Correlation between preoperative frailty and postoperative delirium in elderly patients undergoing hip arthroplasty.

BACKGROUND: Postoperative delirium (POD) refers to acute brain dysfunction occurring within 7 days after operation or before discharge. Frailty refers to the state that the body's physiological reserve is insufficient, so that the compensative capacity to endogenous and exogenous stress stimuli decreases. The purpose of this study is to explore the association of preoperative frailty (PF) with POD in elderly patients undergoing hip arthroplasty. METHODS: Totally 228 elderly patients (age ≥ 65 years) who received elective hip arthroplasty in the Ningbo No. 6 Hospital between December 2021 and June 2022 were enrolled. One day before surgery, the frailty phenotype scale was adopted for evaluation of patients' frailty. On the 1st-3rd day after operation, the confusion assessment method was adopted for evaluation of delirium, and the patients were grouped into a POD group and non-POD group. Logistic regression was conducted to analyze the correlation between PF and POD. RESULTS: Among the patients, the incidence of PF was 30.70% (70/228), and the incidence of delirium within 3 days after operation was 25.88% (59/228). According to binary logistic regression analysis, PF, age, hypertension, diabetes mellitus, and preoperative sleep disorder were independent risk factors for POD in elderly patients undergoing hip arthroplasty (all P < .05). CONCLUSION: PF is a crucial risk factor for POD in elderly patients undergoing hip arthroplasty.

Veratramine ameliorates pain symptoms in rats with diabetic peripheral neuropathy by inhibiting activation of the SIGMAR1-NMDAR pathway.

CONTEXT: Veratramine may have a potential therapeutic effect for diabetic peripheral neuropathy (DPN). OBJECTIVE: To evaluate whether veratramine ameliorates neuropathic pain in a rat diabetic model. MATERIALS AND METHODS: Sprague-Dawley rats were used for a diabetic model induced by a streptozotocin + high-fat diet. Two months after the induction of the diabetic model, the rats with DPN were screened according to the mechanical pain threshold. The rats with DPN were divided into a model group (n = 12) and a treated group (n = 12). Rats with diabetes, but without peripheral neuropathy, were used in the vehicle group (n = 9). The treatment group received 50 µg/kg veratramine via the tail vein once a day for 4 weeks. During modelling and treatment, rats in all three groups were fed a high-fat diet. RESULTS: The mechanical withdrawal threshold increased from 7.5 ± 1.9 N to 17.9 ± 2.6 N in DPN rats treated with veratramine. The tolerance time of the treated group to hot and cold ectopic pain increased from 11.8 ± 4.2 s and 3.4 ± 0.8 s to 20.4 ± 4.1 s and 5.9 ± 1.7 s, respectively. Veratramine effectively alleviated L4-L5 spinal cord and sciatic nerve pathological injury. Veratramine inhibited the expression of SIGMAR1 and the phosphorylation of the N-methyl-d-aspartate receptor (NMDAR) Ser896 site in spinal cord tissue, as well as inhibited the formation of SIGMAR1-NMDAR and NMDAR-CaMKII complexes. DISCUSSION AND CONCLUSIONS: Veratramine may alleviate the occurrence of pain symptoms in rats with DPN by inhibiting activation of the SIGMAR1-NMDAR pathway.

Exosomes carried miR-181c-5p alleviates neuropathic pain in CCI rat models.

Mesenchymal stem cells (MSCs) derived exosomes (Exos) are one of the most promising candidate for the treatment of this condition. However, the underlying molecular mechanism remains uncertain. Here we investigated the therapeutic effect of exosomal miR-181c-5p (ExomiR-181c-5p) on a rat model of neuropathic pain induced by sciatic nerve chronic constriction injury (CCI). In this study NP model was established using the CCI method. NP levels were assessed using PWT and PWL. Microarray analysis and RT-PCR were used to determine the relative expression of miR-181c-5p. MSC-derived exosomes were extracted using the total exosome isolation reagent characterized by WB and NTA. MiR-181c-5p was loading into Exos using electroporation. The inflammation response in microglia cells and CCI rats were assessed by ELISA assay respectively. Our study demonstrates that miR-181c-5p expression was obviously decreased in a time-dependent manner in CCI rats. MiR-181c-5p was effectively electroporated and highly detected in MSC-derived Exos. ExomiR-181c-5p internalized by microglia cells and inhibit the secretion of inflammation factors. ExomiR-181c-5p intrathecal administration alleviated neuropathic pain and neuroinflammation response in CCI rats. Taken together, ExomiR-181c-5p alleviated CCI-induced NP by inhibiting neuropathic inflammation. ExomiR-181c-5p may be a valid alternative for the treatment of neuropathic pain and has vast potential for future development.

Knockdown of lncRNA PCAI protects against cognitive decline induced by hippocampal neuroinflammation via regulating SUZ12.

AIMS: Postoperative cognitive dysfunction (POCD) is a common postoperative complication that is associated with increased morbidity and mortality. However, the mechanism of pathogenesis of POCD still remains largely unknown. The aim of the study was to investigate the function and mechanism of lncRNA PCAI in POCD. MATERIALS AND METHODS: Knockdown and overexpression studies were performed to analyze the function of lncRNA PCAI in cultured BV-2 cell lines treated with LPS to mimic the neuroinflammation. Real-time PCR, western blot, ELISA were used to determine the expression level of inflammation markers. Rescue experiment was performed to prove the relationship between PCAI and SUZ12. RESULTS: We found that the expression of lncRNA PCAI was decreased with the increasing concentrations of LPS. Knockdown of lncRNA PCAI inhibited the cell death rates and attenuated the cell inflammation via ELISA and real-time PCR. Besides, downregulated of lncRNA PCAI can protect the mitochondrial function via membrane potential assay. Overexpression of lncRNA PCAI can promote the cell death and inflammation response induced by LPS. We also provided mechanism study about lncRNA PCAI that negatively regulating SUZ12. Rescue experiment also verified the results. CONCLUSION: We performed comprehensive study of functional analysis of lncRNA PCAI in POCD and proved its mechanism, which negatively regulate SUZ12. Our study provided new clues for the clinical intervention and targets for POCD.

miR-384-5p ameliorates neuropathic pain by targeting SCN3A in a rat model of chronic constriction injury.

Objective: To explore the potential regulation mechanisms of miR-384-5p in Neuropathic pain (NP).Methods: Rat model of chronic constriction injury (CCI) was established to induce NP in vivo. NP levels were assessed using Withdrawal Threshold (PWT) and Paw Withdrawal Latency (PWL). qPCR and Western blotting were used to determine the relative expression of miR-384-5p and SCN3A. The inflammation response in spinal microglia cells was determined by ELISA assay. Immunofluorescence assay was used to demonstrate the co-localization of miR-384-5p with SCN3A in rat dorsal root ganglions (DRGs). The target genes of miR-384-5p were verified by dual-luciferase report assays.Results: In the current study, the miR-384-5p expression level was significantly downregulated in CCI rats when comparing to the sham group. In addition, miR-384-5p agomir significantly repressed mechanical allodynia and heat hyperalgesia in CCI rats. Meanwhile, the current study indicated miR-384-5p could decrease inflammation progress in spinal microglia cells incubated in lipopolysaccharide. Consistently, overexpression of miR-384-5p obviously depressed inflammation cytokine levels in CCI rats. Dual-luciferase reporter assays indicated that SCN3A is a target gene of miR-384-5p.Conclusion: miR-384-5p is a negative regulator in the development of neuropathic pain by regulating SCN3A, indicating that miR-384-5p might be a promising therapeutic target in the treatment of neuropathic pain.Abbreviations: CCI: Chronic constriction injury; ZEB1: Zinc finger E box binding protein-1; MAPK6: Mitogen-activated protein kinase 6; COX-2: cyclooxygenase-2.