The Role of Cytokines in Schwann Cell Damage, Protection, and Repair

Noise exposure (NE) has been recognized as one of the causes of sensorineural hearing loss (SNHL), which can bring about irreversible damage to sensory hair cells in the cochlea, through the launch of oxidative stress pathways and inflammation. Accordingly, determining the molecular mechanism involved in regulating hair cell apoptosis via NE is essential to prevent hair cell damage. However, the role of microRNAs (miRNAs) in the degeneration of sensory cells of the cochlea during NE has not been so far uncovered. Thus, the main purpose of this study was to demonstrate the regulatory role of miRNAs in the oxidative stress pathway and inflammation induced by NE. In this respect, articles related to noise-induced hearing loss (NIHL), oxidative stress, inflammation, and miRNA from various databases of Directory of Open Access Journals (DOAJ), Google Scholar, PubMed; Library, Information Science & Technology Abstracts (LISTA), and Web of Science were searched and retrieved. The findings revealed that several studies had suggested that up-regulation of miR-1229-5p, miR-451a, 185-5p, 186 and down-regulation of miRNA-96/182/183 and miR-30b were involved in oxidative stress and inflammation which could be used as biomarkers for NIHL. There was also a close relationship between NIHL and miRNAs, but further research is required to prove a causal association between miRNA alterations and NE, and also to determine miRNAs as biomarkers indicating responses to NE.

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Flavonoids: Potential Candidates for the Treatment of Neurodegenerative Disorders

Biomedicines ◽

10.3390/biomedicines9020099 ◽

2021 ◽

Vol 9 (2) ◽

pp. 99

Author(s):

Shweta Devi ◽

Vijay Kumar ◽

Sandeep Kumar Singh ◽

Ashish Kant Dubey ◽

Jong-Joo Kim

Keyword(s):

Stress Response ◽

Stress Responses ◽

Neurodegenerative Disorders ◽

Cell Damage ◽

Cellular Stress ◽

Clinical Manifestations ◽

Cellular Stress Response ◽

Dramatic Rise ◽

Cellular Stress Responses

Neurodegenerative disorders, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), Amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), are the most concerning disorders due to the lack of effective therapy and dramatic rise in affected cases. Although these disorders have diverse clinical manifestations, they all share a common cellular stress response. These cellular stress responses including neuroinflammation, oxidative stress, proteotoxicity, and endoplasmic reticulum (ER)-stress, which combats with stress conditions. Environmental stress/toxicity weakened the cellular stress response which results in cell damage. Small molecules, such as flavonoids, could reduce cellular stress and have gained much attention in recent years. Evidence has shown the potential use of flavonoids in several ways, such as antioxidants, anti-inflammatory, and anti-apoptotic, yet their mechanism is still elusive. This review provides an insight into the potential role of flavonoids against cellular stress response that prevent the pathogenesis of neurodegenerative disorders.

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Potential Role of Phospholipases in Virulence and Fungal Pathogenesis

Clinical Microbiology Reviews ◽

10.1128/cmr.13.1.122 ◽

2000 ◽

Vol 13 (1) ◽

pp. 122-143 ◽

Cited By ~ 180

Author(s):

Mahmoud A. Ghannoum

Keyword(s):

Virulence Factor ◽

Cell Damage ◽

Pathogenic Fungi ◽

Microbial Pathogens ◽

Immunogold Electron Microscopy ◽

Lytic Enzymes ◽

Fungal Virulence ◽

Phospholipase B ◽

Genes Encoding

SUMMARY Microbial pathogens use a number of genetic strategies to invade the host and cause infection. These common themes are found throughout microbial systems. Secretion of enzymes, such as phospholipase, has been proposed as one of these themes that are used by bacteria, parasites, and pathogenic fungi. The role of extracellular phospholipase as a potential virulence factor in pathogenic fungi, including Candida albicans, Cryptococcus neoformans, and Aspergillus, has gained credence recently. In this review, data implicating phospholipase as a virulence factor in C. albicans, Candida glabrata, C. neoformans, and A. fumigatus are presented. A detailed description of the molecular and biochemical approaches used to more definitively delineate the role of phospholipase in the virulence of C. albicans is also covered. These approaches resulted in cloning of three genes encoding candidal phospholipases (caPLP1, caPLB2, and PLD). By using targeted gene disruption, C. albicans null mutants that failed to secrete phospholipase B, encoded by caPLB1, were constructed. When these isogenic strain pairs were tested in two clinically relevant murine models of candidiasis, deletion of caPLB1 was shown to lead to attenuation of candidal virulence. Importantly, immunogold electron microscopy studies showed that C. albicans secretes this enzyme during the infectious process. These data indicate that phospholipase B is essential for candidal virulence. Although the mechanism(s) through which phospholipase modulates fungal virulence is still under investigations, early data suggest that direct host cell damage and lysis are the main mechanisms contributing to fungal virulence. Since the importance of phospholipases in fungal virulence is already known, the next challenge will be to utilize these lytic enzymes as therapeutic and diagnostic targets.

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The Neuroinflammatory Role of Pericytes in Epilepsy

Biomedicines ◽

10.3390/biomedicines9070759 ◽

2021 ◽

Vol 9 (7) ◽

pp. 759

Author(s):

Gaku Yamanaka ◽

Fuyuko Takata ◽

Yasufumi Kataoka ◽

Kanako Kanou ◽

Shinichiro Morichi ◽

...

Keyword(s):

Proinflammatory Cytokines ◽

Current Knowledge ◽

Morphological Changes ◽

Cell Damage ◽

Neurovascular Unit ◽

Experimental Studies ◽

Intractable Epilepsy ◽

In Vivo Studies

Pericytes are a component of the blood–brain barrier (BBB) neurovascular unit, in which they play a crucial role in BBB integrity and are also implicated in neuroinflammation. The association between pericytes, BBB dysfunction, and the pathophysiology of epilepsy has been investigated, and links between epilepsy and pericytes have been identified. Here, we review current knowledge about the role of pericytes in epilepsy. Clinical evidence has shown an accumulation of pericytes with altered morphology in the cerebral vascular territories of patients with intractable epilepsy. In vitro, proinflammatory cytokines, including IL-1β, TNFα, and IL-6, cause morphological changes in human-derived pericytes, where IL-6 leads to cell damage. Experimental studies using epileptic animal models have shown that cerebrovascular pericytes undergo redistribution and remodeling, potentially contributing to BBB permeability. These series of pericyte-related modifications are promoted by proinflammatory cytokines, of which the most pronounced alterations are caused by IL-1β, a cytokine involved in the pathogenesis of epilepsy. Furthermore, the pericyte-glial scarring process in leaky capillaries was detected in the hippocampus during seizure progression. In addition, pericytes respond more sensitively to proinflammatory cytokines than microglia and can also activate microglia. Thus, pericytes may function as sensors of the inflammatory response. Finally, both in vitro and in vivo studies have highlighted the potential of pericytes as a therapeutic target for seizure disorders.

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Post-Transplant Diabetes Mellitus and Prediabetes in Renal Transplant Recipients: An Update

Nephron ◽

10.1159/000514288 ◽

2021 ◽

pp. 1-13

Author(s):

Ana Elena Rodríguez-Rodríguez ◽

Esteban Porrini ◽

Mads Hornum ◽

Javier Donate-Correa ◽

Raúl Morales-Febles ◽

...

Keyword(s):

Diabetes Mellitus ◽

Renal Transplant ◽

Cell Function ◽

Cell Damage ◽

Current Evidence ◽

Renal Transplant Recipients ◽

Transplant Recipients ◽

Post Transplant ◽

Β Cell Function

Post-transplant diabetes mellitus (PTDM) is a frequent and relevant complication after renal transplantation: it affects 20–30% of renal transplant recipients and increases the risk for cardiovascular and infectious events. Thus, understanding pathogenesis of PTDM would help limiting its consequences. In this review, we analyse novel aspects of PTDM, based on studies of the last decade, such as the clinical evolution of PTDM, early and late, the reversibility rate, diagnostic criteria, risk factors, including pre-transplant metabolic syndrome and insulin resistance (IR) and the interaction between these factors and immunosuppressive medications. Also, we discuss novel pathogenic factors, in particular the role of β-cell function in an environment of IR and common pathways between pre-existing cell damage and tacrolimus-induced toxicity. The relevant role of prediabetes in the pathogenesis of PTDM and cardiovascular disease is also addressed. Finally, current evidence on PTDM treatment is discussed.

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