Sex differences in PD-L1-induced analgesia in paclitaxel-induced peripheral neuropathy mice depend on TRPV1-based inhibition of CGRP.

AIMS: Paclitaxel (PTX) is extensively utilized in the management of diverse solid tumors, frequently resulting in paclitaxel-induced peripheral neuropathy (PIPN). The present study aimed to investigate sex differences in the behavioral manifestations and underlying pathogenesis of PIPN and search for clinically efficacious interventions. METHODS: Male and female C57BL/6 mice (5-6 weeks and 12 months, weighing 18-30 g) were intraperitoneally (i.p.) administered paclitaxel diluted in saline (NaCl 0.9%) at a dose of 2 mg/kg every other day for a total of 4 injections. Von Frey and hot plate tests were performed before and after administration to confirm the successful establishment of the PIPN model and also to evaluate the pain of PIPN and the analgesic effect of PD-L1. On day 14 after PTX administration, PD-L1 protein (10 ng/pc) was injected into the PIPN via the intrathecal (i.t.) route. To knock down TRPV1 in the spinal cord, adeno-associated virus 9 (AAV9)-Trpv1-RNAi (5 µL, 1 × 1013 vg/mL) was slowly injected via the i.t. route. Four weeks after AAV9 delivery, the downregulation of TRPV1 expression was verified by immunofluorescence staining and Western blotting. The levels of PD-L1, TRPV1 and CGRP were measured via Western blotting, RT-PCR, and immunofluorescence staining. The levels of TNF-α and IL-1ß were measured via RT-PCR. RESULTS: TRPV1 and CGRP protein and mRNA levels were higher in the spinal cords of control female mice than in those of control male mice. PTX-induced nociceptive behaviors in female PIPN mice were greater than those in male PIPN mice, as indicated by increased expression of TRPV1 and CGRP. The analgesic effects of PD-L1 on mechanical hyperalgesia and thermal sensitivity were significantly greater in female mice than in male mice, with calculated relative therapeutic levels increasing by approximately 2.717-fold and 2.303-fold, respectively. PD-L1 and CGRP were partly co-localized with TRPV1 in the dorsal horn of the mouse spinal cord. The analgesic effect of PD-L1 in PIPN mice was observed to be mediated through the downregulation of TRPV1 and CGRP expression following AAV9-mediated spinal cord specific decreased TRPV1 expression. CONCLUSIONS: PTX-induced nociceptive behaviors and the analgesic effect of PD-L1 in PIPN mice were sexually dimorphic, highlighting the significance of incorporating sex as a crucial biological factor in forthcoming mechanistic studies of PIPN and providing insights for potential sex-specific therapeutic approaches.

Inhibiting spinal cord-specific hsp90 isoforms reveals a novel strategy to improve the therapeutic index of opioid treatment.

Opioids are the gold standard for the treatment of chronic pain but are limited by adverse side effects. In our earlier work, we showed that Heat shock protein 90 (Hsp90) has a crucial role in regulating opioid signaling in spinal cord; Hsp90 inhibition in spinal cord enhances opioid anti-nociception. Building on these findings, we injected the non-selective Hsp90 inhibitor KU-32 by the intrathecal route into male and female CD-1 mice, showing that morphine anti-nociceptive potency was boosted by 1.9-3.5-fold in acute and chronic pain models. At the same time, tolerance was reduced from 21-fold to 2.9 fold and established tolerance was rescued, while the potency of constipation and reward was unchanged. These results demonstrate that spinal Hsp90 inhibition can improve the therapeutic index of morphine. However, we also found that systemic non-selective Hsp90 inhibition blocked opioid pain relief. To avoid this effect, we used selective small molecule inhibitors and CRISPR gene editing to identify 3 Hsp90 isoforms active in spinal cord (Hsp90α, Hsp90ß, and Grp94) while only Hsp90α was active in brain. We thus hypothesized that a systemically delivered selective inhibitor to Hsp90ß or Grp94 could selectively inhibit spinal cord Hsp90 activity, resulting in enhanced opioid therapy. We tested this hypothesis using intravenous delivery of KUNB106 (Hsp90ß) and KUNG65 (Grp94), showing that both drugs enhanced morphine anti-nociceptive potency while rescuing tolerance. Together, these results suggest that selective inhibition of spinal cord Hsp90 isoforms is a novel, translationally feasible strategy to improve the therapeutic index of opioids.

A Camelid-Derived STAT-Specific Nanobody Inhibits Neuroinflammation and Ameliorates Experimental Autoimmune Encephalomyelitis (EAE).

Proinflammatory T-lymphocytes recruited into the brain and spinal cord mediate multiple sclerosis (MS) and currently there is no cure for MS. IFN-γ-producing Th1 cells induce ascending paralysis in the spinal cord while IL-17-producing Th17 cells mediate cerebellar ataxia. STAT1 and STAT3 are required for Th1 and Th17 development, respectively, and the simultaneous targeting of STAT1 and STAT3 pathways is therefore a potential therapeutic strategy for suppressing disease in the spinal cord and brain. However, the pharmacological targeting of STAT1 and STAT3 presents significant challenges because of their intracellular localization. We have developed a STAT-specific single-domain nanobody (SBT-100) derived from camelids that targets conserved residues in Src homolog 2 (SH2) domains of STAT1 and STAT3. This study investigated whether SBT-100 could suppress experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. We show that SBT-100 ameliorates encephalomyelitis through suppressing the expansion of Th17 and Th1 cells in the brain and spinal cord. Adoptive transfer experiments revealed that lymphocytes from SBT-100-treated EAE mice have reduced capacity to induce EAE, indicating that the immunosuppressive effects derived from the direct suppression of encephalitogenic T-cells. The small size of SBT-100 makes this STAT-specific nanobody a promising immunotherapy for CNS autoimmune diseases, including multiple sclerosis.

Arctigenin derivative A-1 ameliorates motor dysfunction and pathological manifestations in SOD1G93A transgenic mice via the AMPK/SIRT1/PGC-1α and AMPK/SIRT1/IL-1ß/NF-κB pathways.

AIM: Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease characterized by progressive death of upper and lower motor neurons, leading to generalized muscle atrophy, paralysis, and even death. Mitochondrial damage and neuroinflammation play key roles in the pathogenesis of ALS. In the present study, the efficacy of A-1, a derivative of arctigenin with AMP-activated protein kinase (AMPK) and silent information regulator 1 (SIRT1) activation for ALS, was investigated. METHODS: A-1 at 33.3 mg/kg was administrated in SOD1G93A transgenic mice orally from the 13th week for a 6-week treatment period. Motor ability was assessed before terminal anesthesia. Muscle atrophy and fibrosis, motor neurons, astrocytes, and microglia in the spinal cord were evaluated by H&E, Masson, Sirius Red, Nissl, and immunohistochemistry staining. Protein expression was detected with proteomics analysis, Western blotting, and ELISA. Mitochondrial adenosine triphosphate (ATP) and malondialdehyde (MDA) levels were measured using an assay kit. RESULTS: A-1 administration in SOD1G93A mice enhanced mobility, decreased skeletal muscle atrophy and fibrosis, mitigated loss of spinal motor neurons, and reduced glial activation. Additionally, A-1 treatment improved mitochondrial function, evidenced by elevated ATP levels and increased expression of key mitochondrial-related proteins. The A-1 treatment group showed decreased levels of IL-1ß, pIκBα/IκBα, and pNF-κB/NF-κB. CONCLUSIONS: A-1 treatment reduced motor neuron loss, improved gastrocnemius atrophy, and delayed ALS progression through the AMPK/SIRT1/PGC-1α pathway, which promotes mitochondrial biogenesis. Furthermore, the AMPK/SIRT1/IL-1ß/NF-κB pathway exerted neuroprotective effects by reducing neuroinflammation. These findings suggest A-1 as a promising therapeutic approach for ALS.

Il34 rescues metronidazole-induced impairment of spinal cord regeneration in zebrafish central nervous system.

Metronidazole (MTZ), a commonly used anti-infective drug in clinical practice, has also been employed as a prodrug in cell-targeted ablation systems in scientific research, exhibiting significant application value. However, it has been demonstrated that MTZ can induce neurotoxic symptoms to some extent during its use, and there is currently a lack of effective means to circumvent its toxicity in both clinical and research settings, which limits its application. Therefore, exploring the specific mechanisms underlying MTZ-induced neurotoxic symptoms and elucidating countermeasures will enhance the practical value of MTZ. In this study, using a zebrafish spinal cord injury regeneration model, we confirmed that MTZ neurotoxicity leads to impaired axon regeneration in the central nervous system. By overexpressing il34 in the central nervous system of zebrafish, we eliminated the inhibitory effect of MTZ on axonal regeneration and demonstrated that the pro-regenerative effect against MTZ neurotoxicity is not caused by excessive macrophages/microglia chemoattracted by interleukin 34(Il34). Transcriptome sequencing analysis and GO enrichment analysis of differentially expressed genes between groups revealed that Il34 may counteract MTZ neurotoxicity and promote spinal cord injury repair through biological processes that enhance cellular adhesion and cell location. In summary, our work uncovers a possible cause of MTZ neurotoxicity and provides a new perspective for eliminating MTZ toxicity.

A Switch from Glial to Neuronal Gene Expression Alterations in the Spinal Cord of SIV-infected Macaques on Antiretroviral Therapy.

Despite antiretroviral therapy (ART), HIV-associated peripheral neuropathy remains one of the most prevalent neurologic manifestations of HIV infection. The spinal cord is an essential component of sensory pathways, but spinal cord sampling and evaluation in people with HIV has been very limited, especially in those on ART. The SIV/macaque model allows for assessment of the spinal cord at key time points throughout infection with and without ART. In this study, RNA was isolated from the spinal cord of uninfected, SIV+, and SIV + ART animals to track alterations in gene expression using global RNA-seq. Next, the SeqSeek platform was used to map changes in gene expression to specific cell types. Pathway analysis of differentially expressed genes demonstrated that highly upregulated genes in SIV-infected spinal cord aligned with interferon and viral response pathways. Additionally, this upregulated gene set significantly overlapped with those expressed in myeloid-derived cells including microglia. Downregulated genes were involved in cholesterol and collagen biosynthesis, and TGF-b regulation of extracellular matrix. In contrast, enriched pathways identified in SIV + ART animals included neurotransmitter receptors and post synaptic signaling regulators, and transmission across chemical synapses. SeqSeek analysis showed that upregulated genes were primarily expressed by neurons rather than glia. These findings indicate that pathways activated in the spinal cord of SIV + ART macaques are predominantly involved in neuronal signaling rather than proinflammatory pathways. This study provides the basis for further evaluation of mechanisms of SIV infection + ART within the spinal cord with a focus on therapeutic interventions to maintain synaptodendritic homeostasis.

Hydrogen Sulfide can Scavenge Free Radicals to Improve Spinal Cord Injury by Inhibiting the p38MAPK/mTOR/NF-κB Signaling Pathway.

Spinal cord injury (SCI) causes irreversible cell loss and neurological dysfunctions. Presently, there is no an effective clinical treatment for SCI. It can be the only intervention measure by relieving the symptoms of patients such as pain and fever. Free radical-induced damage is one of the validated mechanisms in the complex secondary injury following primary SCI. Hydrogen sulfide (H2S) as an antioxidant can effectively scavenge free radicals, protect neurons, and improve SCI by inhibiting the p38MAPK/mTOR/NF-κB signaling pathway. In this report, we analyze the pathological mechanism of SCI, the role of free radical-mediated the p38MAPK/mTOR/NF-κB signaling pathway in SCI, and the role of H2S in scavenging free radicals and improving SCI.

Changes in motor behavior and lumbar motoneuron morphology following repeated chlorpyrifos exposure in rats.

Chlorpyrifos is an organophosphate pesticide associated with numerous health effects including motor performance decrements. While many studies have focused on the health effects following acute chlorpyrifos poisonings, almost no studies have examined the effects on motoneurons following occupational-like exposures. The main objective of this study was to examine the broad effects of repeated occupational-like chlorpyrifos exposures on spinal motoneuron soma size relative to motor activity. To execute our objective, adult rats were exposed to chlorpyrifos via oral gavage once a day, five days a week for two weeks. Chlorpyrifos exposure effects were assessed either three days or two months following the last exposure. Three days following the last repeated chlorpyrifos exposure, there were transient effects in open-field motor activity and plasma cholinesterase activity levels. Two months following the chlorpyrifos exposures, there were delayed effects in sensorimotor gating, pro-inflammatory cytokines and spinal lumbar motoneuron soma morphology. Overall, these results offer support that subacute repeated occupational-like chlorpyrifos exposures have both short-term and longer-term effects in motor activity, inflammation, and central nervous system mechanisms.

Astaxanthin alleviates fibromyalgia pain and depression via NLRP3 inflammasome inhibition.

Fibromyalgia is characterised by widespread chronic pain and is often accompanied by comorbidities such as sleep disorders, anxiety, and depression. Because it is often accompanied by many adverse symptoms and lack of effective treatment, it is important to search for the pathogenesis and treatment of fibromyalgia. Astaxanthin, a carotenoid pigment known for its anti-inflammatory and antioxidant properties, has demonstrated effective analgesic effects in neuropathic pain. However, its impact on fibromyalgia remains unclear. Therefore, in this study, we constructed a mouse model of fibromyalgia and investigated the effect of astaxanthin on chronic pain and associated symptoms through multiple intragastrical injections. We conducted behavioural assessments to detect pain and depression-like states in mice, recorded electroencephalograms to monitor sleep stages, examined c-Fos activation in the anterior cingulate cortex, measured activation of spinal glial cells, and assessed levels of inflammatory factors in the brain and spinal cord, including interleukin (IL)-1ß, IL-6, and tumour necrosis factor- α(TNF-α).Additionally, we analysed the expression levels of IL-6, IL-10, NOD-like receptor thermal protein domain associated protein 3 (NLRP3), Apoptosis-associated speck-like protein containing CARD, and Caspase-1 proteins. The findings revealed that astaxanthin significantly ameliorated mechanical and thermal pain in mice with fibromyalgia and mitigated sleep disorders and depressive-like symptoms induced by pain. A potential mechanism underlying these effects is the anti-inflammatory action of astaxanthin, likely mediated through the inhibition of the NLRP3 inflammasome, which could be one of the pathways through which astaxanthin alleviates fibromyalgia. In conclusion, our study suggests that astaxanthin holds promise as a potential analgesic medication for managing fibromyalgia and its associated symptoms.

Systemic administration of a novel Beclin 1-derived peptide significantly upregulates autophagy in the spinal motor neurons of autophagy reporter mice.

Autophagy, an intracellular degradation system, plays a vital role in protecting cells by clearing damaged organelles, pathogens, and protein aggregates. Autophagy upregulation through pharmacological interventions has gained significant attention as a potential therapeutic avenue for proteinopathies. Here, we report the development of an autophagy-inducing peptide (BCN4) derived from the Beclin 1 protein, the master regulator of autophagy. To deliver the BCN4 into cells and the central nervous system (CNS), it was conjugated to our previously developed cell and blood-brain barrier-penetrating peptide (CPP). CPP-BCN4 significantly upregulated autophagy and reduced protein aggregates in motor neuron (MN)-like cells. Moreover, its systemic administration in a reporter mouse model of autophagy resulted in a significant increase in autophagy activity in the spinal MNs. Therefore, this novel autophagy-inducing peptide with a demonstrated ability to upregulate autophagy in the CNS has significant potential for the treatment of various neurodegenerative diseases with protein aggregates as a characteristic feature.

Angiotensin II Type 1 receptor blockade attenuates the neuropathological changes in the spinal cords of diabetic rats with modulation of nuclear factor erythroid 2-related factor 2/ heme oxygenase 1 system.

Peripheral and central neuropathies frequently complicate worldwide diabetes. Compared to peripheral neuropathy, central neuropathy didn`t gain a major research interest. Angiotensin II is reported to be involved in diabetic neuropathic pain but its role in the central pathological changes in the spinal cord is not clear. Here, we study the role of Losartan; an Angiotensin II receptor 1 (AT1) antagonist in suppression of the diabetes-induced changes in the spinal cord. Three groups of rats were applied; a negative control group, a streptozotocin (STZ) diabetic group, and a group receiving STZ and Losartan. After two months, the pathological alteration in the spinal cord was investigated, and an immunohistochemical study was performed for neuronal, astrocytic, and microglial markers; nuclear protein (NeuN), Glial fibrillary acidic protein (GFAP), and Ionized calcium-binding adaptor molecule 1 (Iba1), respectively, and for an apoptosis marker; caspase-3, and the inflammatory marker; nuclear factor kappa B (NF-kB) signaling, heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2); physiological antioxidant system. The results showed that Losartan caused recovery of spinal cord changes, by inhibiting the microglial and astrocytic activation, suppressing neuronal apoptosis and NF-kB expression with activation of Nrf2/HO-1 (P<0.0005). It is suggested, herein, that Losartan can suppress diabetes-induced glial activation, inflammation, neuronal apoptosis, and oxidative stress in the spinal cord; the mechanisms that may underlie the role of AT1 antagonism in suppressing diabetic neuropathic pain.

Oxidative stress mediated decrement of spinal endomorphin-2 contributes to lumbar disc herniation sciatica in rats.

Increasing evidence supported that oxidative stress induced by herniated lumbar disc played important role in the formation of lumbar disc herniation sciatica (LDHS), however, the neural mechanisms underlying LDHS need further clarification. Endomorphin-2 (EM2) is the endogenous ligand for mu-opioid receptor (MOR), and there is increasing evidence implicating the involvement of spinal EM2 in neuropathic pain. In this study, using an nucleus pulposus implantation induced LDHS rat model that displayed obvious mechanical allodynia, it was found that the expression of EM2 in dorsal root ganglion (DRG) and spinal cord was significantly decreased. It was further found that oxidative stress in DRG and spinal cord was significantly increased in LDHS rats, and the reduction of EM2 in DRG and spinal cord was determined by oxidative stress dominated increment of dipeptidylpeptidase IV activity. A systemic treatment with antioxidant could prevent the forming of mechanical allodynia in LDHS rats. In addition, MOR expression in DRG and spinal cord remained unchanged in LDHS rats. Intrathecal injection of MOR antagonist promoted pain behavior in LDHS rats, and the analgesic effect of intrathecal injection of EM2 was stronger than that of endomorphin-1 and morphine. Taken together, our findings suggest that oxidative stress mediated decrement of EM2 in DRG and spinal cord causes the loss of endogenous analgesic effects and enhances the pain sensation of LDHS.

Common alterations in parallel metabolomic profiling of serum and spinal cord and mechanistic studies on neuropathic pain following PPARα administration.

Neuropathic pain (NP) is usually treated with analgesics and symptomatic therapy with poor efficacy and numerous side effects, highlighting the urgent need for effective treatment strategies. Recent studies have reported an important role for peroxisome proliferator-activated receptor alpha (PPARα) in regulating metabolism as well as inflammatory responses. Through pain behavioral assessment, we found that activation of PPARα prevented chronic constriction injury (CCI)-induced mechanical allodynia and thermal hyperalgesia. In addition, PPARα ameliorated inflammatory cell infiltration at the injury site and decreased microglial activation, NOD-like receptor protein 3 (NLRP3) inflammasome production, and spinal dendritic spine density, as well as improved serum and spinal cord metabolic levels in mice. Administration of PPARα antagonists eliminates the analgesic effect of PPARα agonists. PPARα relieves NP by inhibiting neuroinflammation and functional synaptic plasticity as well as modulating metabolic mechanisms, suggesting that PPARα may be a potential molecular target for NP alleviation. However, the effects of PPARα on neuroinflammation and synaptic plasticity should be further explored.

Diclofenac sodium nanomedicine results in pain-relief and differential expression of the RNA transcriptome in the spinal cord of SNI rats.

Neuropathic pain is chronic pain caused by a lesion or disease of the somatosensory nervous system. Neuropathic pain, with a high incidence and complex pathogenesis, is one of the most significant areas of clinical medicine and basic research. Currently, prescribed treatments are still unsatisfactory or have limited effectiveness. A medicinal preparation is required that relieves the neuropathic pain and prolongs action time, which has not yet been discovered. In this study, MIL-101 (Fe) was employed as a drug carrier to regulate the release of diclofenac sodium, thereby achieving the effect of analgesia and sustained release. The release curves demonstrated that diclofenac sodium could be continuously released from MIL-101 (Fe) for more than 48 h. There was no toxicity in vitro and in vivo, and the safety of MIL-101 (Fe) was confirmed by hematoxylin and eosin as well as ELISA tests in vivo. The results of behavioral testing, pharmacokinetics, and RNA sequencing analysis showed that MIL-101 (Fe) loaded with diclofenac sodium could enhance the mechanical withdrawal threshold and alleviate cold allodynia induced by Spared Nerve Injury, prolonging the work time by three days. The results indicated that MIL-101 (Fe) exhibited excellent biocompatibility, while the MIL-101 (Fe)-DS demonstrated analgesic and controlled-release properties. These findings provide a scientific foundation for the clinical management of neuropathic pain and the development of a novel formulation.

Enhancing motor functional recovery in spinal cord injury through pharmacological inhibition of Dickkopf-1 with BHQ880 antibody.

BACKGROUND: Mounting experimental evidence has underscored the remarkable role played by the Wnt family of proteins in the spinal cord functioning and therapeutic potential in spinal cord injury (SCI). We aim to provide a therapeutic prospect associated with the modulation of canonical Wnt signaling, examining the spatio-temporal expression pattern of Dickkopf-1 (Dkk1) and its neutralization after SCI. We employ an intraparenchymal injection of the clinically validated Dkk1-blocking antibody, BHQ880, to elucidate its effects in SCI. METHODS: A rat model of contusion SCI was used. Histological analyses were performed, wherein Dkk1 protein was sought, and ELISA analyses were employed for Dkk1 detection in cerebrospinal fluid and serum. To ascertain the BHQ880 therapeutic effect, rats were subjected to SCI and then injected with the antibody in the lesion epicenter 24 hours post-injury (hpi). Subsequent evaluation of motor functional recovery extended up to 56 days post-injury (dpi). qRT-PCR and histological analyses were conducted. RESULTS: We demonstrate the presence of Dkk1 in the healthy rat spinal cord, with pronounced alterations observed following injury, primarily concentrated in the epicenter regions. Notably, a significative upregulation of Dkk1 was detected at 24 hpi, peaking at 3 dpi and remaining elevated until 42 dpi. Moreover, we revealed that early administration of BHQ880 considerably improved motor functional recovery, promoted preservation of myelinated tissue, and reduced astroglial and microglia/macrophage reactivity. Furthermore, there was a decrease in the acute expression of different inflammatory genes. CONCLUSIONS: Collectively, our findings highlight the therapeutic potential of BHQ880 treatment in the context of SCI.

Injectable Hydrogel Loaded with CDs and FTY720 Combined with Neural Stem Cells for the Treatment of Spinal Cord Injury.

Purpose: Spinal cord injury (SCI) is an incurable and disabling event that is accompanied by complex inflammation-related pathological processes, such as the production of excessive reactive oxygen species (ROS) by infiltrating inflammatory immune cells and their release into the extracellular microenvironment, resulting in extensive apoptosis of endogenous neural stem cells. In this study, we noticed the neuroregeneration-promoting effect as well as the ability of the innovative treatment method of FTY720-CDs@GelMA paired with NSCs to increase motor function recovery in a rat spinal cord injury model. Methods: Carbon dots (CDs) and fingolimod (FTY720) were added to a hydrogel created by chemical cross-linking GelMA (FTY720-CDs@GelMA). The basic properties of FTY720-CDs@GelMA hydrogels were investigated using TEM, SEM, XPS, and FTIR. The swelling and degradation rates of FTY720-CDs@GelMA hydrogels were measured, and each group's ability to scavenge reactive oxygen species was investigated. The in vitro biocompatibility of FTY720-CDs@GelMA hydrogels was assessed using neural stem cells. The regeneration of the spinal cord and recovery of motor function in rats were studied following co-treatment of spinal cord injury using FTY720-CDs@GelMA hydrogel in combination with NSCs, utilising rats with spinal cord injuries as a model. Histological and immunofluorescence labelling were used to determine the regeneration of axons and neurons. The recovery of motor function in rats was assessed using the BBB score. Results: The hydrogel boosted neurogenesis and axonal regeneration by eliminating excess ROS and restoring the regenerative environment. The hydrogel efficiently contained brain stem cells and demonstrated strong neuroprotective effects in vivo by lowering endogenous ROS generation and mitigating ROS-mediated oxidative stress. In a follow-up investigation, we discovered that FTY720-CDs@GelMA hydrogel could dramatically boost NSC proliferation while also promoting neuronal regeneration and synaptic formation, hence lowering cavity area. Conclusion: Our findings suggest that the innovative treatment of FTY720-CDs@GelMA paired with NSCs can effectively improve functional recovery in SCI patients, making it a promising therapeutic alternative for SCI.

Determination of the embryotoxic effects of propofol injected into eggs on the cerebellum and spinal cord using histologic methods: an animal study.

Background/aim: This study aims to determine the possible embryotoxic effects of propofol on the cerebellum and spinal cord using fertile chicken eggs. Materials and methods: A total of 430 fertile eggs were divided into 5 groups: control, saline, 2.5 mg.kg-1, 12.5 mg.kg-1, and 37.5 mg.kg-1 propofol. Injections were made immediately before incubation via the air chamber. On the 15th, 18th, and 21st day of incubation, 6 embryos from each group were evaluated. Serial paraffin sections taken from the cerebellum and spinal cord were stained with hematoxylin-eosin, Kluver-Barrera, toluidine blue, and periodic acid-Schiff's reaction. The outer granular layer and total cortex thickness were measured, and the linear density of the Purkinje cells was determined. The ratios of the substantia grisea surface area to the total surface area of the spinal cord were calculated. The transverse and longitudinal diameters of the canalis centralis were also assessed. Results: No structural malformation was observed in any embryos examined macroscopically. No significant difference was observed between the groups in terms of development and histologic organization of the cerebellum and spinal cord. However, on the 15th, 18th, and 21st day, the outer granular layer (p < 0.001 for all days) and the total cortex thickness (p < 0.01, p < 0.001, and p < 0.001, respectively) decreased significantly in different propofol dose groups in varying degrees in the cerebellum. Similarly, in the spinal cord, there were significant changes in the ratios of the substantia grisea surface area to the total surface area (p < 0.01 and p < 0.001, respectively). Conclusion: It was concluded that the in-ovo-administered propofol given immediately before incubation has adverse effects on the developing cerebellum and spinal cord. Therefore, it is important for anesthesiologists always to remain vigilant when treating female patients of childbearing age.

Exploration on pharmacological mechanisms of YZP against neuropathic pain via inhibiting spinal inflammation and the rationality of its compatibility.

ETHNOPHARMACOLOGICAL RELEVANCE: Yuanhu Zhitong Prescription (YZP) is a well-known traditional Chinese medicine (TCM) formula for neuropathic pain (NP) therapy with a satisfying clinical efficacy. However, the underlying pharmacological mechanism and its compatibility principle remain unclear. AIM OF THE STUDY: This study aims to investigate the analgesic and compatibility mechanisms of YZP on neuropathic pain (NP) at the gene and biological process levels. MATERIALS AND METHODS: The chronic constriction injury (CCI) rats were intragastrically administrated with extracts of YZP, YH and BZ separately, and then mechanical hypersensitivity were measured to evaluate the analgesic effects between YH and BZ before and after compatibility. Then, RNA-seq and bioinformatics analyses were performed to elucidate the potential mechanisms underlying YZP's analgesia and compatibility. Finally, the expression levels and significant differences of key genes were analyzed. RESULTS: Behaviorally, both YZP and YH effectively alleviated mechanical allodynia in CCI rats, with YZP being superior to YH. In contrast, we did not observe an analgesic effect of BZ. Genetically, YZP, YH, and BZ reversed the expression levels of 52, 34, and 42 aberrant genes in the spinal cord of CCI rats, respectively. Mechanically, YZP was revealed to alleviate NP mainly by modulating the inflammatory response and neuropeptide signaling pathway, which are the dominant effective processes of YH. Interestingly, the effective targets of YZP were especially enriched in leukocyte activation and cytokine-mediated signaling pathways. Moreover, BZ was found to exert an adjunctive effect in enhancing the analgesic effect of YH by promoting skeletal muscle tissue regeneration and modulating calcium ion transport. CONCLUSIONS: YH, as the monarch drug, plays a dominant role in the analgesic effect of YZP that effectively relieves NP by inhibiting the spinal inflammation and neuropeptide signaling pathway. BZ, as the minister drug, not only synergistically enhances analgesic processes of YH but also helps to alleviate the accompanying symptoms of NP. Consequently, YZP exerted a more potent analgesic effect than YH and BZ alone. In conclusion, our findings offer new insights into understanding the pharmacological mechanism and compatibility principle of YZP, which may support its clinical application in NP therapy.

The Effect of Pregabalin on Microglia Differentiation in Rat with Neuropathic pain: A Preliminary Study.

This study investigated the effects of pregabalin on microglial differentiation in rats with neuropathic pain (NP) induced by sciatic nerve ligation and transection. After confirming NP, the rats were randomly allocated to either a pregabalin or control group. The pregabalin group received intraperitoneal injections of 10 mg/kg pregabalin, while the control group received an equivalent volume of normal saline following surgery. On postoperative day 28, neuronal damage, microglial activity, and microglial differentiation were assessed. The pregabalin group exhibited significantly less neuronal damage compared to the control group, along with a significant decrease in activated microglial expression in both the brain and spinal cord. Pregabalin treatment also significantly altered the microglial phenotype expression, with a decrease in the M1 phenotype percentage and an increase in the M2 phenotype percentage in both the brain (M1 phenotype: 43.52 ± 12.16% and 18.00 ± 8.57% in the control and pregabalin groups, respectively; difference: 27.26 [15.18-42.10], p = 0.002; M2 phenotype: 16.88 ± 6.47% and 39.63 ± 5.82% in the control and pregabalin groups, respectively; difference 22.04 [17.17-32.70], p < 0.001) and the spinal cord ipsilateral to nerve injury (M1 phenotype: 44.35 ± 12.12% and 13.78 ± 5.39% in the control and pregabalin groups, respectively; difference 30.46 [21.73-44.45], p < 0.001; M2 phenotype: 7.64 ± 3.91% and 33.66 ± 7.95% in the control and pregabalin groups, respectively; difference 27.41 [21.21-36.30], p < 0.001). Overall, pregabalin treatment significantly decreased the microglial M1 phenotype while increasing the microglial M2 phenotype in NP rats.

The effects of acteoside on locomotor recovery after spinal cord injury - The role of autophagy and apoptosis signaling pathway.

In the current study, we investigated the effects of acteoside as a phenylpropanoid glycoside on interaction with neurons to assesses locomotor recovery after spinal cord injury (SCI) in rats by focusing on evaluating the factors involved in autophagy, apoptosis, inflammation and oxidative stress processes. 49 Spargue-Dawley rats were prepared and divided into seven healthy and SCI groups receiving different concentrations of acteoside. After 28 days of disease induction and treatment with acteoside, a BBB score test was used to evaluate locomotor activity. Then, by preparing spinal cord cell homogenates, the expression levels of MAP1LC3A, MAP-2, glial fibrillary acidic protein (GFAP), Nrf2, Keap-1, Caspase 3 (Casp3), Bax, Bcl-2, TNF-a, IL-1B, reactive oxygen species (ROS), and malondialdehyde (MDA) were measured. Improvement of locomotor activity in SCI rats receiving acteoside was observed two weeks after the beginning of the experiment and continued until the fourth week. Both MAP1LC3A and MAP-2 were significantly up-regulated in SCI rats treated with acteoside compared to untreated SCI rats, and GFAP levels were significantly decreased in these animals. Pro-apoptotic proteins Bax and Casp3 and anti-apoptotic protein Bcl-2 were down-regulated and up-regulated, respectively, in SCI rats receiving acteoside. In addition, a significant downregulation of iNOS, TNF-α, and IL-1ß and a decrease in contents of both ROS and MDA as well as increases in Nrf2 and Keap-1 were seen in rats receiving acteoside. Furthermore, acteoside strongly interacted with MAP1LC3A, TNF-α, and Casp3 targets with binding affinities of -8.3 kcal/mol, -8.3 kcal/mol, and -8.5 kcal/mol, respectively, determined by molecular docking studies. In general, it can be concluded that acteoside has protective effects in SCI and can be considered as an adjuvant therapy in the treatment of this disease. However, more studies, especially clinical studies, are needed in this field.