Chemogenetics Modulation of Electroacupuncture Analgesia in Mice Spared Nerve Injury-Induced Neuropathic Pain through TRPV1 Signaling Pathway.

Neuropathic pain, which is initiated by a malfunction of the somatosensory cortex system, elicits inflammation and simultaneously activates glial cells that initiate neuroinflammation. Electroacupuncture (EA) has been shown to have therapeutic effects for neuropathic pain, although with uncertain mechanisms. We suggest that EA can reliably cure neuropathic disease through anti-inflammation and transient receptor potential V1 (TRPV1) signaling pathways from the peripheral to the central nervous system. To explore this, we used EA to treat the mice spared nerve injury (SNI) model and explore the underlying molecular mechanisms through novel chemogenetics techniques. Both mechanical and thermal pain were found in SNI mice at four weeks (mechanical: 3.23 ± 0.29 g; thermal: 4.9 ± 0.14 s). Mechanical hyperalgesia was partially attenuated by 2 Hz EA (mechanical: 4.05 ± 0.19 g), and thermal hyperalgesia was fully reduced (thermal: 6.22 ± 0.26 s) but not with sham EA (mechanical: 3.13 ± 0.23 g; thermal: 4.58 ± 0.37 s), suggesting EA's specificity. In addition, animals with Trpv1 deletion showed partial mechanical hyperalgesia and no significant induction of thermal hyperalgesia in neuropathic pain mice (mechanical: 4.43 ± 0.26 g; thermal: 6.24 ± 0.09 s). Moreover, we found increased levels of inflammatory factors such as interleukin-1 beta (IL1-ß), IL-3, IL-6, IL-12, IL-17, tumor necrosis factor alpha, and interferon gamma after SNI modeling, which decreased in the EA and Trpv1-/- groups rather than the sham group. Western blot and immunofluorescence analysis showed similar tendencies in the dorsal root ganglion, spinal cord dorsal horn, somatosensory cortex (SSC), and anterior cingulate cortex (ACC). In addition, a novel chemogenetics method was used to precisely inhibit SSC to ACC activity, which showed an analgesic effect through the TRPV1 pathway. In summary, our findings indicate a novel mechanism underlying neuropathic pain as a beneficial target for neuropathic pain.

Eicosapentaenoic Acid Modulates Transient Receptor Potential V1 Expression in Specific Brain Areas in a Mouse Fibromyalgia Pain Model.

Pain is an unpleasant sensory and emotional experience accompanied by tissue injury. Often, an individual's experience can be influenced by different physiological, psychological, and social factors. Fibromyalgia, one of the most difficult-to-treat types of pain, is characterized by general muscle pain accompanied by obesity, fatigue, sleep, and memory and psychological concerns. Fibromyalgia increases nociceptive sensations via central sensitization in the brain and spinal cord level. We used intermittent cold stress to create a mouse fibromyalgia pain model via a von Frey test (day 0: 3.69 ± 0.14 g; day 5: 2.13 ± 0.12 g). Mechanical pain could be reversed by eicosapentaenoic acid (EPA) administration (day 0: 3.72 ± 0.14 g; day 5: 3.69 ± 0.13 g). A similar trend could also be observed for thermal hyperalgesia. The levels of elements in the transient receptor potential V1 (TRPV1) signaling pathway were increased in the ascending pain pathway, including the thalamus, medial prefrontal cortex, somatosensory cortex, anterior cingulate cortex, and cerebellum. EPA intake significantly attenuated this overexpression. A novel chemogenetics method was used to inhibit SSC and ACC activities, which presented an analgesic effect through the TRPV1 downstream pathway. The present results provide insights into the role of the TRPV1 signaling pathway for fibromyalgia and its potential as a clinical target.

Clinical efficacy and immune effects of acupuncture in patients with comorbid chronic pain and major depression disorder: A double-blinded, randomized controlled crossover study.

BACKGROUND: Depression and pain are highly comorbid and share biological mechanisms. Acupuncture is commonly used to manage both pain and depression, but the choice of acupoints for specific disorders differs. This study aimed to investigate whether specific acupuncture intervention on pain- and depression-acupoints would have specific efficacy and immune effects in patients with comorbid chronic pain and major depressive disorder (MDD). METHODS: We performed a subject- and assessor-blinded, crossover, and randomized controlled clinical trial of depression- and pain-specific acupuncture intervention and measured clinical responses and proinflammatory cytokines in patients with comorbid chronic pain and MDD. Specific acupoints for pain and depression were used in random order with a washout interval. Forty-seven patients were enrolled and randomly assigned to two groups: (1) the depression-pain group (23 patients who were treated with depression-specific acupoints and then the pain-specific acupoints after the washout) and (2) pain-depression group (24 patients with the reverse order). RESULTS: The pain-specific acupoints for pain did not reduce Brief Pain Inventory scores to a significantly greater degree (-0.97 ± 1.69) than the depression-specific acupoints (-0.28 ± 1.88); likewise, the depression-specific acupoints did not significantly ameliorate Hamilton Depression Rating Scale (-4.59 ± 6.02) than the pain-specific acupoints (-6.69 ± 6.61). The pain-specific acupoints improved Beck Depression Inventory-Second Edition (-6.74 ± 9.76) even better than the depression-specific acupoints (-1.92 ± 10.74). The depression-specific acupoints did not significantly decrease the depression-related interleukin (IL)-6 level (-1.24 ± 6.67) than the pain-specific acupoints (-0.60 ± 4.36). The changed levels of IL-1ß, tumor necrosis factor (TNF)-α between the depression-specific acupoints (-37.41 ± 194.49; -12.53 ± 54.68) and the pain-specific acupoints (-15.46 ± 87.56; -7.28 ± 27.86) could not reach significantly different, too. CONCLUSION: This study rejected our hypothesis that the pain-specific acupoints might produce superior analgesic effects than the depression-specific acupoints and vice versa. The cytokine results might imply that pain and depression share common biological mechanisms. (trial registration: https://www. CLINICALTRIALS: gov: NCT03328819).

Behavioral and brain- transcriptomic synchronization between the two opponents of a fighting pair of the fish Betta splendens.

Conspecific male animals fight for resources such as food and mating opportunities but typically stop fighting after assessing their relative fighting abilities to avoid serious injuries. Physiologically, how the fighting behavior is controlled remains unknown. Using the fighting fish Betta splendens, we studied behavioral and brain-transcriptomic changes during the fight between the two opponents. At the behavioral level, surface-breathing, and biting/striking occurred only during intervals between mouth-locking. Eventually, the behaviors of the two opponents became synchronized, with each pair showing a unique behavioral pattern. At the physiological level, we examined the expression patterns of 23,306 brain transcripts using RNA-sequencing data from brains of fighting pairs after a 20-min (D20) and a 60-min (D60) fight. The two opponents in each D60 fighting pair showed a strong gene expression correlation, whereas those in D20 fighting pairs showed a weak correlation. Moreover, each fighting pair in the D60 group showed pair-specific gene expression patterns in a grade of membership analysis (GoM) and were grouped as a pair in the heatmap clustering. The observed pair-specific individualization in brain-transcriptomic synchronization (PIBS) suggested that this synchronization provides a physiological basis for the behavioral synchronization. An analysis using the synchronized genes in fighting pairs of the D60 group found genes enriched for ion transport, synaptic function, and learning and memory. Brain-transcriptomic synchronization could be a general phenomenon and may provide a new cornerstone with which to investigate coordinating and sustaining social interactions between two interacting partners of vertebrates.

Acupoint Catgut Embedding Diminishes Fibromyalgia Pain through TRPV1 in the Mouse Brain.

BACKGROUND: Chronic pain refers to pain that persists for over three months. Chronic pain may restrict activities of daily living, including work, learning, social life, and can lead to anxiety, depression, and sleep disturbance. Imaging data have demonstrated that central sensitization often occurs in the brain of patients with chronic pain, which arises from imbalanced neurotransmission in the central nervous system. Transient receptor potential vanilloid 1 (TRPV1) is an ion channel to serve as an inflammatory detector in the brain. We aim to determine the properties of acupoint catgut embedding (ACE) on cold stress-induced mice fibromyalgia (FM) and surveyed the character of TRPV1 and linked molecules in chronic FM pain. METHODS: Intermittent cold stress (ICS) was used to induce mice FM model. Mice were subgrouped into normal mice, ICS-induced FM group, FM mice with ACE, and FM in Trpv1-⁣/- group. ACE is a novel acupuncture technique that provides convenience and continuous nerve stimulation that has been reported effective on pain management. RESULTS: Our behavioral experiments showed similar levels of pain response among all groups before treatment. After ICS, prolonged mechanical and thermal pain was initiated (mechanical threshold: 1.96 ± 0.12 g; thermal latency: 4.86 ± 0.21 s) and were alleviated by ACE treatment and TRPV1 gene deletion. Inflammatory mediators were increased in the plasma of FM mice, while TRPV1 and related kinases were amplified in the hypothalamus and cerebellum. These changes were ameliorated in the ACE-treated and Trpv1-⁣/- groups. CONCLUSIONS: These novel findings suggest that chronic FM pain can be modulated by ACE or TRPV1 gene deletion. The analgesic effect of ACE through the TRPV1 pathway may reflect its potential as a therapeutic target for FM treatment.

Tumor Necrosis Factor Superfamily 14 (LIGHT) Restricts Neovascularization by Decreasing Circulating Endothelial Progenitor Cells and Function.

Tumor necrosis factor superfamily 14 (TNFSF14) is also known as the LT-related inducible ligand (LIGHT). It can bind to the herpesvirus invasion mediator and lymphotoxin-ß receptor to perform its biological activity. LIGHT has multiple physiological functions, including strengthening the synthesis of nitric oxide, reactive oxygen species, and cytokines. LIGHT also stimulates angiogenesis in tumors and induces the synthesis of high endothelial venules; degrades the extracellular matrix in thoracic aortic dissection, and induces the expression of interleukin-8, cyclooxygenase-2, and cell adhesion molecules in endothelial cells. While LIGHT induces tissue inflammation, its effects on angiogenesis after tissue ischemia are unclear. Thus, we analyzed these effects in the current study. In this study, the animal model of hind limb ischemia surgery in C57BL/6 mice was performed. Doppler ultrasound, immunohistochemical staining, and Western blotting were employed to analyze the situation of angiogenesis. In addition, human endothelial progenitor cells (EPCs) were used for in vitro studies to analyze the possible mechanisms. The results in the animal study showed that LIGHT injection inhibited angiogenesis in ischemic limbs. For the in vitro studies, LIGHT inhibited the expression of integrins and E-selectin; decreased migration and tube formation capabilities, mitochondrial respiration, and succinate dehydrogenase activity; and promoted senescence in EPCs. Western blotting revealed that the impairment of EPC function by LIGHT may be due to its effects on the proper functioning of the intracellular Akt signaling pathway, endothelial nitrite oxide synthase (eNOS), and mitochondrial respiration. In conclusion, LIGHT inhibits angiogenesis after tissue ischemia. This may be related to the clamped EPC function.

Neuroprotective effect of l-theanine in a rat model of chronic constriction injury of sciatic nerve-induced neuropathic pain.

BACKGROUND/PURPOSE: We investigated the protective efficacy of l-theanine (LT), the major amino acid components of green tea, on chronic constriction injury (CCI) of sciatic nerve-induced neuropathic pain (NP) development and neuronal functional changes in rats. METHODS: Rats with NP induced by CCI of the left sciatic nerve and sham-operated rats received LT or saline solution, with pain sensitive tests of thermal hyperalgesia and mechanical allodynia. Motor and sensory nerve conduction velocities were measured after surgery. Subsequently, the rats were sacrificed; the sciatic nerve was excised, homogenized, prepared and subjected for estimation of nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), myeloperoxidase (MPO), and caspase-3. RESULTS: CCI produced a significant increase in hyperalgesia and allodynia, an increase in SFI, a decrease in nerve conduction velocity, increases in NO, MDA, TNF-α, IL-1ß, IL-6, MPO, and caspase-3 levels, as well as reduction of GSH, SOD, and CAT in the rat sciatic nerve. LT treatment significantly and dose-dependently alleviated CCI-induced nociceptive pain thresholds and ameliorated abnormal nerve conduction and functional loss in rats with CCI. Moreover, LT treatment reduced NO and MDA levels, increased antioxidative strength, and markedly suppressed the levels of neuroinflammatory and apoptotic markers in injured sciatic nerves. CONCLUSION: This is the first report on the ameliorative effect of LT in CCI-induced NP in rats. This effect might be attributed to its anti-oxidative, anti-inflammatory, anti-apoptotic, and neuroprotective, thus making it potentially useful as an adjuvant to conventional treatment.

Metformin-Incorporated Gelatin/Nano-Hydroxyapatite Scaffolds Promotes Bone Regeneration in Critical Size Rat Alveolar Bone Defect Model.

In this study, we fabricated gelatin/nano-hydroxyapatite/metformin scaffold (GHMS) and compared its effectiveness in bone regeneration with extraction-only, Sinbone, and Bio-Oss Collagen® groups in a critical size rat alveolar bone defect model. GHMS was synthesized by co-precipitating calcium hydroxide and orthophosphoric acid within gelatin solution, incorporating metformin, and cross-linked by microbial transglutaminase. The morphology, characterization, and biocompatibility of scaffold were examined. The in vitro effects of GHMS on osteogenic gene and protein expressions were evaluated. In vivo bone formation was assessed in a critical size rat alveolar bone defect model with micro-computed tomography and histological examination by comparing GHMS with extraction-only, Sinbone, and Bio-Oss Collagen®. The synthesized GHMS had a highly interconnected porous structure with a mean pore size of 81.85 ± 13.8 µm. GHMS exhibited good biocompatibility; promoted ALPL, RUNX2, SP7, BGLAP, SPARC and Col1a1 gene expressions; and upregulated the synthesis of osteogenic proteins, including osteonectin, osteocalcin, and collagen type I. In critical size rat alveolar bone defects, GHMS showed superior bone regeneration compared to extraction-only, Sinbone, and Bio-Oss Collagen® groups as manifested by greater alveolar ridge preservation, while more bone formation with a lower percentage of connective tissue and residual scaffold at the defect sites grafted with GHMS in histological staining. The GHMS presented in this study may be used as a potential bone substitute to regenerate alveolar bone. The good biocompatibility, relatively fast degradation, interconnected pores allowing vascularization, and higher bioactivity properties of the components of the GHMS (gelatin, nHA, and metformin) may contribute to direct osteogenesis.

Dipeptidyl Peptidase-4 Inhibitor Decreases Allograft Vasculopathy Via Regulating the Functions of Endothelial Progenitor Cells in Normoglycemic Rats.

PURPOSE: Chronic rejection induces the occurrence of orthotopic allograft transplantation (OAT) vasculopathy, which results in failure of the donor organ. Numerous studies have demonstrated that in addition to regulating blood sugar homeostasis, dipeptidyl peptidase-4 (DPP-4) inhibitors can also provide efficacious therapeutic and protective effects against cardiovascular diseases. However, their effects on OAT-induced vasculopathy remain unknown. Thus, the aim of this study was to investigate the direct effects of sitagliptin on OAT vasculopathy in vivo and in vitro. METHODS: The PVG/Seac rat thoracic aorta graft to ACI/NKyo rat abdominal aorta model was used to explore the effects of sitagliptin on vasculopathy. Human endothelial progenitor cells (EPCs) were used to investigate the possible underlying mechanisms. RESULTS: We demonstrated that sitagliptin decreases vasculopathy in OAT ACI/NKyo rats. Treatment with sitagliptin decreased BNP and HMGB1 levels, increased GLP-1 activity and stromal cell-derived factor 1α (SDF-1α) expression, elevated the number of circulating EPCs, and improved the differentiation possibility of mononuclear cells to EPCs ex vivo. However, in vitro studies showed that recombinant B-type natriuretic peptide (BNP) and high mobility group box 1 (HMGB1) impaired EPC function, whereas these phenomena were reversed by glucagon-like peptide 1 (GLP-1) receptor agonist treatment. CONCLUSIONS: We suggest that the mechanisms underlying sitagliptin-mediated inhibition of OAT vasculopathy probably occur through a direct increase in GLP-1 activity. In addition to the GLP-1-dependent pathway, sitagliptin may regulate SDF-1α levels and EPC function to reduce OAT-induced vascular injury. This study may provide new prevention and treatment strategies for DPP-4 inhibitors in chronic rejection-induced vasculopathy.

Stimulatory effects of Porphyromonas gingivalis GroEL protein on interleukin-6 and interleukin-8 in human osteoblasts.

BACKGROUND/PURPOSE: Porphyromonas gingivalis is an oral pathogen associated with periodontal diseases. P. gingivalis GroEL protein is a stimulator of inflammatory cytokines in macrophages. This study inspected effects of P. gingivalis GroEL protein on production of interleukin (IL)-6 and IL-8 by human osteoblasts. METHODS: Viability of GroEL-treated osteoblasts was analyzed with 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide. Secretion of IL-6 and IL-8 was analyzed using the enzyme-linked immunosorbent assay. Levels of mRNA were analyzed using the reverse transcription and real-time polymerase chain reaction. The antioxidant (curcumin), the p38 mitogen-activated protein kinase (MAPK) inhibitor (SB203580) and the c-Jun N-terminal kinase (JNK) inhibitor (SP600125) were employed to elucidate possible signaling pathways involved. RESULTS: Treatment with GroEL did not affect morphology and viability of osteoblasts. GroEL significantly induced the secretion of IL-6 and IL-8 by osteoblasts in a concentration-dependent pattern. Moreover, the mRNA levels of IL-6 and IL-8 were stimulated by GroEL. The application of SP600125 (10 µM) significantly suppressed the induction of IL-6 and IL-8 by GroEL-treated cells. However, curcumin (20 µM) and SB203580 (20 µM) only down-regulated the stimulatory effects of GroEL on IL-6. CONCLUSION: GroEL protein stimulated the inflammatory reaction of osteoblasts, probably through the activation of p38 MAPK or JNK pathway. The findings suggest that P. gingivalis GroEL may influence the immune functions of osteoblasts and endanger the periodontal health.

TRPV1 Responses in the Cerebellum Lobules VI, VII, VIII Using Electroacupuncture Treatment for Chronic Pain and Depression Comorbidity in a Murine Model.

Depression is a prominent complex psychiatric disorder, usually complicated through expression of comorbid conditions, with chronic pain being among the most prevalent. This comorbidity is consistently associated with a poor prognosis and has been shown to negatively impact patient outcomes. With a global rise in this condition presenting itself, the importance of discovering long-term, effective, and affordable treatments is crucial. Electroacupuncture has demonstrated renowned success in its use for the treatment of pain and is a widely recognized therapy in clinical practice for the treatment of various psychosomatic disorders, most notably depression. Our study aimed to investigate the effects and mechanisms of Acid-Saline (AS) inducing states of chronic pain and depression comorbidity in the cerebellum, using the ST36 acupoint as the therapeutic intervention. Furthermore, the role of TRPV1 was relatedly explored through the use of TRPV1-/- mice (KO). The results indicated significant differences in the four behavioral tests used to characterize pain and depression states in mice. The AS and AS + SHAM group showed significant differences when compared to the Control and AS + EA groups in the von Frey and Hargreaves's tests, as well as the Open-Field and Forced Swimming tests. This evidence was further substantiated in the protein levels observed in immunoblotting, with significant differences between the AS and AS + SHAM groups when compared to the AS + EA and AS + KO groups being identified. In addition, immunofluorescence visibly served to corroborate the quantitative outcomes. Conclusively these findings suggest that AS-induced chronic pain and depression comorbidity elicits changes in the cerebellum lobules VI, VII, VIII, which are ameliorated through the use of EA at ST36 via its action on TRPV1 and related molecular pathways. The action of TRPV1 is not singular in CPDC, which would suggest other potential targets such as acid-sensing ion channel subtype 3 (ASIC3) or voltage-gated sodium channels (Navs) that could be explored in future studies.

Modified Low-Temperature Extraction Method for Isolation of Bletilla striata Polysaccharide as Antioxidant for the Prevention of Alzheimer's Disease.

Amyloid-ß (Aß) peptides play a key role in Alzheimer's disease (AD), the most common type of dementia. In this study, a polysaccharide from Bletilla striata (BSP), with strong antioxidant and anti-inflammatory properties, was extracted using a low-temperature method and tested for its efficacy against AD, in vitro using N2a and BV-2 cells, and in vivo using an AD rat model. The characterization of the extracted BSP for its molecular structure and functional groups demonstrated the effectiveness of the modified method for retaining its bioactivity. In vitro, BSP reduced by 20% reactive oxygen species (ROS) levels in N2a cells (p = 0.0082) and the expression levels of inflammation-related genes by 3-fold TNF-α (p = 0.0048), 4-fold IL-6 (p = 0.0019), and 2.5-fold IL-10 (p = 0.0212) in BV-2 cells treated with Aß fibrils. In vivo, BSP recovered learning memory, ameliorated morphological damage in the hippocampus and cortex, and reduced the expression of the ß-secretase protein in AlCl3-induced AD rats. Collectively, these findings demonstrated the efficacy of BSP for preventing and alleviating the effects of AD.

A Novel Relative High-Density Lipoprotein Index to Predict the Structural Changes in High-Density Lipoprotein and Its Ability to Inhibit Endothelial-Mesenchymal Transition.

Therapeutic elevation of high-density lipoprotein (HDL) is thought to minimize atherogenesis in subjects with dyslipidemia. However, this is not the case in clinical practice. The function of HDL is not determined by its concentration in the plasma but by its specific structural components. We previously identified an index for the prediction of HDL functionality, relative HDL (rHDL) index, and preliminarily explored that dysfunctional HDL (rHDL index value > 2) failed to rescue the damage to endothelial progenitor cells (EPCs). To confirm the effectiveness of the rHDL index for predicting HDL functions, here we evaluated the effects of HDL from patients with different rHDL index values on the endothelial-mesenchymal transition (EndoMT) of EPCs. We also analyzed the lipid species in HDL with different rHDL index values and investigated the structural differences that affect HDL functions. The results indicate that HDL from healthy adults and subjects with an rHDL index value < 2 protected transforming growth factor (TGF)-ß1-stimulated EndoMT by modulating Smad2/3 and Snail activation. HDL from subjects with an rHDL index value > 2 failed to restore the functionality of TGF-ß1-treated EPCs. Lipidomic analysis demonstrated that HDL with different rHDL index values may differ in the composition of triglycerides, phosphatidylcholine, and phosphatidylinositol. In conclusion, we confirmed the applicability of the rHDL index value to predict HDL function and found structural differences that may affect the function of HDL, which warrants further in-depth studies.

Transient receptor potential V1 (TRPV1) modulates the therapeutic effects for comorbidity of pain and depression: The common molecular implication for electroacupuncture and omega-3 polyunsaturated fatty acids.

Chronic pain and depression are conditions that are highly comorbid and present with overlapping clinical presentations and common pathological biological pathways in neuroinflammation, both of which can be reversed by the use of electroacupuncture (EA) and omega-3 polyunsaturated fatty acids (PUFAs). Transient receptor potential V1 (TRPV1), a Ca2+ permeable ion channel that can be activated by inflammation, is reported to be involved in the development of chronic pain and depression. Here, we investigated the role of TRPV1 and its related pathways in the murine models of cold stress-induced nociception and depression. Female C57BL/6 wild type and TRPV1 knockout mice were subjected to intermittent cold-stress (ICS) to initiate depressive-like and chronic pain behaviors, respectively. The Bio-Plex ELISA technique was utilized to analyze inflammatory mediators in mice plasma. The western blot and immunostaining techniques were used to analyze the presence of TRPV1 and related molecules in the medial prefrontal cortex (mPFC), hippocampus, periaqueductal gray (PAG), and amygdala. The ICS model significantly induced chronic pain (mechanical: 2.55 ± 0.31 g; thermal: 8.12 ± 0.87 s) and depressive-like behaviors (10.95 ± 0.95% in the center zone; 53.14 ± 4.01% in immobility). The treatment efficacy of EA, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) were observed in both nociceptive and depression test results. Inflammatory mediators were increased after ICS induction and further reversed by the use of EA, EPA and DHA. A majority of TRPV1 proteins and related molecules were significantly decreased in the mPFC, hippocampus and PAG of mice. This decrease can be reversed by the use of EA, EPA and DHA. In contrast, these molecules were increased in the mice's amygdala, and were attenuated by the use of EA, EPA and DHA. Our findings indicate that these inflammatory mediators can regulate the TRPV1 signaling pathway and initiate new potential therapeutic targets for chronic pain and depression treatment.

l-Theanine improves functional recovery after traumatic spinal cord injury in rats.

BACKGROUND/PURPOSE: Spinal cord injury (SCI) is a devastating medical condition for which no effective pharmacological interventions exist. l-Theanine (LT), a major amino acid component of green tea, exhibits potent antioxidative and anti-inflammatory activities and protects against various neural injuries. Here, we evaluated the potential therapeutic effects of LT on the recovery of behavioral motor functions after SCI in rats and the underlying neuroprotective mechanisms. METHODS: SCI was induced by applying vascular clips to the dura through a four-level T5-T8 laminectomy, and saline or LT (10/30 mg/kg) was intrathecally administered at 1-, 6-, and 24-h post-SCI. At 72-h post-SCI, half of the rats from each group for each parameter were sacrificed, and their spinal cord was excised for measurement of malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase, catalase, tumor necrosis factor-α, interleukin-1ß/-6, myeloperoxidase, and caspase-3. The remaining rats from each group were subjected to Bresnahan locomotor-rating scale (BBB), inclined-plane, toe-spread, and hindfoot bar-grab tests at 1-, 4-, 7-, 10-, and 14-days post-SCI. RESULTS: LT treatment reduced NO and MDA levels, increased antioxidative strength, and markedly suppressed the levels of neuroinflammatory and apoptotic markers in the spinal cord after SCI. Moreover, LT treatment drastically promoted the recovery of behavioral motor functions post-SCI. CONCLUSION: Our findings revealed that LT can enhance the recovery of behavioral motor functions after SCI in rats, which related to the suppression of post-traumatic oxidative response, neural inflammation, and apoptosis. This evidence indicates that LT holds considerable potential for use in the clinical treatment/prevention of SCI-induced motor dysfunction.

TRPV1 Responses in the Cerebellum Lobules V, VIa and VII Using Electroacupuncture Treatment for Inflammatory Hyperalgesia in Murine Model.

Inflammatory pain sensation is an important symptom which protects the body against additional tissue damage and promotes healing. Discovering long-term and effective treatments for pain remains crucial in providing efficient healthcare. Electroacupuncture (EA) is a successful therapy used for pain relief. We aimed to investigate effects and mechanisms of Complete Freund's Adjuvant (CFA)-inducing inflammatory pain in the cerebellum, and the inhibition of this inflammatory hyperalgesia using EA at Zusanli acupoint (ST36). The results display a significant increase in mechanical and thermal sensitivities in the CFA and CFA + SHAM groups, which was significantly reduced in the CFA+EA and CFA + KO groups. This evidence was substantiated in the protein levels observed using immunoblotting, and presented with significant escalations after CFA inducing inflammatory hyperalgesia in CFA and CFA + SHAM groups. Then, they were significantly attenuated by EA in the CFA + EA group. Furthermore, the CFA + transient receptor vanilloid member 1 (TRPV1)-/- group indicated similar significant decreases of protein expression. Additionally, a concomitant overexpression in lobule VIa was also observed in immunofluorescence. These consequences suggest that CFA-induced inflammatory pain provokes modifications in cerebellum lobules V, VIa and VII, which can subsequently be regulated by EA treatment at the ST36 through its action on TRPV1 and related molecular pathways.

Hyaluronic Acid Loaded with Cerium Oxide Nanoparticles as Antioxidant in Hydrogen Peroxide Induced Chondrocytes Injury: An In Vitro Osteoarthritis Model.

Osteoarthritis (OA) is the most common joint disease type and is accompanied by varying degrees of functional limitation. Both hyaluronic acid (HA) joint injections and pain relievers are efficient treatments for early-stage osteoarthritis. However, for the decomposition by hyaluronidase and free radicals in the knee joint, HA injection treatment has limited effect time. The cerium oxide nanoparticles (CeO2) is a long time free radical scavenger. CeO2 combined with HA expected, may extend the HA decomposition time and have a positive effect on osteoarthritis therapy. In this study, CeO2 was successfully synthesized using the hydrothermal method with a particle size of about 120 nm, which possessed excellent dispersibility in the culture medium. The in vitro OA model was established by cell treated with H2O2 for 30 min. Our study found that the inhibition of chondrocyte proliferation dose-dependently increased with H2O2 concentration but was significantly decreased by supplementation of cerium oxide nanoparticles. COL2a1 and ACAN gene expression in chondrocytes was significantly decreased after H2O2 treatment; however, the tendency was changed after cerium oxide nanoparticles treatment, which suggested that damaged chondrocytes were protected against oxidative stress. These findings suggest that cerium oxide nanoparticles are potential therapeutic applications in the early stage of OA.

Short-term auricular electrical stimulation rapidly elevated cortical blood flow and promoted the expression of nicotinic acetylcholine receptor α4 in the 2 vessel occlusion rats model.

BACKGROUND: Vascular dementia is the second dementing illness after Alzheimer's disease and caused by reduced blood flow to the brain, and affects cognitive abilities. Our previous study found that auricular electrical stimulation (ES) improved motor and learning impairment, and this phenomenon related with nicotinic acetylcholine receptor (nAChR) expressed cells. However, the underlying mechanism was not clear. In the present study, we investigated the effects of auricular ES on cortical blood flow (CBF) and acetylcholine (ACh) - nAChRs expressed cells. METHODS: Vascular dementia rat animal model was established by permanent occlusions of common carotid arteries with 6-0 nylon suture filament. At 21 day after surgery, motor impairment was confirmed by rotarod test. 15-Hz auricular ES were applied to the ears for 20 min and CBF was recorded at the mean time. The brains were immediately dissected for immunohistochemical stain and western blot analysis. RESULTS: Our results showed that 15-Hz auricular ES rapidly elevated CBF in the middle cerebral artery. The numbers of nAChR α4 immuno-positive cells and western blot levels were significally increased by 15-Hz auricular ES in the hippocampal CA2 output cortex. The numbers of choline acetyltransferase (ChAT) - a key enzyme for biosynthesis of ACh - immuno-positive cells and western blot levels had no significant differences. CONCLUSIONS: The present data suggested that the 15-Hz auricular ES for 20 min rapidly elevated cortical blood flow, promoted the expression of nAChR α4, and would be beneficial for the treatment of Alzheimer type and vascular type dementia.

miR-200a-3p modulates gene expression in comorbid pain and depression: Molecular implication for central sensitization.

Chronic pain and depression are often comorbid exhibiting common clinical presentations and biological connections related to central nervous system sensitization. Epigenetic regulation of gene expression in the brain plays a crucial role in response to long-lasting stress and chronic pain, and microRNA imbalance in the prefrontal cortex (PFC) might be involved in central sensitization. Male Sprague Dawley rats were subjected to unpredictable chronic mild stress (UCMS) and spared nerve injury (SNI) to initiate depressive-like behavior and chronic pain behavior, respectively. The next-generation sequencing technique was employed to analyze PFC microRNAs in both the UCMS and SNI models. Rats exposed to either UCMS or SNI exhibited both depressive-like and chronic pain behaviors. Five specific microRNAs (miR-10a-5p, miR-182, miR-200a-3p, miR-200b-3p, and miR-429) were simultaneously down-regulated in the depressive-like and chronic pain models after 4 weeks of short-term stress. Gene ontology revealed that the 4-week period of stress enhanced neurogenesis. Only the miR-200a-3p level was continuously elevated under prolonged stress, suggesting roles of reduced neurogenesis, inflammatory activation, disturbed circadian rhythm, lipid metabolism, and insulin secretion in the co-existence of pain and depression. Thus we conclude that miR-200a-3p might be a specific biomarker of central sensitization in chronic pain and depression.

Platelet MicroRNA 365-3p Expression Correlates with High On-treatment Platelet Reactivity in Coronary Artery Disease Patients.

PURPOSE: The expression level of platelet microRNAs (miRNAs) correlates with heart disease and may be altered by antiplatelet therapy. This study aims to assess whether certain miRNAs are associated with treatment response by platelets in patients who received percutaneous coronary intervention and antiplatelet therapy. The dynamic expression of certain miRNAs in patients receiving different antiplatelet regimens was also investigated. METHODS: Healthy subjects (N = 20) received no-stent or antiplatelet therapy (as control), and patients (N = 155) who underwent stent implant and received treatment regimens that included aspirin plus clopidogrel, ticagrelor, or cilostazol were included. The association of miR-96-5p, miR-495-3p, miR-107, miR-223-3p, miR-15a-5, miR-365-3p, and miR-339-3p levels with treatment response, SYNTAX score, and HTPR was determined. RESULTS: Of the different treatment regimens, ticagrelor was the most efficacious. At 24 h following drug administration, ROC analysis revealed that miR-339-3p and miR-365-3p had the highest sensitivity (74.3% and 90.0%, respectively) and specificity (71.4% and 93.3%) for detecting HTPR compared with the five other miRNAs. The SYNTAX score positively correlated with miR-223-3p and miR-365-3p levels at 24 h (P ≤ 0.006) and with miR-365-3p levels 7 days following drug administration (P = 0.014). The expression of all three miRNAs reached the highest levels in hyperresponsive (P2Y12 reaction unit < 85) followed by hyporesponsive (P2Y12 reaction unit ≥ 208) and then normoreactive. The normoreactive value was very close to that of controls. CONCLUSIONS: Our data suggest that miR-365-3p expression level correlates with the antiplatelet treatment response. CLINICAL TRIAL REGISTRATION: NCT02101437.