Sex Differences in Brain Disorders.

A remarkable feature of the brain is its sexual dimorphism. Sexual dimorphism in brain structure and function is associated with clinical implications documented previously in healthy individuals but also in those who suffer from various brain disorders. Sex-based differences concerning some features such as the risk, prevalence, age of onset, and symptomatology have been confirmed in a range of neurological and neuropsychiatric diseases. The mechanisms responsible for the establishment of sex-based differences between men and women are not fully understood. The present paper provides up-to-date data on sex-related dissimilarities observed in brain disorders and highlights the most relevant features that differ between males and females. The topic is very important as the recognition of disparities between the sexes might allow for the identification of therapeutic targets and pharmacological approaches for intractable neurological and neuropsychiatric disorders.

Analysis of Givinostat/ITF2357 Treatment in a Rat Model of Neonatal Hypoxic-Ischemic Brain Damage.

The histone deacetylase inhibitor (HDACi) Givinostat/ITF2357 provides neuroprotection in adult models of brain injury; however, its action after neonatal hypoxia-ischemia (HI) is still undefined. The aim of our study was to test the hypothesis that the mechanism of Givinostat is associated with the alleviation of inflammation. For this purpose, we analyzed the microglial response and the effect on molecular mediators (chemokines/cytokines) that are crucial for inducing cerebral damage after neonatal hypoxia-ischemia. Seven-day-old rat pups were subjected to unilateral carotid artery ligation followed by 60 min of hypoxia (7.6% O2). Givinostat (10 mg/kg b/w) was administered in a 5-day regimen. The effects of Givinostat on HI-induced inflammation (cytokine, chemokine and microglial activation and polarization) were assessed with a Luminex assay, immunohistochemistry and Western blot. Givinostat treatment did not modulate the microglial response specific for HI injury. After Givinostat administration, the investigated chemokines and cytokines remained at the level induced by HI. The only immunosuppressive effect of Givinostat may be associated with the decrease in MIP-1α. Neonatal hypoxia-ischemia produces an inflammatory response by activating the proinflammatory M1 phenotype of microglia, disrupting the microglia-neuron (CX3CL1/CX3CR1) axis and elevating numerous proinflammatory cytokines/chemokines. Givinostat/ITF2357 did not prevent an inflammatory reaction after HI.

Sexual Dimorphism in Neurodegenerative Diseases and in Brain Ischemia.

Epidemiological studies and clinical observations show evidence of sexual dimorphism in brain responses to several neurological conditions. It is suggested that sex-related differences between men and women may have profound effects on disease susceptibility, pathophysiology, and progression. Sexual differences of the brain are achieved through the complex interplay of several factors contributing to this phenomenon, such as sex hormones, as well as genetic and epigenetic differences. Despite recent advances, the precise link between these factors and brain disorders is incompletely understood. This review aims to briefly outline the most relevant aspects that differ between men and women in ischemia and neurodegenerative disorders (AD, PD, HD, ALS, and SM). Recognition of disparities between both sexes could aid the development of individual approaches to ameliorate or slow the progression of intractable disorders.

Aberrant Complement System Activation in Neurological Disorders.

The complement system is an assembly of proteins that collectively participate in the functions of the healthy and diseased brain. The complement system plays an important role in the maintenance of uninjured (healthy) brain homeostasis, contributing to the clearance of invading pathogens and apoptotic cells, and limiting the inflammatory immune response. However, overactivation or underregulation of the entire complement cascade within the brain may lead to neuronal damage and disturbances in brain function. During the last decade, there has been a growing interest in the role that this cascading pathway plays in the neuropathology of a diverse array of brain disorders (e.g., acute neurotraumatic insult, chronic neurodegenerative diseases, and psychiatric disturbances) in which interruption of neuronal homeostasis triggers complement activation. Dysfunction of the complement promotes a disease-specific response that may have either beneficial or detrimental effects. Despite recent advances, the explicit link between complement component regulation and brain disorders remains unclear. Therefore, a comprehensible understanding of such relationships at different stages of diseases could provide new insight into potential therapeutic targets to ameliorate or slow progression of currently intractable disorders in the nervous system. Hence, the aim of this review is to provide a summary of the literature on the emerging role of the complement system in certain brain disorders.

The Impact of the CX3CL1/CX3CR1 Axis in Neurological Disorders.

Fractalkine (FKN, CX3CL1) is a transmembrane chemokine expressed by neurons in the central nervous system (CNS). CX3CL1 signals through its unique receptor, CX3CR1, that is expressed in microglia. Within the CNS, fractalkine acts as a regulator of microglia activation in response to brain injury or inflammation. During the last decade, there has been a growing interest in the roles that the CX3CL1/CX3CR1 signaling pathway plays in the neuropathology of a diverse array of brain disorders. However, the reported results have proven controversial, indicating that a disruption of the CX3CL1 axis induces a disease-specific microglial response that may have either beneficial or detrimental effects. Therefore, it has become clear that the understanding of neuron-to-glia signals mediated by CX3CL1/CX3CR1 at different stages of diseases could provide new insight into potential therapeutic targets. Hence, the aim of this review is to provide a summary of the literature on the emerging role of CX3CL1 in animal models of some brain disorders.

Correction to: Cardiospecific deletion of αE-catenin leads to heart failure and lethality in mice.

The original version of this article unfortunately contained a mistake. The published paper presented an incorrect version of Table 1. The corrected Table is given here.

Cardiospecific deletion of αE-catenin leads to heart failure and lethality in mice.

αE-catenin is a component of adherens junctions that link the cadherin-catenin complex to the actin cytoskeleton. The signaling function of this protein was recently revealed. In the present study, we investigated the role of αE-catenin in the pathogenesis of heart failure. We mated αE-catenin conditional knockout mice with αMHC-Cre mice and evaluated their mutant offspring. We found that αE-catenin knockout caused enlargement of the heart and atria, fibrosis, the upregulation of hypertrophic genes, and the dysregulation of fatty acid metabolism via the transcriptional activity of Yap and ß-catenin. The activation of canonical Wnt and Yap decreased the activity of main regulators of energy metabolism (i.e., adenosine monophosphate-activated protein kinase and peroxisome proliferator-activated receptor α) and dysregulated hypertrophic pathway activity (i.e., phosphatidylinositide 3-kinase/Akt, cyclic adenosine monophosphate/protein kinase A, and MEK1/extracellular signal regulated kinase 1/2). The loss of αE-catenin also negatively affected cardio-hemodynamic function via the protein kinase A pathway. Overall, we found that the embryonic heart-specific ablation of αE-catenin leads to the development of heart failure with age and premature death in mice. Thus, αE-catenin appears to have a crucial signaling function in the postnatal heart, and the dysfunction of this gene causes heart failure through canonical Wnt and Yap activation.

The Good, the Bad, and the Ugly - role of the pancreas, endothelium, and adipose tissue axis in the management of pancreatic ß-cell failure in obesity-related type 2 diabetes.

During long-standing obesity and insulin resistance, pancreatic ß-cells adapt in order to meet the growing demand of the periphery for insulin. The development of type 2 diabetes requires parallel pathological processes, during which ß-cells are continuously exposed to an overabundant supply of specific lipid derivatives. The metabolic events that lead to inevitable ß-cell damage are not completely uncovered, and for the time being, our understanding of the dynamic endothelium-adipose tissue-ß-cell interactions is limited. Here, we explore various links between continuous obesity, adipose tissue spillover, a dysfunctional endothelium, and defects in islet angioarchitecture to elucidate the crosstalk between signaling systems, cellular mediators, and cell types that contribute to ß-cell failure through diverse actions of fatty acids. These molecular and biochemical mechanisms initiate critical rearrangements of the pancreatic vasculature, intraorgan lipid storage capacity, and inflammatory status that subsequently have severe repercussions on ß-cell function and promote diabetes.