Injury In Rats Research Articles

Sex differences in the affective-cognitive dimension of neuropathic pain: Insights from the Spared Nerve Injury rat model

Over 40% of neuropathic pain patients experience mood and cognitive disturbances, often showing reduced response to analgesics, with most affected individuals being female. This highlights the critical role of biological sex in pain-related affective and cognitive disorders, making it essential to understand the emotional and cognitive circuits linked to pain for improving treatment strategies. However, research on sex differences in preclinical pain models is lacking. This study aimed to investigate these differences using the spared nerve injury (SNI) rat model, conducting a comprehensive series of behavioural tests over 100 days post-injury to identify key time points for observing sex-specific behaviours indicative of pain-related conditions. The findings revealed that female rats exhibited greater mechanical and cold hypersensitivity compared to males following nerve injury and showed earlier onset of depression-related behaviours, while males were more prone to anxiety, social, and memory-related alterations. Interestingly, by the 14th week post-injury, females displayed no signs of these emotional and cognitive impairments. Additionally, fluctuations in the oestrous cycle or changes in testosterone and oestradiol levels did not correlate with sex differences in pain sensitivity or negative affect. Recognizing the influence of biological sex on pain-induced affective and cognitive alterations, especially in later stages post-injury, is crucial for enhancing our understanding of this complex pain disorder. Data availabilityAccess to the raw data constituting the findings presented in this manuscript can be requested from the corresponding author of the publication.

Pharmacokinetics and brain uptake of sodium selenate and selenium in naïve rats and a lateral fluid percussion injury ratmodel.

Post-traumatic epilepsy (PTE) is a life-long complication of traumatic brain injury (TBI). The development of PTE is associated with neurological morbidity and increases the risk of mortality. An aim of EpiBioS4Rx (Epilepsy Bioinformatics Study for Antiepileptogenic Therapy) was to test potential therapies to prevent the development of PTE in the lateral fluid percussion injury (LFPI) rat model of TBI, in which rats were subjected to injury at the left parietal cortex. Sodium selenate has been reported to be antiepileptogenic post-TBI in rodent models by activating protein phosphatase 2A and reducing phosphorylated tau (p-tau) protein. We aimed to characterize the pharmacokinetics (PK) and brain uptake of sodium selenate using naïve control and LFPI rats. Rats received either a single bolus dose or a single bolus dose followed by a 7-day subcutaneous minipump infusion of sodium selenate. Sodium selenate and selenium concentrations in plasma and brain were analyzed and used for PK estimation and brain exposure assessment. Selenium concentrations rapidly increased after sodium selenate administration, demonstrating biotransformation from sodium selenate to selenium. Sodium selenate and selenium PK parameters were estimated using non-compartmental analysis. Sodium selenate clearance (CL/F) and volume of distribution (Vd/F) varied by dose and route of administration, suggesting differences in bioavailability and nonlinear pharmacokinetics at the doses tested. Brain-to-plasma partition coefficients (AUCbrain/AUCplasma) for sodium selenate and selenium were found to be 0.7-1.3 and 0.1-0.3 following single-dose injection, respectively, indicating active transport of sodium selenate across the blood-brain barrier (BBB).

Photobiomodulation reduces spinal cord edema by decreasing the expression of AQP4 in the astrocytes of male spinal cord injury rats via the JAK2/STAT3 signaling pathway.

BackgroundSpinal cord swelling commonly occurs following SCI. Previous studies suggest that PBM may reduce inflammation and scar formation after SCI. However, whether PBM can alleviate post-spinal cord injury edema and its underlying mechanisms have not yet been reported. This study aims to investigate the effects of PBM on spinal cord swelling in rats following SCI and explore the underlying mechanisms. MethodsA rat model of SCI was established, and the rats received continuous PBM therapy for two weeks. Tissue hydration, motor function, AQP4 expression, and pathological changes in the spinal cord were evaluated at different time points. In vitro, astrocytes were subjected to PBM and treated with either cucurbitacin I or TGN020 following OGD. ResultsThe results indicate that PBM reduces tissue swelling in rats with SCI, improves motor function recovery, and inhibits the upregulation of AQP4 and GFAP associated with SCI. In vitro, PBM reduces abnormal activation of the JAK2/STAT3 signaling pathway in astrocytes, leading to decreased AQP4 synthesis and astrocyte activation. ConclusionsThese findings suggest that PBM reduces spinal cord swelling in rats after injury. This effect is associated with the inhibition of JAK2/STAT3 signaling pathway activation in astrocytes and the reduction in AQP4 expression.

Electroacupuncture of "Jiaji" (EX-B2) inhibits inflammatory response by regulating HMGB1/TLR4/NF-κB signaling pathway in rats with spinal cord injury

To observe the effect of electroacupuncture (EA) of "Jiaji" (EX-B2) on expression of high mobility group box 1 (HMGB1)/Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) related proteins and inflammation-related factors in spinal cord injury (SCI) rats, so as to explore the dynamic process of inhibiting inflammatory response in rats with SCI, and to provide a new idea and theoretical basis of molecular biology for the treatment of SCI. Fifty-four SD rats were randomly divided into sham operation, model, and EA groups (n=18 in each group), which were further divided into 3 d, 7 d and 14 d subgroups, with 6 rats at each time point. The SCI model was established according to the Allen's method. Rats in EA group received EA (1 mA, 100 Hz) intervention at EX-B2 of T9 and T11 24 hours after modeling for 30 min, once a day for 3 d, 7 d, or 14 d, respectively. The motor function of rats' hind limbs was evaluated using BBB scale, the morphological structure of rats' spinal cord tissue was observed by H.E. staining. The contents of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in spinal cord tissue were detected by ELISA. Western blot and immunofluorescence staining were used to detect the relative protein expression and fluorescence positive expression of HMGB1, TLR4 and NF-κB p65 in spinal cord tissue, respectively. Compared with the sham operation group, the BBB scores after modeling and on day 3, 7 and 14 were all decreased (P<0.05), while the contents of iNOS and COX-2 in spinal cord tissue, the protein expression and fluorescence positive expression of HMGB1, TLR4, and NF-κB p65 were increased (P<0.05) in the model group. In comparison with the model group, the BBB scores on day 3, 7 and 14 were obviously increased (P<0.05), while the contents of iNOS and COX-2, the protein expression and fluorescence positive expression of HMGB1, TLR4, and NF-κB p65 were significantly down-regulated in the EA group (P<0.05). EA of "Jiaji" can promote the recovery of SCI neurological function, which may be related to its function in regulating the HMGB1/TLR4/NF-κB signaling pathway, down-regulating the expression of iNOS and COX-2, and inhibiting the neuroinflammatory response after SCI.

Silencing of SH3BP2 Inhibits Microglia Activation Via the JAK/STAT Signaling in Spinal Cord Injury Models.

The purpose of our study was to investigate the expression of SH3 domain-binding protein 2 (SH3BP2) in spinal cord injury (SCI) rats and lipopolysaccharide (LPS)-induced microglia, and explored its impact as well as potential mechanism. We examined the level of SH3BP2 in SCI rats using GEO data, immunofluorescence co-staining, qRT-PCR and western blotting. Next, we constructed a rat model with SH3BP2 silencing by injecting LV-shSH3BP2 into the injury site of SCI rats, and then evaluated its neurological outcome, functional recovery, M1 polarization and neuroinflammation by Basso-Beattie-Bresnahan (BBB) score, inclined plane test, Nissl staining and hematoxylin-eosin (H&E). The SH3BP2-related signaling pathway was predicted by KEGG analysis in GSE45006 dataset. BV2 microglial cells and primary microglia were incubated with LPS, and then measured its activation and inflammation by qRT-PCR, western blotting and immunofluorescence. Further complement experiments were performed to explore the molecular mechanisms of SH3BP2. The expression of SH3BP2 was increased in the spinal dorsal horn tissues of SCI rats and LPS-induced microglia. Silencing of SH3BP2 improved neurological outcomes and functional recovery, attenuated neuroinflammation and microglia polarization in SCI rats. Additionally, the JAK/STAT pathway was regulated by SH3BP2. Silencing of SH3BP2 inhibited LPS-induced microglia inflammation and activation, decreased the phosphorylation levels of JAK and STAT. Silencing of SH3BP2 attenuated SCI by regulating the JAK/STAT pathway to inhibit the activation of microglia.

Astragaloside IV Inhibits Lung Injury and Fibrosis Induced by PM2.5 by Targeting RUNX1 Through miR-362-3p.

To discover the molecular mechanism of Astragaloside IV (AS IV) in PM2.5-induced lung injury and pulmonary fibrosis (PF). A lung injury rat model was induced by PM2.5 and injected intraperitoneally with AS IV. Lungs were harvested to evaluate lung tissue injury and apoptosis. Rat alveolar epithelial cells L2 were exposed to PM2.5 and treated with AS IV. After cellular transfection, cell proliferation, LDH production, and apoptosis were measured. In both models, inflammatory factors and fibrotic indices were measured by ELISA and Western blot. miR-362-3p and RUNX1 interplay was explored and confirmed. Administration of AS IV attenuated PM2.5-induced lung tissue injury, inflammation, apoptosis, and PF in rats. AS IV enhanced proliferation and reduced LDH release, apoptosis, inflammation, and PF in PM2.5-treated L2 cells. MiR-362-3p upregulation improved PM2.5-induced L2 cell injury. AS IV improved PM2.5-induced lung injury by upregulating miR-362-3p. miR-362-3p had an inhibition effect on RUNX1 expression. RUNX1 upregulation weakened the therapeutic effect of AS IV on PM2.5-induced alveolar epithelial cell injury. AS IV inhibits lung injury and PF induced by PM2.5 by targeting RUNX1 through upregulation of miR-362-3p.

Neuroprotective Effects of Ethanol Extract Polyscias guilfoylei (EEPG) Against Glutamate Induced Neurotoxicity in HT22 Cells.

Oxidative stress induced by glutamate is a significant contributor to neuronal cell damage and can lead to neurodegenerative diseases such as Alzheimer's, Huntington's, and ischemic brain injury. At the cellular level, oxidative stress increases Ca2+ ion influx and reactive oxygen species (ROS), which activate the MAPK signaling pathway. Additionally, the generation of ROS causes mitochondrial dysfunction, triggering apoptosis by promoting the translocation of AIF to the nucleus from the mitochondria. The neuroprotective potential of Polyscias guilfoylei has not yet been reported. Therefore, in this study, the ethanol extract of Polyscias guilfoylei (EEPG) was examined for its protective effect against oxidative cell damage caused by glutamate in neuronal cells. EEPG treatment increased the viability of HT22 cells exposed to high concentrations of glutamate. Cellular Ca2+ ion influx and ROS generation decreased with EEPG treatment in glutamate-treated HT22 cells. EEPG treatment inhibited MAPK activation and AIF nuclear translocation. In an in vivo study, EEPG attenuated brain cell death in an ischemic brain injury rat model. This study demonstrates the potential therapeutic effects of Polyscias guilfoylei in the treatment of ischemic brain injury.

Harnessing the regenerative effects of human amniotic stem cells (hAFSCs) on restoring erectile function in a bilateral cavernous nerve crush (BCNC) injury rat model.

Intracavernous (IC) injections of stem cells has been shown to ameliorate cavernous nerve (CN)-induced erectile dysfunction (ED). However, the regenerative effects underlying the recovery of erectile function (EF) in human amniotic fluid-derived stem cells (hAFSCs) remain unclear. In the bilateral cavernous nerve crushing (BCNC) injury rat paradigm, we sought to ascertain the effects of hAFSC treatment on EF recovery during the incipient phase. Three groups of 45 male rats were used in this study: sham (Group 1), saline IC injection after BCNC (Group 2), and hAFSC intracavernous injection (ICI) after BCNC (Group 3). hAFSCs from the fourth passage showed potential to differentiate into trilineage cells. All animals were subjected to EF analysis on the 28th day post-injection and tissues were retrieved for histopathological and immunohistochemical analyses. IC injections of hAFSC significantly improved EF parameters in BCNC-ED rats at 28 days post-injury. AFSC treatment enhanced the smooth muscle condition and increased the smooth muscle/collagen ratio, as evidenced by histological analysis. Immunohistology revealed increased expression of 𝛼-SMA andvWf in the corpus cavernosum and enhanced expression of nNOS in the dorsal penile nerve in BCNC-ED rats (p < 0.05). Western blotting showed that hAFSC treatment significantly increased α-SMA expression in the hAFSC group compared with that in the BCNC group. Electron microscopy revealed significantly elevated myelination in the CN (p < 0.05), maintenance of smooth muscle structures, and restoration of EF in BCNC-ED rats treated with hAFSC. hAFSC treatment increased EF in BCNC-ED rats at a single dose. As BCNC-ED resembles ED caused by radical prostatectomy (RP), this therapy has high potential for ED patients after RP surgery.

The exploration of active components of 701 Dieda Zhentong patch and analgesic properties on chronic constriction injury rats.

An increasing number of traditional Chinese medicine(TCM) have been confirmed to possess analgesic bioactivity. 701 Dieda Zhentong patch(701-DZP) which includes 14 kinds of TCMs exhibited excellent efficacy in alleviating back or leg pain after a soft-tissue injury. In this study, UPLC/MS was used to construct the fingerprint of 701-DZP and excavate the potential bioactive ingredients of it. 21 compounds were detected and identified in the fingerprint including 12 compounds that pass through the skin and 6 compounds observed in the plasma. Then, the role of 701-DZP in neuropathic pain(NPP) was assessed by network pharmacology and CCI rats. 701-DZP inhibited pain sensitization(MWT and TWL) and the release of inflammation mediators(IL-1β and IL-6) in CCI rats which were in keeping with the core targets of the PPI network. The results of IHC and Western blot showed that the expression of the P2X3 receptor in the DRG and SC of CCI rats was significantly reduced after the treatment with 701-DZP. Moreover, the 701-DZP down-regulated the level of phosphorylation of ERK1/2 MAPK instead of P38 MAPK in the DRG of CCI rats. In conclusion, this study has clarified 6 potential analgesic active compounds of 701-DZP and explored the analgesic properties, which may inhibit the expression of the P2X3 receptor to reduce the release of inflammatory mediators based on the ERK1/2 MAPK pathway to alleviate the NPP.

Integration of transcriptomics and metabolomics to study the mechanism of Siwei Huangqi powder in Tibetan medicine for protecting against high-altitude hypoxic brain injuries

Background and aimSiwei Huangqi powder (SWHQP) is a folk medicine that is extensively used in Tibetan medicine. It is widely employed at the medical institutions of various monasteries in the Tibetan region and is highly recommended by esteemed folk practitioners. It is mainly used in clinical practice for high-altitude diseases caused by an imbalance of the three bases of Tibetan medicine, namely, Long, Chiba, and Peigen, which leads to disorders of qi and blood circulation. This study aimed to investigate the potential molecular mechanism underlying the therapeutic and preventive effects of SWHQP in a high-altitude hypoxia brain injury (HHBI) rat model. MethodsAn HCP-III experimental animal low-pressure simulation chamber was used to simulate high-altitude hypoxic environmental exposure in rats to establish an HHBI model. The severity of brain injury, including the brain wet/dry (W/D) ratio and H&E staining, was evaluated through a series of assessments. Transcriptomic and metabolomic analyses were performed to identify gene expression changes and metabolite alterations in brain tissue. Western blotting and immunofluorescence were used to assess the relative expression of proteins involved in the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor-kappa B p65 (NF-kB p65) pathway. The expression levels of genes related to the PI3K/AKT/NF-κB p65 signaling pathway were detected via real-time PCR. Enzyme-linked immunosorbent assays (ELISAs) were conducted to measure the serum levels of proinflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β). ResultsSWHQP significantly improved brain function, reduced the wet/dry ratio, and alleviated brain tissue damage. Transcriptomic and metabolomic analyses revealed that the PI3K/AKT/NF-κB signaling pathway was significantly upregulated in the HHM group and that the expression of inflammatory factors related to amino acid metabolism and lipid metabolism was increased. A previous study also revealed that SWHQP inhibited the activation of the PI3K/AKT/NF-κB p65 signaling pathway in brain tissue, reducing the release of the downstream proinflammatory cytokines IL-6, IL-1β, and TNF-α. ConclusionThe therapeutic effect of SWHQP on brain injury in HHBI rats is attributed to its ability to regulate inflammation-related amino acid synthesis and lipid metabolism and modulate inflammation-related pathways. These findings provide a robust research foundation for the potential clinical application of SWHQP in Tibetan medicine.

Myocardial ischemia-reperfusion injury upregulates nucleostemin expression via HIF-1α and c-Jun pathways and alleviates apoptosis by promoting autophagy

Myocardial ischemia-reperfusion (I/R) injury, often arising from interventional therapy for acute myocardial infarction, leads to irreversible myocardial cell death. While previous studies indicate that nucleostemin (NS) is induced by myocardial I/R injury and mitigates myocardial cell apoptosis, the underlying mechanisms are poorly understood. Here, our study reveals that NS upregulation is critical for preventing cardiomyocyte death following myocardial I/R injury. Elevated NS protein levels were observed in myocardial I/R injury mouse and rat models, as well as Hypoxia/reoxygenation (H/R) cardiac cell lines (H9C2 cells). We identified binding sites for c-Jun and HIF-1α in the NS promoter region. Inhibition of JNK and HIF-1α led to a significant decrease in NS transcription and protein expression. Furthermore, inhibition of autophagy and NS expression promoted myocardial cell apoptosis in H/R. Notably, the cell model showed reduced LC3I transformation to LC3II, downregulated Beclin1, upregulated p62, and altered expression of autophagy-related proteins upon NS interference in H/R cells. These findings suggest that NS expression, driven by c-Jun and HIF-1α pathways, facilitates autophagy, providing protection against both myocardial I/R injury and H/R-induced cardiomyocyte apoptosis.

Optimal Parameters of Magnetic Field Action and their Influence on Some Index Improvement in Traumatic Brain Injury Rat Modell

Optimal Parameters of Magnetic Field Action and their Influence on Some Index Improvement in Traumatic Brain Injury Rat Modell

Long-term hypothermia amplified neuroprotection by antagonizing intracranial pressure rebound after severe traumatic brain injury in rats.

Long-term hypothermia has been reported to prevent intracranial pressure (ICP) rebound in clinical patients, but the duration for hypothermia and the corresponding ICP data are not available. This study investigated the optimal duration of long-term hypothermia in traumatic brain injury (TBI) rats, and observed the effect on ICP and neurological function. In this study, we established a rat severe TBI model with electronic Controlled Cortical Injury device, and implemented hypothermia (33 °C) for different durations. The motor function of the rats in each group was evaluated by beam walking test and inclined-grid climbing test, brain water content was calculated by the wet-dry weight method, Evan's blue staining was used to measure the blood-brain barrier (BBB) permeability, the change of hippocampal neurons was observed by Nissl staining, the expressions of BrdU, NeuN, and CD86 positive cells were detected by immunofluorescence staining, and the expressions of Bcl-2, Bax, iNOS, IL-10, and Arg-1 were detected by Western blot. We found that therapeutic hypothermia improved neurological recovery after TBI with declining ICP, reducing brain edema, decreasing BBB permeability, promoting neurogenesis, inhibiting apoptosis, and regulating inflammation. Moreover, 48 h hypothermia amplified the neuroprotective effect after injury on the basis of 4 or 24 h hypothermic treatment. Both 4 and 24 h hypothermia led to ICP rebound during or after rewarming, whereas 48 h hypothermia completely abolished ICP rebound. Our study suggests that long-term hypothermia amplifies neuroprotection after TBI by antagonizing ICP rebound.

Paeoniflorin regulates microglia-astrocyte crosstalk, inhibits inflammatory response, and alleviates neuropathic pain through HSP90AA1/HMGB1 signaling pathway

Given the unclear, complex pathogenesis of neuropathic pain and the potential of paeoniflorin in relieving neuropathic pain, this study aimed to further clarify the therapeutic effect of paeoniflorin on neuropathic pain and to preliminarily explore the possible protective mechanisms of paeoniflorin. Chronic constrictive injury-induced Sprague Dawley rats and lipopolysaccharide-induced BV-2 cells were used for in vivo and in vitro experiments, respectively. The exosome uptake assay of mouse astrocytes (PKH-67 fluorescent labeling) and the mechanical nociceptive assay (the von Frey fibrous filaments) were performed. The effects of paeoniflorin and its downstream mechanisms on microglial and astrocyte activation, inflammation-associated proteins and exosome marker were determined. Paeoniflorin alleviated mechanical abnormal pain, decreased levels of ionized calcium binding adapter molecule-1 (Iba-1), glial fibrillary acidic protein, Heat Shock Protein 90 Alpha Family Class A Member 1 (HSP90AA1, inflammatory factor) and High Mobility Group Box 1 (HMGB1, inflammation-related protein), and inhibited neuronal apoptosis in chronic constrictive injury rats or lipopolysaccharide-induced BV-2 cells. However, these effects were offset by HSP90AA1 overexpression in lipopolysaccharide-induced BV-2 cells. Exosomes of BV-2 cells could be absorbed by mouse astrocytes. In addition, HSP90AA1 overexpression reversed the effects of paeoniflorin on HMGB1 expression and inflammatory factors and proteins in mouse astrocytes co-cultured with exosome. Collectively, paeoniflorin alleviates neuropathic pain and inhibits inflammatory responses in chronic constrictive injury by modulating microglia-astrocyte crosstalk through HSP90AA1/HMGB1 pathways, which further evidences the potential of paeoniflorin in the treatment of neuropathic pain.

Therapeutic effects of fecal microbial transplantation on alcoholic liver injury in rat models

ObjectiveDisruption of gut microbiota is closely related to the progression of alcoholic liver disease (ALD). This study aimed to explore the therapeutic effect of fecal microbiota transplantation (FMT) in ALD rats using a combination of microbiological and metabolomic techniques. MethodsThree liver injury rat models were constructed using alcohol, CCL4, and alcohol combined with CCL4, and administered an FMT treatment comprising the fecal microbiota of healthy rats via the gastric route for 12 consecutive weeks. We measured the therapeutic effect of FMT treatment on liver inflammation, intestinal mucosal barrier, and bacterial translocation in ALD rats using 16S rRNA and UPLC-Q/TOF-MS technology to detect the effects of FMT on the intestinal microbiota and metabolic patterns of ALD rats. ResultsFMT treatment effectively improved liver function, prolonged survival time, improved the intestinal mucosal barrier, reduced bacterial translocation, alleviated liver inflammation, and delayed the progression of liver fibrosis in three types of liver injury models. The microbiome and metabolomic results showed that FMT can effectively improve gut microbiota disorder in ALD rats and improve metabolic patterns by regulating metabolic pathways such as the arachidonic acid and retinol pathways. ConclusionFMT treatment could reverse alcohol induced liver injury by improving gut microbiota and metabolic patterns in ALD rats, and oral FMT could be an effective therapeutic approach for ALD.

Investigation of the effects of electrical stimulation on BDNF and NGF levels in the sciatic nerve injury rat model

The current study aimed to investigate the effects of electrical stimulation on brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) levels in rats with sciatic nerve injury. Twenty-eight rats were divided into four groups of sham (S, n=7), electrical stimulation (ES, n=7), sciatic nerve injury (SNI, n=7) and sciatic nerve injury+electrical stimulation (SNI+ES, n=7). An experimental nerve damage model was produced by applying a closing force to compress the sciatic nerve. Electrical stimulation was applied for twenty minutes at 200 μs, 2mA, and 20 Hz for fifteen days. Enzyme-linked immunosorbent assay analysis was used to evaluate the levels of NGF and BDNF. It was shown that the SNI group had higher brain BDNF levels than the other groups, while the S group had lower brain BDNF levels than the other groups (P

Magnetic resonance imaging classification in a percutaneous needle injury rat model of intervertebral disc degeneration

BackgroundDuring the development of disease-modifying intervertebral disc degeneration (IDD) drugs, the rat model of IDD is frequently used for disease progression assessment. The aim of this study was to describe a magnetic resonance (MRI) scoring system for the assessment of different disc conditions in puncture-induced IDD, allowing standardization and comparison of results obtained by different investigators.MethodsA total of 36 Sprague-Dawley rats were utilized in the present study. The animals were divided into two groups: a sham group and an IDD group caused by puncture. The rats in the IDD group were subsequently divided into six categories based on time frames, with five rats in each category. The sham group was divided into two sub-groups (n = 3) for 28 and 56 days, respectively. T2-weighted images of rats consecutively studied with MRI of the coccygeal discs were classified according to the time course using the corresponding histological data. Additional scoring of the micro-CT was employed to identify the progression of bone destruction of the rat model of IDD.ResultsA comparison of the MRI results between the sham group and the IDD group revealed a significant reduction in NP height, area, T2WI value, and DHI in the latter group (P < 0.05). The micro-CT results demonstrated that following acupuncture, there was a notable decline in the BV, Tb.N, and height of the coccygeal vertebra, while the BS/BV and Tb.Sp exhibited a significant increase (P < 0.05). The histological results were analogous to the MRI results, indicating a progressive exacerbation of IDD and a corresponding increase in NP score (P < 0.05). The results of the MRI were found to be consistent with those of the micro-CT and histological analyses (P < 0.05). The results of the study demonstrate a robust correlation between MRI analysis and histological findings. Live animals are employed for MRI analysis to improve experiment comparability. The reliability of the MRI scoring system ensures assessment of disease progression in live animals, while promoting cost savings and animal welfare by avoiding the sacrifice of animals at different times.ConclusionsThe described scoring paradigm has quantitatively been found to differentiate IDD disease progression in an in vivo rat model. Hence, we suggest employing it to evaluate the rat IDD model and assess the effects of treatments in this model.

N-Terminal Capping of the αO-Conotoxin Analogue GeX-2 Improves the Serum Stability and Selectivity toward the Human α9α10 Nicotinic Acetylcholine Receptor.

α9α10 nicotinic acetylcholine receptors (nAChRs) are a promising nonopioid analgesic target, with α9α10 nAChR antagonists showing efficacy against chemotherapy-induced hyperalgesia and allodynia. GeX-2, a potent analgesic conotoxin antagonist of α9α10 nAChRs, has limited serum stability. This study improved GeX-2 stability by capping its N-terminal with fatty acids or polyethylene glycol chains, which enhanced its serum stability but eliminated activity at G protein-coupled γ-aminobutyric acid type B (GABAB) receptor-coupled CaV2.2 channels while preserving activity at α9α10 nAChRs. In vivo, α9α10 nAChRs antagonism alone did not alleviate neuropathic pain, highlighting the importance of GABAB receptor-coupled CaV2.2 channels in GeX-2's antinociceptive effects in the chronic constriction injury rat model. The GeX-2 analogue, with an N-terminal methyl group, showed improved activity and selectivity for α9α10 nAChRs, increased serum half-life, and strong analgesic effects in oxaliplatin-induced cold allodynia models. AlphaFold3 and molecular dynamics simulations provided insights into the binding modes and the effects of N-terminal capping, which informed future peptide therapeutic developments.

KDM2B and its peptides promote the stem cells from apical papilla mediated nerve injury repair in rats by intervening EZH2 function.

How to improve the neurogenic potential of mesenchymal stem cells (MSCs) and develop biological agent based on the underlying epigenetic mechanism remains a challenge. Here, we investigated the effect of histone demethylase Lysine (K)-specific demethylase 2B (KDM2B) on neurogenic differentiation and nerve injury repair by using MSCs from dental apical papilla (SCAP). We found that KDM2B promoted the neurogenic indicators expression and neural spheres formation in SCAP, and modified the Histone H3K4 trimethylation (H3K4me3) methylation on neurogenesis-related genes. KDM2B improved the SCAP mediated recovery of motor ability at the early healing stage of spinal cord injury rats. Meanwhile, KDM2B acted as a negative regulator to its partner EZH2 during neurogenic differentiation, enhancer of zeste homologue 2 (EZH2) suppressed the neurogenic ability of SCAP. Further, the protein interaction between KDM2B and EZH2 was identified which decreased during neurogenic differentiation. On this basis, we revealed seven key protein binding sequences of KDM2B to EZH2, and synthesized KDM2B-peptides based on these sequences. By the usage of KDM2B-peptides, EZH2 function was effectively intervened and the neurogenic ability of SCAP was promoted. More, KDM2B-peptides significantly improved the SCAP mediated functional recovery at SCI early phase. Our study revealed that KDM2B acted as a promotor to neurogenic differentiation ability of dental MSCs through binding and negatively regulating EZH2, and provided the KDM2B-peptides as candidate agents for improving the neurogenic ability of MSCs and nerve injury repair.

Effect of phosphatase and tensin homolog-induced putative kinase 1/ E3 ubiquitin ligase Parkin mediated mitochondrial autophagy on chronic kidney disease myocardial injury and the intervention mechanism of Shenshuai recipe.

To study whether Shenshuai recipe (, SSR) can play a protective role on chronic kidney disease myocardial injury model through phosphatase and tensin homolog-induced putative kinase 1 (PINK1)/E3 ubiquitin ligase Parkin (Parkin) mitochondrial autophagy pathway. Forty-eight nephrectomized rats were randomly divided into six groups: sham-operated group, model group, Benazepril group, low, medium and high-dose groups of SSR. The rats were given the cor-responding intervention for six weeks, then were sacrificed. Serum was examined by enzyme linked immunosorbent assay (ELISA). Cardiac ultrasound was used to detect cardiac function in 5/6 nephrectomized rats. Myocardial tissue was examined by light and electron microscopy; PINK1, Parkin, microtubule-associated protein1 light chain 3 II (LC3B), sequestosome 1 (P62), BECN1 (Beclin-1) and dynamin-related protein 1 (Drp-1) were measured by real time polymerase chain reaction (RT-PCR), Western blot (WB) and immunohistochemistry (IHC). The expression levels of blood urea nitrogen (BUN) and creatinine (SCr) in the model group were significantly higher than those in the sham-operated group, indicating that modeling was successful. SSR can protect myocardium by reducing the relative expression of creatine kinase myocardial isoenzyme and hypersensitivity cardiac troponin I (P<0.05). SSR can improve cardiac function in rats after ultrasound testing. SSR can improve the pathological manifestations of myocardial tissue after Masson staining. SSR can increase the number of autophagosomes and autophagiclysosomes in 5/6 nephrectomized rats (P<0.05). Determined by RT-PCR, WB and IHC, SSR can increase the relative expression of PINK1, Parkin, and LC3B (P<0.05), and decrease the relative expression of P62, Beclin-1 and Drp-1 (P<0.05). The PINK1/Parkin mitochondrial autophagy pathway in myocardial tissues in 5/6 nephrectomy CKD myocardial injury rats was inhibited. SSR can activate PINK1/Parkin mitochondrial autophagy to enhance mitochondrial autophagy, and play a protective role in myocardial tissues.