CD8+ CTL priming by exact peptide epitopes in incomplete Freund's adjuvant induces a vanishing CTL response, whereas long peptides induce sustained CTL reactivity

Therapeutic vaccination trials, in which patients with cancer were vaccinated with minimal CTL peptide in oil-in-water formulations, have met with limited success. Many of these studies were based on the promising data of mice studies, showing that vaccination with a short synthetic peptide in IFA results in protective CD8(+) T cell immunity. By use of the highly immunogenic OVA CTL peptide in IFA as a model peptide-based vaccine, we investigated why minimal CTL peptide vaccines in IFA performed so inadequately to allow full optimization of peptide vaccination. Injection of the minimal MHC class I-binding OVA(257-264) peptide in IFA transiently activated CD8(+) effector T cells, which eventually failed to undergo secondary expansion or to kill target cells, as a result of a sustained and systemic presentation of the CTL peptides gradually leaking out of the IFA depot without systemic danger signals. Complementation of this vaccine with the MHC class II-binding Th peptide (OVA(323-339)) restored both secondary expansion and in vivo effector functions of CD8(+) T cells. Simply extending the CTL peptide to a length of 30 aa also preserved these CD8(+) T cell functions, independent of T cell help, because the longer CTL peptide was predominantly presented in the locally inflamed draining lymph node. Importantly, these functional differences were reproduced in two additional model Ag systems. Our data clearly show why priming of CTL with minimal peptide epitopes in IFA is suboptimal, and demonstrate that the use of longer versions of these CTL peptide epitopes ensures the induction of sustained effector CD8(+) T cell reactivity in vivo.

Mycobacteria attenuate nociceptive responses by formyl peptide receptor triggered opioid peptide release from neutrophils

In inflammation, pain is regulated by a balance of pro- and analgesic mediators. Analgesic mediators include opioid peptides which are secreted by neutrophils at the site of inflammation, leading to activation of opioid receptors on peripheral sensory neurons. In humans, local opioids and opioid peptides significantly downregulate postoperative as well as arthritic pain. In rats, inflammatory pain is induced by intraplantar injection of heat inactivated Mycobacterium butyricum, a component of complete Freund's adjuvant. We hypothesized that mycobacterially derived formyl peptide receptor (FPR) and/or toll like receptor (TLR) agonists could activate neutrophils, leading to opioid peptide release and inhibition of inflammatory pain. In complete Freund's adjuvant-induced inflammation, thermal and mechanical nociceptive thresholds of the paw were quantified (Hargreaves and Randall-Selitto methods, respectively). Withdrawal time to heat was decreased following systemic neutrophil depletion as well as local injection of opioid receptor antagonists or anti-opioid peptide (i.e. Met-enkephalin, beta-endorphin) antibodies indicating an increase in pain. In vitro, opioid peptide release from human and rat neutrophils was measured by radioimmunoassay. Met-enkephalin release was triggered by Mycobacterium butyricum and formyl peptides but not by TLR-2 or TLR-4 agonists. Mycobacterium butyricum induced a rise in intracellular calcium as determined by FURA loading and calcium imaging. Opioid peptide release was blocked by intracellular calcium chelation as well as phosphoinositol-3-kinase inhibition. The FPR antagonists Boc-FLFLF and cyclosporine H reduced opioid peptide release in vitro and increased inflammatory pain in vivo while TLR 2/4 did not appear to be involved. In summary, mycobacteria activate FPR on neutrophils, resulting in tonic secretion of opioid peptides from neutrophils and in a decrease in inflammatory pain. Future therapeutic strategies may aim at selective FPR agonists to boost endogenous analgesia.

Immunoadjuvant action of liposomes: comparison with other adjuvants

Dehydration-rehydration vesicles (DRV liposomes) composed of equimolar phospholipid and cholesterol and containing bovine serum albumin (BSA) were used together with free BSA to immunize Balb/C mice. Primary and secondary immune responses (IgG1) to the liposomal antigen, as measured by ELISA in mouse sera, were similar for egg phosphatidylcholine (PC) and distearoyl phosphatidylcholine (DSPC) DRV, and much greater than those elicited by free BSA. The adjuvanticity of PC DRV was compared with that of aluminium salts (alum), complete Freund's adjuvant (CFA) and N-acetyl muramyl-L-threonyl-D-isoglutamine ([Thr1]MDP), the latter used as such or in a liposome form co-entrapped with the antigen. DRV (with or without co-entrapped [Thr1]MDP), and alum were equally strong in producing primary and secondary immune responses (IgG1) to BSA. Such responses were significantly higher than those achieved with CFA and [Thr1]MDP alone. The implications of these results for the potential role of liposomes as immunological adjuvants in vaccines are discussed.

Recombinant mouse PAP has pH-dependent ectonucleotidase activity and acts through A(1)-adenosine receptors to mediate antinociception

Prostatic acid phosphatase (PAP) is expressed in nociceptive neurons and functions as an ectonucleotidase. When injected intraspinally, the secretory isoforms of human and bovine PAP protein have potent and long-lasting antinociceptive effects that are dependent on A(1)-adenosine receptor (A(1)R) activation. In this study, we purified the secretory isoform of mouse (m)PAP using the baculovirus expression system to determine if recombinant mPAP also had antinociceptive properties. We found that mPAP dephosphorylated AMP, and to a much lesser extent, ADP at neutral pH (pH 7.0). In contrast, mPAP dephosphorylated all purine nucleotides (AMP, ADP, ATP) at an acidic pH (pH 5.6). The transmembrane isoform of mPAP had similar pH-dependent ectonucleotidase activity. A single intraspinal injection of mPAP protein had long-lasting (three day) antinociceptive properties, including antihyperalgesic and antiallodynic effects in the Complete Freund's Adjuvant (CFA) inflammatory pain model. These antinociceptive effects were transiently blocked by the A(1)R antagonist 8-cyclopentyl-1, 3-dipropylxanthine (CPX), suggesting mPAP dephosphorylates nucleotides to adenosine to mediate antinociception just like human and bovine PAP. Our studies indicate that PAP has species-conserved antinociceptive effects and has pH-dependent ectonucleotidase activity. The ability to metabolize nucleotides in a pH-dependent manner could be relevant to conditions like inflammation where tissue acidosis and nucleotide release occur. Lastly, our studies demonstrate that recombinant PAP protein can be used to treat chronic pain in animal models.

Mapping epitopes and antigenicity by site-directed masking

Here we describe a method for mapping the binding of antibodies to the surface of a folded antigen. We first created a panel of mutant antigens (beta-lactamase) in which single surface-exposed residues were mutated to cysteine. We then chemically tethered the cysteine residues to a solid phase, thereby masking a surface patch centered on each cysteine residue and blocking the binding of antibodies to this region of the surface. By these means we mapped the epitopes of several mAbs directed to beta-lactamase. Furthermore, by depleting samples of polyclonal antisera to the masked antigens and measuring the binding of each depleted sample of antisera to unmasked antigen, we mapped the antigenicity of 23 different epitopes. After immunization of mice and rabbits with beta-lactamase in Freund's adjuvant, we found that the antisera reacted with both native and denatured antigen and that the antibody response was mainly directed to an exposed and flexible loop region of the native antigen. By contrast, after immunization in PBS, we found that the antisera reacted only weakly with denatured antigen and that the antibody response was more evenly distributed over the antigenic surface. We suggest that denatured antigen (created during emulsification in Freund's adjuvant) elicits antibodies that bind mainly to the flexible regions of the native protein and that this explains the correlation between antigenicity and backbone flexibility. Denaturation of antigen during vaccination or natural infections would therefore be expected to focus the antibody response to the flexible loops.

Synthetic mycobacterial molecular patterns partially complete Freund's adjuvant

Complete Freund's adjuvant (CFA) has historically been one of the most useful tools of immunologists. Essentially comprised of dead mycobacteria and mineral oil, we asked ourselves what is special about the mycobacterial part of this adjuvant, and could it be recapitulated synthetically? Here, we demonstrate the essentiality of N-glycolylated peptidoglycan plus trehalose dimycolate (both unique in mycobacteria) for the complete adjuvant effect using knockouts and chemical complementation. A combination of synthetic N-glycolyl muramyl dipeptide and minimal trehalose dimycolate motif GlcC14C18 was able to upregulate dendritic cell effectors, plus induce experimental autoimmunity qualitatively similar but quantitatively milder compared to CFA. This research outlines how to substitute CFA with a consistent, molecularly-defined adjuvant which may inform the design of immunotherapeutic agents and vaccines benefitting from cell-mediated immunity. We also anticipate using synthetic microbe-associated molecular patterns (MAMPs) to study mycobacterial immunity and immunopathogenesis.

Immunogenicity for CD8+ and CD4+ T cells of 2 formulations of an incomplete freund's adjuvant for multipeptide melanoma vaccines

An incomplete Freund's adjuvant (IFA) commonly used in experimental cancer vaccines has recently been reformulated. Oleic acid used in the surfactant was purified from a vegetable source (olives, IFA-VG) rather than an animal source (beef tallow, IFA-AN). To provide an insight into the adjuvant properties of the new formulation, we reviewed T-cell responses, by enzyme-linked immunospot assay, to multipeptide vaccines in 2 sequential clinical trials that spanned this transition of adjuvants. Analyses included 194 patients who received either IFA-AN or IFA-VG for all vaccines, and a subset of 93 patients best matched by study arm for vaccine antigens (12 melanoma peptides restricted by major histocompatibility complex class I, 12MP; plus a tetanus helper peptide, tet) administered with IFA but without granulocyte macrophage-colony stimulating factor. Inflammation was observed at vaccine sites clinically for almost all patients, even including ulceration in a subset with each IFA formulation. CD8 T-cell response rates to the 12 melanoma peptides were 53% [95% confidence interval (CI), 44%, 61%)] for IFA-AN and 46% [95% CI, 32%, 59%)] for IFA-VG. In the 93 patient subset, these rates were 73% [95% CI, 61%, 83%)] and 70% [95% CI, 47%, 87%)], respectively. CD4 T-cell responses to tetanus helper peptide were identified in 94% [95% CI, 86%, 98%)] and 96% [95% CI, 78%, 100%)], respectively. Responses to individual human leukocyte antigen (HLA)-A1, A2, and DR associated peptides were largely preserved, but reactivity trended lower for some HLA-A3 associated peptides. Despite the necessarily retrospective nature of the analysis and limitations of multiple comparisons, our summary data support the use of IFA-VG as an adjuvant with multipeptide vaccines in melanoma patients.

Different adjuvanticity of incomplete freund's adjuvant derived from beef or vegetable components in melanoma patients immunized with a peptide vaccine

Adjuvants are requisite components of many vaccines designed to elicit T-cell immunity although the exact components of commonly used adjuvants are not always fully defined. In 2006, owing to concerns of prion contamination, the formulation of Montanide ISA 51 Incomplete Freund's Adjuvant (IFA) was changed from using oleic acid isolated from beef tallow to that isolated from olives. In sequential clinical trials in the Surgery Branch, NCI patients at high risk for recurrence of melanoma were immunized with the gp100 melanoma/melanocyte antigenic peptide, gp100: 209-217 (210M), emulsified in the beef-derived IFA or the olive-derived IFA. The in vivo generation of gp100 reactive T cells was significantly less in patients receiving the olive compared with the beef IFA as assessed by both ELISPOT (P2=0.0001) and in vitro sensitization assays (P2=0.0001). Local skin reactions to the peptide emulsion were also far less severe using the olive IFA (P2=0.0003). Thus it seems likely that contaminants in the beef-derived IFA played an important role in the increased adjuvanticity of this preparation compared with the olive-derived IFA. These findings raise serious concerns related to the use of the available olive-derived IFA for immunization in clinical trials. A survey of ongoing clinical trials listed in ClinicalTrials.gov revealed 36 trials currently accruing patients that are using the olive-derived Montanide ISA 51 IFA.

Non-specific binding of mouse IgM antibodies to lipid antigens

Galactocerebroside (GC) is a major component expressed on the surface of oligodendrocytes and Schwann cells. It plays a role in neuronal-glial interaction that results in myelinization. In this paper we describe a method to estimate anti-GC antibodies by ELISA. Furthermore we found that IgM antibodies of mice immunized with GC-unrelated antigens, and which are not specific for GC, bind in a non-specific way to this compound. Thus only assays which avoid the detection of IgM antibody can be used to estimate anti-GC antibodies. Moreover, we showed that serum of immunized mice bind also non-specifically to brain cells of newborn mice.

Cross-reactivity and inhibition of haemolysis by polyclonal antibodies raised against St II, a cytolysin from the sea anemone Stichodactyla helianthus

The immunogenicity of sticholysin II (St II), a pore-forming polypeptide from the sea anemone Stichodactyla helianthus, was studied in rabbits using two adjuvants, Freund's and aluminium hydroxide. High titres of antibodies were raised against St II with Freund's adjuvant (FA). The structural homology between sticholysins I and II was also revealed by cross-reactivity assays. Since the oil constituent of FA neutralized the St II haemolytic activity, immunizations with St II-Freund's emulsions were carried out with the inactivated cytolysin. Purified anti-St II IgG also neutralized the St II haemolytic activity.

Production and transfer of IVF embryos from individual inhibin-immunized cows by ultrasound-guided transvaginal follicular aspiration

Ultrasound-guided transvaginal follicular aspiration (UTA) was performed on 8 multiparous Japanese Black cows which had not been successful in a conventional superovulation program. These cows were actively immunized with a synthetic peptide replica of porcine inhibition alpha N1-26 (pINH) conjugated with rabbit serum albumin (RSA) using Freund's complete adjuvant. Booster injections of the peptide were given at 6, 10, 14 and 20 wk after the primary injection. Twelve follicular aspirations were performed between 10 and 33 wk after the primary injection. Cumulus-oocyte complexes (COCs) were aspirated from follicles > or = 2 mm in diameter. The recovered COCs were classified into 5 categories according to the surrounding cumulus cells: Grade 1 (> 4 layers), Grade 2 (3 to 4 layers), Grade 3 (1 to 2 layers), Grade 4 (denuded) and Grade 5 (expanded and fluffy cumulus cell mass or degenerated ooplasm). The recovered COCs available for in vitro fertilization (IVF; Grades 1, 2, 3 and 4) were matured with granulosa cells (1 x 10(6) cells/ml) for 20 to 23 hr, fertilized with frozen-thawed spermatozoa, and cultured in vitro. At day 7 after insemination, a portion of the embryos were transferred to Holstein heifers. There were great variations among donors in the number of recovered COCs in the numbers of COCs in each grade, and also in the developmental ability of fertilized COCs. IVF procedures were carried out on 685 oocytes and produced 120 embryos (17.5%). The transfer of 36 fresh IVF embryos resulted in 20 pregnancies (55.6%) at 60 days after the transfer. This study has demonstrated first, that the number of COCs collected from individual inhibin-immunized cows by UTA greatly varies among donors. Second, recovered COCs vary greatly in the classification of the morphological categories of surrounding cumulus cell mass among donors and had different developmental abilities when they were cultured after fertilization in vitro. Third, the production of pregnancy in previously nonproductive problem donors is possible using the UTA technique.

TRAF6 Contributes to CFA-Induced Spinal Microglial Activation and Chronic Inflammatory Pain in Mice

Tumor necrosis factor receptor-associated factor 6 (TRAF6) has been reported to be expressed in spinal astrocytes and is involved in neuropathic pain. In this study, we investigated the role and mechanism of TRAF6 in complete Freund's adjuvant (CFA)-evoked chronic inflammatory hypersensitivity and the effect of docosahexaenoic acid (DHA) on TRAF6 expression and inflammatory pain. We found that TRAF6 was dominantly increased in microglia at the spinal level after intraplantar injection of CFA. Intrathecal TRAF6 siRNA alleviated CFA-triggered allodynia and reversed the upregulation of IBA-1 (microglia marker). In addition, intrathecal administration of DHA inhibited CFA-induced upregulation of TRAF6 and IBA-1 in the spinal cord and attenuated CFA-evoked mechanical allodynia. Furthermore, DHA prevented lipopolysaccharide (LPS)-caused increase of TRAF6 and IBA-1 in both BV2 cell line and primary cultured microglia. Finally, intrathecal DHA reduced LPS-induced upregulation of spinal TRAF6 and IBA-1, and alleviated LPS-induced mechanical allodynia. Our findings indicate that TRAF6 contributes to pain hypersensitivity via regulating microglial activation in the spinal dorsal horn. Direct inhibition of TRAF6 by siRNA or indirect inhibition by DHA may have therapeutic effects on chronic inflammatory pain.

Macrophages are activated in the rat anterior pituitary under chronic inflammatory conditions

In the anterior lobe of the pituitary gland (AP), non-endocrine cells regulate hormone secretion by endocrine cells. However, the functions of non-endocrine cells in the AP during chronic pain are largely unclear. Here, we show that macrophages, but not folliculostellate (FS) cells, were selectively increased in the AP in the complete Freund's adjuvant (CFA)-induced chronic inflammatory pain model in rats. In addition, IL-1β expression was increased in the AP, and the IL-1β-immunopositive cells were identified as macrophages. On the other hand, increased macrophage density and IL-1β expression were not detected in a neuropathic pain model induced by partial sciatic nerve ligation (PSL). Furthermore, we found c-Fos expression specifically in the somatotrophs under the chronic inflammatory pain condition. Because IL-1β promotes growth hormone (GH) synthesis and release, our results suggest that AP macrophage contributes to GH release through IL-1βduring chronic inflammatory pain.　.

Excitatory neurons in the lateral parabrachial nucleus mediate the interruptive effect of inflammatory pain on a sustained attention task

BACKGROUND

Attentional deficits are among the most common pain-induced cognitive disorders. Pain disrupts attention and may excessively occupy attentional resources in pathological states, leading to daily function impairment and increased disability. However, the neural circuit mechanisms by which pain disrupts attention are incompletely understood.

METHODS

We used a three-choice serial reaction time task (3CSRTT) to construct a sustained-attention task model in male C57BL/6J mice. Formalin or complete Freund's adjuvant was injected into a paw to establish an inflammatory pain model. We measured changes in 3CSRTT performance in the two inflammatory pain models, and investigated the neural circuit mechanisms of pain-induced attentional deficits.

RESULTS

Acute inflammatory pain impaired 3CSRTT performance, while chronic inflammatory pain had no effect. Either inhibition of the ascending pain pathway by blockade of the conduction of nociceptive signals in the sciatic nerve using the local anesthetic lidocaine or chemogenetic inhibition of Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα) neurons in the lateral parabrachial nucleus (LPBN) attenuated the acute inflammatory pain-induced impairment of 3CSRTT performance, while chemogenetic activation of CaMKIIα neurons in the LPBN disrupted the 3CSRTT. Furthermore, the activity of CaMKIIα neurons in the LPBN was significantly lower on Day 2 after complete Freund's adjuvant injection than on the day of injection, which correlated with the recovery of 3CSRTT performance during chronic inflammatory pain.

CONCLUSIONS

Activation of excitatory neurons in the LPBN is a mechanism by which acute inflammatory pain disrupts sustained attention. This finding has implications for the treatment of pain and its cognitive comorbidities.

Determination of citrinin in barley by indirect and direct enzyme immunoassay

Polyclonal antibodies against the mycotoxin citrinin were raised in rabbits after immunization with citrinin conjugated to keyhole limpet hemocyanin. The antibodies were used in a competitive indirect enzyme immunoassay (EIA) with citrinin coupled to glucose oxidase as the solid-phase antigen for coating microtiter plates. Detection limits of this indirect EIA for citrinin ranged from 0.4 to 0.8 ng/mL for buffer solutions. Recoveries of citrinin added to ground barley at 100-2000 ng/g ranged from 105 to 112%, with coefficients of variation between 4.5 and 12%. A direct competitive EIA also was established, with citrinin coupled to horseradish peroxidase as the labeled antigen. Detection limits of this direct EIA for citrinin ranged from 2 to 4 ng/mL for buffer solutions. Recoveries of citrinin added to ground barley at 500-2000 ng/g ranged from 108 to 111%, with coefficients of variation between 8.4 and 26.9%. In naturally contaminated barley samples assayed with the indirect EIA, optimum extraction of citrinin was obtained in 30 min, and only one extraction was necessary to recover 72-76% of the analyte.

PGE2 Potentiates Orai1-Mediated Calcium Entry Contributing to Peripheral Sensitization

Peripheral sensitization is one of the primary mechanisms underlying the pathogenesis of chronic pain. However, candidate molecules involved in peripheral sensitization remain incompletely understood. We have shown that store-operated calcium channels (SOCs) are expressed in the dorsal root ganglion (DRG) neurons. Whether SOCs contribute to peripheral sensitization associated with chronic inflammatory pain is elusive. Here we report that global or conditional deletion of Orai1 attenuates Complete Freund's adjuvant (CFA)-induced pain hypersensitivity in both male and female mice. To further establish the role of Orai1 in inflammatory pain, we performed calcium imaging and patch-clamp recordings in wild-type (WT) and Orai1 knockout (KO) DRG neurons. We found that SOC function was significantly enhanced in WT but not in Orai1 KO DRG neurons from CFA- and carrageenan-injected mice. Interestingly, the Orai1 protein level in L3/4 DRGs was not altered under inflammatory conditions. To understand how Orai1 is modulated under inflammatory pain conditions, prostaglandin E2 (PGE2) was used to sensitize DRG neurons. PGE2-induced increase in neuronal excitability and pain hypersensitivity was significantly reduced in Orai1 KO mice. PGE2-induced potentiation of SOC entry (SOCE) was observed in WT, but not in Orai1 KO DRG neurons. This effect was attenuated by a PGE2 receptor 1 (EP1) antagonist and mimicked by an EP1 agonist. Inhibition of Gq/11, PKC, or ERK abolished PGE2-induced SOCE increase, indicating PGE2-induced SOCE enhancement is mediated by EP1-mediated downstream cascade. These findings demonstrate that Orai1 plays an important role in peripheral sensitization. Our study also provides new insight into molecular mechanisms underlying PGE2-induced modulation of inflammatory pain.Significance Statement Store-operated calcium channel (SOC) Orai1 is expressed and functional in dorsal root ganglion (DRG) neurons. Whether Orai1 contributes to peripheral sensitization is unclear. The present study demonstrates that Orai1-mediated SOC function is enhanced in DRG neurons under inflammatory conditions. Global and conditional deletion of Orai1 attenuates complete Freund's adjuvant (CFA)-induced pain hypersensitivity. We also demonstrate that prostaglandin E2 (PGE2) potentiates SOC function in DRG neurons through EP1-mediated signaling pathway. Importantly, we have found that Orai1 deficiency diminishes PGE2-induced SOC function increase and reduces PGE2-induced increase in neuronal excitability and pain hypersensitivity. These findings suggest that Orai1 plays an important role in peripheral sensitization associated with inflammatory pain. Our study reveals a novel mechanism underlying PGE2/EP1-induced peripheral sensitization. Orai1 may serve as a potential target for pathological pain.

[Effect of heat-reinforcing needling on expression of serum inflammatory factors and autophagy of knee joint synovial tissue in rheumatoid arthritis rabbits with cold syndrome]

OBJECTIVE

To observe the effect of heat-reinforcing needling on the expression of serum inflammatory factors and autophagy of knee synovial tissue in rheumatoid arthritis (RA) rabbits with cold syndrome, so as to explore its mechanism of anti-inflammatory in the treatment of RA.

METHODS

Fifty rabbits were randomly divided into normal, model, heat-reinforcing needling, inhibitor and agonist groups (n=10 rabbits in each group). The model of RA with cold syndrome was established by Freund's adjuvant and ovalbumin mixed solution injection combined with freezing and wind-cold dampness method. Heat-reinforcing needling was applied at "Zusanli" (ST36) for 30 min, once a day for 14 days. Rabbits of the inhibitor and agonist groups were given intraperitoneally injected with autophagy inhibitor 3-methyladenine (3-MA) or autophagy agonist rapamycin, once every 2 days for 7 days. The knee circumference and skin temperature of the rabbits in each group were measured. Color doppler ultrasonography was applied to examine the synovial membrane, joint effusion and blood flow signals in the knee joints of the rabbits in each group. Serum tumor necrosis factor (TNF) -α, interleukin (IL)-1β, IL-6 and C-creactive protein (CRP) were detected by ELISA. Transmission electron microscopy was applied to observe the ultrastructure and autophagosomes of synovial cells. The protein expressions of autophagy-related protein Atg5, serine/threonine protein kinase-dysregulated 51-like kinase 1 (ULK1), microtubule-associated protein light chain 3B (LC3B), and Beclin-1 were detected by Western blot. Fluorescence quantitative PCR was used to detect the mRNA expressions of NOD-like receptor 3 (NLRP3) and nuclear factor-κB (NF-κB).

RESULTS

Compared with the normal group, the circumference of the knee joint was increased (P<0.01), the skin temperature was decreased (P<0.01), the knee joint synovium was thickened and the blood flow signal was abundant, the contents of serum TNF-α, IL-1β, IL-6, and CRP were increased (P<0.01), the protein expressions of Atg5, ULK1, Beclin-1 and LC3BⅡ/LC3BⅠof synovial tissue were significantly decreased (P<0.01), the mRNA expressions of NLRP3 and NF-κB were increased (P<0.01) in the model group. In comparison with the model and inhibitor groups, the circumference of the knee joint was decreased (P<0.01), whlie the skin temperature was increased (P<0.01), the synovial membrane became thinner and the blood flow signal was wea-kened, the contents of TNF-α, IL-1β, IL-6 and CRP were decreased (P<0.01), the protein expressions of Atg5, ULK1, Beclin-1 and LC3B Ⅱ/LC3B Ⅰ were increased (P<0.01), and the mRNA expressions of NLRP3 and NF-κB were decreased (P<0.01) in the heat-reinforcing needling and agonist groups.

CONCLUSION

Heat-reinforcing needling can alleviate the inflammatory response of the knee joint synovium in RA rabbits with cold syndrome, which may be related to its function in enhancing the autophagy activity of synovial cells and inhibiting the synthesis and release of inflammatory factors TNF-α, IL-1β, IL-6 and CRP.

Macrophage Activation in Synovitis and Osteoarthritis of Temporomandibular Joint and Its Relationship with the Progression of Synovitis and Bone Remodeling

This study investigates the regulatory mechanisms of synovial macrophages and their polarization in the progression of temporomandibular joint osteoarthritis (TMJOA). Macrophage depletion models were established by intra-articular injection of clodronate liposomes and unloaded liposomes. TMJOA was induced by intra-articular injection of 50 μL Complete Freund's Adjuvant and the surgery of disc perforation. The contralateral joint was used as the control group. The expression of F4/80, CD86, and CD206 in the synovium was detected by immunofluorescence staining analysis. Hematoxylin and eosin staining and TMJOA synovial score were detected to show the synovial changes in rat joints after TMJOA induction and macrophage depletion. Changes in rat cartilage after TMJOA induction and macrophage depletion were shown by safranin fast green staining. The bone-related parameters of rats' joints were evaluated by micro-computed tomography analysis. The TMJOA model induced by Complete Freund's Adjuvant injection and disc perforation aggravated synovial hyperplasia and showed a significant up-regulation of expression of F4/80-, CD86-, and CD206-positive cells. F4/80, CD86, and CD206 staining levels were significantly decreased in macrophage depletion rats, whereas the synovitis score further increased and cartilage and subchondral bone destruction was slightly aggravated. Macrophages were crucially involved in the progression of TMJOA, and macrophage depletion in TMJOA synoviocytes promoted synovitis and cartilage destruction.

Proteomic Analysis of the Amygdala Reveals Dynamic Changes in Glutamate Transporter-1 During Progression of Complete Freund's Adjuvant-Induced Pain Aversion

Pain sufferer usually show an aversion to the environment associated with pain, identified as pain aversion. The amygdala, an almond-shaped limbic structure in the medial temporal lobe, exerts a critical effect on emotion and pain formation. However, studies on inflammatory pain-induced aversion are still relatively limited, and the available evidence is not enough to clarify its inherent mechanisms. Proteomics is a high-throughput, comprehensive, and objective study method that compares the similarities and differences of protein expression under different conditions to screen potential targets. The current study aimed to identify potential pivotal proteins in the amygdala of rats after complete Freund's adjuvant (CFA)-induced pain aversion via proteomics analysis. Immunohistochemistry was performed to confirm the expression of glutamate transporter-1 (GLT-1) in the amygdala during different periods of pain aversion. Thirteen proteins were found to be different between the day 2 and day 15 groups. Among the 13 differentially expressed proteins, Q8R64 denotes GLT-1, which utilises synaptic glutamate to remain optimal extracellular glutamic levels, thereby preventing accumulation in the synaptic cleft and consequent excitotoxicity. The variation in GLT-1 expression was correlated with the variation tendency of pain aversion, which implies a potential link between the modulation of pain aversion and the excitability of glutamatergic neurons. This study demonstrated that exposure to inflammatory pain results in aversion induced from pain, leading to extensive biological changes in the amygdala.