MiR-423-5p Regulates Cells Apoptosis and Extracellular Matrix Degradation via Nucleotide-Binding, Leucine-Rich Repeat Containing X1 (NLRX1) in Interleukin 1 beta (IL-1ß)-Induced Human Nucleus Pulposus Cells.

BACKGROUND Disc degeneration is characterized partly by the degradation in the extracellular matrix (ECM) and excess apoptosis of nucleus pulposus (NP) cells. NLRX1 (nucleotide-binding, leucine-rich repeat containing X1) is different from the other nucleotide-binding-domain and leucine-rich-repeat proteins and mainly located to the mitochondrial. It negatively regulates NF-κB (nuclear factor kappa B) and apoptosis inhibition. However, how NLRX1 is regulated and exerts effects in disc degeneration is unclear. Thus, the study aimed to analyze the effects of NLRX1 on NP cells. MATERIAL AND METHODS NLRX1 expression was detected in interleukin (IL)-1ß-induced NP cells by western blot and quantitative real-time polymerase chain reaction (qRT-PCR). Then, NLRX1 was overexpressed in IL-1ß-induced NP cells to detect apoptosis-related proteins and the extracellular matrix (ECM) by western blot, along with the detection of apoptosis levels using flow cytometry. StarBase predicted miR-423-5p target 3'UTR of NLRX1. Dual luciferase reporter assay showed that miR-423-5p could bind to the 3'UTR of NLRX1. Besides, miR-423-5p significantly affected NLRX1 levels detected by qRT-qPCR. RESULTS The miR-423-5p overexpression markedly, and negatively regulated the protective effects of NLRX1 on IL-1ß induced NP cells. Thus, our results suggested that miR-423-5p mediated the regulation of NLRX1 to affect apoptosis and ECM levels in IL-1ß induced NP cells. CONCLUSIONS miR-423-5p and NLRX1 could be potential therapeutic targets for patients with disc degeneration.

Rim plate fixation for a rare fracture pattern of the lateral femoral condyle: A case report.

Osteochondral fractures of the lateral femoral condyle caused by lateral patella dislocation have been rarely reported. The AO/OTA Classification is not suitable for this uncommon injury. Comminution of the anterior cartilage surface of the lateral condyle with bone impaction is challenging to reduce and repair accurately, leading to uncertainty in joint function recovery. The treatment for this rare fracture is not commonly reported. We, herein, report a unique case where the lateral condyle osteochondral fracture occurred alongside patellar dislocation and instability of the patellofemoral joint. Autogenous bone grafting, open reduction, and internal fixation with a rim plate resulted in a satisfactory outcome.

[Diagnosis and treatment of 11 patients with cevical spondylotic amyotrophy].

OBJECTIVE: To explore clinical features, treatment methods and clinical effects of cervical spondylosis with proximal muscular atrophy. METHODS: Eleven patients with proximal-type cervical spondylotic amyotrophy were retrospectively studied from September 2016 to November 2020, including 7 males and 4 females, aged 38 to 68 years old. Clinical symptoms, MRI and neuroelectrophysiological manifestations were analyzed, and patients were treated with conservative treatment or anterior cervical decompression fusion surgery, respectively. The efficacy was evaluated by manual muscle test (MMT) before and after treatment, and patients' satisfaction was followed up at the same time. RESULTS: All patients were followed up for 6 to 19 months. All 11 patients were unilateral, mainly manifested by atrophy of deltoid muscle, supraspinatus muscle and infraspinatus muscle, and may be accompanied by ipsilateral neck and shoulder pain at early stage. MRI showed lesions at C4,5, C5,6 segments were more common. Electrophysiological examination showed the affected muscle was denervated, and amplitude of compound muscle action potential (CMAP) of innervated nerve on the affected side was lower than that on the healthy side. All patients were obtained bone fusion. One patient who were underwent anterior cervical corpectomy and fusion (ACCF) occurred developed contralateral C5 nerve root paralysis after operation, which recovered completely after 10 weeks of symptomatic treatment. At 12 months after operation, the efficacy was evaluated according to MMT, 3 patients were treated conservatively, 2 patients excellent and 1 good;in 8 patients treated by operation, 3 patients were excellent, 4 good, and 1 moderate. CONCLUSION: The incidence of cervical spondylosis with proximal muscular atrophy is low, which is manifested as unilateral proximal muscle atrophy and may be accompanied by ipsilateral neck and shoulder pain in the early stage. Combined with MRI and neuroelectrophysiological examination, misdiagnosis could be reduced. In the early stage of disease, especially in the case of nucleus pulposus protrusion leading to nerve compression, conservative treatment could be taken. When the conservative treatment is ineffective or the pain cannot be tolerated, anterior decompression surgery is recommended, and the overall effect is satisfactory.

Microglia prevent beta-amyloid plaque formation in the early stage of an Alzheimer's disease mouse model with suppression of glymphatic clearance.

BACKGROUND: Soluble beta-amyloid (Aß) can be cleared from the brain through various mechanisms including enzymatic degradation, glial cell phagocytosis, transport across the blood-brain barrier, and glymphatic clearance. However, the relative contribution of each clearance system and their compensatory effects in delaying the pathological process of Alzheimer's disease (AD) are currently unknown. METHODS: Fluorescent trace, immunofluorescence, and Western blot analyses were performed to compare glymphatic clearance ability and Aß accumulation among 3-month-old APP695/PS1-dE9 transgenic (APP/PS1) mice, wild-type mice, aquaporin 4 knock out (AQP4-/-) mice, and AQP4-/-/APP/PS1 mice. The consequence of selectively eliminating microglial cells, or downregulating apolipoprotein E (apoE) expression, on Aß burden, was also investigated in the frontal cortex of AQP4-/-/APP/PS1 mice and APP/PS1 mice. RESULTS: AQP4 deletion in APP/PS1 mice significantly exaggerated glymphatic clearance dysfunction, and intraneuronal accumulation of Aß and apoE, although it did not lead to Aß plaque deposition. Notably, microglia, but not astrocytes, increased activation and phagocytosis of Aß in the cerebral cortex of AQP4-/-/APP/PS1 mice, compared with APP/PS1 mice. Selectively eliminating microglia in the frontal cortex via local injection of clodronate liposomes resulted in deposition of Aß plaques in AQP4-/-/APP/PS1 mice, but not APP/PS1 mice. Moreover, knockdown of apoE reduced intraneuronal Aß levels in both APP/PS1 mice and AQP4-/-/APP/PS1 mice, indicating an inhibitory effect of apoE on Aß clearance. CONCLUSION: The above results suggest that the glymphatic system mediated Aß and apoE clearance and microglia mediated Aß degradation synergistically prevent Aß plague formation in the early stages of the AD mouse model. Protecting one or both of them might be beneficial to delaying the onset of AD.

Clinical significance of high expression of proliferating cell nuclear antigen in non-small cell lung cancer.

Although proliferating cell nuclear antigen (PCNA) plays an important role in tumor proliferation and its expression level is closely related to the biological activity of tumor cells, PCNA expression in non-small cell lung cancer (NSCLC) has been seldom reported. In this study, we aimed to investigate the significance of PCNA expression in NSCLC tissues. PCNA expression in NSCLC and adjacent tissues were assessed by immunohistochemistry (IHC), western blotting, and reverse transcription polymerase chain reaction. Single factor analysis was used to study the relationship between the expression of PCNA and clinicopathological features of NSCLC. Multi-factor Cox survival analysis was used to evaluate the relationship between the expression of PCNA and overall survival of postoperative NSCLC patients. The areas under the receiver operating characteristics were calculated to evaluate the value of PCNA expression level in predicting the 3-year survival of NSCLC patients. IHC analysis showed that the positive expression rates of PCNA protein in NSCLC and adjacent tissues were 91.79% (257/280) and 25.83% (31/120), respectively. Western blotting confirmed that PCNA protein level was significantly higher in NSCLC tissues than in the adjacent tissues (P < .05). Reverse transcription polymerase chain reaction showed that the positive rate of PCNA mRNA in NSCLC was 88.93% (249/280), which was significantly higher than that in adjacent tissues 29.17% (35/120) (P < .05). Both PCNA mRNA and protein levels were correlated with tumor differentiation, size, metastasis, and stage in NSCLC. Patients exhibiting higher PCNA protein expression had a significantly shorter disease-specific survival rate than the other patients. PCNA protein level and tumor pathological type, metastasis, differentiation degree, and stage were independent factors affecting the overall survival of postoperative patients. The areas under the receiver operating characteristics of PCNA mRNA for predicting the 3-year survival of NSCLC patients was 0.89 (0.79-0.98), with a sensitivity and specificity of 0.84 and 0.76, respectively. In conclusion, high PCNA protein and mRNA levels may be associated with the occurrence, development, and prognosis of NSCLC.

Deletion of aquaporin-4 aggravates brain pathology after blocking of the meningeal lymphatic drainage.

The glymphatic pathway and meningeal lymphatic vessels are involved in clearance of metabolic macromolecules from the brain. However, the functional interaction between the two systems in the maintenance of brain homeostasis remains unclear. Here we reported that deletion of aquaporin-4 (AQP4), a functional regulator of glymphatic clearance, aggravated brain pathology of 3 month-old mice after blocking of the meningeal lymphatic drainage for 2 weeks via ligation of the deep cervical lymphatic nodes (LdcLNs). LdcLNs increased total and phosphorylated Tau protein levels in the hippocampus of both genotype mice, but increased hippocampal amyloid beta 1-40 and 1-42 levels only in AQP4 null mice, with up-regulation of beta-site amyloid precursor protein-cleaving enzyme 1 and down-regulation of insulin degrading enzyme. Consistently, LdcLNs caused microglial reactivity and activation of nod-like receptor protein-3 inflammasomes in the AQP4 null hippocampus. These mice also showed hippocampal neuronal apoptosis and declines in exploring and cognitive abilities. Deletion of AQP4, but not LdcLNs, increased brain water content. Together, these findings have revealed respective and interactive roles of the glymphatic system and the dural lymphatic system in maintaining amyloid beta, Tau proteins and water homeostasis in the brain, helping to understand the pathogenesis of neurological diseases associated with mis-accumulation of brain macromolecules.