Identification of glia phenotype modulators based on select glial function regulatory signaling pathways

MicroRNAs Play a Role in Parkinson’s Disease by Regulating Microglia Function: From Pathogenetic Involvement to Therapeutic Potential

Parkinson’s disease (PD) is a clinically common neurodegenerative disease of the central nervous system (CNS) characterized by loss of dopamine neurons in the substantia nigra. Microglia (MG), as an innate immune cell in the CNS, are involved in a variety of immunity and inflammatory responses in the CNS. A number of studies have shown that the overactivation of MG is one of the critical pathophysiological mechanisms underlying PD. MicroRNAs (miRNAs) are considered to be an important class of gene expression regulators and are involved in a variety of physiological and pathological mechanisms, including immunity and inflammation. In addition, miRNAs can affect the progress of PD by regulating the expression of various MG genes and the polarization state of the MG. Here, we summarize recent articles and describe the important role of MG pathological polarization in the progression of PD, the diverse mechanisms responsible for how miRNAs regulate MG, and the potential therapeutic prospects of miRNAs for PD. We also propose that the regulation of miRNAs may be a novel protective approach against the pathogenesis of PD.

Plant-Derived Natural Compounds for the treatment of Amyotrophic Lateral Sclerosis: An Update

Background

Amyotrophic lateral sclerosis (ALS) is a motor neuron disease (MND) that typically causes death within 3-5 years after diagnosis. Regardless of the substantial scientific knowledge accrued more than a century ago, truly effective therapeutic strategies remain distant. Various conventional drugs are being used but are having several adverse effects.

Objective/Aim

The current study aims to thoroughly review plant-derived compounds with well-defined ALS activities and their structure-activity relationships. Moreover, the review also focuses on complex genetics, clinical trials, and the use of natural products that might decrypt the future and novel therapeutics in ALS.

Methods

The collection of data for the compilation of this review work was searched in PubMed Scopus, Google Scholar, and Science Direct.

Results

Results showed that phytochemicals like-Ginkgolides, Protopanaxatriol, Genistein, epigallocatechingallate, resveratrol, cassoside, and others possess Amyotrophic lateral sclerosis (ALS) activity by various mechanisms.

Conclusion

These plant-derived compounds may be considered as supplements for conventional (ALS). Moreover, further preclinical and clinical studies are required to understand the structure-activity relationships, metabolism, absorption, and mechanisms of plant-derived natural agents.

Huanglian Jiedu decoction remodels the periphery microenvironment to inhibit Alzheimer's disease progression based on the "brain-gut" axis through multiple integrated omics

BACKGROUND

In recent years, excellent results have suggested an association between the "brain-gut" axis and Alzheimer's disease (AD) progression, yet the role of the "brain-gut" axis in AD pathogenesis still remains obscure. Herein, we provided a potential link between the central and peripheral neuroinflammatory disorders in AD progression.

METHODS

The Morris water maze (MWM) test, immunohistochemistry, ELISA, ProcartaPlex Multiplex immunoassay, multiple LC-MS/MS methods, and the V3-V4 regions of 16S rRNA genes were applied to explore potential biomarkers.

RESULTS

In Tg-APP/PS1 mice, gut dysbiosis and lipid metabolism were highly associated with AD-like neuroinflammation. The combination of inflammatory factors (IL-6 and INF-γ), phosphatidylcholines (PCs) and SCFA-producing bacteria were expected to be early diagnostic biomarkers for AD. Huanglian Jiedu decoction (HLJDD) suppressed gut dysbiosis and the associated Aβ accumulation, harnessed neuroinflammation and reversed cognitive impairment.

CONCLUSION

Together, our findings highlighted the roles of neuroinflammation induced by gut dysbiosis and lipid metabolism disorder in AD progression. This integrated metabolomics approach showed its potential to understand the complex mechanisms of HLJDD in the treatment of AD.

Interferon-Gamma and Interleukin-1Beta Enhance the Secretion of Brain-Derived Neurotrophic Factor and Promotes the Survival of Cortical Neurons in Brain Injury

Neuro-inflammation is associated with the production of cytokines, which influence neuronal and glial functions. Although the proinflammatory cytokines interferon-γ (IFN-γ) and interleukin-1Beta (IL-1β) are thought to be the major mediators of neuro-inflammation, their role in brain injury remains ill-defined. The objective of this study was to examine the effect of IFN-γ and IL-1β on survival of cortical neurons in stab wound injury in mice. A stab wound injury was made in the cortex of male BALB/c mice. Injured mice (I) were divide into IFN-γ and IL-1β treatment experiments. Mice in I + IFN-γ group were treated with IFN-γ (ip, 10 µg/kg/day) for 1, 3 and 7 days and mice in I + IL-1β group were treated with 5 IP injection of IL-1β (0.5 µg /12 h). Appropriate control mice were maintained for comparison. Immunostaining of frozen brain sections for astrocytes (GFAP), microglia (Iba-1) and Fluoro-Jade B staining for degenerating neurons were used. Western blotting and ELISA for brain-derived neurotrophic factor (BDNF) were done on the tissues isolated from the injured sites. Results showed a significant increase in the number of both astrocytes and microglia in I + IFN-γ and I + IL-1β groups. There were no significant changes in the number of astrocytes or microglia in noninjury groups (NI) treated with IFN-γ or IL-1β. The number of degenerating neurons significantly decreased in I + IFN-γ and I + IL-1β groups. GFAP and BDNF levels were significantly increased in I + IFN-γ and I + IL-1β groups. Interferon-γ and IL-1β induce astrogliosis, microgliosis, enhance the secretion of BDNF, one of the many neurotrophic factors after brain injury, and promote the survival of cortical neurons in stab wound brain injury.

Regulation of microglia by glutamate and its signal pathway in neurodegenerative diseases

Microglia are an essential component of the central nervous system (CNS) and are involved in the primary response to microorganisms, neuroinflammation, homeostasis, and tissue regeneration, as well as contributing to the pathogenesis of neurodegenerative diseases. Research has shown that microglial diversity, multifunctionality, and their relationship with glutamate are crucial to determining their roles in these diseases. In this review, we focus on recent progress in determining microglial characteristics and the role of glutamate and its receptors in microglia regulation, which could be a novel therapeutic strategy for neurodegenerative diseases.

Role of NADPH oxidase-2 in the progression of the inflammatory response secondary to striatum excitotoxic damage

Background

During excitotoxic damage, neuronal death results from the increase in intracellular calcium, the induction of oxidative stress, and a subsequent inflammatory response. NADPH oxidases (NOX) are relevant sources of reactive oxygen species (ROS) during excitotoxic damage. NADPH oxidase-2 (NOX-2) has been particularly related to neuronal damage and death, as well as to the resolution of the subsequent inflammatory response. As ROS are crucial components of the regulation of inflammatory response, in this work, we evaluated the role of NOX-2 in the progression of inflammation resulting from glutamate-induced excitotoxic damage of the striatum in an in vivo model.

Methods

The striata of wild-type C57BL/6 J and NOX-2 KO mice (gp91^Cybbtm1Din/J) were stereotactically injected with monosodium glutamate either alone or in combination with IL-4 or IL-10. The damage was evaluated in histological sections stained with cresyl violet and Fluoro-Jade B. The enzymatic activity of caspase-3 and NOX were also measured. Additionally, the cytokine profile was identified by ELISA and motor activity was verified by the tests of the cylinder, the adhesive tape removal, and the inverted grid.

Results

Our results show a neuroprotective effect in mice with a genetic inhibition of NOX-2, which is partially due to a differential response to excitotoxic damage, characterized by the production of anti-inflammatory cytokines. In NOX-2 KO animals, the excitotoxic condition increased the production of interleukin-4, which could contribute to the production of interleukin-10 that decreased neuronal apoptotic death and the magnitude of striatal injury. Treatment with interleukin-4 and interleukin-10 protected from excitotoxic damage in wild-type animals.

Conclusions

The release of proinflammatory cytokines during the excitotoxic event promotes an additional apoptotic death of neurons that survived the initial damage. During the subsequent inflammatory response to excitotoxic damage, ROS generated by NOX-2 play a decisive role in the extension of the lesion and consequently in the severity of the functional compromise, probably by regulating the anti-inflammatory cytokines production.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1478-4) contains supplementary material, which is available to authorized users.

Kinase-Based Taming of Brain Microglia Toward Disease-Modifying Therapy

Microglia are the primary immune cells residing in the central nervous system (CNS), where they play essential roles in the health and disease. Depending on the CNS inflammatory milieu, they exist in either resting or activated states. Chronic neuroinflammation mediated by activated microglia is now considered to be a common characteristic shared by many neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis, which currently pose a significant socioeconomic burden to the global healthcare system. Accumulating evidence has indicated protein kinases (PKs) as important drug targets for therapeutic interventions of these detrimental diseases. Here, we review recent findings suggesting that selected PKs potentially participate in microglia-mediated neuroinflammation. Taming microglial phenotypes by modulating the activity of these PKs holds great promise for the development of disease-modifying therapies for many neurodegenerative diseases.