Immunological response of using emulsifying elongation factor 1 alpha of Plasmodium falciparum-based vaccines in complete Freund's adjuvant.

Analgesic effect of cinobufagin is mediated by human-selective P2X7R antagonism governed by distinct extracellular domains.

EAE models of neuropathic pain in multiple sclerosis do not require pertussis toxin.

Rheumatoid arthritis can affect extra-articular organs such as the liver, and the problem of drug-induced liver injury caused by traditional antirheumatic drugs for improving the condition cannot be ignored. This study aims to investigate the therapeutic effects of resveratrol (Res) on hepatic inflammation and oxidative stress in mice with collagen-induced arthritis (CIA) and to elucidate the relationship between the regulatory mechanisms of the nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) signaling pathway. In this study, we used chicken type II collagen in combination with complete Freund's adjuvant to induce arthritis in a mouse model, and Res was administered by tube feeding to detect the serum biochemical liver function and inflammation levels, oxidative stress, and apoptosis in the livers of mice. An in vitro cellular model of liver inflammation and oxidative stress was established by treating mouse primary hepatocytes (MPHs) with tumor necrosis factor-α (TNF-α) and H2O2. The intrinsic mechanism of Res in attenuating hepatic inflammation and oxidative stress in CIA mice was explored by treating MPHs with an Nrf2 inhibitor and Keap1 overexpression plasmid. Res significantly reduced the levels of inflammation and oxidative stress in liver tissues of CIA mice as well as in MPHs treated with TNF-α and H2O2 and activated the Nrf2/Keap1 signaling pathway. Inflammation and oxidative stress levels in MPHs were exacerbated by the use of Nrf2 inhibitors and Keap1 overexpression, which promoted apoptosis. This study demonstrated the intrinsic mechanism of Res of attenuating hepatic inflammation and oxidative stress in CIA mice through the Nrf2/Keap1 pathway, which provides a new idea for finding hepatoprotective treatments for rheumatoid arthritis.

Astragalin alleviates neuroinflammation in LPS-injured HT22 cells and CFA mice by regulating neuronal excitability and autophagy via CXCR4-Beclin1/VPS34 axis.

Temporal dynamics of mechanical hypersensitivity and dorsal root ganglion transcription in a bilateral CFA-Induced inflammation model in mice.

This study aimed to investigate the role of 5-hydroxytryptamine 1A (5-HT1A) receptors in the anterior cingulate cortex (ACC) in regulating the affective pain in rats. In the ACC, normal saline (NS), the 5-HT1A receptor agonist 8-OH-DPAT or the 5-HT1A receptor antagonist WAY-100635 was pre-injected respectively. A persistent inflammatory pain model was established by subcutaneously injecting 0.08 mL of complete Freund's adjuvant (CFA) into the left hind paw of rats, which was then paired with a specific environment to induce a conditioned place avoidance (CPA) response. Then the electroacupuncture (EA, 10 Hz, 3 mA) was applied to stimulate the Huantiao acupoint (GB30). The CPA responses of rats in the pain-paired environment and the firing activities of ACC neurons were simultaneously observed. Subsequently, open-field behavior, paw withdrawal latency (PWL), and 50% paw withdrawal threshold (PWT) tests were conducted. The results showed that: (1) Rats injected with CFA showed significant reductions in PWL and 50% PWT, and spent less time in the "pain-paired environment" and the center of the open field, compared to the control group (P < 0.05). (2) Immunofluorescence double-labeling results showed a high co-expression of Fos protein and 5-HT1A receptors in the ACC of the EA-treated normal rats. (3) Pre-treatment with the 5-HT1A receptor agonist 8-OH-DPAT (8 μg) in the ACC alleviated CFA-induced affective pain (P < 0.05) and reversed the increase in firing frequency of pyramidal neurons in the ACC induced by CFA (P < 0.05). (4) Pre-treatment with the 5-HT1A receptor antagonist WAY-100635 (8 μg) in the ACC, combined with EA stimulation, reversed the CPA-like behavioral responses induced by CFA in rats and increased the firing frequency of pyramidal neurons in the ACC (P < 0.05). These results suggest that the 5-HT1A receptors in ACC mediate the alleviating effect of EA on the affective pain of CFA-induced rats.

Herbal remedies have been utilised in traditional medicine systems to manage chronic illnesses. The present research investigated the antioxidant, anti-inflammatory, and antiarthritic effects of Chenopodium murale L. The C. murale (CMMeE) methanolic extract, prepared from the whole plant by maceration, was analysed for phytochemicals using LC-MS. The antioxidant effects of CMMeE were assessed in an in vitro DPPH assay. The efficacy of CMMeE was assessed in in vivo carrageenan and histamine-induced acute inflammatory models, and in formaldehyde and complete Freund's adjuvant (CFA)-induced chronic arthritis models. Three different doses of CMMeE (250, 500, and 750 mg/kg) and 10 mg/kg of diclofenac sodium were administered orally to the animals. Different parameters, including reductions in paw oedema, arthritic index (AI), histopathological, biochemical, and haematological changes, were noted. ELISA and qPCR methods were used to assess the expression of antioxidant and inflammatory biomarkers in serum samples. CMMeE possesses moderate antioxidant activity (IC50 = 199.7 µg/mL) when compared to gallic acid (IC50 = 178.9 µg/mL) in an in vitro DPPH assay. Treatment with CMMeE alleviated paw oedematous conditions in the acute models. The CMMeE and diclofenac sodium-treated groups demonstrated a noticeable decline (p < 0.05) in joint inflammation and overall arthritic scores. Treatment with the extract and diclofenac sodium resulted in reductions in superoxide dismutase (SOD), malondialdehyde (MDA), tumour necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) levels in the serum samples. Moreover, remarkable (p < 0.05) induction of interleukin-4 and -10 and suppression of COX-2, IL-1, IL-6, NF-kβ, mPGE, and TNF-α was noticed in a dose-dependent manner in the samples of CMMeE and dilcofenac sodium treated animals. Complete blood count (CBC) data indicated no noticeable differences (p > 0.05) in RBCs and Hb levels, but a decline in platelet and WBCs levels in CMMeE-treated groups. Reduced pannus formation, bone deterioration, and synovitis were observed in tissue sections of animals treated with CMMeE and diclofenac sodium. Overall, CMMeE exhibits anti-inflammatory and antiarthritic effects, which may be due to TNF-α-directed downregulation of oxidative stress and inflammatory mediators.

Noradrenergic projections from the locus coeruleus (LC) to the thalamus and anterior cingulate cortex (ACC) contribute to pain-like behaviors, yet their hierarchical organization remains unclear. This article examines how locus coeruleus-derived norepinephrine inputs to the paraventricular thalamic nucleus (PVA) and ACC differentially regulate nociceptive sensitization. In adult male and female mice, complete Freund's adjuvant was used to induce pain-like behaviors. To examine functional connectivity among locus coeruleus, PVA, and ACC, targeted recombination in active populations (Fos-TRAP), in vivo recordings, and viral tracing were combined. Then optogenetic and chemogenetic tools were used to selectively manipulate locus coeruleus projections and assess their impact on neural activity and pain behaviors. Complete Freund's adjuvant led to enhanced c-Fos expression in locus coeruleus, PVA, and ACC (cells per microscopic field; locus coeruleus: 13.60 ± 2.24 vs. 44.50 ± 7.72; PVA: 8.00 ± 1.58 vs. 66.40 ± 9.45; ACC: 12.80 ± 2.28 vs. 36.70 ± 2.59; P < 0.001), alongside increased γ-band activity and single-unit firing rates. Monosynaptic LC-ACC and polysynaptic LC-PVA-ACC circuits were identified. Notably, nociception-related locus coeruleus neurons preferentially projected to PVA, which subsequently targeted hyperactive ACC neurons. Under inflammatory pain conditions, activation of the LC-PVA-ACC circuits evoked greater ACC firing (Hz; LC-PVA-ACC vs. LC-ACC: 15.75 ± 2.88 vs. 9.72 ± 2.06; P < 0.001) and tactile stimulus-evoked responses (Hz; 22.98 ± 2.60 vs. 15.34 ± 1.86; P < 0.001) than direct LC-ACC activation. Consistently, optogenetic or chemogenetic manipulation of the LC-PVA-ACC circuit produced stronger modulation of mechanical and thermal pain sensitivity than direct LC-ACC stimulation. This study identified the LC-PVA-ACC pathway as a hierarchical noradrenergic circuit that modulates nociceptive sensitization via a thalamocortical relay, thereby revealing a circuit-specific mechanism by which the locus coeruleus-norepinephrine system regulates pain processing.

Potential crosstalk between the renin-angiotensin system and Neuropilin-1 pathways in experimental rheumatoid arthritis.

Inbred mouse models of autoimmune myocarditis are routinely used to investigate the immune mechanisms underlying dilated cardiomyopathy. However, their translational relevance is limited because observations made in a single inbred strain may not reflect those of outbred human populations. This limitation can be overcome by using Diversity Outbred (DO) mice, whose genetic variability is comparable to that of humans. To investigate the utility of DO mice, we characterized their immune cell distributions and induced myocarditis by immunization with porcine cardiac myosin (PCM) emulsified in complete Freund's adjuvant. Antigen-specific T cell and antibody responses were evaluated using lymphocytes and serum samples, respectively, and hearts were examined histologically for inflammatory changes. First, we noted no significant variations in the majority of immune cell populations, which include T cells and B cells. However, NK cells, double positive for CD49b and NK1.1, were lacking in both sexes. While we noted sex differences in the expression of major histocompatibility complex class II molecules in antigen-presenting cells, expression of costimulatory molecules was similar in both sexes. Second, upon immunization, we demonstrated that the PCM was immunogenic, and the PCM-reactive T cell responses were generated in both males and females, as measured by a proliferation assay. Third, cytokine analysis revealed marginal detection of Th1 (IFN-γ) and Th17 (IL-17 and IL-22) cytokines, mainly with three doses of immunization. Fourth, determination of PCM-reactive antibody responses revealed significant amounts of IgG1 and IgG2b isotypes. Finally, histological analysis revealed varying degrees of myocarditis in individual mice of both sexes. Our data suggest that mild autoimmune myocarditis can be induced in DO mice. However, to capture the heterogeneity in disease susceptibility, large sample cohorts are required.

Neutrophilic asthma is one of the main types of severe asthma. Our previous studies demonstrated that neutrophil extracellular traps (NETs) contribute to its pathological process. However, the underlying mechanisms remains unclear. This study aimed to investigate the potential mechanisms of NETs in neutrophilic asthma. Clinical samples were collected from patients with neutrophilic asthma and healthy controls. A neutrophil-dominant asthmatic murine model was established using ovalbumin (OVA), Freund's complete adjuvant (CFA) and lipopolysaccharide (LPS). Airway inflammation and remodeling were assessed by pathological staining. The expression of EMT markers and Hedgehog (Hh)/Gli1 pathway markers were measured by Western blot, qPCR, and immunofluorescence. We found that the expression of dsDNA, one of the skeleton components of NETs, was significantly higher in the peripheral plasma of patients with neutrophilic asthma than that of healthy controls, and neutrophils in neutrophilic asthma patients were more likely to induce the production of NETs. We further demonstrated that NETs induced EMT in airway epithelial cells. Both in vivo and in vitro, we confirmed that reducing NETs formation or enhancing NETs degradation reversed EMT process, attenuated airway hyperresponsiveness (AHR) and alleviated airway inflammation in neutrophil-dominant asthmatic mouse model. We also found that the Hh/Gli1 pathway was activated during this process, and inhibition of the Hh/Gli1 pathway also reversed the EMT process of airway epithelium. Similarly, AHR and airway inflammation in neutrophil-dominant asthmatic mice were reduced. We confirmed that NETs promote EMT in airway epithelium via activation the Hh/Gli1 signaling pathway, thus playing an important role in the pathogenesis of neutrophilic asthma. Targeting NETs or the Hh/Gli1 pathway may provide a promising therapeutic strategy for the treatment of severe neutrophilic asthma.

Objective Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder for which current therapeutic options are often insufficient. This study aimed to evaluate the therapeutic potential of hesperidin (HSP), in suppressing complete Freund's adjuvant (CFA)-induced RA in Wistar albino rats, through modulation of key pro-inflammatory markers (TNF-α, IL-6, IL-1β, NF-κB, and COX-2), supported by in silico docking and pharmacokinetic profiling. Methods Forty-eight female Wistar albino rats were randomized into six groups (n = 8). Group 1 received normal saline; Group 2 was induced with RA via 0.1 ml CFA and left untreated; Group 3 received CFA + naproxen (8 mg/kg). Groups 4, 5, and 6 received hesperidin at 100, 200, and 400 mg/kg, respectively, following RA induction. Serum pro-inflammatory markers were quantified using standard biochemical assays. Molecular docking was performed to assess HSP binding affinity toward COX-2, TNF-α, IL-1β, and IL-6, while ADMET profiling was carried out to predict pharmacokinetic and toxicity attributes. Results In vivo results revealed that RA induction significantly elevated TNF-α, IL-6, IL-1β, and NF-κB levels ( p &lt; .05) across the treated groups. Whereas, hesperidin treatment produced a dose-dependent and significant ( p &lt; .05 ) reduction in these markers, restoring them to levels comparable to naproxen-treated rats. In silico docking analysis revealed that hesperidin has multi-target binding capability inhibitor to COX-2, TNF-α, IL-1β, and IL-6. Protein-ligand binding was predominantly surface-oriented except for COX-2, which showed interior pocket binding. ADMET predictions indicated that HSP is a P-glycoprotein substrate with low gastrointestinal absorption, does not cross the blood–brain barrier, shows no cytochrome P450 enzyme subunit inhibition, and lacks carcinogenic or hepatotoxic potential. Conclusion Combined in vivo and in silico findings demonstrate that hesperidin exhibits strong anti-inflammatory effects by inhibiting key mediators of RA pathogenesis, alongside a favorable safety pharmacokinetic profile.

Electroacupuncture alleviates inflammatory pain via the activation of GABAergic inhibitory interneurons in mouse spinal dorsal horn.

Impact of stress on pain sensitization and emotional responses in a rat model of persistent TMJ inflammation.

Isoliquiritigenin inhibited complete Freund's adjuvant-induced chronic inflammatory pain via the CCL7/CCR2/ERK pathway in dorsal root ganglia neurons of mice.

Inhibition of the NF-κB/STAT3 pathway to reduce spinal microglia activation: a mechanism by which manual acupuncture alleviates rheumatoid arthritis.

Myofasciitis, a prevalent cause of musculoskeletal pain, is associated with thoracolumbar fascial changes. Acupuncture is effective for pain relief, but its role in fascial repair remains unclear. This study examined the effects of electroacupuncture (EA) at BL23 (Shenshu) and BL40 (Weizhong) on fascial tissue repair in a rat model of thoracolumbar fasciitis (TLF). The study involved 42 six-week-old Sprague-Dawley rats divided into control (n = 15) and modeling (n = 27) groups. TLF was induced by injecting complete Freund's adjuvant into the thoracolumbar fascia. Three rats in the control and modeling groups were used for model validation. The remaining 24 modeled rats were split into model and EA groups (n = 12 each). EA was administered at BL23 and BL40 to rats in the EA group for 20 min daily for 9 days. Assessments included skin pain sensitivity, musculoskeletal ultrasound, histological evaluation of fascial thickness, and measurement of inflammatory markers and fibroblast activity. EA-treated rats showed significant improvements, including reduced mechanical pain sensitivity, decreased fascial thickness and lower expression of pro-inflammatory markers (tumor necrosis factor-α, interleukin 1β) and fibroblast activity markers (proliferating cell nuclear antigen, α-smooth muscle actin, and vimentin). There was also a favorable balance in extracellular matrix components (increased type I/III collagen and matrix metalloproteinase (MMP)-1/tissue inhibitor of MMP (TIMP)-1 ratios), which was linked to reduced activity of the transforming growth factor (TGF)-β1/suppressor of mother against decapentaplegic (Smad)2 pathway. EA at BL23 and BL40 reduces inflammation, inhibits fibroblast proliferation and activation, and promotes fascial repair, likely via modulation of the TGF-β1/Smad2 pathway. These findings support the therapeutic potential of EA for the treatment of myofasciitis, potentially aiding in chronic musculoskeletal pain management and fascial tissue repair.

Gastrointestinal motility is regulated primarily by the enteric and the central nervous systems. Our previous studies revealed that central circuits regulating colorectal motility partially overlap with those involved in pain modulation, suggesting functional interactions between the nociceptive modulatory pathway and the autonomic regulatory pathway of colorectal motility. Here, we examined whether peripheral inflammatory pain alters the neural components of the descending pathway regulating colorectal motility. Complete Freund's adjuvant (CFA) was administered unilaterally into the hind paw of rats to induce inflammation. Colorectal motility was assessed in vivo under anesthesia with α-chloralose and ketamine. In sham-treated rats, intraluminal administration of capsaicin, a noxious stimulus to the colorectal lumen, enhanced colorectal motility. In contrast, the capsaicin-induced colorectal motility response was suppressed in rats 3 days after CFA treatment. This suppression was rescued by the intrathecal administration of a GABAA receptor antagonist or an oxytocin (OXT) receptor antagonist. Furthermore, spinal OXT administration and chemogenetic activation of OXT neurons in naïve rats elicited a marked inhibition of capsaicin-induced motility responses of the colorectum. Notably, the inhibitory effect of activated OXT neurons was abolished by the intrathecal administration of a GABAA receptor antagonist. These results indicate that the descending OXT pathway becomes operative in response to persistent pain caused by peripheral inflammation and that the inhibitory effect on colorectal motility may involve local GABAergic transmission within the spinal cord. These changes may reduce parasympathetic outflow to the colorectum and contribute to defecation disorders involving central neural mechanisms.NEW & NOTEWORTHY This study focused on the remodeling of the neural pathways regulating colorectal motility and examined whether peripheral inflammation outside the gastrointestinal tract affects this process. In rats administered a complete Freund's adjuvant into their hind paw, colorectal motility responses induced by intracolonic administration of capsaicin were suppressed. This suppression involved oxytocinergic and GABAergic transmission in the spinal cord. These results demonstrate that inflammatory pain in the hind paw induces remodeling of the neural pathways regulating colorectal motility.

Mesaconine alleviates hyperalgesia in CFA-induced mice by modulating YAP1 to suppress cell ferroptosis within the spinal cord.