Expanding from unilateral to bilateral: A robust deep learning-based approach for predicting radiographic osteoarthritis progression.

OBJECTIVE: To develop and validate a deep learning (DL) model for predicting osteoarthritis (OA) progression based on bilateral knee joint views. METHODS: In this retrospective study, knee joints from bilateral posteroanterior knee radiographs of participants in the Osteoarthritis Initiative were analyzed. At baseline, participants were divided into testing set 1 and development set according to the different enrolled sites. The development set was further divided into a training set and a validation set in an 8:2 ratio for model development. At 48-month follow-up, eligible patients were formed testing set 2. The Bilateral Knee Neural Network (BikNet) was developed using bilateral views, with the knee to be predicted as the main view and the contralateral knee as the auxiliary view. DenseNet and ResNext were also trained and compared as the unilateral model. Two reader tests were conducted to evaluate the model's value in predicting incident OA. RESULTS: Totally 3583 participants were evaluated. The BikNet we proposed outperformed ResNext and DenseNet (all area under the curve [AUC] < 0.71, P < 0.001) with AUC values of 0.761 and 0.745 in testing sets 1 and 2, respectively. With assistance of the BikNet increased clinicians' sensitivity (from 28.1-63.2% to 42.1-68.4%) and specificity (from 57.4-83.4% to 64.1-87.5%) of incident OA prediction and improved inter-observer reliability. CONCLUSION: The DL model, constructed based on bilateral knee views, holds promise for enhancing the assessment of OA and demonstrates greater robustness during subsequent follow-up evaluations as compared with unilateral models. BikNet represents a potential tool or imaging biomarker for predicting OA progression.

Transformer-Based Multilabel Deep Learning Model Is Efficient for Detecting Ankle Lateral and Medial Ligament Injuries on Magnetic Resonance Imaging and Improving Clinicians' Diagnostic Accuracy for Rotational Chronic Ankle Instability.

PURPOSE: To develop a deep learning (DL) model that can simultaneously detect lateral and medial collateral ligament injuries of the ankle, aiding in the diagnosis of chronic ankle instability (CAI), and assess its impact on clinicians' diagnostic performance. METHODS: DL models were developed and externally validated on retrospectively collected ankle magnetic resonance imaging (MRI) between April 2016 and March 2022 respectively at 3 centers. Included patients had confirmed diagnoses of CAI through arthroscopy, as well as individuals who had undergone MRI and physical examinations that ruled out ligament injuries. DL models were constructed based on a multilabel paradigm. A transformer-based multilabel DL model (AnkleNet) was developed and compared with 4 convolution neural network (CNN) models. Subsequently, a reader study was conducted to evaluate the impact of model assistance on clinicians when diagnosing challenging cases: identifying rotational CAI (RCAI). Diagnostic performance was assessed using area under the receiver operating characteristic curve (AUC). RESULTS: Our transformer-based model achieved AUCs of 0.910 and 0.892 for detecting lateral and medial collateral ligament injury, respectively, both of which were significantly higher than those of CNN-based models (all P < .001). In terms of further CAI diagnosis, there was a macro-average AUC of 0.870 and a balanced accuracy of 0.805. The reader study indicated that incorporation with our model significantly enhanced the diagnostic accuracy of clinicians (P = .042), particularly junior clinicians, and led to a reduction in diagnostic variability. The code of the model can be accessed at https://github.com/ChiariRay/AnkleNet. CONCLUSIONS: Our transformer-based model was able to detect lateral and medial collateral ligament injuries based on MRI and outperformed CNN-based models, demonstrating a promising performance in diagnosing CAI, especially patients with RCAI. CLINICAL RELEVANCE: Developing such an algorithm can improve the diagnostic performance of clinicians, aiding in identifying patients who would benefit from arthroscopy, such as patients with RCAI.

Endoscopic reconstruction for chronic Achilles tendon ruptures using a hamstring tendon autograft.

BACKGROUND: To determine the safety and efficacy of endoscopic reconstruction of chronic Achilles tendon ruptures using a hamstring tendon autograft at mid-term follow-up. METHODS: We reviewed the medical records of patients with chronic Achilles tendon rupture treated surgically by endoscopic reconstruction using a hamstring tendon autograft at our institution between March 2010 and October 2015. Radiologic outcomes were assessed using pre- and postoperative magnetic resonance imaging (MRI). Functional outcomes were evaluated with the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, the Plantar Flexion Strength (PFS), the Victorian Institute of Sport Assessment-Achilles (VISA-A) scale, the Visual Analogue Scale (VAS) pain score, and the Arner-Lindholm standard. All patients achieved primary healing with no lengthening of the Achilles tendon, skin necrosis, infection, deep vein thrombosis or other complications. RESULTS: Mean follow-up period was 15 ± 3 months (range, 12-18 months). There was no Achilles tendon re-rupture. MRI examination revealed that Achilles tendon continuity was restored. Patients' mean AOFAS, PFS, and VISA-A scores were significantly higher and mean VAS pain score was significantly lower after surgery compared to before (P < 0.05). According to Arner-Lindholm standards, there were twenty (76.9%) excellent, six (23.1%) good, and zero bad outcomes. CONCLUSION: Endoscopic reconstruction utilizing a hamstring tendon autograft is a safe and efficacious option for repair of chronic Achilles tendon ruptures. Studies with larger sample sizes and a longer follow-up are required to confirm the advantage of this technique compared to open surgery.

A modified all-inside arthroscopic remnant-preserving technique of lateral ankle ligament reconstruction: medium-term clinical and radiologic results comparable with open reconstruction.

BACKGROUND: The aim of this study was to compare clinical and radiologic outcomes of a modified all-inside arthroscopic remnant-preserving technique of lateral ankle ligament reconstruction with traditional open reconstruction. METHODS: From January 2012 and March 2016, 60 eligible patients with chronic lateral ankle instability (CLAI) received all arthroscopic remnant-preserving reconstruction or open reconstruction of the anterior talofibular ligament and calcaneofibular ligament using semitendinosus autograft. They were divided into the arthroscopic group (n = 28) and the open group (n = 32). The American Orthopaedic Foot and Ankle Society (AOFAS),visual analog scale (VAS), and Karlsson scores and ankle range of motion (ROM) were used to evaluate clinical outcomes pre-operatively and at six and 12 months and the final follow-up of at least 24 months post-operatively, with SF-36 physical component summary (PCS) and mental component summary (MCS) scores evaluated for quality of life, and the anterior talar translation and talar tilt measurements for radiologic outcomes. RESULTS: There was no difference in pre-operative demographics between two groups (P > 0.05). At the final follow-up, the AOFAS, VAS, Karlsson, SF-36 PCS, and MCS scores improved significantly in both groups (P < 0.05). However, no significant difference was found in AOFAS (91.9 ± 6.8 vs 91.1 ± 5.5), VAS (2.7 ± 1.7 vs 2.5 ± 1.6), Karlsson (95.3 ± 6.7 vs 94.8 ± 6.5), SF-36 PCS (53.2 ± 6.1 vs 52.9 ± 5.7), and MCS scores (55.7 ± 5.8 vs 54.2 ± 5.4) between the two groups (P > 0.05). There was no significant difference in post-operative operated/non-operated ankle ROM between two groups (P > 0.05). No significant difference was observed in talar tilt angle (7.6 ± 4.1° vs 6.8 ± 3.6°) and anterior talar translation (5.8 ± 1.7 mm vs 5.7 ± 1.5 mm) between the two groups at the final follow-up (P > 0.05), although these two variables improved significantly in both groups (P < 0.05). No severe complications were encountered in both groups during the follow-up period. CONCLUSIONS: The modified all-inside arthroscopic remnant-preserving technique of lateral ankle ligament reconstruction could produce excellent clinical and radiologic outcomes comparable with open reconstruction.

Relationship of vitamin D receptor gene polymorphisms with susceptibility, surgical outcome and prognosis of hallux valgus in a Chinese Han population.

BACKGROUND: This study aimed to identify the relationship between the vitamin D receptor (VDR) BsmI gene polymorphism and risk factors, surgical outcome and prognosis of hallux valgus (HV). METHODS: A case-control study was performed on a cohort of 236 HV patients and 236 controls in a Chinese Han population. Detection of the VDR BsmI/G2A polymorphism was performed using restriction fragment length polymorphism-polymerase chain reaction. RESULTS: We detected a statistically significant difference in the allele distribution of the BsmI polymorphism between cases and controls (p<0.01). Significant loss of hallux valgus angle (HVA) and intermetatarsal angle (IMA) correction was only noted in patients with the bb genotype during the 2-year follow-up period (p<0.01). The average American Orthopaedic Foot and Ankle Society (AOFAS) scores at the 2-year follow-up were decreased in both groups when compared with those at the 6 month follow-up, and 1.45 points more decrease in patients with the bb genotype was observed as compared to those with the BB and Bb genotypes (p<0.0001). The average visual analogue scales (VAS) also had the tendency with more pains in the bb genotype group (p<0.0001). Furthermore, larger numbers of transfer metatarsalgia were found in patients with the bb genotype upon 2-year follow-up (p=0.049). CONCLUSIONS: We report the first candidate gene polymorphism associated with susceptibility, surgical outcome and prognosis of HV in a Chinese Han population. Moreover, development of genetically-based method to predict the surgical outcome accurately and individualized therapy for HV are warranted.

Zedoarondiol Attenuates Endothelial Cells Injury Induced by Oxidized Low-Density Lipoprotein via Nrf2 Activation.

BACKGROUND/AIMS: Zedoarondiol, a sesquiterpene lactone compound, showed an anti-proliferative activity on vascular smooth muscle cells in our previous study. However, whether it has a beneficial effect on endothelial cells injury induced by oxidized low-density lipoprotein (ox-LDL) remains unclear. This study was designed to investigate the protective effect of zedoarondiol on ox-LDL-induced injury of endothelial cells and explored its underlying mechanism. METHODS: The protective effect of zedoarondiol on ox-LDL-induced human umbilical vein endothelial cells (HUVECs) injury were evaluated by Cell Counting Kit-8 (CCK-8) assay and released lactic dehydrogenase (LDH) activity assay. Oxidative stress was determined by malonedialdehyde (MDA) content and superoxide dismutase (SOD) activity. The level of reactive oxygen species (ROS) was measured by dichlorodihydrofluorescin diacetate (DCFH-DA) staining. The culture supernatant was collected for enzyme linked immune-sorbent assays (ELISA) of interleukine-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1). Immunofluorescence staining was used to observe NF-E2-related factor 2 (Nrf2) translocation. Western blotting was performed to determine the expression of IL-1ß, TNF-α, MCP-1, Kelch-like ECH associated protein 1 (Keap1), heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase-1 (NQO1), and Nrf2. RESULTS: Zedoarondiol attenuated HUVECs injury, up-regulated SOD activity, suppressed formation of MDA and ROS, and secretion and protein expression of IL-1ß, TNF-α, and MCP-1 in injured HUVECs induced by ox-LDL. Zedoarondiol induced nuclear Nrf2 translocation from cytoplasm into nucleus and up-regulated expression of HO-1, NQO1, and Nrf2 in nucleus. All-trans-retinoic acid (ATRA), an inhibitor of Nrf2, abolished zedoarondiol-mediated anti-oxidative effect. CONCLUSION: Zedoarondiol attenuates ox-LDL-induced endothelial cells injury by inhibiting oxidative stress and inflammation via Nrf2/HO-1 pathway, suggesting that zedoarondiol might be meaningful on prevention and treatment of atherosclerosis.

All arthroscopic remnant-preserving reconstruction of the lateral ligaments of the ankle: A biomechanical study and clinical application.

Lateral ankle sprains are one of the most common injuries in sports. Recently, arthroscopic lateral ligament reconstruction has been recently advocated, however no biomechanical studies and clinical application of this technique are available. In this biomechanical study, eighteen fresh-frozen cadaveric ankles were randomized into three groups: (1) intact anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), (2) arthroscopic anatomic reconstruction of ATFL and CFL, and (3) all arthroscopic remnant-preserving reconstruction of ATFL and CFL. The specimens were then tested for stiffness and load to ultimate failure using a customized jig. In biomechanical test, the all arthroscopic remnant-preserving reconstruction of ATFL and CFL produced a reconstruction that could withstand loads to failure and stiffness similar to the arthroscopic anatomic reconstruction. However, both two reconstruction groups were much weaker than the intact, uninjured ATFL and CFL. Moreover, we used the technique of all arthroscopic remnant-preserving reconstruction of ATFL and CFL on 20 patients from September 2016 to September 2017. American Orthopaedic Foot and Ankle Society (AOFAS) scores and Anterior Talar Translation (ATT) were applied for statistical collection at preoperative and postoperative 12 months to evaluate clinical efficacy. The differences of the preoperative and postoperative 12 months AOFAS scores and ATT of patients were both statistical significant (P < 0.01). We confirmed that all arthroscopic remnant-preserving reconstruction of ATFL and CFL exhibited positive effect, thus promoting the recovery of ankle function and had good short-term clinical effect.

Association of Vitamin D Receptor Gene TaqI, BsmI, FokI, and ApaI Polymorphisms and Susceptibility to Hallux Valgus in the Chinese Population.

Previous studies have indicated that vitamin D receptor (VDR) TaqI, BsmI, FokI and ApaI gene polymorphisms are associated with the risk of skeletal malformations with inflammation. However, the potential association of VDR gene polymorphisms with the susceptibility to hallux valgus remains unclear. To clarify this association, we compared the genotypes of 228 patients with hallux valgus with those of 200 controls using the Multiplex SNaPshot system. The χ2 test was used to compare the allele and genotype frequencies between groups, and p ≤ .05 was considered statistically significant. The frequencies of the mutant allele C in TaqI (p= .036; odds ratio [OR] 1.57; 95% confidence interval [CI] 1.03-2.39) and mutant allele A in BsmI (p= .036; OR 1.33; 95% CI 1.02-1.74) were significantly greater in the patients than in the controls. In addition, after adjusting for sex and age, TaqI (p= .047; OR 1.61; 95% CI 1.00-2.58) and BsmI (p= .025; OR 1.67; 95% CI 1.06-2.61) were associated with the risk of hallux valgus through a dominant genetic model. A homozygous genetic model of BsmI was also significantly associated with the risk of hallux valgus (p= .033; OR 1.81; 95% CI 1.05-2.57). However, neither ApaI nor FokI were associated with increased susceptibility. To the best of our knowledge, we have reported for the first time that VDR gene TaqI and BsmI polymorphisms might contribute to the increased risk of hallux valgus in Chinese population.

Zedoarondiol Inhibits Platelet-Derived Growth Factor-Induced Vascular Smooth Muscle Cells Proliferation via Regulating AMP-Activated Protein Kinase Signaling Pathway.

BACKGROUND/AIMS: Vascular smooth muscle cells (VSMCs) proliferation contributes significantly to atherosclerosis and in-stent restenosis. Platelet-derived growth factor-BB (PDGF-BB) plays a vital role in VSMCs proliferation. Zedoarondiol, a sesquiterpene lactone compound, has an anti-inflammatory activity. However, the role of zedoarondiol in PDGF-BB-mediated VSMCs proliferation remains unclear. In this study, we investigated the effects of zedoarondiol on PDGF-BB-induced VSMCs proliferation and explored the possible mechanisms. METHODS: The inhibitory effects of zedoarondiol on PDGF-BB-induced VSMCs proliferation were evaluated by direct cell counting and the Cell Counting Kit-8 (CCK-8) assay. DNA synthesis was examined by bromodeoxyuridine (BrdU) incorporation assay. Cell cycle was assessed by propidium iodide staining. Western blotting was performed to determine the expression of cyclin-dependent kinase 2 (CDK2), cyclin E, p53, p21, total and phosphorylated adenosine monophosphate-activated protein kinase (AMPK), acetyl CoA carboxylase (ACC), mammalian target of rapamycin (mTOR), and p70 ribosomal protein S6 kinase (p70S6K). RESULTS: Zedoarondiol suppressed PDGF-BB-induced VSMCs proliferation and DNA synthesis, and induced cell cycle arrest in G0/G1 phase. In addition, zedoarondiol activated AMPK and ACC, inhibited the phosphorylation of mTOR and p70S6K, increased the expression of p53 and p21, and decreased the expression of CDK2 and cyclin E. Compound C (an AMPK inhibitor) abrogated, whereas 5-aminoimidazole-4-carboxamide 1-ß-ribofuranoside (AICAR, an AMPK activator) enhanced zedoarondiol-mediated inhibition of VSMCs proliferation and DNA synthesis. CONCLUSION: Zedoarondiol inhibits PDGF-BB-induced VSMCs proliferation via AMPK-mediated down-regulation of the mTOR/p70S6K pathway and up-regulation of the p53/p21 pathway. These findings suggest that zedoarondiol might be a promising compound against atherosclerosis and in-stent restenosis.

Molecular Mechanisms of Stress-Induced Myocardial Injury in a Rat Model Simulating Posttraumatic Stress Disorder.

OBJECTIVE: Posttraumatic stress disorder (PTSD) is an independent risk factor for cardiovascular diseases. This study investigated the molecular mechanisms underlying myocardial injury induced by simulated PTSD. METHODS: Sprague-Dawley rats were randomly divided into two groups: control group (n = 18) and PTSD group (n = 30). The PTSD model was replicated using the single prolonged stress (SPS) method. On the 14th day poststress, the apoptotic cells in myocardium were assessed using both TUNEL method and transmission electron microscopy; the protein levels of the endoplasmic reticulum stress (ERS) molecules were measured by using Western blotting analysis. RESULTS: Exposure to SPS resulted in characteristic morphologic changes of apoptosis in cardiomyocytes assessed by transmission electron microscopy. Moreover, TUNEL staining was also indicative of the elevated apoptosis rate of cardiomyocytes from the SPS rats (30.69% versus 7.26%, p < .001). Simulated PTSD also induced ERS in myocardium, demonstrated by up-regulation of protein levels of glucose-regulated protein 78 (0.64 versus 0.26, p = .017), calreticulin (p = .040), and CCAAT/enhancer-binding protein-homologous protein (0.95 versus 0.43, p = .047), phosphorylation of protein kinase RNA-like ER kinase (p = .003), and caspase 12 activation (0.30 versus 0.06, p < .001) in myocardium from the SPS rats. The ratio of Bcl-2 to Bax decreased significantly in myocardium from the SPS rats (p = .005). CONCLUSIONS: The ERS-related apoptosis mediated by the protein kinase RNA-like ER kinase/CCAAT/enhancer-binding protein-homologous protein and caspase 12 pathways may be associated with myocardial injury in a rat model simulating PTSD. This study may advance our understanding of how PTSD contributes to myocardial injury on a molecular level.

Myofibrillogenesis regulator-1 attenuates hypoxia/reoxygenation-induced injury by repairing microfilaments in neonatal rat cardiomyocytes.

Hypoxia/reoxygenation (H/R) injury is characterized by microfilament reorganization in cardiomyocytes. Previous studies have shown that myofibrillogenesis regulator-1 (MR-1) is expressed in the myocardium and promotes actin organization in cardiomyocytes. The purpose of this study was to investigate the role of MR-1 in attenuating hypoxia/reoxygenation injury in cardiomyocytes through promoting restoration of the microfilament. To address this aim, an H/R model of cultured neonatal cardiomyocytes was used to assess filamentous actin (F-actin) and α-actinin organization through immunofluorescence microscopy analysis. RT-PCR was used to detect mRNA levels of MR-1 and myosin regulatory light chain-2 (MLC-2). Western blot analysis was used to detect protein levels of MR-1 and filamentous actin/globular actin (F-/G-actin) as well as MLC-2 and myosin light chain kinase (MLCK) phosphorylation and protein expression. We also explored the effects of overexpressing or knocking down MR-1 on H/R injury and the MLCK/MLC-2/F-actin pathway. We found that H/R induced cardiomyocyte injury and disruption of F-actin and α-actinin with a decrease in the F-/G-actin ratio compared with controls. Compared with the H/R group, MR-1 overexpression attenuated H/R-induced injury and disruption of F-actin and α-actinin in cardiomyocytes with an increase in the F-/G-actin ratio. MR-1 overexpression also up-regulated H/R-induced MLCK and MLC-2 phosphorylation. However, MR-1 knockdown aggravated H/R injury by further disrupting F-actin and α-actinin, as well as decreasing the F-/G-actin ratio. MR-1 knockdown also down-regulated MLCK and MLC-2 phosphorylation induced by H/R injury. These findings suggest that MR-1 attenuates H/R-induced cardiomyocyte injury by promoting microfilament reorganization through the activation of the MLCK/MLC-2 pathway.

Myofibrillogenesis regulator-1 attenuated hypoxia/reoxygenation-induced apoptosis by inhibiting the PERK/Nrf2 pathway in neonatal rat cardiomyocytes.

The purpose of this study was to investigate the role of myofibrillogenesis regulator-1 (MR-1) in cardiomyocyte apoptosis induced by hypoxia/reoxygenation (H/R), through protein kinase R-like ER kinase (PERK)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. To address this aim, an H/R model of neonatal rat cardiomyocytes was used. MR-1 was overexpressed using an adenoviral vector system and knocked down using MR-1 specific siRNA. Apoptosis was assessed by using Annexin V/PI double staining, terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling assay, and the Bcl-2/Bax ratio. Western blotting was used to detect the protein levels of MR-1, glucose-regulated protein 78 (GRP78), total and phosphorylated PERK, Nrf2, activating transcription factor 4 (ATF4), C/EBP homologous protein (CHOP), Bcl-2 and Bax. Immunofluorescence staining was used to assess the subcellular location of Nrf2. We found that H/R induced significant apoptosis in neonatal rat cardiomyocytes. MR-1 overexpression attenuated H/R-induced apoptosis, decreased GRP78 (P < 0.01) and CHOP expression (P < 0.05), and increased the Bcl-2/Bax ratio (P < 0.01). MR-1 overexpression suppressed H/R-induced PERK phosphorylation, Nrf2 nuclear translocation, and ATF4 expression (P < 0.01). While MR-1 knockdown aggravated H/R-induced apoptosis, increased expression of GRP78 and CHOP (P < 0.05), and decreased the Bcl-2/Bax ratio (P < 0.01). MR-1 knockdown significantly increased H/R-induced PERK phosphorylation (P < 0.05), Nrf2 nuclear translocation, and ATF4 expression (P < 0.01). These findings suggest that MR-1 alleviates H/R-induced cardiomyocyte apoptosis through inhibition of the PERK/Nrf2 pathway.

Panax quinquefolium saponin attenuates cardiomyocyte apoptosis and opening of the mitochondrial permeability transition pore in a rat model of ischemia/reperfusion.

AIMS: Opening of the mitochondrial permeability transition pore (mPTP) is a critical event during ischemia/reperfusion (I/R) injury. Recently, we showed that Panax quinquefolium saponin (PQS) alleviates apoptosis of cardiomyocytes by suppressing excessive endoplasmic reticulum stress (ERS) during I/R injury. Here, we hypothesized that this anti-apoptotic effect might be mediated through inhibition of mPTP and the mitochondrial apoptotic pathway. METHODS: Ninety-six healthy male Sprague-Dawley rats were randomly divided into sham, I/R, I/R+PQS (200 mg/kg/d), Cyclosporine A (CsA, 10 mg/kg), I/R+CsA (10 mg/kg), and I/R+PQS+CsA. I/R was modeled in rats by ligating the left anterior descending artery (LAD) for 30 min followed by 120 min of reperfusion. To evaluate the cardioprotective function of PQS, we measured hemodynamics, serum content of creatine kinase-MB (CK-MB), myocardial infarct size, and myocardial apoptotic index (AI). We investigated the underlying mechanism by examining changes in the mitochondrial ultrastructure and membrane potential (ΔΨm), dynamics of mPTP opening, expression of cleaved caspase-3, cleaved caspase-9 in the myocardium, Bcl-2 and Bax in the mitochondria versus cytosol, and translocation of cytochrome c. RESULTS: Administration of PQS to I/R rats significantly reduced serum CK-MB level, infarct size and AI. In addition, PQS protected the mitochondrial structure, markedly inhibited mPTP opening and ΔΨm depolarization, led to upregulation of Bcl-2 and downregulation of Bax in the mitochondria compared to the cytosol, and suppressed the expression of cleaved caspase-9 and cleaved caspase-3, as well as I/R induced translocation of cytochrome c to the cytoplasm. CONCLUSION: Our results show that PQS can alleviate apoptosis of cardiomyocytes during I/R injury, possibly due to repressed mitochondrial apoptotic pathway associated with the opening of mPTP induced by myocardial I/R injury.

Microwave radiation injuries microvasculature through inducing endoplasmic reticulum stress.

OBJECTIVE: The study aimed to investigate the effect of microwave radiation on microvasculature as well as the underlying mechanisms. METHODS: Sprague Dawley rats were exposed to microwave radiation. Microvascular diameters, flow velocity, blood perfusion and permeability were measured. Cultured endothelial cells from microvessels were subjected to microwave radiation. Cytoskeleton, apoptosis, protein synthesis and the markers of endoplasmic reticulum stress including 78-kDa glucose-regulated protein and calreticulin in endothelial cells were examined. RESULTS: Microwave radiation decreased microvascular diameters and blood perfusion, increased the permeability of microvessles. And microwave radiation induced the formation of stress fibers, apoptosis, and LDH leakage from microvascular endothelial cells. Also, when microvascular endothelial cells were exposed to microwaves, protein synthesis was significantly elevated. We found that upon microwave radiation, the expression of 78-kDa glucose-regulated protein and calreticulin were greatly upregulated in microvascular endothelial cells. We also investigated possible signaling pathways for endoplasmic reticulum stress-initiated apoptosis. C/EBP homologous protein (CHOP) pathway was activated in microvascular endothelial cells exposed to microwaves. CONCLUSIONS: Microwave radiation induces microvascular injury by triggering the apoptotic pathway of endoplasmic reticulum stress. This article is protected by copyright. All rights reserved.

Cytosolic calreticulin inhibits microwave radiation-induced microvascular endothelial cell injury through the integrin-focal adhesion kinase pathway.

OBJECTIVE: To determine the effects of cytosolic CRT on MR-induced MMEC injury, and the underlying mechanism. METHODS: MMECs were randomized into eight groups: control, AdCRT (infected with pAdCMV/V5-DEST-CRT adenovirus), stCRT (transfected with rCRT-siRNAs), Mock (transfected with scrambled siRNAs), MR (exposed to MR for six minutes), AdCRT + MR, stCRT + MR, and Mock + MR. The magnitude of cell injury were assessed by Annexin V-PI staining, LDH activity in culture medium, MMEC migration ability, ultrastructure and cytoskeletal stability. Subcellular colocalization of CRT and ConA or integrin were evaluated by immunocytochemistry. The mRNA and protein expression levels of target genes were examined by qRT-PCR and western blotting, respectively. RESULTS: MR-induced cytotoxicity was dose-dependent. Overexpression of cytosolic CRT suppressed MR injury, shown as decreased cell apoptosis, reduced LDH activity, enhanced cell migration capability, and maintenance of ultrastructure and cytoskeleton integrity. Conversely, CRT deficiency aggravated MR-induced injury. Exposure of AdCRT MMECs to MR promoted membrane translocation of CRT and the interaction of CRT-integrin-α. Correlation analysis revealed that integrin-α expression or FAK phosphorylation was positively associated with cytosolic CRT expression. CONCLUSIONS: Cytosolic CRT inhibits MR-induced MMEC injury through activation of the integrin-FAK pathway.

Kidney protection against ischemia/reperfusion injury by myofibrillogenesis regulator-1.

BACKGROUND/AIMS: Ischemia/reperfusion (I/R) injury is characterized by cytoskeletal reorganization and loss of polarity in proximal tubule epithelial cells. Previously, we showed that myofibrillogenesis regulator (MR)-1 promoted actin organization in cardiomyocytes. MR-1 is also expressed in the kidney. METHODS: In this study, we investigated MR-1 expression in acute renal failure induced by I/R in Sprague-Dawley rats. We determined the MR-1 expression and the ratio of fibrous actin (F-actin) to globular actin (G-actin). HK-2 cells were treated with or without hypoxia/reoxygenation (H/R), and MR-1 levels were increased by adenoviral overexpression or silenced by RNA interference. RESULTS: I/R and H/R resulted in cellular injury and decreases of MR-1, the F-/G-actin ratio, and myosin light chain (MLC)-2. MR-1 overexpression attenuated H/R-induced cell injury and loss of surface membrane polarity of actin. MR-1 overexpression also increased the expression and phosphorylation of MLC-2 and MLC kinase, which were decreased in MR-1-silenced and H/R-treated cells. CONCLUSION: Together, these data show that MR-1 promoted actin polarity on the membrane surface and protected HK-2 cells from H/R injury. The mechanism might involve the rapid organization of F-actin through the upregulation and phosphorylation of MLC-2.

Systematic Pharmacology and Experimental Validation to Reveal the Alleviation of Astragalus membranaceus Regulating Ferroptosis in Osteoarthritis.

Background: Astragalus membranaceus (AM) shows promise as a therapeutic agent for osteoarthritis (OA), a debilitating condition with high disability rates. OA exacerbation is linked to chondrocyte ferroptosis, yet the precise pharmacological mechanisms of AM remain unclear. Methods: We validated AM's protective efficacy in an anterior cruciate ligament transection (ACLT) mouse model of OA. The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database was utilized to identify AM's active components and their targets. FerrDb (a database for regulators and markers of ferroptosis and ferroptosis-disease associations) pinpointed ferroptosis-related targets, while GeneCards, Online Mendelian Inheritance in Man (OMIM), Pharmacogenomics Knowledgebase (PharmGKB), Therapeutic Target Database (TTD), and DrugBank sourced OA-related genes. Molecular docking analysis further validated these targets. Ultimately, the validation of the results was accomplished through in vitro experiments. Results: AM exhibited anabolic effects and suppressed catabolism in OA chondrocytes. Network pharmacology identified 19 common genes, and molecular docking suggested quercetin, an AM constituent, interacts with key proteins like HO-1 and NRF2 to inhibit chondrocyte ferroptosis. In vitro experiments confirmed AM's ability to modulate the NRF2/HO-1 pathway via quercetin, mitigating chondrocyte ferroptosis. Conclusion: This study elucidates how AM regulates chondrocyte ferroptosis, impacting OA progression, providing a theoretical basis and experimental support for AM's scientific application.

The PIEZO1/miR-155-5p/GDF6/SMAD2/3 signaling axis is involved in inducing the occurrence and progression of osteoarthritis under excessive mechanical stress.

OBJECTIVE: To elucidate the molecular mechanism of overloading-induced osteoarthritis (OA) and to find a novel therapeutic target. METHODS: We utilized human cartilage specimens, mouse chondrocytes, a destabilization of the medial meniscus (DMM) mouse model, and a mouse hindlimb weight-bearing model to validate the role of overloading on chondrocyte senescence and OA development. Then, we observed the effect of PIEZO1-miR-155-5p-GDF6-SMAD2/3 signaling axis on the preservation of joint metabolic homeostasis under overloading in vivo, in vitro and ex vivo by qPCR, Western blot, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, immunofluorescence, SA-ß-gal staining, CCK8 assay, et al. Finally, we verified the therapeutic effects of intra-articular injection of miR-155-5p inhibitor or recombinant GDF6 on the murine overloading-induced OA models. RESULTS: Chondrocytes sensesed the mechanical overloading through PIEZO1 and up-regulated miR-155-5p expression. MiR-155-5p mimics could copy the effects of overloading-induced chondrocyte senescence and OA. Additionally, miR-155-5p could suppress the mRNA expression of Gdf6-Smad2/3 in various tissues within the joint. Overloading could disrupt joint metabolic homeostasis by downregulating the expression of anabolism indicators and upregulating the expression of catabolism indicators in the chondrocytes and synoviocytes, while miR-155-5p inhibition or GDF6 supplementation could exert an antagonistic effect by preserving the joint homeostasis. Finally, in the in vivo overloading models, intra-articular injection of miR-155-5p inhibitor or recombinant GDF6 could significantly mitigate the severity of impending OA and lessened the progression of existing OA. CONCLUSION: GDF6 overexpression or miR-155-5p inhibition could attenuate overloading-induced chondrocyte senescence and OA through the PIEZO1-miR-155-5p-GDF6-SMAD2/3 signaling pathway. Our study provides a new therapeutic target for the treatment of overloading-induced OA.

Mortality Benefits of Cardiac Rehabilitation in Coronary Artery Disease Are Mediated by Comprehensive Risk Factor Modification: A Retrospective Cohort Study.

BACKGROUND: Cardiac rehabilitation (CR) is a multicomponent intervention to reduce adverse outcomes from coronary artery disease, but its mechanisms are not fully understood. The aims of this study were to examine the impact of CR on survival and cardiovascular risk factors, and to determine potential mediators between CR attendance and reduced mortality. METHODS AND RESULTS: A retrospective mediation analysis was conducted among 11 196 patients referred to a 12-week CR program following an acute coronary syndrome event between 2009 and 2019. A panel of cardiovascular risk factors was assessed at a CR intake visit and repeated on CR completion. All-cause and cardiovascular mortality were ascertained via health care administrative data sets at mean 4.2-year follow-up (SD, 2.81 years). CR completion was associated with reduced all-cause (adjusted hazard ratio [HR], 0.67 [95% CI, 0.54-0.83]) and cardiovascular (adjusted HR, 0.57 [95% CI, 0.40-0.81]) mortality, as well as improved cardiorespiratory fitness, lipid profile, body composition, psychological distress, and smoking rates (P<0.001). CR attendance had an indirect effect on all-cause mortality via improved cardiorespiratory fitness (ab=-0.006 [95% CI, -0.008 to -0.003]) and via low-density lipoprotein cholesterol (ab=-0.002 [95% CI, -0.003 to -0.0003]) and had an indirect effect on cardiovascular mortality via cardiorespiratory fitness (ab=-0.007 [95% CI, -0.012 to -0.003]). CONCLUSIONS: Cardiorespiratory fitness and lipid control partly explain the mortality benefits of CR and represent important secondary prevention targets.

Identification of molecular markers for predicting the severity of heart failure after AMI: An Olink precision proteomic study.

BACKGROUND: Acute myocardial infarction (AMI) still has a high incidence of varying degrees of heart failure (HF). The aim of this study is to identify new molecular markers for predicting the severity of HF after AMI. METHODS: We analyzed demographic indicators, past medical history, clinical indicators, major adverse cardiac events (MACEs) and molecular markers in patients with different Killip classifications after AMI. Olink proteomics was used to explore new molecular markers for predicting different severity of HF after AMI. RESULTS: Neutrophil count was the independent risk factors for in-hospital MACEs. Nineteen differentially expressed proteins (DEPs) increased significantly with increasing Killip classification. Five DEPs were also found to have an AUC (95 % CI) value greater than 0.8: GDF-15, NT-pro BNP, TNF-R2, TNF-R1 and TFF3. CONCLUSIONS: Neutrophil count, GDF-15, TNF-R2, TNF-R1 and TFF3 were closely related to the Killip classification of HF after AMI, which suggests that the inflammatory response plays an important role in the severity of HF after AMI and that regulating inflammation might become a new target for controlling HF.