Circular RNA PDK1 targets miR-4731-5p to enhance TNXB expression in ligamentum flavum hypertrophy.

Hypertrophic ligamentum flavum (LF) is a main factor responsible for lumbar spinal stenosis (LSS); however, the exact mechanisms of the pathogenesis of these processes remain unknown. This study aimed to elucidate whether circular RNAs and microRNAs regulate the pathogenesis of LF and LSS, especially focusing on circPDK1 (hsa_circ_0057105), a circRNA targeting pyruvate dehydrogenase kinase 1 and differentially expressed in LF tissues between lumbar disk herniation and LSS patients. The circPDK1/miR-4731 and miR-4731/TNXB (Tenascin XB) interactions were predicted and validated by luciferase reporter assay. Colony formation, wound-healing, and MTT assays were used for estimating cell proliferation and migration. Protein expression levels were evaluated using Western blotting. TNXB expression was verified using immunohistochemistry (IHC). Overexpressing circPDK1 promoted the proliferation, migration, and expression of fibrosis-related protein (alpha smooth muscle actin (α-SMA), lysyl oxidase like 2 (LOXL2), Collagen I, matrix metalloproteinase-2 (MMP-2) and TNXB) in LF whereas miR-4731-5p showed opposite effects. The expression of TNXB was promoted by circPDK1; contrary results were observed with miR-4731-5p. Co-overexpression of miR-4731-5p partially reversed the proliferative and fibrosis-prompting effects of circPDK1 or TNXB. The circPDK1-miR-4731-TNXB pathway may be proposed as a regulatory axis in LF hypertrophy, which might shed light on in-depth research of LSS, as well as providing a novel therapeutic target for LF hypertrophy-induced LSS.

[Study on mechanism of salidroside against liver fibrosis by regulating CXCL16].

In order to investigate the effect of salidroside on inhibiting liver fibrosis and its relationship with CXC chemokine ligand 16(CXCL16) in vivo and in vitro, totally 45 C57 BL/6 J male mice were randomly divided into normal group, model group and salidroside group, with 15 mice in each group. The mice in model group and salidroside group were injected intraperitoneally with 15% carbontetrachloride(CCl_4) olive oil solution to establish liver fibrosis model, and the mice in normal group were injected intraperitoneally with the same dose of olive oil. Salidroside group was given with 100 mg·kg~(-1 )salidroside by gavage, while the normal group and model group received the same amount of double distilled water by gavage. All mice were sacrificed after 5 weeks of intragastric administration. The pathological changes of mouse liver were observed by hematoxylin-eosin(HE) staining, and the degree of liver fibrosis was observed by sirius red staining. The protein expressions of collagen Ⅰ(ColⅠ), α-smooth muscle actin(α-SMA), fibronectin(FN), CXCL16, phosphorylated Akt(p-Akt), Akt in liver tissues were detected by Western blot. Hepatic stellate cell line JS 1 was cultured in vitro and divided into control group, model group(100 µg·L~(-1) CXCL16) and salidroside group(100 µg·L~(-1) CXCL16+1×10~(-5) mol·L~(-1) salidroside). Cell migration was detected by cell scratch, the mRNA expressions of ColⅠ and α-SMA were detected by RT-PCR, and the protein expressions of p-Akt and Akt were detected by Western blot. As compared with the normal group, the protein expressions of ColⅠ, α-SMA, FN, CXCL16, and p-Akt in the model group were significantly increased, and salidroside could reduce the expression of these indicators(P<0.05 or P<0.01). In vitro, CXCL16 could promote the migration of JS 1, increase the mRNA expressions of ColⅠ and α-SMA in JS 1, and enhance Akt phosphorylation in JS 1(P<0.05 or P<0.01). As compared with the model group, salidroside could inhibit the migration of JS 1 induced by CXCL16(P<0.05), and reduce the high expression of ColⅠ and α-SMA mRNA and the phosphorylation of Akt in JS 1 induced by CXCL16(P<0.05). In conclusion, salidroside might attenuate CCl_4-induced liver fibrosis in mice by inhibiting the migration, activation and Akt phosphorylation of hepatic stellate cells induced by CXCL16.

Vertebral Body Compressive Strength Evaluated by Dual-Energy X-Ray Absorptiometry and Hounsfield Units In Vitro.

Dual-energy X-ray absorptiometry (DXA) and Hounsfield unit (HU) are 2 technologies used in vivo to assess bone mineral density and to predict fracture risk. However, few in vitro studies focus on the difference between the 2 technologies in the ability to determine vertebral body compressive strength. Forty-two lumbar vertebrates were harvested from 7 mature goats. All the vertebrae were imaged using clinical computed tomography and assessed by DXA subsequently. The individual vertebral body was then mechanically tested to failure in compression, to determine ultimate load and stress. HU has a moderate correlation with DXA (r = 0.64). DXA has significant associations with ultimate load and stress (r = 0.59 and 0.69, respectively). Significant positive linear correlations were also found between HU and ultimate load (r = 0.65) and stress (r = 0.81). There was no significant difference between HU and DXA to predict the ultimate load (t = 0.56, p = 0.577) or the ultimate stress (t = 1.62, p = 0.112). HU has an equal predictive value as the DXA for whole vertebral body compressive strength. This work supports the application of the HU measurement using clinical computed tomography imaging technology to assess bone strength and fracture risk.

The role of cage height on the flexibility and load sharing of lumbar spine after lumbar interbody fusion with unilateral and bilateral instrumentation: a biomechanical study.

BACKGROUND: One- and two-level lumbar interbody fusion with unilateral instrumentation is as effective as that with bilateral instrumentation. The height of the interbody cage influences the operated segment stability and the fusion technique success. The purpose of this research was to determine the effect of the fusion cage height (i.e. long and short) on both the stability (based on flexibility measures) and load sharing of the unilateral and bilateral instrumented transforaminal lumbar interbody fusion (TLIF) technique. METHODS: The flexibility and load sharing tests were performed on seven human lumbar spines. Different configurations combining a long or short cage with a unilateral, bilateral, or no posterior fixation were used to stabilize the operated segment. Two sets of modular cages were designed for each type of test to simulate the long and short cages. During the flexibility test, a pure-moment load of 7.5 Nm was applied. The range of motion (ROM) was recorded for flexion-extension, lateral bending, and axial rotation. During the load sharing test, an axial-compression load of 400 N was applied. The load bearing of the cages was recorded using a cage-embedded load cell. RESULTS: When the fusion cage height decreased 2 mm, the segment flexibility with unilateral fixation showed a significant increase in the ROM for flexion-extension, lateral bending, and axial rotation of 74.9, 83.8, and 175.2% (P < 0.01), respectively. In contrast, for bilateral fixation, the height decrease resulted in no significant change in ROM for flexion-extension (P = 0.686), lateral bending (P = 0.698), and axial rotation (P = 0.133). Using a short fusion cage, the load bearing decreased in 17.1, 21.5, and 54.1% (P < 0.05) for the cage alone, unilateral, and bilateral fixation, respectively. CONCLUSIONS: A cage longer than the intervertebral space should be chosen to increase the stability and intervertebral graft load borne when performing TLIF with unilateral instrumentation.

Beta1 integrin inhibits apoptosis induced by cyclic stretch in annulus fibrosus cells via ERK1/2 MAPK pathway.

Low back pain is associated with intervertebral disc degeneration (IVDD) due to cellular loss through apoptosis. Mechanical factors play an important role in maintaining the survival of the annulus fibrosus (AF) cells and the deposition of extracellular matrix. However, the mechanisms that excessive mechanical forces lead to AF cell apoptosis are not clear. The present study was to look for how AF cells sense mechanical changes. In vivo experiments, the involvement of mechanoreceptors in apoptosis was examined by RT-PCR and/or immunoblotting in the lumbar spine of rats subjected to unbalanced dynamic and static forces. In vitro experiments, we investigated apoptotic signaling pathways in untransfected and transfected AF cells with the lentivirus vector for rat ß1 integrin overexpression after cyclic stretch. Apoptosis in AF cells was assessed using flow cytometry, Hoechst 33258 nuclear staining. Western blotting was used to analyze expression of ß1 integrin and caspase-3 and ERK1/2 MAPK signaling molecules. In the rat IVDD model, unbalanced dynamic and static forces induced apoptosis of disc cells, which corresponded to decreased expression of ß1 integrin. Cyclic stretch-induced apoptosis in rat AF cells correlated with the activation of caspase-3 and with decreased levels of ß1 integrin and the phosphorylation levels of ERK1/2 activation level. However, the overexpression of ß1 integrin in AF cells ameliorated cyclic stretch-induced apoptosis and decreased caspase-3 activation. Furthermore, ERK1/2-specific inhibitor promotes apoptosis in vector ß1-infected AF cells. These results suggest that the disruption of ß1 integrin signaling may underlie disc cell apoptosis induced by mechanical stress. Further work is necessary to fully elucidate the pathophysiological mechanisms that underlie IVDD caused by unbalanced dynamic and static forces.

TIMP3 regulates osteosarcoma cell migration, invasion, and chemotherapeutic resistances.

Tissue inhibitors of metalloproteinases (TIMPs) inhibit matrix metalloproteinases (MMPs) to limit degradation of the extracellular matrix. Low levels of TIMP3 have been demonstrated in cancer tissues at advanced clinical stages, with positive distant metastasis and chemotherapeutic resistance. We examined the role of TIMP3 in osteosarcoma (OS) cell invasiveness and chemoresistance. TIMP3 was overexpressed or knocked down in the human OS cell lines Saos2 and MG63. Cell migration and invasion capacities were then evaluated using Transwell assays, and resistance to cisplatin was assessed by CCK-8 assay and flow cytometry. Real-time PCR and western blotting were used to investigate activation of signaling pathways downstream of TIMP3. Overexpression of TIMP3 inhibited the migration and invasion of Saos2 and MG63 cells, while knockdown of TIMP3 had the opposite effect. Cell survival after exposure to cisplatin was inhibited by TIMP3 overexpression in both Saos2 and MG63 cells. Consistently, downregulation of TIMP3 gene expression significantly decreased the sensitivity of OS cells to cisplatin treatment. MMP1, MMP2, Bcl-2, and Akt1 were all downregulated following TIMP3 overexpression, while Bax and cleaved caspase-3 were upregulated. TIMP3 knockdown had opposite effects on the regulation of these genes. Taken together, our findings suggest TIMP3 as a new target for inhibition of OS progression and chemotherapeutic resistance.

Unilateral versus bilateral instrumented transforaminal lumbar interbody fusion in two-level degenerative lumbar disorders: a prospective randomised study.

PURPOSE: The aim of this study was to analyse the clinical and radiological outcomes of unilateral versus bilateral instrumented TLIF in two-level degenerative lumbar disorders. METHODS: A prospective randomised clinical study was performed from January 2008 to May 2011. Sixty-eight consecutive patients with severe low back pain and radicular pain were divided randomly into the unilateral (n = 33) or bilateral (n = 35) pedicle screw fixation group based on a random number list. Operative time, blood loss, duration of hospital stay, fusion rate, complication rate and implant costs were recorded and analysed statistically. Visual analog scale (VAS) scores, Oswestry Disability Index (ODI), and SF-36 were used to assess the preoperative and postoperative clinical results in the two groups. RESULTS: No differences were observed between the two groups with respect to demographic data. The patients of the two groups had significant improvement in functional outcome compared to preoperatively. There was no significant difference comparing fusion rate, complication rate and duration of hospital stay between the two groups at postoperative follow-up (P > 0.05). However, compared with the bilateral pedicle screw group, a significant decrease occurred in operative time, blood loss and implant costs in the unilateral group. CONCLUSION: Two-level unilateral instrumented TLIF is an effective and safe method with reduced operative time and blood loss for multiple-level lumbar diseases. But it is imperative that the larger cage should be appropriately positioned to support the contralateral part of the anterior column by crossing the midline of the vertebral body.

[Performance of FibroScan in evaluating the curative effects of traditional Chinese medicine on liver fibrosis].

OBJECTIVE: To assess the performance of FibroScan in evaluating the curative effects of traditional Chinese medicine (TCM) on liver fibrosis, and to analyze factors influencing the diagnostic accuracy. METHODS: Data of FibroScan values, types of disease, use of drug, liver function indexes, prothrombin time (PT) and international normalized ratio (INR) were collected at both pre- (1 month prior) and post-FibroScan for 102 patients who underwent at least two FibroScan procedures. Patients were subgrouped according to presence of fibrosis, presence of cirrhosis, and TCM formulation and statistically analyzed. RESULTS: The pre- and post-FibroScan mean liver stiffness measurements (LSMs) were significantly different when the variation of LSM was more than or equal to2 kPa for the non-fibrotic group (vs. the fibrotic group), or when the variation wasmore than or equal to4 kPa for the cirrhotic group (vs. the non-cirrhotic group). In addition, the three TCM formulation groups showed significant differences, with the most robust difference exhibited between the FuZheng HuaYu formulation group and the other treatment groups (P = 0.010). No significant differences were observed for the liver function indexes, PT, or INR. However, the post-FibroScan levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) was significantly reduced in patients with reduced LSM. CONCLUSION: FibroScan may be a useful non-invasive clinical tool for evaluating the comprehensive curative effect of treatments for chronic liver diseases, and its performance is not obviously impacted by ALT, AST, GGT, PT, and INR. The criteria for efficacy established by FibroScan are 2 kPa for the patients without liver fibrosis and 4 kPa for patients with liver cirrhosis.

Incidence and prognosis of olfactory and gustatory dysfunctions related to SARS-CoV-2 Omicron strain infection in China: A national multicenter survey of 35,566 individuals.

Objective: This cross-sectional study aimed to determine the epidemiology of olfactory and gustatory dysfunctions related to COVID-19 in China. Methods: This study was conducted by 45 tertiary Grade-A hospitals in China. Online and offline questionnaire data were obtained from patients infected with COVID-19 between December 28, 2022, and February 21, 2023. The collected information included basic demographics, medical history, smoking and drinking history, vaccination history, changes in olfactory and gustatory functions before and after infection, and other postinfection symptoms, as well as the duration and improvement status of olfactory and gustatory disorders. Results: Complete questionnaires were obtained from 35,566 subjects. The overall incidence of olfactory and taste dysfunction was 67.75%. Being female or being a cigarette smoker increased the likelihood of developing olfactory and taste dysfunction. Having received four doses of the vaccine or having good oral health or being a alcohol drinker decreased the risk of such dysfunction. Before infection, the average olfactory and taste VAS scores were 8.41 and 8.51, respectively; after infection, they decreased to 3.69 and 4.29 and recovered to 5.83 and 6.55 by the time of the survey. The median duration of dysosmia and dysgeusia was 15 and 12 days, respectively, with 0.5% of patients having symptoms lasting for more than 28 days. The overall self-reported improvement rate was 59.16%. Recovery was higher in males, never smokers, those who received two or three vaccine doses, and those that had never experienced dental health issues, or chronic accompanying symptoms. Conclusions: The incidence of dysosmia and dysgeusia following infection with the SARS-CoV-2 virus is high in China. Incidence and prognosis are influenced by several factors, including sex, SARS-CoV-2 vaccination, history of head-facial trauma, nasal and oral health status, smoking and drinking history, and the persistence of accompanying symptoms.

Ubiquitin E3 ligase A20 facilitates processing microbial product in nasal epithelial cells.

Microbial products play a role in the pathogenesis of allergic diseases; ubiquitin E3 ligase A20 (A20) is an important molecule in regulating inflammation in the body. The present study aims to elucidate the role of A20 in processing the absorbed microbial products in nasal epithelial cells. Human nasal mucosal specimens were collected from patients with or without chronic rhinitis and analyzed by immunohistochemistry. Human nasal epithelial cell line, RPMI2650 cell, was employed to assess the role of A20 in processing the absorbed staphylococcal enterotoxin B (SEB). The RPMI2650 cells absorbed SEB in the culture. The increase in A20 was observed in RPMI2650 cells in parallel to the absorption of SEB. A20 is a critical molecule in the degradation of SEB in the nasal epithelial cells by promoting the tethering of endosomes and lysosomes. A20 plays a critical role in processing of the absorbed SEB in nasal epithelial cells.

Quantitative T2 mapping to characterize the process of intervertebral disc degeneration in a rabbit model.

BACKGROUND: To investigate the potential of T2 mapping for characterizing the process of intervertebral disc degeneration (IDD) in a rabbit model. METHODS: Thirty-five rabbits underwent an annular stab to the L4/5 discs (L5/6 discs served as internal normal controls). Degenerative changes were graded according to the modified Thompson classification and quantified in T2 respectively at pre-operation, 1, 3, 6, 12 and 24 weeks postoperatively. After MRI analysis, expression analysis of aggrecan and type II collagen gene in nucleus pulposus (NP) was performed using real time polymerase chain reaction (real-time PCR). The longitudinal changes in NP T2 and gene expressions were studied by repeated measures and ANOVA, linear regression was performed for their correlations through the process of IDD. The reliability analysis of method of measurement of NP T2 was also performed. RESULTS: There was a strong inverse correlation between NP T2 and Thompson grades (r = -0.85). The decline of L4/5 NP T2 through 24 weeks was nonlinear, the most significant decrease was observed in 3 weeks postoperatively (P<0.05). The tendency was confirmed at gene expression levels. NP T2 correlated strongly with aggrecan (R² = 0.85, P<0.01) and type II collagen (R² = 0.78, P<0.01) gene expressions. The intraclass correlation coefficients for interobserver and intraobserver reliability were 0.963 and 0.977 respectively. CONCLUSIONS: NP T2 correlates well with aggrecan and type II collagen gene expressions. T2 mapping could act as a sensitive, noninvasive tool for quantitatively characterizing the process of IDD in longitudinal study, help better understanding of the pathophysiology of IDD, assist us to detect the degenerative cascade, and develop a T2-based quantification scale for evaluation of IDD and efficacy of therapeutic interventions.

Integrin alphaMbeta2 clustering triggers phosphorylation and activation of protein kinase C delta that regulates transcription factor Foxp1 expression in monocytes.

Integrins are type I membrane and heterodimeric (alphabeta) cell adhesion receptors. Intracellular signals triggered by ligand-bound integrins are important for cell growth, differentiation, and migration. Integrin alpha(M)beta(2) plays key roles in myeloid cell adhesion, phagocytosis, and degranulation. In this study, we show that protein kinase C (PKC) delta is involved in alpha(M)beta(2) signaling. In human monocytic U937 cells and peripheral blood monocytes, alpha(M)beta(2) clustering induced PKCdelta translocation to the plasma membrane, followed by Tyr(311) phosphorylation and activation of PKCdelta by the src family kinases Hck and Lyn. Interestingly, alpha(M)beta(2)-induced PKCdelta Tyr(311) phosphorylation was not mediated by the tyrosine kinase Syk, which is a well reported kinase in beta(2) integrin signaling. Analysis of the beta(2) cytoplasmic tail showed that the sequence Asn(727)-Ser(734) is important in alpha(M)beta(2)-induced PKCdelta Tyr(311) phosphorylation. It has been shown that alpha(M)beta(2) clustering regulates the expression the transcription factor Foxp1 that has a role in monocyte differentiation. We show that Foxp1 expression was reduced in monocytes that were allowed to adhere to human microvascular endothelial cells. However, the expression of Foxp1 was not affected in monocytes that were treated with PKCdelta-targeting small interfering RNA, suggesting that PKCdelta regulates Foxp1 expression. These results demonstrate a role of PKCdelta in alpha(M)beta(2)-mediated Foxp1 regulation in monocytes.

Reliability and Validity Analysis of Pelvic Sagittal Inclination Calculated by Inverse Cosine Function Method on Pelvic Anteroposterior Radiographs.

OBJECTIVE: Evaluation of sagittal pelvic tilt is significant for hip surgeons. However, the accurate measurement of pelvic sagittal inclination (PSI) is still a challenge. The objective of this study is to propose a new method for measurement of PSI from pelvic anteroposterior radiograph based on the inverse cosine function obtained from individualized pelvic model. METHODS: Collecting the imaging data of 30 patients with both pelvic CT and full-length spine radiographs. Establishing pelvic model by customized 3D reconstruction software. The length of three groups of longitudinal and transverse line segments (A'p and B') were measured from full-length spine anteroposterior radiographs. The corresponding anatomical parameters, including A, B, b, ∠α, ∠γ, were measured and calculated on the same patient's pelvic model. The estimated PSI (ePSI) based on three groups of anatomical landmarks, including ePSI-1, ePSI-2, and ePSI-3, were calculated by equation, ePSI = arccos A ' p b * B ' - ∠ α , and compared with the actual PSI (aPSI) measured by Surgamap software. For the reliability and validation evaluation, three observers measured these parameters in two rounds. Intra-class correlation and inter-class correlation were both calculated. Bland-Altman method was used to evaluate the consistency between the estimated PSI (ePSI) and the actual PSI (aPSI). RESULTS: ePSI-1 and ePSI-2 showed excellent intra-observer reliability (0.921-0.997, p < 0.001) and inter-observer reliability (0.801-0.977, p < 0.001). ePSI-3 had a fair inter-observer reliability (0.239-0.823, p < 0.001). ePSI-1 showed the strongest correlation with aPSI (r = 0.917, p < 0.001). Mean (maximum) absolute difference of ePSI-1, ePSI-2, and ePSI-3 is 2.62° (7.42°), 4.23° (13.78°), and 7.74° (31.47°), respectively. The proportion of cases with absolute difference less than 5° in three groups were 86.7% (ePSI-1), 66.7% (ePSI-2), 56.7% (ePSI-3). CONCLUSION: This new method based on inverse cosine function has good reliability and validity when used in the evaluation of PSI on pelvic anteroposterior radiographs.

Circadian rhythm disruption exacerbates Th2-like immune response in murine allergic airway inflammation.

BACKGROUND: Chronic jet lag (CJL)-induced circadian rhythm disruption (CRD) is positively correlated with an increased risk of allergic diseases. However, little is known about the mechanism involved in allergic rhinitis (AR). METHODS: Aberrant light/dark cycles-induced CRD mice were randomly divided into negative control (NC) group, AR group, CRD+NC group, and CRD+AR group (n = 8/group). After ovalbumin (OVA) challenge, nasal symptom scores were recorded. The expression of Occludin and ZO-1 in both nasal mucosa and lung tissues was detected by reverse transcription-quantitative polymerase chain reaction (RT-PCR) and immunohistochemical staining. The level of OVA-specific immunoglobulin E (sIgE) and T-helper (Th)-related cytokines in the plasma was measured by enzyme-linked immunosorbent assay (ELISA), and the proportion of Th1, Th2, Th17, and regulatory T cell (Treg) in splenocytes was evaluated by flow cytometry. RESULTS: The nasal symptom score in the CRD+AR group was significantly higher than those in the AR group with respect to eosinophil infiltration, mast cell degranulation, and goblet cell hyperplasia. The expression of ZO-1 and Occludin in the nasal mucosa and lung tissues in the CRD+AR group were significantly lower than those in the AR group. Furthermore, Th2 and Th17 cell counts from splenocytes and OVA-sIgE, interleukin 4 (IL-4), IL-6, IL-13, and IL-17A levels in plasma were significantly increased in the CRD+AR group than in the AR group, whereas Th1 and Treg cell count and interferon γ (IFN-γ) level were significantly decreased in the CRD+AR group. CONCLUSION: CRD experimentally mimicked CJL in human activities, could exacerbate local and systemic allergic reactions in AR mice, partially through decreasing Occludin and ZO-1 level in the respiratory mucosa and increasing Th2-like immune response in splenocytes.

Lentiviral shRNA silencing of CHOP inhibits apoptosis induced by cyclic stretch in rat annular cells and attenuates disc degeneration in the rats.

The expression of CHOP (C/EBP homologous protein), an apoptosis regulated gene, increases during endoplasmic reticulum (ER) stress induced by cyclic stretch and leads to rat AF cells apoptosis. However, whether the suppression of CHOP can inhibit apoptosis and attenuates disc degeneration by cyclic stretch remains unclear. The aim of this study was to evaluate the suppressive effects of lentiviral CHOP shRNA on apoptosis induced by cyclic stretch in rat annulus fibrosus (AF) cells in vitro and disc degeneration of rat lumber spine in vivo. Lentiviral CHOP shRNA was constructed and introduced into AF cells. After stretched by the Flexcell Tension Plus system with 20% elongation for 36 h, silencing of the CHOP gene was identified by RT-PCR and Western blot. Inhibition of apoptosis was detected by flow cytometry, and nuclei morphologic changes were visualized by Hoechst 33258 staining. The effect of CHOP shRNA on disc degeneration was determined in vivo by using a rat model. At 7 weeks after intradiscal injection of the control or CHOP shRNA in the L4/L5 and L5/L6 discs, disc degeneration was assessed by X-ray examination, magnetic resonance imaging (MRI) assessment, and HE and TUNEL staining. A significant decrease in CHOP mRNA and protein expression was detected in AF cells with CHOP shRNA transfection after 36 h stretch. There was a significant decrease in apoptotic incidence in cells treated with CHOP shRNA, which was parallel to the expression of CHOP. Injection of CHOP shRNA in vivo resulted in the improvement in MRI and histologic score, and decrease in the apoptosis in the disc. No significant change in disc height was observed. In conclusion, a novel lentiviral vector expressing CHOP shRNA efficiently inhibits apoptosis in rat AF cells by silencing CHOP expression. In a rat model, intradiscal injection of CHOP shRNA induces the suppression of disc degeneration. The therapeutic effects of lentiviral CHOP shRNA should be further explored.

Cyclic stretch-induced apoptosis in rat annulus fibrosus cells is mediated in part by endoplasmic reticulum stress through nitric oxide production.

Various mechanical stresses in vivo induce disc cell apoptosis and intervertebral disc (IVD) degeneration, but the underlying molecular mechanism is not fully known. The aim of this study was to investigate the role of endoplasmic reticulum stress in cyclic stretch-induced apoptosis of rat annulus fibrosus (AF) cells. Flexercell Tension Plus system was used to apply cyclic stretch to rat annulus fibrosus cells at a frequency of 0.5 Hz with 20% elongation for 12, 24, 36, or 48 h. Apoptosis was detected by flow cytometry, and nuclei morphologic changes were visualized by Hoechst 33258 staining and caspase-8, 9 activity assays. The expression of the markers of endoplasmic reticulum stress including CHOP, GRP78, and caspase-12 were determined by RT-PCR and Western blot. Mitochondrial membrane potential change was observed by JC-1 staining in situ. In addition, the levels of the nitric oxide (NO) were determined with the Griess reaction and fluorescence staining. The results indicated that cyclic stretch at a frequency of 0.5 Hz with 20% elongation-induced apoptosis in rat AF cells. Prolonged exposure of the unphysiologically cyclic stretch to AF cells caused NO overproduction, up-regulation of endoplasmic reticulum stress markers including CHOP, GRP78, and caspase-12, depolarization of mitochondria and activation of caspase-9. However, cyclic stretch at this level had no effect on caspase-8 activity. In addition, specific inhibitor of caspase-12 (Z-ATAD-FMK) and caspase-9 (Z-LEHD-FMK) partly suppressed cyclic stretch-induced AF cell apoptosis and the anti-apoptotic effects of the caspase inhibitors were additive. Our data suggest that endoplasmic reticulum stress, likely mediated by NO, contributes to the AF cell apoptosis induced by cyclic stretch in addition to the mitochondrial pathway. These findings could be helpful to understand the mechanism of disc cell apoptosis, the root cause of IVD degeneration.

Subdural fluid collection rather than meningitis contributes to hydrocephalus after cervical laminoplasty: A case report.

BACKGROUND: Hydrocephalus following dural tear after spinal surgery is rare. Although a few cases of obstructive hydrocephalus caused by subdural fluid collection and communicating hydrocephalus associated with meningitis have been reported, the mechanism remains uncertain. Herein we describe a patient complicated with hydrocephalus after cervical laminoplasty in whom subdural fluid collection in the cervical spine and posterior cranial fossa rather than chronic meningitis was the main mechanism. CASE SUMMARY: A 45-year-old man underwent cervical laminoplasty for cervical spondylotic myelopathy at a local hospital. Ten days postoperatively, a high fever occurred and magnetic resonance imaging (MRI) showed cerebrospinal fluid (CSF) leakage. Pseudomeningocele liquid test showed high levels of protein and white blood cell (WBC) count with negative bacterial culture. The patient was treated with short-term intravenous antibiotic and discharged with normal body temperature. The patient was uneventful during the first 8 mo follow-up although repeated MRI showed persistent pseudomeningocele. At the 9th mo postoperatively, the patient gradually presented with dizziness and headache accompanied by recurrent weakness of his left arm. Imaging examinations demonstrated hydrocephalus and a cystic lesion around the cervical spinal cord. CSF test from lumbar puncture indicated chronic meningitis. MRI on 1 d after pseudomeningocele drainage showed a significant decrease in the cystic volume, suggesting that the cystic lesion would be subdural fluid collection rather than adhesive arachnoiditis. After dural defect repair, the patient's symptoms completely resolved and hydrocephalus gradually disappeared. CSF analysis at the 21-mo follow-up revealed significantly decreased protein level and WBC count. CONCLUSION: Subdural fluid collection rather than meningitis contributes to the hydrocephalus formation after cervical laminoplasty.

Livin in synergy with Ras induces and sustains corticosteroid resistance in the airway mucosa.

Rationale: Corticosteroid resistance (CR) seriously affects the therapeutic effects of steroids on many chronic inflammatory disorders, including airway allergy. The mechanism of CR development is unclear. Recent research indicates that livin, an apoptosis inhibitor, is associated with the regulation in cell activities. This study investigates the role of livin in the inducing and sustaining CR in the airway mucosa. Methods: Nasal epithelial cells (NECs) were isolated from surgically removed nasal mucosal tissues of patients with allergic rhinitis (AR) and nasal polyps with or without CR. Differentially expressed genes in NECs were analyzed by the RNA sequencing. A CR mouse model was developed to test the role of livin in CR development. Results: The results showed that NECs of AR patients with CR expressed high levels of livin, that was positively correlated with the thymic stromal lymphopoietin (TSLP) expression and the high Ras activation status in NECs. Livin and Ras activation mutually potentiating each other in the inducing and sustaining the TSLP expression in NECs. TSLP induced eosinophils and neutrophils to express glucocorticoid receptor-ß (GRß). Eosinophils and neutrophils with high CRß expression were resistant to corticosteroids. Depletion of livin or inhibition of TSLP markedly attenuated CR and airway allergy. Conclusions: Livin facilitates CR development in the airways by promoting TSLP expression in epithelial cells and the GRß expression in eosinophils and neutrophils. Depletion of livin or inhibiting TSLP attenuates CR development and inhibits airway allergy, this has the translational potential to be used in the treatment of airway allergy.

Role of FcγRI in Antigen-Dependent Eosinophil Activation in Patients With Allergic Rhinitis.

BACKGROUND: The eosinophil (Eo) activation is a crucial factor evoking allergic rhinitis (AR) attacks; factors; the mechanism of triggering Eo activation remains to be further investigated. The interaction of antigen (Ag) and antibody plays a critical role in evoking allergy attacks. This study aims to elucidate the role of FcγRI, the high affinity receptor of IgG, in the Ag-mediated Eo activation. METHODS: Nasal lavage fluids (NLF) were collected from AR patients and healthy control (HC) subjects. Eos were isolated by flow cytometry cell sorting and analyzed by pertinent immunological approaches. RESULTS: Eos composed more than 60% of the cellular components in AR NLF. Exposure to specific Ags (sAgs) in the culture triggered Eos to release inflammatory mediators. High levels of FcγRI were detected on the surface of AR NLF Eos. Exposure to lipopolysaccharide markedly increased the FcγRI expression in naive Eos, which could be bound by Ag-specific IgG (sIgG) to form complexes on the surface of Eos; this made Eos at the sensitized status. Eos bore with the sIgG/FcγRI complexes could be activated upon exposure to sIgG in the culture; these Eos can be designated as Ag-specific Eos. Passive transfer of Ag-specific Eos resulted in profound AR response in mice upon sAg challenge. Depletion of FcγRI on Eos efficiently abolished AR response in mice. CONCLUSIONS: AR Eos express high levels FcγRI, that can be bound by sIgG to make Eos sensitized. Re-exposure to specific Ags can activate the sensitized Eos.

A nationwide survey of otolaryngologists' compliance with Chinese guidelines for diagnosis and treatment of allergic rhinitis.

BACKGROUND: A higher compliance with clinical guidelines helps improve treatment outcomes. But the clinical practice of otolaryngologists is not always consistent with guidelines. OBJECTIVE: To describe otolaryngologists' compliance with guidelines about allergic rhinitis (AR) management and identify factors responsible for the discordance between clinical practice and guideline recommendations in China. METHODS: A cross-sectional nationwide survey was designed and conducted via an online platform. Recruitment was done by emailing otolaryngologists registered in the Chinese Society of Otorhinolaryngology-Head and Neck Surgery or by inviting otolaryngologists to scan a Quick Respond (QR) code that linked to the questionnaire at various academic meetings. RESULTS: A total of 2142 otolaryngologists were eligible and completed the survey. Of them, 64.7% had over 10 years work experience and 97.4% had a bachelor's degree or higher. About 18.3% of the participants strictly copied the guideline in clinical practice, while 73.7% used the guideline that had been adjusted according to their clinical experience. Otolaryngologists were most concerned about the efficacy, safety, and minimum age of AR medications, and least concerned about patient preferences. Regarding the use of intranasal steroids (INS), leukotriene receptor antagonists (LTRA), and H1-antihistamines, 86.8%, 55.7% and 51.2% of otolaryngologists complied with the guideline recommendations, respectively. Educational background was a factor affecting the compliance with guidelines and acceptance of INS. CONCLUSION: A vast majority of Chinese otolaryngologists complied with the current Chinese AR guidelines. A difference still existed between the otolaryngologists' real-world and guideline-recommended management. The otolaryngologists should pay more attention to patient preferences. A higher education could improve otolaryngologists' adherence to the guidelines.