High-intensity interval training (HIIT) is considered an effective therapy strategy for improving chronic pain associated with osteoarthritis (OA). Perineuronal nets (PNNs) are specialized extracellular matrix structures in the cerebral cortex that play a crucial role in regulating chronic pain. However, little is unknown whether HIIT could alleviate OA pain sensitization by reducing PNN levels. This study aimed to determine whether HIIT could reduce sensitivity of the affected joint(s) to pain in a chronic pain model in rats with OA. A rat model of interest was induced by intra-articular injection of monosodium iodoacetate (MIA) into the right knee. Thereafter, the mechanical withdrawal thresholds (MWTs) and PNN levels in the contralateral medial prefrontal cortex (mPFC) were measured in rats in the presence or absence of HIIT alone or in combination with injection of chondroitinase-ABC (ChABC) into the contralateral mPFC (inducing the degradation of PNNs), respectively. Results indicated that rats with OA exhibited significant reductions in MWTs, but a significant increase in the PNN levels; that HIIT reversed changes in MWTs and PNN levels in rats with OA, and that pretreatment of ChABC abolished effects of HIIT on MWTs, with PNN levels not changed. We concluded that pain sensitization in rats with OA may correlate with an increase in PNN levels in the mPFC, and that HIIT may increases OA pain-sensitive threshold by reduction of the PNN levels in the mPFC. Keywords: Osteoarthritis, Chronic pain, Pain sensitization, High-intensity interval training, Perineuronal nets.

• MeSH
• kondiční příprava zvířat metody   MeSH
• krysa rodu Rattus MeSH
• nervová síť * metabolismus   MeSH
• osteoartróza * patofyziologie   terapie   MeSH
• potkani Sprague-Dawley MeSH
• práh bolesti * fyziologie   MeSH
• prefrontální mozková kůra * metabolismus   patofyziologie   MeSH
• vysoce intenzivní intervalový trénink * metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Structural neuroplasticity such as neurite extension and dendritic spine dynamics is enhanced by brain-derived neurotrophic factor (BDNF) and impaired by types of inhibitory molecules that induce growth cone collapse and actin depolymerization, for example, myelin-associated inhibitors, chondroitin sulfate proteoglycans, and negative guidance molecules. These inhibitory molecules can activate RhoA/rho-associated coiled-coil containing protein kinase (ROCK) signaling (known to restrict structural plasticity). Intermittent hypoxia (IH) and high-intensity interval training (HIIT) are known to upregulate BDNF that is associated with improvements in learning and memory and greater functional recovery following neural insults. We investigated whether the RhoA/ROCK signaling pathway is also modulated by IH and HIIT in the hippocampus, cortex, and lumbar spinal cord of male Wistar rats. The gene expression of 25 RhoA/ROCK signaling pathway components was determined following IH, HIIT, or IH combined with HIIT (30 min/day, 5 days/wk, 6 wk). IH included 10 3-min bouts that alternated between hypoxia (15% O2) and normoxia. HIIT included 10 3-min bouts alternating between treadmill speeds of 50 cm·s-1 and 15 cm·s-1. In the hippocampus, IH and HIIT significantly downregulated Acan and NgR2 mRNA that are involved in the inhibition of neuroplasticity. However, IH and IH + HIIT significantly upregulated Lingo-1 and NgR3 in the cortex. This is the first time IH and HIIT have been linked to the modulation of plasticity-inhibiting pathways. These results provide a fundamental step toward elucidating the interplay between the neurotrophic and inhibitory mechanisms involved in experience-driven neural plasticity that will aid in optimizing physiological interventions for the treatment of cognitive decline or neurorehabilitation.NEW & NOTEWORTHY Intermittent hypoxia (IH) and high-intensity interval training (HIIT) enhance neuroplasticity and upregulate neurotrophic factors in the central nervous system (CNS). We provide evidence that IH and IH + HIIT also have the capacity to regulate genes involved in the RhoA/ROCK signaling pathway that is known to restrict structural plasticity in the CNS. This provides a new mechanistic insight into how these interventions may enhance hippocampal-related plasticity and facilitate learning, memory, and neuroregeneration.

• Klíčová slova
• exercise, inhibitory molecules, intermittent hypoxia, neuroplasticity, treadmill training,
• MeSH
• hipokampus * metabolismus   MeSH
• hypoxie metabolismus   patofyziologie   MeSH
• kinázy asociované s Rho * metabolismus   genetika   MeSH
• krysa rodu Rattus MeSH
• mícha metabolismus   fyziologie   MeSH
• mozková kůra metabolismus   fyziologie   MeSH
• neuroplasticita fyziologie   MeSH
• potkani Wistar * MeSH
• Rho proteiny vázající GTP MeSH
• rhoA protein vázající GTP metabolismus   MeSH
• signální transdukce * fyziologie   MeSH
• vysoce intenzivní intervalový trénink * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kinázy asociované s Rho * MeSH
• Rho proteiny vázající GTP MeSH
• rhoA protein vázající GTP MeSH
• RhoA protein, rat MeSH Prohlížeč

Spinal cord injury (SCI) induces the upregulation of chondroitin sulfate proteoglycans (CSPGs) at the glial scar and inhibits neuroregeneration. Under normal physiological condition, CSPGs interact with hyaluronan (HA) and other extracellular matrix on the neuronal surface forming a macromolecular structure called perineuronal nets (PNNs) which regulate neuroplasticity. 4-methylumbelliferone (4-MU) is a known inhibitor for HA synthesis but has not been tested in SCI. We first tested the effect of 4-MU in HA reduction in uninjured rats. After 8 weeks of 4-MU administration at a dose of 1.2 g/kg/day, we have not only observed a reduction of HA in the uninjured spinal cords but also a down-regulation of CS glycosaminoglycans (CS-GAGs). In order to assess the effect of 4-MU in chronic SCI, six weeks after Th8 spinal contusion injury, rats were fed with 4-MU or placebo for 8 weeks in combination with daily treadmill rehabilitation for 16 weeks to promote neuroplasticity. 4-MU treatment reduced the HA synthesis by astrocytes around the lesion site and increased sprouting of 5-hydroxytryptamine fibres into ventral horns. However, the current dose was not sufficient to suppress CS-GAG up-regulation induced by SCI. Further adjustment on the dosage will be required to benefit functional recovery after SCI.

• MeSH
• chondroitinsulfát proteoglykany MeSH
• glióza * patologie   MeSH
• hymekromon terapeutické užití   MeSH
• krysa rodu Rattus MeSH
• kyselina hyaluronová MeSH
• mícha patologie   MeSH
• poranění míchy * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chondroitinsulfát proteoglykany MeSH
• hymekromon MeSH
• kyselina hyaluronová MeSH

4-methylumbelliferone (4MU) has been suggested as a potential therapeutic agent for a wide range of neurological diseases. The current study aimed to evaluate the physiological changes and potential side effects after 10 weeks of 4MU treatment at a dose of 1.2 g/kg/day in healthy rats, and after 2 months of a wash-out period. Our findings revealed downregulation of hyaluronan (HA) and chondroitin sulphate proteoglycans throughout the body, significantly increased bile acids in blood samples in weeks 4 and 7 of the 4MU treatment, as well as increased blood sugars and proteins a few weeks after 4MU administration, and significantly increased interleukins IL10, IL12p70 and IFN gamma after 10 weeks of 4MU treatment. These effects, however, were reversed and no significant difference was observed between control treated and 4MU-treated animals after a 9-week wash-out period.

• Klíčová slova
• 4-methylumbelliferone, chondroitin sulphates, hyaluronan, neuroplasticity,
• MeSH
• hymekromon * škodlivé účinky   terapeutické užití   MeSH
• interleukin-12 MeSH
• krysa rodu Rattus MeSH
• kyselina hyaluronová * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hymekromon * MeSH
• interleukin-12 MeSH
• kyselina hyaluronová * MeSH

Perineuronal nets (PNNs) are extracellular matrix structures surrounding neuronal sub-populations throughout the central nervous system, regulating plasticity. Enzymatically removing PNNs successfully enhances plasticity and thus functional recovery, particularly in spinal cord injury models. While PNNs within various brain regions are well studied, much of the composition and associated populations in the spinal cord is yet unknown. We aim to investigate the populations of PNN neurones involved in this functional motor recovery. Immunohistochemistry for choline acetyltransferase (labelling motoneurones), PNNs using Wisteria floribunda agglutinin (WFA) and chondroitin sulphate proteoglycans (CSPGs), including aggrecan, was performed to characterise the molecular heterogeneity of PNNs in rat spinal motoneurones (Mns). CSPG-positive PNNs surrounded ~70-80% of Mns. Using WFA, only ~60% of the CSPG-positive PNNs co-localised with WFA in the spinal Mns, while ~15-30% of Mns showed CSPG-positive but WFA-negative PNNs. Selective labelling revealed that aggrecan encircled ~90% of alpha Mns. The results indicate that (1) aggrecan labels spinal PNNs better than WFA, and (2) there are differences in PNN composition and their associated neuronal populations between the spinal cord and cortex. Insights into the role of PNNs and their molecular heterogeneity in the spinal motor pools could aid in designing targeted strategies to enhance functional recovery post-injury.

• Klíčová slova
• alpha motoneurone, chondroitin sulphate proteoglycans, gamma motoneurone, perineuronal nets, spinal cord,
• MeSH
• cholin-O-acetyltransferasa metabolismus   MeSH
• chondroitinsulfát proteoglykany metabolismus   MeSH
• extracelulární matrix - proteiny metabolismus   MeSH
• extracelulární matrix metabolismus   MeSH
• krysa rodu Rattus MeSH
• mícha cytologie   metabolismus   MeSH
• motorické neurony cytologie   metabolismus   MeSH
• neuroplasticita MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cholin-O-acetyltransferasa MeSH
• chondroitinsulfát proteoglykany MeSH
• extracelulární matrix - proteiny MeSH

Perineuronal nets (PNNs) are mesh-like structures, composed of a hierarchical assembly of extracellular matrix molecules in the central nervous system (CNS), ensheathing neurons and regulating plasticity. The mechanism of interactions between PNNs and neurons remain uncharacterized. In this review, we pose the question: how do PNNs regulate communication to and from neurons? We provide an overview of the current knowledge on PNNs with a focus on the cellular interactions. PNNs ensheath a subset of the neuronal population with distinct molecular aspects in different areas of the CNS. PNNs control neuronal communication through molecular interactions involving specific components of the PNNs. This review proposes that the PNNs are an integral part of neurons, crucial for the regulation of plasticity in the CNS.

• Klíčová slova
• chondroitin sulfates, hyaluronan, interneurons, neuronal communication, perineuronal nets, plasticity,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH