Comparative transcriptome profiling reveals RNA splicing alterations and biological function in patients exposed to occupational noise.

Genetic factors play an important role in susceptibility to noise-induced hearing loss (NIHL). Alternative splicing (AS) is an essential mechanism affecting gene expression associated with disease pathogenesis at the post-transcriptional level, but has rarely been studied in NIHL. To explore the role of AS in the development of NIHL, we performed a comprehensive analysis of RNA splicing alterations by comparing the RNA-seq data from blood samples from NIHL patients and subjects with normal hearing who were exposed to the same noise environment. A total of 356 differentially expressed genes, including 23 transcription factors, were identified between the two groups. Of particular note was the identification of 56 aberrant alternative splicing events generated by 41 differentially expressed genes between the two groups, with exon skipping events accounting for 54% of all the differentially alternative splicing (DAS) events. The results of functional enrichment analysis showed that these intersecting DAS genes and differentially expressed genes were significantly enriched in autophagy and mitochondria-related pathways. Together, our findings provide insights into the role of AS events in susceptibility and pathogenesis of NIHL.

Identification of hub biomarkers and immune cell infiltration characteristics of polymyositis by bioinformatics analysis.

Background: Polymyositis (PM) is an acquirable muscle disease with proximal muscle involvement of the extremities as the main manifestation; it is a category of idiopathic inflammatory myopathy. This study aimed to identify the key biomarkers of PM, while elucidating PM-associated immune cell infiltration and immune-related pathways. Methods: The gene microarray data related to PM were downloaded from the Gene Expression Omnibus database. The analyses using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes, gene set enrichment analysis (GSEA), and protein-protein interaction (PPI) networks were performed on differentially expressed genes (DEGs). The hub genes of PM were identified using weighted gene co-expression network analysis (WGCNA) and least absolute shrinkage and selection operator (LASSO) algorithm, and the diagnostic accuracy of hub markers for PM was assessed using the receiver operating characteristic curve. In addition, the level of infiltration of 28 immune cells in PM and their interrelationship with hub genes were analyzed using single-sample GSEA. Results: A total of 420 DEGs were identified. The biological functions and signaling pathways closely associated with PM were inflammatory and immune processes. A series of four expression modules were obtained by WGCNA analysis, with the turquoise module having the highest correlation with PM; 196 crossover genes were obtained by combining DEGs. Subsequently, six hub genes were finally identified as the potential biomarkers of PM using LASSO algorithm and validation set verification analysis. In the immune cell infiltration analysis, the infiltration of T lymphocytes and subpopulations, dendritic cells, macrophages, and natural killer cells was more significant in the PM. Conclusion: We identified the hub genes closely related to PM using WGCNA combined with LASSO algorithm, which helped clarify the molecular mechanism of PM development and might have great significance for finding new immunotherapeutic targets, and disease prevention and treatment.

Mitochondrial Oxidative Stress Enhances Vasoconstriction by Altering Calcium Homeostasis in Cerebrovascular Smooth Muscle Cells under Simulated Microgravity.

OBJECTIVE: Exposure to microgravity results in postflight cardiovascular deconditioning in astronauts. Vascular oxidative stress injury and mitochondrial dysfunction have been reported during this process. To elucidate the mechanism for this condition, we investigated whether mitochondrial oxidative stress regulates calcium homeostasis and vasoconstriction in hindlimb unweighted (HU) rat cerebral arteries. METHODS: Three-week HU was used to simulate microgravity in rats. The contractile responses to vasoconstrictors, mitochondrial fission/fusion, Ca 2+ distribution, inositol 1,4,5-trisphosphate receptor (IP 3R) abundance, and the activities of voltage-gated K + channels (K V) and Ca 2+-activated K + channels (BK Ca) were examined in rat cerebral vascular smooth muscle cells (VSMCs). RESULTS: An increase of cytoplasmic Ca 2+ and a decrease of mitochondrial/sarcoplasmic reticulum (SR) Ca 2+ were observed in HU rat cerebral VSMCs. The abundance of fusion proteins (mitofusin 1/2 [MFN1/2]) and fission proteins (dynamin-related protein 1 [DRP1] and fission-mitochondrial 1 [FIS1]) was significantly downregulated and upregulated, respectively in HU rat cerebral VSMCs. The cerebrovascular contractile responses to vasoconstrictors were enhanced in HU rats compared to control rats, and IP 3R protein/mRNA levels were significantly upregulated. The current densities and open probabilities of K V and BK Ca decreased and increased, respectively. Treatment with the mitochondrial-targeted antioxidant mitoTEMPO attenuated mitochondrial fission by upregulating MFN1/2 and downregulating DRP1/FIS1. It also decreased IP 3R expression levels and restored the activities of the K V and BK Ca channels. MitoTEMPO restored the Ca 2+ distribution in VSMCs and attenuated the enhanced vasoconstriction in HU rat cerebral arteries. CONCLUSION: The present results suggest that mitochondrial oxidative stress enhances cerebral vasoconstriction by regulating calcium homeostasis during simulated microgravity.

Military medical research on internal diseases in modern warfare: new concepts, demands, challenges, and opportunities.

Battlefield internal medicine aims at the treatment of combatants and noncombatants with various internal diseases on the battlefield. The military medical research on battlefield internal diseases focuses on the pathogenesis, clinical management, and prevention of internal diseases under military war conditions. In both wartime and peacetime, the soldiers suffer from more internal diseases than surgical wounds. With the introduction of high-tech weapons, including chemical, physical, and biological agents, a large number of special internal illnesses and casualties will appear in future wars. The battles often occur in special environments, such as high or low temperatures, plateau or polar areas, and micro- or hyper-gravity. The current theories of battlefield internal medicine are mainly derived from wars decades ago and cannot meet the needs of military medical support under the conditions of modern warfare. Therefore, the military medical research on battlefield internal medicine should be based on contemporary military situations, focus on the purpose of treating battlefield internal diseases, and adhere to the actual needs of the troops in peacetime and wartime. We should investigate the pathogenesis of battlefield internal diseases and explore the threats that may arise in future wars to ensure the advancement of battlefield internal medicine. This review highlights new concepts, demands, challenges, and opportunities for the further development of military medical research on battlefield internal medicine.

Allele-specific expression and alternative splicing in horse×donkey and cattle×yak hybrids.

Divergence of gene expression and alternative splicing is a crucial driving force in the evolution of species; to date, however the molecular mechanism remains unclear. Hybrids of closely related species provide a suitable model to analyze allele-specific expression (ASE) and allele-specific alternative splicing (ASS). Analysis of ASE and ASS can uncover the differences in cis-regulatory elements between closely related species, while eliminating interference of trans-regulatory elements. Here, we provide a detailed characterization of ASE and ASS from 19 and 10 transcriptome datasets across five tissues from reciprocal-cross hybrids of horse×donkey (mule/hinny) and cattle×yak (dzo), respectively. Results showed that 4.8%-8.7% and 10.8%-16.7% of genes exhibited ASE and ASS, respectively. Notably, lncRNAs and pseudogenes were more likely to show ASE than protein-coding genes. In addition, genes showing ASE and ASS in mule/hinny were found to be involved in the regulation of muscle strength, whereas those of dzo were involved in high-altitude adaptation. In conclusion, our study demonstrated that exploration of genes showing ASE and ASS in hybrids of closely related species is feasible for species evolution research.

Activation of SphK1 by K6PC-5 Inhibits Oxygen-Glucose Deprivation/Reoxygenation-Induced Myocardial Cell Death.

In the current study, we evaluated the potential effect of a novel sphingosine kinase 1 (SphK1) activator, K6PC-5, on oxygen-glucose deprivation (OGD)/reoxygenation-induced damages to myocardial cells. We demonstrated that K6PC-5 increased intracellular sphingosine-1-phosphate (S1P) content and remarkably inhibited OGD/reoxygenation-induced death of myocardial cells (H9c2/HL-1 lines and primary murine myocardiocytes). SphK1 inhibitors, B-5354c and SKI-II, or SphK1-siRNA knockdown not only aggregated OGD/reoxygenation-induced cytotoxicity but also nullified the cytoprotection by K6PC-5. On the other hand, overexpression of SphK1 alleviated H9c2 cell death by OGD/reoxygenation, and K6PC-5-mediated cytoprotection was also enhanced in SphK1 overexpressed cells. Molecularly, OGD/reoxygenation activated the mitochondrial death pathway, evidenced by reactive oxygen species (ROS) production, mitochondrial membrane potential reduction, and p53-cyclophilin D (Cyp-D) association, which were all alleviated by K6PC-5 or overexpression of SphK1, but exacerbated by SphK1 knockdown. Furthermore, OGD/reoxygenation induced prodeath ceramide production in myocardial cells, which was largely suppressed by K6PC-5. In the meantime, adding a cell-permeable short-chain ceramide (C6) mimicked OGD/reoxygenation actions and induced ROS production and the mitochondrial death pathway in myocardial cells. Together, we conclude that K6PC-5 inhibits OGD/reoxygenation-induced myocardial cell death probably through activating SphK1. The results of the study indicate a potential benefit of K6PC-5 on ischemic heart disease.

Anatomical references for tibial sagittal alignment in total knee arthroplasty: a comparison of three anatomical axes based on 3D reconstructed CT images.

BACKGROUND: This study was designed to analyze three tibial axis reference lines including the anterior tibial cortex (ATC) line, the fibular line (FL), and the anatomical axis of tibia (AAT) line, to determine which line most closely parallels the mechanical axis (MA) of the tibia in the sagittal plane. The clinical relevance of the study is that through finding a reliable landmark on the leg, a surgeon may minimize posterior tibial slope measurement errors thereby and improving the technique for assuring proper alignment of total knee arthroplasty. METHODS: The material for this study included CT scans of the tibia from 85 consecutive patients and 168 knees (78 without osteoarthritis (OA) and 90 knees with OA). Measurements of the angles between the tibial mechanical axis and each of three reference lines in the sagittal plane were carried out using 3D imaging software. RESULTS: Mean angles of 168 knees were as follows: aMT (3.96±0.85)°, aMF (0.70±0.58)°, and aMA (1.40±0.66)°, (aMT: an angle between MA and ATC, aMF: an angle between MA and FL, aMA: an angle between MA and AAT. All abovementioned angles were measured in the sagittal plane of tibia) and the aMF was significantly smaller than the others (P < 0.0001). The mean value of the medial tibial slope angle vs. the MA was (9.19±3.97)°, and this was significantly larger than the mean lateral slope angle of (6.62±4.23)° (P < 0.0001). The difference between aMF without OA and with OA was not statistically significant (P = 0.5015) and the association between the aMT and aMA was strong (r = 0.82, P < 0.01). CONCLUSIONS: FL was more closely parallel to the MA of tibia, and more showed less variation between OA and non- OA controls than ATC and AAT lines. Furthermore, the amount of posterior slope in medial plateau was greater than that in lateral plateau. The findings of this analysis suggest that when using the anterior tibial cortex line as is commonly done with extramedullary tibial resection guides, the tibial resection should be sloped approximately four degrees more posteriorly.

[Cementless total hip arthroplasty for the management of advanced tuberculous coxitis].

OBJECTIVE: The question of whether a total joint arthroplasty should be attempted in a patient with a current or previous infection of tuberculosis continues to arouse controversy. The aim of this report was to evaluate the clinical outcomes of cementless total hip arthroplasty for the treatment of advanced tuberculosis of hip. METHODS: A total of 14 patients with advanced tuberculosis of hip treated by cementless total hip arthroplasty were retrospectively analyzed. For the patients with a definite diagnosis of tuberculosis and elevated levels of CRP (C-reactive protein) and ESR (erythrocyte sedimentation rate) before surgery, preoperative antituberculous medications were prescribed for at least 2 weeks. The inflamed soft tissues and destroyed bones were completely curetted out at the time of operation. Twelve of 14 patients received one-stage cementless total hip arthroplasty after a thorough debridement. For the remaining 2 patients, two-stage strategy was taken with cement articulating spacer implanted after a thorough debridement and followed by cementless total hip arthroplasty at 6-8 months later. All patients were prescribed antituberculous medications postoperatively for the first 6 months. RESULTS: The mean Harris Hip Score (HHS) was 36 preoperatively and 87 at the last follow-up. Within an average follow-up period of 49 months (range: 27 - 77), only one patient had reactivation of tuberculosis 7 months after primary THA (total hip arthroplasty) and received resection arthroplasty. Another 13 patients had no reactivation of tuberculosis and revealed stability by bone ingrowth on both socket and femoral stem. CONCLUSION: Cementless total hip arthroplasty is a safe and effective procedure for advanced tuberculosis of hip. With a thorough debridement followed by a complete course of antituberculous chemotherapy, active tuberculous infection should not be considered a contraindication for THA. In patients whose diagnosis of tuberculosis is confirmed intraoperatively and with no preoperative antituberculous chemotherapy, or in those a thorough debridement can not be achieved, a two-stage surgery may be considered.

[Cementless two-staged total hip arthroplasty for chronic periprosthetic infection].

OBJECTIVE: To determine the clinical outcomes of two-staged cementless revision arthroplasty for the treatment of deep periprosthetic infection after total hip arthroplasty. METHODS: Twenty-three patients with deep periprosthetic infection treated with a standard protocol of two-staged cementless revision hip arthroplasty were enrolled in this study. There were 9 male patients and 14 female patients with an average age of 64 years (range, 52-78 years). In all cases, antibiotics-loaded cement spacers were implanted after removal of all the prosthetic components and thorough debridements had been done. All patients had a minimum of 2 weeks of intravenous antibiotics followed by 4 weeks of oral antibiotics after implant removal. After a mean interval of 6.7 months (3-28 months), revision arthroplasties were carried out with cementless femoral components followed by 2 weeks of intravenous antibiotics and 4 weeks of oral antibiotics. RESULTS: The mean follow-up period was (4.3±3.5) years. There were 2 cases of recurrent infections in this study. Intraoperative periprosthetic fractures were observed in 3 patients. One patient had dislocation of the implanted spacer during the interval period and 2 patients had hip dislocation after reimplantation. Mild subsidence of femoral component occurred in 1 patient. There were no cases of loosening of femoral components and cementless acetabular components in patients without infection recurrence. The Harris hip score increased from a preoperative mean of 36±13 to 85±13 at 12 months after reimplantation. CONCLUSIONS: Using cementless prostheses in two-staged revisions of hip periprosthetic infections can provide low rate of infection recurrence and good implant stability, but cautions must be taken when treating patients with infection caused by multidrug-resistant organisms.