-converting enzyme 2 in lung tissues in severe acute respiratory syndrome coronavirus 2 infection: reflections from the study of RAS pathway expression in mice].

OBJECTIVE: To study the expression of angiotensin-converting enzyme 2 (ACE2) and other key molecules of the RAS pathway in normal mice at different developmental stages, and to provide ideas for understanding the infection mechanism of coronavirus disease 2019 (COVID-19) as well as the diagnosis and treatment of children with COVID-19. METHODS: The mice at different developmental stages were enrolled, including fetal mice (embryonic days 14.5 and 18.5), neonatal mice (0, 3, 7, 14, and 21 days old), young mice (28 and 42 days old), and adult mice (84 days old). The lung tissues of all fetal mice from 4 pregnant mice were collected at each time point in the fetal group. Four mice were sampled in other age groups at each time point. Whole transcriptome resequencing was used to measure the mRNA expression of AGT, ACE, ACE2, Renin, Agtr1a, Agtr1b, Agtr2, and Mas1 in mouse lung tissue. RESULTS: The expression of ACE2 in the lungs showed changes from embryonic stage to adult stage. It increased gradually after birth, reached a peak on day 3 after birth, and reached a nadir on day 14 after birth (P<0.05). The expression of AGT reached a peak on days 0 and 7 after birth and reached a nadir on day 21 after birth (P<0.05). The expression of ACE increased rapidly after birth and reached a peak on day 21 after birth (P<0.05). Agtr1a expression reached a peak on day 21 after birth (P<0.05). Agtr2 expression gradually decreased to a low level after birth. Renin, Agtr1b, and Mas1 showed low expression in lung tissues at all developmental stages. CONCLUSIONS: At different developmental stages of mice, ACE2 has dynamic expression changes, with high expression in early neonatal and adult mice. The other key molecules of the RAS pathway have their own expression patterns. These suggest that the difference in clinical features between children and adults with COVID-19 might be associated with the different expression levels of ACE2 in the different stages, and further studies are needed for the mechanism.

Self-repair behaviour of the neuronal cell membrane by conductive atomic force indentation.

Conductive atomic force indentation (CAFI) was proposed to study the self-repair behaviour of the neuronal cell membrane here. CAFI was used to detect the changes of membrane potentials by performing the mechanical indentation on neurons with a conductive atomic force microscope. In the experiment, a special insulation treatment was made on the conductive probe, which turned out to be a conductive nanoelectrode, to implement the CAFI function. The mechanical properties of the neuronal cell membrane surface were tested and the membrane potential changes of neurons cultured in vitro were detected. The self-repair behaviour of the neuronal cell membrane after being punctured was investigated. The experiment results show that CAFI provides a new way for the study of self-repair behaviours of neuronal cell membranes and mechanical and electrical properties of living cells.

WITHDRAWN: KLF5 promoted symmetric cell division in KRT5 positive keratinocytes through suppression of Notch1 expression.

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Ataxia-Telangiectasia Mutated (ATM) Protein Signaling Participates in Development of Pulmonary Arterial Hypertension in Rats.

BACKGROUND Previous studies revealed physiological and pathogenetic similarity between vascular smooth muscles cells with severe pulmonary arterial hypertension and tumors. The DNA damage response was found in both pulmonary arterial hypertension (PAH) cells and tumors. The ataxia-telangiectasia mutated proteins (ATM) pathway is considered an important factor in the DNA damage response of tumor formation, but its function in the development of PAH remains unknown. MATERIAL AND METHODS The Sprague-Dawley rat PAH model was established. Three weeks (Group M1), 5 weeks (Group M2), and 7 weeks (Group M3) after drug injection, pulmonary expression of ATM, Checkpoint kinase 2 (Chk2), P53, and P21 were measured. A section of the lungs from Group M2 was used for pulmonary artery vascular smooth muscles cells (PA-SMCs) isolation and culture. The effect of KU60019 in the proliferation and apoptosis of primary cultured rat PA-SMCs was measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and TdT-mediated dUTP nick-end labeling (TUNEL), respectively. RESULTS Immunohistochemistry results show that the expression of ATM, Chk2, and P21 increased in Groups M1 and M2, and decreased in Group M3. Additionally, expression of P53 increased in Group M1, and decreased in Groups M2 and M3. RT-PCR and Western blotting demonstrated that in Groups M1 and M2, the expression of ATM, Chk2, P53, and P21 increased, whereas it decreased in Group M3. In cell culture, 0.3 µM and 0.5 µM KU60019 increased the growth of PA-SMCs, and 0.5 µM KU60019 reduced cell apoptosis. CONCLUSIONS Expression of the ATM-Chk2 pathway increased in early stages of PAH formation, but decreased in late stages. In primary cultured PA-SMCs, KU60019 increased cell proliferation and inhibited cell apoptosis.

[Effect of Taohong Qinlian Decoction on HMGB1 in Septic Rat Cardiac Muscle].

OBJECTIVE: To observe the levels of high mobility group box-1 protein (HMGB1), tumor necrosis factor-alpha (TNF-α), IL-6, troponin I (Tn I) release in septic rats, and to explore themechanism of Taohong Qinlian Decoction (TQD) in the treatment of septic myocardial injury. METHODS: A total of 48 healthy male Wistar rats of clean grade were randomly divided into the sham-operation group (Sham), the sepsis model group (CLP), and the TQD treatment group (ZY), 16 in each group. Concen-trations of TNF-α, IL-6, Tn I, and HMGB1 expression were detected in each group at 24 and 48 h after operation. Pathological changes of cardiac muscle were observed under light microscope. RESULTS: Concentrations of TNF-α, IL-6, Tn I and HMGB1 at 24 and 48 h after operation were significantly higher in the CLP group than in the Sham group (P < 0.01). Concentrations of TNF-α, IL-6, Tn I, and HMGB1 at 24 and 48 h after operation were significantly lower in the ZY group than in the CLP group (P < 0.05). Myocardial injury occurred in the CLP and the ZY group under light microscope. And this injury was more severe in the CLP group than in the ZY group. CONCLUSION: TQL could reduce the level of sepsis-related inflammatory cytokines and protect myocardium in septic rats.

Resistin Promotes Intervertebral Disc Degeneration by Upregulation of ADAMTS-5 Through p38 MAPK Signaling Pathway.

STUDY DESIGN: Rat nucleus pulposus (NP) cells were activated with resistin with or without p38 mitogen-activated protein kinase (MAPK) pathway inhibition. The expression of a disintegrin and metalloprotease with thrombospondin motif-5 (ADAMTS-5), which plays an important role in intervertebral disc degeneration (IDD), was determined. OBJECTIVE: The aim of this study was to demonstrate whether resistin can influence the ADAMTS-5 expression and to further investigate the underlying mechanisms. SUMMARY OF BACKGROUND DATA: Obesity has been demonstrated to promote IDD, whereas the exact mechanism remains poorly understood. Resistin, as an important adipokine, is increased with obesity and has been shown to play pro-inflammatory and catabolic role in cartilage metabolism. However, the effect of resistin on the catabolic enzymes within NP cells remains unknown. METHODS: We exposed NP cells to resistin, and the transcriptional activity, gene expression, and protein levels of ADAMTS-5 were measured by luciferase reporter assay, qRT-polymerase chain reaction, immunofluorescence, and western blot, respectively. The activation of p38 MAPK pathways was detected using western blot analysis. RESULTS: Resistin had no effect on cell viability. Resistin increased ADAMTS-5 expression in rat NP cells time and dose dependently. The p38 MAPK signaling pathway was activated after exposure to resistin. Treatment with p38 inhibitor decreased the upregulation of ADAMTS-5 by resistin. CONCLUSION: The current study, for the first time, investigated the role of resistin in ADAMTS-5 regulation in IDD. These findings provide novel evidence supporting the causative role of obesity in IDD, which is important to develop novel preventative or therapeutic treatment in disc degenerative disorders. LEVEL OF EVIDENCE: N/A.

CDC42 is required for structural patterning of the lung during development.

The formation of highly branched epithelial structures is critical for the development of many essential organs, including lung, liver, pancreas, kidney and mammary glands. Elongation and branching of these structures require precise control of complex morphogenetic processes that are dependent upon coordinate regulation of cell shape, apical-basal polarity, proliferation, migration, and interactions among multiple cell types. Herein, we demonstrate that temporal-spatial regulation of epithelial cell polarity by the small GTPase, CDC42, is essential for branching morphogenesis of the developing lung. Epithelial cell-specific deletion of CDC42 in fetal mice disrupted epithelial cell polarity, the actin cytoskeleton, intercellular contacts, directional trafficking of proteins, proliferation and mitotic spindle orientation, impairing the organization and patterning of the developing respiratory epithelium and adjacent mesenchyme. Transition from a pseudostratified to a simple columnar epithelium was impaired, consistent with coordinate dysregulation of epithelial cell polarity, mitotic spindle orientation, and repositioning of mitotic cells within the epithelium during cell cycle progression. Expression of sonic hedgehog and its receptor, patched-1, was decreased, while fibroblast growth factor 10 expression in the mesenchyme was expanded, resulting in disruption of branching morphogenesis and bronchiolar smooth muscle formation in this model. CDC42 is required for spatial positioning of proliferating epithelial cells, as well as signaling interactions between the epithelium and mesenchyme and is, therefore, essential for formation and maintenance of the respiratory tract during morphogenesis of the fetal lung.