I am a
Home I AM A Search Login

Accepted

Share this

NWD1 facilitates synaptic transmission and contributes to neuropathic pain.

Neuropathic pain is the most common symptom for which patients seek medical attention. Existing treatments to control pain are largely ineffective because of poor understanding the underlying mechanisms. Synaptic plasticity is fundamental to the spinal sensitivity of neuropathic pain. In the present study, we showed that SNL induced significant allodynia and hyperalgesia as well as upregulation of Nwd1 and GluN2B, which were reversed by knockdown of NWD1. Electrophysiological experiments demonstrated that SNL enhanced synaptic transmission, which was prevented by knockdown of NWD1. In vitro experiments showed that knockdown of NWD1 inhibited dendritic growth and synaptogenesis. Taken together, our results suggest that NWD1 enhances synaptic transmission and contributes to the development of neuropathic pain by enhancing GluN2B synaptic expression and anchor and promoting excitatory synaptogenesis.

Learn More >

MicroRNA-155-5p promotes neuroinflammation and central sensitization via inhibiting SIRT1 in a nitroglycerin-induced chronic migraine mouse model.

Previous studies have confirmed that the microglial activation and subsequent inflammatory responses in the trigeminal nucleus caudalis (TNC) are involved in the central sensitization of chronic migraine (CM). MicroRNA-155-5p has been shown to modulate the polarization of microglia and participate in inflammatory processes in a variety of neurological diseases. However, its role in CM remains unclear. The purpose of this study was to determine the precise role of miR-155-5p in CM.

Learn More >

Targeting GATA1 and p2x7r Locus Binding in Spinal Astrocytes Suppresses Chronic Visceral Pain by Promoting DNA Demethylation.

Irritable bowel syndrome is a gastrointestinal disorder of unknown etiology characterized by widespread, chronic abdominal pain associated with altered bowel movements. Increasing amounts of evidence indicate that injury and inflammation during the neonatal period have long-term effects on tissue structure and function in the adult that may predispose to gastrointestinal diseases. In this study we aimed to investigate how the epigenetic regulation of DNA demethylation of the p2x7r locus guided by the transcription factor GATA binding protein 1 (GATA1) in spinal astrocytes affects chronic visceral pain in adult rats with neonatal colonic inflammation (NCI). The spinal GATA1 targeting to DNA demethylation of p2x7r locus in these rats was assessed by assessing GATA1 function with luciferase assay, chromatin immunoprecipitation, patch clamp, and interference in vitro and in vivo. In addition, a decoy oligodeoxynucleotide was designed and applied to determine the influence of GATA1 on the DNA methylation of a p2x7r CpG island. We showed that NCI caused the induction of GATA1, Ten-eleven translocation 3 (TET3), and purinergic receptors (P2X7Rs) in astrocytes of the spinal dorsal horn, and demonstrated that inhibiting these molecules markedly increased the pain threshold, inhibited the activation of astrocytes, and decreased the spinal sEPSC frequency. NCI also markedly demethylated the p2x7r locus in a manner dependent on the enhancement of both a GATA1-TET3 physical interaction and GATA1 binding at the p2x7r promoter. Importantly, we showed that demethylation of the p2x7r locus (and the attendant increase in P2X7R expression) was reversed upon knockdown of GATA1 or TET3 expression, and demonstrated that a decoy oligodeoxynucleotide that selectively blocked the GATA1 binding site increased the methylation of a CpG island in the p2x7r promoter. These results demonstrate that chronic visceral pain is mediated synergistically by GATA1 and TET3 via a DNA-demethylation mechanism that controls p2x7r transcription in spinal dorsal horn astrocytes, and provide a potential therapeutic strategy by targeting GATA1 and p2x7r locus binding.

Learn More >

Characterization of patients with and without painful peripheral neuropathy after receiving neurotoxic chemotherapy: traditional quantitative sensory testing vs C-fiber and Aδ-fiber selective diode laser stimulation.

Painful chemotherapy induced peripheral neuropathy (CIPN) is a common complication of chemotherapy with drugs such as taxanes and platinum compounds. Currently, no methods are available for early detection of sensory changes that are associated with painful CIPN, nor are there biomarkers that are specific to painful CIPN. This study aimed to compare Diode Laser fiber type-selective stimulator (DLss), a method to selectively stimulate cutaneous C and Aδ fibers, to traditional quantitative sensory testing (QST) in determining psychophysical differences between patients with painful CIPN and a control group. Sensory testing was performed on the dorsal mid-foot of 20 patients with painful neuropathy after taxane- or platinum-based chemotherapy, and 20 patients who received similar neurotoxic chemotherapy, without painful CIPN. In a multivariable analysis, C-fiber to Aδ fiber detection threshold ratio, measured by DLss, was significantly different between the groups (p<0.05). While QST parameters such as warmth detection threshold were different between the groups in univariate analyses, these findings were likely attributable to group differences in patient age and cumulative chemotherapy dose. PERSPECTIVE: In this study, fiber-specific DLss test showed potential in identifying sensory changes that are specific for painful neuropathy, encouraging future testing of this approach as a biomarker for early detection of painful CIPN. TRIAL REGISTRATION: The study was approved by the Washington University Institutional Review Board (#201807162) and registered at ClinicalTrials.gov (NCT03687970).

Learn More >

The immune microenvironment in cartilage injury and repair.

The ability of articular cartilage to repair itself is limited because it lacks blood vessels, nerves, and lymph tissue. Once damaged, it can lead to joint swelling and pain, accelerating the progression of osteoarthritis. To date, complete regeneration of hyaline cartilage exhibiting mechanical properties remains an elusive goal, despite the many available technologies. The inflammatory milieu created by cartilage damage is critical for chondrocyte death and hypertrophy, extracellular matrix breakdown, ectopic bone formation, and progression of cartilage injury to osteoarthritis. In the inflammatory microenvironment, mesenchymal stem cells (MSCs) undergo aberrant differentiation, and chondrocytes begin to convert or dedifferentiate into cells with a fibroblast phenotype, thereby resulting in fibrocartilage with poor mechanical qualities. All these factors suggest that inflammatory problems may be a major stumbling block to cartilage repair. To produce a milieu conducive to cartilage repair, multi-dimensional management of the joint inflammatory microenvironment in place and time is required. Therefore, this calls for elucidation of the immune microenvironment of cartilage repair after injury. This review provides a brief overview of: (1) the pathogenesis of cartilage injury; (2) immune cells in cartilage injury and repair; (3) effects of inflammatory cytokines on cartilage repair; (4) clinical strategies for treating cartilage defects; and (5) strategies for targeted immunoregulation in cartilage repair. STATEMENT OF SIGNIFICANCE: : Immune response is increasingly considered the key factor affecting cartilage repair. It has both negative and positive regulatory effects on the process of regeneration and repair. Proinflammatory factors are secreted in large numbers, and necrotic cartilage is removed. During the repair period, immune cells can secrete anti-inflammatory factors and chondrogenic cytokines, which can inhibit inflammation and promote cartilage repair. However, inflammatory factors persist, which accelerate the degradation of the cartilage matrix. Furthermore, in an inflammatory microenvironment, MSCs undergo abnormal differentiation, and chondrocytes begin to transform or dedifferentiate into fibroblast-like cells, forming fibrocartilage with poor mechanical properties. Consequently, cartilage regeneration requires multi-dimensional regulation of the joint inflammatory microenvironment in space and time to make it conducive to cartilage regeneration.

Learn More >

Training on adequate use of opioid analgesics in West and Central Africa: a neglected step on the way to access to essential medicines?

Alleviating acute and chronic pain is a moral imperative for health professionals and health systems, and it requires adequate access to and use of essential opioid analgesics. However, this is still a neglected issue in global health, with striking inequalities in opioids availability between high and low- and middle-income countries. Countries most affected by lack of access are those with a fragile political situation and weak regulatory and healthcare systems. The main threats to accessibility, availability and affordability are situated at different levels: legislation and policy, financing, knowledge and cultural behavior, erroneous beliefs, and training and education. Among these threats, the lack of (adequate) training and education seems to be a cross-cutting issue. Exploring the current body of knowledge about training and educational activities related to use of opioid analgesics and palliative care, is helpful to understand gaps and to delineate priorities for setting up adequate interventions. When applied to West and Central Africa, this exercise reveals that there is little information (easily) available in the public domain. The African Palliative Care Association (APCA) appears to be the leading provider of capacity building activities in this region for key stakeholders, including national authorities, healthcare professionals and the general population; it is also very active in publishing and communicating about these issues. However, apart from APCA, there is little information on training programs' contents and long-term outcomes. Furthermore, trainings rarely target important stakeholders such as lawmakers, regulators, supply officers and the lay public (i.e., patients, caregivers, community leaders and members of the society as a whole). Hence, it is urgent to fill the existing gaps in training and educational activities to improve access to essential opioid analgesics in West and Central Africa, involving different stakeholders at the national and regional level. Furthermore, such experiences should be published and made publicly available to allow for mutual learning and further upscale.

Learn More >

Therapeutic potential of opioid receptor heteromers in chronic pain and associated comorbidities.

Chronic pain affects 20 to 45% of the global population and is often associated with the development of anxio-depressive disorders. Treatment of this debilitating condition remains particularly challenging with opioids prescribed to alleviate moderate to severe pain. However, despite strong antinociceptive properties, numerous adverse effects limit opioid use in the clinic. Moreover, opioid misuse and abuse have become a major health concern worldwide. This prompted efforts to design original strategies that would efficiently and safely relieve pain. Targeting of opioid receptor heteromers is one of these. This review summarizes our current knowledge on the role of heteromers involving opioid receptors in the context of chronic pain and anxio-depressive comorbidities. It also examines how heteromerization in native tissue affects ligand binding, receptor signalling and trafficking properties. Finally, the therapeutic potential of ligands designed to specifically target opioid receptor heteromers is considered.

Learn More >

Non-steroidal anti-inflammatory drugs for acute gout.

Gout is an inflammatory arthritis resulting from the deposition of monosodium urate crystals in and around joints. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat acute gout. This is an update of a Cochrane Review first published in 2014.

Learn More >

Peripherally delivered Adeno-associated viral vectors for spinal cord injury repair.

Via the peripheral and autonomic nervous systems, the spinal cord directly or indirectly connects reciprocally with many body systems (muscular, intengumentary, respiratory, immune, digestive, excretory, reproductive, cardiovascular, etc). Accordingly, spinal cord injury (SCI) can result in catastrophe for multiple body systems including muscle paralysis affecting movement and loss of normal sensation, as well as neuropathic pain, spasticity, reduced fertility and autonomic dysreflexia. Treatments and cure for an injured spinal cord will likely require access of therapeutic agents across the blood-CNS (central nervous system) barrier. However, some types of repair within the CNS may be possible by targeting treatment to peripherally located cells or by delivering Adeno-Associated Viral vectors (AAVs) by peripheral routes (e.g., intrathecal, intravenous). This review will consider some future possibilities for SCI repair generated by therapeutic peripheral gene delivery. There are now six gene therapies approved worldwide as safe and effective medicines of which three were created by modification of the apparently nonpathogenic Adeno-Associated Virus. One of these AAVs, Zolgensma, is injected intrathecally for treatment of spinal muscular atrophy in children. One day, delivery of AAVs into peripheral tissues might improve recovery after spinal cord injury in humans; we discuss experiments by us and others delivering transgenes into nerves or muscles for sensorimotor recovery in animal models of SCI or of stroke including human Neurotrophin-3. We also describe ongoing efforts to develop AAVs that are delivered to particular targets within and without the CNS after peripheral administration using capsids with improved tropisms, promoters that are selective for particular cell types, and methods for controlling the dose and duration of expression of a transgene. In conclusion, in the future, minimally invasive administration of AAVs may improve recovery after SCI with minimal side effects.

Learn More >

Clinimetrics: The Central Sensitisation Inventory: a useful screening tool for clinicians, but not the gold standard.

Learn More >

Search