Evaluating nitric oxide produced by rat inflamed microglial cell Lline, CHME-5, under the effect of IMOD

Nitric oxide (NO), as a free radical, is produced by inflamed microglia cells and is one of the destructive factors of the immune system and a factor in myelin degradation. Therefore, inhibition of microglia activity is a chief strategy in reducing neurotoxic damage to the central nervous system. In this study, an herbal Immunomodulatory Drug (IMOD) was used to evaluate the effects of this drug in controlling the amount of nitric oxide. Nitric oxide induction was performed by bacterial lipopolysaccharide (LPS) in rat inflamed microglial cell line, CHME-5. ELISA test was used to measure the produced nitric oxide at 24, 48, and 72 hours. The results showed that the high concentrations of IMOD (1.2, and 4% V/V) had anti-inflammatory effects on microglial cells and were able to reduce the amount of nitric oxide in these cells but the effective dose of IMOD was in the range of 1.2% V/V. Therefore, the safest dose and the best time for the effect of IMOD on inflammatory cell groups are 1.2% V/V and 72h, respectively. Hence, with further studies, IMOD can be considered as an herbal anti-inflammatory drug that is effective in controlling neurodegenerative diseases.

Neuronal Activity and its Impact on Neuronal Growth

Myelination is one of the most important aspect of membrane remodeling, hence it is very much essential to understand the factors that can aid in remyelination once the myelin layer gets reduced or is lost due to several physiological factors. Studies have shown that the activities taking place within the nervous system itself can aid in remyelination. The current study is based on understanding the role action potential play in aiding in remyelination of the nerve fiber which would not only help in regaining the strength of the signal and also for the faster propagation of the impulse thus addressing several neurological issues arising due to myelin degradation. The idea is to develop an appropriate mathematical model to study the effects of the action potential in remyelination which will be computationally viable and to understand its role in neuronal growth. The findings of this study suggest that variation in the rate at which the membrane potential changes can have a significant impact on neuronal growth and therefore the issues arising out of myelin degradation such as multiple scheloris could be addressed.

Microglial autophagy–associated phagocytosis is essential for recovery from neuroinflammation

Multiple sclerosis (MS) is a leading cause of incurable progressive disability in young adults caused by inflammation and neurodegeneration in the central nervous system (CNS). The capacity of microglia to clear tissue debris is essential for maintaining and restoring CNS homeostasis. This capacity diminishes with age, and age strongly associates with MS disease progression, although the underlying mechanisms are still largely elusive. Here, we demonstrate that the recovery from CNS inflammation in a murine model of MS is dependent on the ability of microglia to clear tissue debris. Microglia-specific deletion of the autophagy regulator Atg7, but not the canonical macroautophagy protein Ulk1, led to increased intracellular accumulation of phagocytosed myelin and progressive MS-like disease. This impairment correlated with a microglial phenotype previously associated with neurodegenerative pathologies. Moreover, Atg7-deficient microglia showed notable transcriptional and functional similarities to microglia from aged wild-type mice that were also unable to clear myelin and recover from disease. In contrast, induction of autophagy in aged mice using the disaccharide trehalose found in plants and fungi led to functional myelin clearance and disease remission. Our results demonstrate that a noncanonical form of autophagy in microglia is responsible for myelin degradation and clearance leading to recovery from MS-like disease and that boosting this process has a therapeutic potential for age-related neuroinflammatory conditions.

Reduction of AMPA receptor activity on mature oligodendrocytes attenuates loss of myelinated axons in autoimmune neuroinflammation

Glutamate dysregulation occurs in multiple sclerosis (MS), but whether excitotoxic mechanisms in mature oligodendrocytes contribute to demyelination and axonal injury is unexplored. Although current treatments modulate the immune system, long-term disability ensues, highlighting the need for neuroprotection. Glutamate is elevated before T2-visible white matter lesions appear in MS. We previously reported that myelin-reactive T cells provoke microglia to release glutamate from the system xc− transporter promoting myelin degradation in experimental autoimmune encephalomyelitis (EAE). Here, we explore the target for glutamate in mature oligodendrocytes. Most glutamate-stimulated calcium influx into oligodendrocyte somas is AMPA receptor (AMPAR)–mediated, and genetic deletion of AMPAR subunit GluA4 decreased intracellular calcium responses. Inducible deletion of GluA4 on mature oligodendrocytes attenuated EAE and loss of myelinated axons was selectively reduced compared to unmyelinated axons. These data link AMPAR signaling in mature oligodendrocytes to the pathophysiology of myelinated axons, demonstrating glutamate regulation as a potential neuroprotective strategy in MS.