Protective Effects of Pioglitazone on Cognitive Impairment and the Underlying Mechanisms: A Review of Literature

The possible role of neurogenesis activators in temporal lobe epilepsy: State of art and future perspective

Neurogenesis is a complex process by which the neurons and supporting cells of the central nervous system (CNS) are generated by neural stem cells. Adult hippocampal neurogenesis (AHN) in the human brain is an active process during life and plays a critical role in the regulation of memory, cognition, and mood. It has been shown that epilepsy is linked with dysregulation of AHN. Of note, AHN is very sensitive to the pathological electrical stimuli during epileptic seizures, which result in the induction of neurogenesis in acute epilepsy and inhibition of neurogenesis in chronic epilepsy. Epileptic seizure-induced neurodegeneration activates the mobilization of neural stem cells during neurogenesis to substitute for neural loss in temporal lobe epilepsy (TLE), which is the most refractory type of epilepsy. Moreover, recurrent epileptic seizures in TLE trigger neurogenesis in certain brain regions. However, AHN is a transient acute epileptic seizure that terminated with 1-4 weeks following status epilepticus (SE). Nevertheless, adult AHN is dramatically reduced in chronic epilepsy and associated with the development of cognitive impairment in TLE. These findings indicate that impairment of AHN is linked with the severity of epileptic seizures. Hence, neurogenesis activators may attenuate the pathogenesis of TLE. Therefore, this review aims to discuss and explain the beneficial role of AHN in TLE and how neurogenesis activators could be effective in the management of epilepsy.

Pioglitazone mitigates acetic acid-induced colitis in rats via epigenetic-modulation and antioxidant mechanisms

Ulcerative colitis (UC) is one of the inflammatory bowel diseases characterized by colonic damage. Epigenetic mechanisms are suggested to play a role in the pathogenesis of UC. Pioglitazone has shown promise for the treatment of UC; however, the role of epigenetic pathways in this effect is unclear. The current study aimed to explore the therapeutic and protective effects of pioglitazone against acetic acid-induced colitis (AA-C) in rats and the role of epigenetic modulation and antioxidant mechanisms in this effect. Forty male albino rats were divided into four groups (n = 10/group): control (normal saline), acetic-acid-induced ulcerative colitis (AA-C) (3 days, 2 ml acetic acid 4%), pioglitazone-treated (AA, followed by 3-week oral pioglitazone 25 mg/kg/day), and pioglitazone-protected groups (3-day oral pioglitazone 25 mg/kg/day before AA, continued with AA, and 3 weeks later). After the experiment, the body weight, colon weight-to-length ratio, and colonic tissue were evaluated. The colonic expression of epigenetic markers (DNA methyltransferase- 1 and methylated E-cadherin), oxidative stress marker (malondialdehyde), antioxidant enzyme (superoxide dismutase), and angiotensin-converting enzyme- 2 (ACE- 2) was evaluated. The pioglitazone-protected and treated groups showed significant inhibition of DNA methyltransferase- 1 and methylated E-cadherin with improvement in colonic tissue macroscopic and microscopic signs of inflammation, improved weight, less oxidative stress, and less ACE- 2 expression. These beneficial actions were more pronounced among the pioglitazone-protected group. Pioglitazone could mitigate AA-C in rats by inhibiting epigenetic DNA methyltransferase- 1 and E-cadherin gene methylation. It also inhibits oxidative stress and prevents the overexpression of ACE- 2.

Peroxisome proliferator-activated receptor gamma: A promising therapeutic target for the treatment of chronic pain

Chronic pain represents an incapacitating medical condition that profoundly impacts the patients' quality of life. Managing chronic pain poses a significant challenge for healthcare professionals due to its multifaceted nature and the limited effectiveness of current treatment options. Therefore, novel therapeutic interventions are crucially required for the management of chronic pain. Peroxisome proliferator-activated receptor gamma (PPARγ), a nuclear receptor, exerts regulatory effects on physiological processes such as glucose and lipid metabolism. Emerging studies demonstrate that PPARγ is a critical regulator of the expression of various genes, including those of anti-inflammatory cytokines and antioxidant enzymes. Substantial evidence indicates decreased expression of PPARγ in the sciatic nerve, dorsal root ganglia, and spinal cord dorsal horn in animal models of chronic pain. Furthermore, natural or synthetic PPARγ agonists had inhibitory effects on nociceptive hypersensitivity in various animal models of chronic pain. This review summarizes and discusses preclinical evidence demonstrating the therapeutic potential of PPARγ agonists in chronic pain management. The available evidence indicates that PPARγ activation reduces chronic pain by inhibiting neuroinflammation and oxidative stress as well as modulation of opioidergic system. Overall, the use of PPARγ agonists is a promising therapeutic approach for treating chronic pain; however, further research regarding its detailed mechanisms is warranted.

Interconnections of screen time with neuroinflammation

The increasing prevalence of screen time among modern citizens has raised concerns regarding its potential impact on neuroinflammation and overall brain health. This review examines the complex interconnections between screen time and neuroinflammatory processes, particularly in children and adolescents. We analyze existing literature that explores how excessive digital media use can lead to alterations in neurobiological pathways, potentially exacerbating inflammatory responses in the brain. Key findings suggest that prolonged exposure to screens may contribute to neuroinflammation through mechanisms such as disrupted sleep patterns, diminished cognitive engagement, and increased stress levels. Similarly, we discuss the implications of these findings for mental health and cognitive development, emphasizing the need for a balanced approach to screen time. This review highlights the necessity for further research to elucidate the causal relationships and underlying mechanisms linking screen time and neuroinflammation, thereby informing guidelines for healthy media consumption.

Ketamine impairs the performance of male mice in novel recognition object test and reduces the immunoreactivity of GAD67 in the hippocampus: Role of pioglitazone

Schizophrenia is a mental disorder characterized by positive, negative, and cognitive symptoms which is treated with antipsychotics. However, these drugs present several side effects and, some schizophrenia symptoms, like cognitive, are difficult to treat. The peroxisome proliferator-activated receptors-gamma (PPAR-γ) are expressed in dopaminergic neurons of the midbrain participating in the modulation of dopamine-mediated behavior . We investigated the effects of pioglitazone, an agonist of PPAR-γ, on the behavioral alterations induced by ketamine and, whether alterations in monoamine oxidase (MAO) activity, glutamic acid decarboxylase (GAD67), PPAR-γ or tyrosine hydroxylase (TH) immunoreactivity in brain tissues are involved in these effects. Male mice received ketamine (30 mg/kg), intraperitoneally, for 14 consecutive days, and pioglitazone (3 or 9 mg/kg), by gavage (day 8 up to day 14). Ketamine decreased nail-biting increasing the time exploring the center of the open field on day 8 and the number of rearing evaluated 30 min after its administration on day 14. Furthermore, ketamine decreased the percentage of investigation in the NOR test and the immunoreactivity of GAD67 in the hippocampus. No significant changes were found in other behavioral and biochemical tests. Pioglitazone attenuated the effects of ketamine on rearing and GAD67 immunoreactivity in the hippocampus, recovering the ketamine effects on NOR test. At a dose of 9 mg/kg, pioglitazone alone reduced the immunoreactivity of GAD67 in the hippocampus. Pioglitazone at both doses recovered the cognitive symptoms induced by ketamine an effect that seems to involve the modulation of GAD67 immunoreactivity in the hippocampus. In conclusion, pioglitazone improved the effects of ketamine on the NOR test which was, at least in part, associated with the modulation of GAD67 immunoreactivity in the hippocampus suggesting its beneficial role in cognitive symptoms.

Investigation of Thiazolidine-2,4-Dione Derivatives as Acetylcholinesterase Inhibitors: Synthesis, In Vitro Biological Activities and In Silico Studies

The inhibition of acetylcholinesterase (AChE), an enzyme responsible for the inactivation and decrease in acetylcholine in the cholinergic pathway, has been considered an attractive target for small-molecule drug discovery in Alzheimer's disease (AD) therapy. In the present study, a series of TZD derivatives were designed, synthesized, and studied for drug likeness, blood-brain barrier (BBB) permeability, and adsorption, distribution, metabolism, excretion, and toxicity (ADMET). Additionally, docking studies of the designed compounds were performed on AChE. Additionally, all the TZD derivatives (CHT1-5) showed an acceptable affinity for AChE inhibition, and the results showed convincing binding modes in the active site of AChE. Among them, 5-(4-methoxybenzylidene) thiazolidine-2,4-dione (CHT1) was identified as the most potent AChE inhibitor (IC50 of 165.93 nM) with the highest antioxidant activity. Following the exposure of PC12 cells to Aβ1-42 (100 μM), a marked reduction in cell survival was observed. Pretreatment of PC12 cells with TZD derivatives had a neuroprotective effect and significantly enhanced cell survival in response to Aβ-induced toxicity. Western blotting analysis revealed that CHT1 (5 and 8 μM) downregulated p-Tau and HSP70 expression levels. The results indicate that CHT1 is a promising and effective AchE-I that could be utilized as a powerful candidate against AD.

The growing range of complications of diabetes mellitus

With the rising prevalence of type 2 diabetes mellitus (T2DM) and obesity, several previously under-recognised complications associated with T2DM are becoming more evident. The most common of these emerging complications are metabolic dysfunction-associated steatotic liver disease (MASLD), cancer, dementia, sarcopenia, and frailty, as well as other conditions involving the lung, heart, and intestinal tract. Likely causative factors are chronic inflammation and insulin resistance, whereas blood glucose levels appear to play a lesser role. We discuss these complications and the new approaches being developed to prevent and manage them, especially incretin-based therapies. We argue that these new interventions may work in a complementary way to other proven cardiorenal protective therapies to reduce the burden of T2DM complications.

The interaction between sleep patterns and oxidative balance scores on the risk of cognitive function decline: Results from the national health and nutrition examination survey 2011-2014

BACKGROUND

Unhealthy sleep and exposures to oxidative factors are both associated with poor cognitive performance (PCP), but limited evidence has been found regarding the relationship between sleep patterns and oxidative factor exposures independently or jointly with the risk of PCP.

METHODS

We analyzed data from 2249 adults aged ≥60 years in the National Health and Nutrition Examination Survey (NHANES) database (2011-2014). Self-reported questionnaires were used to collect data on sleep duration and sleep disorder, categorizing sleep duration into three groups based on responses: short (6 hours or less per night), normal (7-8 hours per night), or long (9 hours or more per night). Sleep disorder were categorized into two groups: sleep disorder, non-sleep disorder. Oxidative balance score (OBS) was calculated based on 20 oxidative stress exposures related to diet and lifestyle factors, with higher scores indicating greater antioxidant exposures. Survey-based multivariable adjusted regression analyses were conducted to examine the associations between sleep patterns or OBS alone and in combination with overall and PCP risks.

RESULTS

Compared to the normal sleep duration group, the long sleep duration group had a higher risk of PCP (DSST<34) (OR = 1.91, 95% CI = 1.05-3.48, P = 0.021); while OBS was negatively correlated with the risk of PCP (DSST<34) [Q4 vs Q1 (OR = 0.50, 95% CI = 0.29-0.92, P = 0.004)]. There was an interaction effect between sleep patterns (sleep duration, sleep disturbances) and OBS on PCP (DSST<34) (P = 0.002). Further stratified analysis showed that in individuals with normal sleep duration, long sleep duration, or no sleep disturbances, antioxidant exposures, compared to pro-oxidant exposures, reduced the risk of low cognitive function occurrence.

CONCLUSIONS

In older populations, unhealthy sleep patterns (especially excessive sleep duration) and low OBS alone or in combination increase the risk of cognitive decline. Healthy sleep and lifestyle habits rich in antioxidant factors are crucial for protecting cognitive function in older adults.

Anti-diabetic agents and the risks of dementia in patients with type 2 diabetes: a systematic review and network meta-analysis of observational studies and randomized controlled trials

OBJECTIVE

To evaluate the association between anti-diabetic agents and the risks of dementia in patients with type 2 diabetes (T2D).

METHODS

Literature retrieval was conducted in PubMed, Embase, the Cochrane Central Register of Controlled Trials and Clinicaltrial.gov between January 1995 and October 2024. Observational studies and randomized controlled trials (RCTs) in patients with T2D, which intercompared anti-diabetic agents or compared them with placebo, and reported the incidence of dementia were included. Conventional and network meta-analyses of these studies were implemented. Results were exhibited as the odds ratio (OR) or risk ratio (RR) with 95% confidence interval (CI).

RESULTS

A total of 41 observational studies (3,307,483 participants) and 23 RCTs (155,443 participants) were included. In the network meta-analysis of observational studies, compared with non-users, sodium glucose cotransporter-2 inhibitor (SGLT-2i) (OR = 0.56, 95%CI, 0.45 to 0.69), glucagon-like peptide-1 receptor agonist (GLP-1RA) (OR = 0.58, 95%CI, 0.46 to 0.73), thiazolidinedione (TZD) (OR = 0.68, 95%CI, 0.57 to 0.81) and metformin (OR = 0.89, 95%CI, 0.80 to 0.99) treatments were all associated with reduced risk of dementia in patients with T2D. The surface under the cumulative ranking curve (SUCRA) evaluation conferred a rank order as SGLT-2i > GLP-1RA > TZD > dipeptidyl peptidase-4 inhibitor (DPP-4i) > metformin > α-glucosidase inhibitor (AGI) > glucokinase activator (GKA) > sulfonylureas > glinides > insulin in terms of the cognitive benefits. Meanwhile, compared with non-users, SGLT-2i (OR = 0.43, 95%CI, 0.30 to 0.62), GLP-1RA (OR = 0.54, 95%CI, 0.30 to 0.96) and DPP-4i (OR = 0.73, 95%CI, 0.57 to 0.93) were associated with a reduced risk of Alzheimer's disease while a lower risk of vascular dementia was observed in patients receiving SGLT-2i (OR = 0.42, 95%CI, 0.22 to 0.80) and TZD (OR = 0.52, 95%CI, 0.36 to 0.75) treatment. In the network meta-analysis of RCTs, the risks of dementia were comparable among anti-diabetic agents and placebo.

CONCLUSION

Compared with non-users, SGLT-2i, GLP-1RA, TZD and metformin were associated with the reduced risk of dementia in patients with T2D. SGLT-2i, and GLP-1RA may serve as the optimal choice to improve the cognitive prognosis in patients with T2D.

Neuroprotective effect of PPAR gamma agonist in rat model of autism spectrum disorder: Role of Wnt/β-catenin pathway

BACKGROUND

The clinical manifestation of autism spectrum disorder (ASD) is linked to the disruption of fundamental neurodevelopmental pathways. Emerging evidences claim to have an upregulation of canonical Wnt/β-catenin pathway while downregulation of PPARγ pathway in ASD. This study aims to investigate the therapeutic potential of pioglitazone, a PPARγ agonist, in rat model of ASD. The study further explores the possible role of PPARγ and Wnt/β-catenin pathway and their interaction in ASD by using their modulators.

MATERIAL AND METHODS

Pregnant female Wistar rats received 600 mg/kg of valproic acid (VPA) to induce autistic symptoms in pups. Pioglitazone (10 mg/kg) was used to evaluate neurobehaviors, relative mRNA expression of inflammatory (IL-1β, IL-6, IL-10, TNF-α), apoptotic markers (Bcl-2, Bax, & Caspase-3) and histopathology (H&E, Nissl stain, Immunohistochemistry). Effect of pioglitazone was evaluated on Wnt pathway and 4 μg/kg dose of 6-BIO (Wnt modulator) was used to study the PPARγ pathway.

RESULTS

ASD model was established in pups as indicated by core autistic symptoms, increased neuroinflammation, apoptosis and histopathological neurodegeneration in cerebellum, hippocampus and amygdala. Pioglitazone significantly attenuated these alterations in VPA-exposed rats. The expression study results indicated an increase in key transcription factor, β-catenin in VPA-rats suggesting an upregulation of canonical Wnt pathway in them. Pioglitazone significantly downregulated the Wnt signaling by suppressing the expression of Wnt signaling-associated proteins. The inhibiting effect of Wnt pathway on PPARγ activity was indicated by downregulation of PPARγ-associated protein in VPA-exposed rats and those administered with 6-BIO.

CONCLUSION

In the present study, upregulation of canonical Wnt/β-catenin pathway was demonstrated in ASD rat model. Pioglitazone administration significantly ameliorated these symptoms potentially through its neuroprotective effect and its ability to downregulate the Wnt/β-catenin pathway. The antagonism between the PPARγ and Wnt pathway offers a promising therapeutic approach for addressing ASD.

Pathology and Treatments of Alzheimer's Disease Based on Considering Changes in Brain Energy Metabolism Due to Type 2 Diabetes

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with cognitive dysfunction, memory decline, and behavioral disturbance, and it is pathologically characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain. Although various hypotheses have been proposed to explain the pathogenesis of AD, including the amyloid beta hypothesis, oxidative stress hypothesis, and abnormal phosphorylation of tau proteins, the exact pathogenic mechanisms underlying AD remain largely undefined. Furthermore, effective curative treatments are very limited. Epidemiologic studies provide convincing evidence for a significant association between type 2 diabetes and AD. Here, we showed energy metabolism using glucose, lactate, ketone bodies, and lipids as energy substrates in a normal brain, and changes in such energy metabolism due to type 2 diabetes. We also showed the influences of such altered energy metabolism due to type 2 diabetes on the pathology of AD. Furthermore, we comprehensively searched for risk factors related with type 2 diabetes for AD and showed possible therapeutic interventions based on considering risk factors and altered brain energy metabolism due to type 2 diabetes for the development of AD.

The inhibitory influence of carvacrol on behavioral modifications, brain oxidation, and general inflammation triggered by paraquat exposure through inhalation

The current study investigated how carvacrol (C) can prevent behavioral and brain oxidative changes, along with systemic inflammation caused by inhaled paraquat (PQ). Control rats exposed to saline solution, whereas six rat groups were subjected to PQ aerosols at a concentration of 54 mg/m3 in 16 days. The PQ-exposed groups received saline (PQ group), C at dosages of 20 (C-L) and 80 mg/kg/day (C-H), dexamethasone at a dosage of 0.03 mg/kg/day, pioglitazone at dose of 5 and 10 mg/kg/day (Pio-L and Pio-H), and a combination of C-L + Pio-L. Various parameters were assessed following the end of the treatment duration. There were marked elevation in total and differential white blood cell counts (WBCs), and malondialdehyde levels in the blood, hippocampus, and cerebral tissue but, thiol, superoxide dismutase (SOD), and catalase (CAT) exhibited a notable decrease (p < 0.05 to p < 0.001). The escape delay and traveled distance exhibited enhancement, however, on the probe day, the duration spent in the target quadrant and the time taken to enter the dark room at 3, 24, 48, and 72 hours post an electrical shock, showed a reduction in the PQ group (P<0.05 to P<0.001). Inhaled PQ-induced changes were significantly improved in C, Pio, Dexa, and C-L + Pio-L treated groups (P<0.05 to P<0.001). The effects of C-L + Pio-L on most measured variables were higher than C-L and Pio-L (P<0.05 to P<0.001). C improved PQ-induced changes similar to dexamethasone and C-L showed additive effects when administered in combination with Pio.

Decoding Neurodegeneration: A Review of Molecular Mechanisms and Therapeutic Advances in Alzheimer's, Parkinson's, and ALS

Neurodegenerative diseases, such as Alzheimer's, Parkinson's, ALS, and Huntington's, remain formidable challenges in medicine, with their relentless progression and limited therapeutic options. These diseases arise from a web of molecular disturbances-misfolded proteins, chronic neuroinflammation, mitochondrial dysfunction, and genetic mutations-that slowly dismantle neuronal integrity. Yet, recent scientific breakthroughs are opening new paths to intervene in these once-intractable conditions. This review synthesizes the latest insights into the underlying molecular dynamics of neurodegeneration, revealing how intertwined pathways drive the course of these diseases. With an eye on the most promising advances, we explore innovative therapies emerging from cutting-edge research: nanotechnology-based drug delivery systems capable of navigating the blood-brain barrier, gene-editing tools like CRISPR designed to correct harmful genetic variants, and stem cell strategies that not only replace lost neurons but foster neuroprotective environments. Pharmacogenomics is reshaping treatment personalization, enabling tailored therapies that align with individual genetic profiles, while molecular diagnostics and biomarkers are ushering in an era of early, precise disease detection. Furthermore, novel perspectives on the gut-brain axis are sparking interest as mounting evidence suggests that microbiome modulation may play a role in reducing neuroinflammatory responses linked to neurodegenerative progression. Taken together, these advances signal a shift toward a comprehensive, personalized approach that could transform neurodegenerative care. By integrating molecular insights and innovative therapeutic techniques, this review offers a forward-looking perspective on a future where treatments aim not just to manage symptoms but to fundamentally alter disease progression, presenting renewed hope for improved patient outcomes.

The Neuroprotective Mechanisms of PPAR-γ: Inhibition of Microglia-Mediated Neuroinflammation and Oxidative Stress in a Neonatal Mouse Model of Hypoxic-Ischemic White Matter Injury

BACKGROUND

Neuroinflammation and oxidative stress, mediated by microglial activation, hinder the development of oligodendrocytes (OLs) and delay myelination in preterm infants, leading to white matter injury (WMI) and long-term neurodevelopmental sequelae. Peroxisome proliferator-activated receptor gamma (PPAR-γ) has been reported to inhibit inflammation and oxidative stress via modulating microglial polarization in various central nervous system diseases. However, the relationship between PPAR-γ and microglial polarization in neonatal WMI is not well understood. Therefore, this study aimed to elucidate the role and mechanisms of PPAR-γ in preterm infants affected by WMI.

METHODS

In this study, an in vivo hypoxia-ischemia (HI) induced brain WMI neonatal mouse model was established. The mice were administered intraperitoneally with either RSGI or GW9662 to activate or inhibit PPAR-γ, respectively. Additionally, an in vitro oxygen-glucose deprivation (OGD) cell model was established and pretreated with pcDNA 3.1-PPAR-γ or si-PPAR-γ to overexpress or silence PPAR-γ, respectively. The neuroprotective effects of PPAR-γ were investigated in vivo. Firstly, open field test, novel object recognization test, and beam-walking test were employed to assess the effects of PPAR-γ on neurobehavioral recovery. Furthermore, assessment of OLs loss and OL-maturation disorder, the number of myelinated axons, myelin thickness, synaptic deficit, activation of microglia and astrocyte, and blood-brain barrier (BBB) were used to evaluate the effects of PPAR-γ on pathological repair. The mechanisms of PPAR-γ were explored both in vivo and in vitro. Assessment of microglia polarization, inflammatory mediators, reactive oxygen species (ROS), MDA, and antioxidant enzymes was used to evaluate the anti-inflammatory and antioxidative effects of PPAR-γ activation. An assessment of HMGB1/NF-κB and NRF2/KEAP1 signaling pathway was conducted to clarify the mechanisms by which PPAR-γ influences HI-induced WMI in neonatal mice.

RESULTS

Activation of PPAR-γ using RSGI significantly mitigated BBB disruption, promoted M2 polarization of microglia, inhibited activation of microglia and astrocytes, promoted OLs development, and enhanced myelination in HI-induced WMI. Conversely, inhibition of PPAR-γ using GW9662 further exacerbated the pathologic hallmark of WMI. Neurobehavioral tests revealed that neurological deficits were ameliorated by RSGI, while further aggravated by GW91662. In addition, activation of PPAR-γ significantly alleviated neuroinflammation and oxidative stress by suppressing HMGB1/NF-κB signaling pathway and activating NRF2 signaling pathway both in vivo and in vitro. Conversely, inhibition of PPAR-γ further exacerbated HI or OGD-induced neuroinflammation, oxidative stress via modulation of the same signaling pathway.

CONCLUSIONS

Our findings suggest that PPAR-γ regulates microglial activation/polarization as well as subsequent neuroinflammation/oxidative stress via the HMGB1/NF-κB and NRF2/KEAP1 signaling pathway, thereby contributing to neuroprotection and amelioration of HI-induced WMI in neonatal mice.

Alzheimer's Disease, Obesity, and Type 2 Diabetes: Focus on Common Neuroglial Dysfunctions (Critical Review and New Data on Human Brain and Models)

BACKGROUND/OBJECTIVES

Obesity, type 2 diabetes (T2D), and Alzheimer's disease (AD) are pathologies that affect millions of people worldwide. They have no effective therapy and are difficult to prevent and control when they develop. It has been known for many years that these diseases have many pathogenic aspects in common. We highlight in this review that neuroglial cells (astroglia, oligodendroglia, and microglia) play a vital role in the origin, clinical-pathological development, and course of brain neurodegeneration. Moreover, we include the new results of a T2D-AD mouse model (APP+PS1 mice on a high-calorie diet) that we are investigating.

METHODS

Critical bibliographic revision and biochemical neuropathological study of neuroglia in a T2D-AD model.

RESULTS

T2D and AD are not only "connected" by producing complex pathologies in the same individual (obesity, T2D, and AD), but they also have many common pathogenic mechanisms. These include insulin resistance, hyperinsulinemia, hyperglycemia, oxidative stress, mitochondrial dysfunction, and inflammation (both peripheral and central-or neuroinflammation). Cognitive impairment and AD are the maximum exponents of brain neurodegeneration in these pathological processes. both due to the dysfunctions induced by metabolic changes in peripheral tissues and inadequate neurotoxic responses to changes in the brain. In this review, we first analyze the common pathogenic mechanisms of obesity, T2D, and AD (and/or cerebral vascular dementia) that induce transcendental changes and responses in neuroglia. The relationships between T2D and AD discussed mainly focus on neuroglial responses. Next, we present neuroglial changes within their neuropathological context in diverse scenarios: (a) aging involution and neurodegenerative disorders, (b) human obesity and diabetes and obesity/diabetes models, (c) human AD and in AD models, and (d) human AD-T2D and AD-T2D models. An important part of the data presented comes from our own studies on humans and experimental models over the past few years. In the T2D-AD section, we included the results of a T2D-AD mouse model (APP+PS1 mice on a high-calorie diet) that we investigated, which showed that neuroglial dysfunctions (astrocytosis and microgliosis) manifest before the appearance of amyloid neuropathology, and that the amyloid pathology is greater than that presented by mice fed a normal, non-high-caloric diet A broad review is finally included on pharmacological, cellular, genic, and non-pharmacological (especially diet and lifestyle) neuroglial-related treatments, as well as clinical trials in a comparative way between T2D and AD. These neuroglial treatments need to be included in the multimodal/integral treatments of T2D and AD to achieve greater therapeutic efficacy in many millions of patients.

CONCLUSIONS

Neuroglial alterations (especially in astroglia and microglia, cornerstones of neuroinflammation) are markedly defining brain neurodegeneration in T2D and A, although there are some not significant differences between each of the studied pathologies. Neuroglial therapies are a very important and p. promising tool that are being developed to prevent and/or treat brain dysfunction in T2D-AD. The need for further research in two very different directions is evident: (a) characterization of the phenotypic changes of astrocytes and microglial cells in each region of the brain and in each phase of development of each isolated and associated pathology (single-cell studies are mandatory) to better understand the pathologies and define new therapeutic targets; (b) studying new therapeutic avenues to normalize the function of neuroglial cells (preventing neurotoxic responses and/or reversing them) in these pathologies, as well as the phenotypic characteristics in each moment of the course and place of the neurodegenerative process.

Pioglitazone as a Possible Treatment for Ataxia-Telangiectasia

Ataxia-telangiectasia (AT) is a rare autosomal recessive disorder characterized by immunodeficiency, progressive cerebellar ataxia, and an increased malignancy risk. Cells derived from individuals with AT show multiple defects, including high oxidant and ionizing radiation sensitivities, poor DNA repair, low iron-sulfur cluster levels, and low reduced glutathione. The clinical course of AT is progressive and unrelenting, with most individuals having a survival time of approximately twenty-five years. Presently, AT has no effective treatments, and most patients receive supportive care only. Recently, pioglitazone, a thiazolidinedione class used to treat type 2 diabetes, has been demonstrated to exert beneficial effects on AT cells and on diabetic individuals with AT. Here, I will discuss the possible molecular mechanisms of pioglitazone's favorable effects on the AT phenotype and why it may have utility in treating some aspects of AT.

Restoration of Spatial Learning Through Oral Administration of Lipopolysaccharides in Diabetes-related Cognitive Dysfunction

BACKGROUND/AIM

In a previous report, our group showed that oral administration of lipopolysaccharides (LPS) from Pantoea agglomerans can prevent the progression of streptozotocin (STZ)-induced diabetes-related cognitive dysfunction (DRCD) in mice without causing significant side-effects. However, the treatment effects of oral administration of LPS to DRCD remain unknown.

MATERIALS AND METHODS

We modified our previous animal experimental model to investigate whether oral administration of LPS can recover cognitive function after DRCD onset.

RESULTS

The Morris water maze (MWM) revealed a significant decrease in learning and memory abilities at 13 days after intracerebroventricular administration of STZ, thereby providing evidence of the occurrence of DRCD in the animal model. Oral administration of LPS (1 mg/kg per day) started after cognitive impairment was observed. After 28 days of treatment, mice receiving LPS via the oral route showed significant recovery of spatial learning ability, a symptom of early dementia, while only a trend toward recovery was seen for spatial memory compared to the untreated group.

CONCLUSION

These results, limited to MWM, suggest that oral administration of LPS is a promising therapeutic strategy for restoring decreased spatial learning ability.

Effect of aortic smooth muscle BK channels on mediating chronic intermittent hypoxia-induced vascular dysfunction

Chronic intermittent hypoxia (CIH) can lead to vascular dysfunction and increase the risk of cardiovascular diseases, cerebrovascular diseases, and arterial diseases. Nevertheless, mechanisms underlying CIH-induced vascular dysfunction remain unclear. Herein, this study analyzed the role of aortic smooth muscle calciumactivated potassium (BK) channels in CIH-induced vascular dysfunction. CIH models were established in rats and rat aortic smooth muscle cells (RASMCs). Hemodynamic parameters such as mean blood pressure (MBP), diastolic blood pressure (DBP), and systolic blood pressure (SBP) were measured in rats, along with an assessment of vascular tone. NO and ET-1 levels were detected in rat serum, and the levels of ET-1, NO, eNOS, p-eNOS, oxidative stress markers (ROS and MDA), and inflammatory factors (IL-6 and TNF-α) were tested in aortic tissues. The Ca2+ concentration in RASMCs was investigated. The activity of BK channels (BKα and BKβ) was evaluated in aortic tissues and RASMCs. SBP, DBP, and MBP were elevated in CIH-treated rats, along with endothelial dysfunction, cellular edema and partial detachment of endothelial cells. BK channel activity was decreased in CIH-treated rats and RASMCs. BK channel activation increased eNOS, p-eNOS, and NO levels while lowering ET-1, ROS, MDA, IL-6, and TNF-α levels in CIH-treated rats. Ca2+ concentration increased in RASMCs following CIH modeling, which was reversed by BK channel activation. BK channel inhibitor (Iberiotoxin) exacerbated CIH-induced vascular disorders and endothelial dysfunction. BK channel activation promoted vasorelaxation while suppressing vascular endothelial dysfunction, inflammation, and oxidative stress, thereby indirectly improving CIH-induced vascular dysfunction.

Exploring the molecular mechanisms of PPARγ agonists in modulating memory impairment in neurodegenerative disorders

Neurodegenerative diseases are characterized by progressive memory impairment and cognitive decline. This review aims to unravel the molecular mechanisms involved in the enhancement of memory function and mitigation of memory impairment through the activation of PPARγ agonists in neurodegenerative diseases. The findings suggest that PPARγ agonists modulate various molecular pathways involved in memory formation and maintenance. Activation of PPARγ enhances synaptic plasticity, promotes neuroprotection, suppresses neuroinflammation, attenuates oxidative stress, and regulates amyloid-beta metabolism. The comprehensive understanding of these molecular mechanisms would facilitate the development of novel therapeutic approaches targeting PPARγ to improve memory function and ultimately to alleviate the burden of neurodegenerative diseases. Further research, including clinical trials, is warranted to explore the efficacy, safety, and optimal use of specific PPARγ agonists as potential therapeutic agents in the treatment of memory impairments associated with neurodegenerative diseases.

Insulin resistance as the molecular link between diabetes and Alzheimer's disease

Diabetes mellitus (DM) and Alzheimer's disease (AD) are two major health concerns that have seen a rising prevalence worldwide. Recent studies have indicated a possible link between DM and an increased risk of developing AD. Insulin, while primarily known for its role in regulating blood sugar, also plays a vital role in protecting brain functions. Insulin resistance (IR), especially prevalent in type 2 diabetes, is believed to play a significant role in AD's development. When insulin signalling becomes dysfunctional, it can negatively affect various brain functions, making individuals more susceptible to AD's defining features, such as the buildup of beta-amyloid plaques and tau protein tangles. Emerging research suggests that addressing insulin-related issues might help reduce or even reverse the brain changes linked to AD. This review aims to explore the rela-tionship between DM and AD, with a focus on the role of IR. It also explores the molecular mechanisms by which IR might lead to brain changes and assesses current treatments that target IR. Understanding IR's role in the connection between DM and AD offers new possibilities for treatments and highlights the importance of continued research in this interdisciplinary field.

Immunomodulation through Nutrition Should Be a Key Trend in Type 2 Diabetes Treatment

An organism's ability to function properly depends not solely on its diet but also on the intake of nutrients and non-nutritive bioactive compounds that exert immunomodulatory effects. This principle applies both to healthy individuals and, in particular, to those with concomitant chronic conditions, such as type 2 diabetes. However, the current food industry and the widespread use of highly processed foods often lead to nutritional deficiencies. Numerous studies have confirmed the occurrence of immune system dysfunction in patients with type 2 diabetes. This article elucidates the impact of specific nutrients on the immune system function, which maintains homeostasis of the organism, with a particular emphasis on type 2 diabetes. The role of macronutrients, micronutrients, vitamins, and selected substances, such as omega-3 fatty acids, coenzyme Q10, and alpha-lipoic acid, was taken into consideration, which outlined the minimum range of tests that ought to be performed on patients in order to either directly or indirectly determine the severity of malnutrition in this group of patients.

Evidence from an Avian Embryo Model that Zinc-Inducible MT4 Expression Protects Mitochondrial Function Against Oxidative Stress

BACKGROUND

Metallothioneins (MTs) have a strong affinity for zinc (Zn) and remain at a sufficiently high level in mitochondria. As the avian embryo is highly susceptible to oxidative damage and relatively easy to manipulate in a naturally closed chamber, it is an ideal model of the effects of oxidative stress on mitochondrial function. However, the protective roles and molecular mechanisms of Zn-inducible protein expression on mitochondrial function in response to various stressors are poorly understood.

OBJECTIVES

The study aimed to investigate the mechanisms by which Zn-induced MT4 expression protects mitochondrial function and energy metabolism subjected to oxidative stress using the avian embryo and embryonic primary hepatocyte models.

METHODS

First, we investigated whether MT4 expression alters mitochondrial function. Then, we examined the effects of Zn-induced MT4 overexpression and MT4 silencing on embryonic primary hepatocytes from breeder hens fed a normal Zn diet subjected to a tert-butyl hydroperoxide (BHP) oxidative stress challenge during incubation. In vivo, the avian embryos from hens fed the Zn-deficient and Zn-adequate diets were used to determine the protective roles of Zn-induced MT4 expression on the function of mitochondria exposed to oxidative stress induced by in ovo BHP injection.

RESULTS

An in vitro study revealed that Zn-induced MT4 expression reduced reactive oxygen species accumulation in primary hepatocytes. MT4 silencing exacerbated BHP-mediated mitochondrial dysfunction whereas Zn-inducible MT4 overexpression mitigated it. Another in vivo study disclosed that maternal Zn-induced MT4 expression protected mitochondrial function in chick embryo hepatocytes against oxidative stress by inhibiting the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α)/peroxisome proliferators-activated receptor-γ (PPAR-γ) pathway.

CONCLUSION

This study underscores the potential protective roles of Zn-induced MT4 expression via the downregulation of the PGC-1α/PPAR-γ pathway on mitochondrial function stimulated by the stress challenge in the primary hepatocytes in an avian embryo model. Our findings suggested that Zn-induced MT4 expression could provide a new therapeutic target and preventive strategy for repairing mitochondrial dysfunction in disease.

Pioglitazone ameliorates DOX-induced cognitive impairment by mitigating inflammation, oxidative stress, and apoptosis of hippocampal neurons in rats

Doxorubicin (DOX) is broadly used as a medication for cancer treatment. However, DOX has been connected with chemotherapy-related complications, for instance, cognitive impairment (chemobrain). Chemobrain developed in up to 70% of cancer patients; therapeutic is unavailable. This study investigated the preventive effect of pioglitazone (PIO) on neurotoxicity caused by (DOX) in the hippocampus. Forty rats were separated into four groups; control (normal saline 10 ml/kg), DOX (5 mg/kg, intraperitoneally every 3rd day, equivalent to 20 mg/kg cumulative dose), PIO (2 mg/kg in drinking water), and DOX+PIO (DOX, 5 mg/kg, intraperitoneally every 3rd day concurrently PIO, 2 mg/kg in drinking water) and duration of drug treatment lasted for 14 days. The animals were subjected to contextual fear memory tests to characterize the cognitive impairment following DOX treatment. ELISA assessed hippocampal protein expression related to inflammation, oxidative damage, and apoptosis. DOX-treatment produced significant reduction in freezing duration in contextual fear memory tests, which was reversed by PIO co-administration. DOX increased neuroinflammation, oxidative stress, apoptosis, and mitochondrial activity by increasing NF-κB and COX-2 levels, reducing SOD levels, and increasing Bax, caspase-3, and lipid peroxidation. However, DOX did not affect GSH or catalase levels. PIO co-administration reduces NF-κB, COX-2, MDA, Bax, and caspase-3 levels and improves mitochondrial activity and SOD expression. To sum up, DOX therapy accelerates cognitive decline in rats by increasing neuroinflammation, oxidative stress, mitochondrial dysfunction, lipid peroxidation, and apoptosis. PIO is a promising treatment for DOX-induced cognitive impairment.

Inflammation, Autoimmunity and Neurodegenerative Diseases, Therapeutics and Beyond

Neurodegenerative disease (ND) incidence has recently increased due to improved life expectancy. Alzheimer's (AD) or Parkinson's disease (PD) are the most prevalent NDs. Both diseases are poly genetic, multifactorial and heterogenous. Preventive medicine, a healthy diet, exercise, and controlling comorbidities may delay the onset. After the diseases are diagnosed, therapy is needed to slow progression. Recent studies show that local, peripheral and age-related inflammation accelerates NDs' onset and progression. Patients with autoimmune disorders like inflammatory bowel disease (IBD) could be at higher risk of developing AD or PD. However, no increase in ND incidence has been reported if the patients are adequately diagnosed and treated. Autoantibodies against abnormal tau, β amyloid and α- synuclein have been encountered in AD and PD and may be protective. This discovery led to the proposal of immune-based therapies for AD and PD involving monoclonal antibodies, immunization/ vaccines, pro-inflammatory cytokine inhibition and anti-inflammatory cytokine addition. All the different approaches have been analysed here. Future perspectives on new therapeutic strategies for both disorders are concisely examined.

Prostaglandins in the Inflamed Central Nervous System: Potential Therapeutic Targets

The global burden of neurological disorders is evident, yet there remains limited efficacious therapeutics for their treatment. There is a growing recognition of the role of inflammation in diseases of the central nervous system (CNS); among the numerous inflammatory mediators involved, prostaglandins play a crucial role. Prostaglandins are small lipid mediators derived from arachidonic acid via multi-enzymatic pathways. The actions of prostaglandins are varied, with each prostaglandin having a specific role in maintaining homeostasis. In the CNS, prostaglandins can have neuroprotective or neurotoxic properties depending on their specific G-protein receptor. These G-protein receptors have varying subfamilies, tissue distribution, and signal transduction cascades. Further studies into the impact of prostaglandins in CNS-based diseases may contribute to the clarification of their actions, hopefully leading to the development of efficacious therapeutic strategies. This review focuses on the roles played by prostaglandins in neural degeneration, with a focus on Alzheimer's Disease, Multiple Sclerosis, and Amyotrophic Lateral Sclerosis in both preclinical and clinical settings. We further discuss current prostaglandin-related agonists and antagonists concerning suggestions for their use as future therapeutics.

Conquering Insulin Network Dysfunctions in Alzheimer's Disease: Where Are We Today?

Functional impairments in the brain's insulin and insulin-like growth factor (IGF) signal transduction networks are recognized mediators of dysregulated energy metabolism, a major driver of the Alzheimer's disease (AD) neurodegeneration cascade. AD-associated insulin-deficient and insulin-resistant states mimic those of diabetes mellitus and affect all cell types in the brain. Besides accounting for abundant amyloid-β and hyperphosphorylated tau lesions in AD, insulin/IGF pathway dysfunctions cause cortical atrophy, loss of synaptic plasticity, white matter myelin/oligodendrocyte degeneration, astrocyte and microglial neuroinflammation and oxidative stress, deficits in energy metabolism, mitochondrial dysfunction, and microvascular disease. These same neuropathological processes have been linked to cognitive impairment in type 2 diabetes mellitus, Parkinson's disease, and vascular dementia. Strategies to address metabolic mediators of cognitive impairment have been borrowed from diabetes and other insulin-resistant diseases and leveraged on preclinical AD model data. The repurposing of diabetes drugs led to clinical trials with intranasal insulin, followed by insulin sensitizers including metformin and peroxisome-proliferator-activated receptor agonists, and then incretin mimetics primarily targeting GLP-1 receptors. In addition, other glucose-lowering agents have been tested for their efficacy in preventing cognitive declines. The strengths and limitations of these approaches are discussed. The main conclusion of this review is that we have now arrived at a stage in which it is time to address long-term deficits in trophic factor availability and receptor responsiveness, signaling abnormalities that extend beyond insulin and include IGFs and interconnected pathways, and the need for multi-pronged rather than single-pronged therapeutic targeting to remediate AD and other forms of neurodegeneration.

An Overview of the Role of Peroxisome Proliferator-activated Receptors in Liver Diseases

Peroxisome proliferator-activated receptors (PPARs) are a superfamily of nuclear transcription receptors, consisting of PPARα, PPARγ, and PPARβ/δ, which are highly expressed in the liver. They control and modulate the expression of a large number of genes involved in metabolism and energy homeostasis, oxidative stress, inflammation, and even apoptosis in the liver. Therefore, they have critical roles in the pathophysiology of hepatic diseases. This review provides a general insight into the role of PPARs in liver diseases and some of their agonists in the clinic.

Dipeptidyl peptidase-4 inhibitors alleviate cognitive dysfunction in type 2 diabetes mellitus

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) are commonly at high risk for developing cognitive dysfunction. Antidiabetic agents might be repurposed for targeting cognitive dysfunction in addition to modulation on glucose homeostasis. This study aimed to evaluate the impact of dipeptidyl peptidase-4 inhibitors (DPP-4i) on cognitive function in T2DM.

METHODS

PubMed, Embase, Cochrane Library and Web of Science were systematically searched from inception to September 30, 2023. Weighted mean differences were calculated using the Mantel-Haenszel (M-H) fixed or random effects model based on the degree of heterogeneity among studies. Heterogeneity was evaluated using a Chi-squared test and quantified with Higgins I2. Sensitivity analysis was performed with the leave-one-out method, and publication bias was evaluated according to Begg's and Egger's tests.

RESULTS

Six clinical trials involving 5,178 participants were included in the pooled analysis. Administration of DPP-4i generally correlated with an increase of Mini-Mental State Examination (MMSE) scores (1.09, 95% CI: 0.22 to 1.96). DPP-4i alleviated cognitive impairment in the copying skill subdomain of MMSE (0.26, 95% CI: 0.12 to 0.40). Treatment with DPP-4i also resulted in an increase of Instrumental Activities of Daily Living (IADL) scores (0.82, 95% CI: 0.30 to 1.34). However, DPP-4i produced no significant effects on Barthel Activities of Daily Living (BADL) scores (0.37, 95% CI: -1.26 to 1.99) or other test scores.

CONCLUSIONS

DPP-4i treatment favourably improved cognitive function in patients with T2DM. Further trials with larger samples should be performed to confirm these estimates and investigate the association of different DPP-4i with cognitive function among diabetic patients.

TRIAL REGISTRATION IN PROSPERO

CRD42023430873.

Dopamine in the Regulation of Glucose Homeostasis, Pathogenesis of Type 2 Diabetes, and Chronic Conditions of Impaired Dopamine Activity/Metabolism: Implication for Pathophysiological and Therapeutic Purposes

Dopamine regulates several functions, such as voluntary movements, spatial memory, motivation, sleep, arousal, feeding, immune function, maternal behaviors, and lactation. Less clear is the role of dopamine in the pathophysiology of type 2 diabetes mellitus (T2D) and chronic complications and conditions frequently associated with it. This review summarizes recent evidence on the role of dopamine in regulating insular metabolism and activity, the pathophysiology of traditional chronic complications associated with T2D, the pathophysiological interconnection between T2D and chronic neurological and psychiatric disorders characterized by impaired dopamine activity/metabolism, and therapeutic implications. Reinforcing dopamine signaling is therapeutic in T2D, especially in patients with dopamine-related disorders, such as Parkinson's and Huntington's diseases, addictions, and attention-deficit/hyperactivity disorder. On the other hand, although specific trials are probably needed, certain medications approved for T2D (e.g., metformin, pioglitazone, incretin-based therapy, and gliflozins) may have a therapeutic role in such dopamine-related disorders due to anti-inflammatory and anti-oxidative effects, improvement in insulin signaling, neuroinflammation, mitochondrial dysfunction, autophagy, and apoptosis, restoration of striatal dopamine synthesis, and modulation of dopamine signaling associated with reward and hedonic eating. Last, targeting dopamine metabolism could have the potential for diagnostic and therapeutic purposes in chronic diabetes-related complications, such as diabetic retinopathy.

Targeting immunometabolic pathways for combination therapy in Alzheimer's disease

The recent success of disease-modifying anti-amyloid monoclonal antibodies in slowing Alzheimer's disease (AD) symptoms has been an exciting step forward for the field. Despite successfully clearing amyloid from the brain, however, only modest symptomatic improvement has been demonstrated, and treatment-related side effects such as amyloid-related imaging abnormalities (ARIA) limit use for some. These limitations suggest that fully efficacious AD treatment may require combination therapy regimens, as are used in other complex disorders such as cancer and HIV. One reasonable strategy may be to use agents that address the biological changes that predict future amyloid accumulation, or accompany amyloid accumulation in preclinical disease states. Immunometabolic pathways, including the insulin signaling pathway, are dysregulated at the earliest stages of AD, concomitant with amyloid accumulation. It is plausible that agents that target these pathways may work synergistically with anti-amyloid therapies to halt AD progression. Insulin signaling is integrally involved in innate and adaptive immune systems, with pleiotropic effects that moderate pro- and anti-inflammatory responses. Metabolic modulators that enhance insulin sensitivity and function, such as GLP-1 receptor agonists, SGLT2 inhibitors, and insulin itself have been shown to improve immune function and reduce chronic inflammation. Additional effects of insulin and metabolic modulators demonstrated in preclinical and clinical studies of AD include increased clearance of amyloid-β, slowed tau progression, improved vascular function and lipid metabolism, reduced synaptotoxicity, and improved cognitive and functional outcomes. A large number of compounds that treat metabolic disorders have been extensively characterized with respect to mechanism of action and safety, and thus are readily available to be repurposed for combination therapy protocols. Determining the most successful combination regimens of these agents together with disease-modifying therapies, and the appropriate timing of treatment, are promising next steps in the quest to treat and prevent AD.

NF-κB Pathway and Its Inhibitors: A Promising Frontier in the Management of Alzheimer's Disease

The nuclear factor kappa B (NF-κB) pathway has emerged as a pivotal player in the pathogenesis of various diseases, including neurodegenerative illnesses like Alzheimer's disease (AD). The involvement of the NF-κB pathway in immune system responses, inflammation, oxidative stress, and neuronal survival highlights its significance in AD progression. We discuss the advantages of NF-κB pathway inhibition, including the potential to mitigate neuroinflammation, modulate amyloid beta (Aβ) production, and promote neuronal survival. However, we also acknowledge the limitations and challenges associated with this approach. Balancing the fine line between dampening inflammation and preserving physiological immune responses is critical to avoid unintended consequences. This review combines current knowledge on the NF-κB pathway's intricate involvement in AD pathogenesis, emphasizing its potential as a therapeutic target. By evaluating both advantages and limitations, we provide a holistic view of the feasibility and challenges of NF-κB pathway modulation in AD treatment. As the quest for effective AD therapies continues, an in-depth understanding of the NF-κB pathway's multifaceted roles will guide the development of targeted interventions with the potential to improve AD management.

Brain Mitochondrial Bioenergetics in Genetic Neurodevelopmental Disorders: Focus on Down, Rett and Fragile X Syndromes

Mitochondria, far beyond their prominent role as cellular powerhouses, are complex cellular organelles active as central metabolic hubs that are capable of integrating and controlling several signaling pathways essential for neurological processes, including neurogenesis and neuroplasticity. On the other hand, mitochondria are themselves regulated from a series of signaling proteins to achieve the best efficiency in producing energy, in establishing a network and in performing their own de novo synthesis or clearance. Dysfunctions in signaling processes that control mitochondrial biogenesis, dynamics and bioenergetics are increasingly associated with impairment in brain development and involved in a wide variety of neurodevelopmental disorders. Here, we review recent evidence proving the emerging role of mitochondria as master regulators of brain bioenergetics, highlighting their control skills in brain neurodevelopment and cognition. We analyze, from a mechanistic point of view, mitochondrial bioenergetic dysfunction as causally interrelated to the origins of typical genetic intellectual disability-related neurodevelopmental disorders, such as Down, Rett and Fragile X syndromes. Finally, we discuss whether mitochondria can become therapeutic targets to improve brain development and function from a holistic perspective.

The Ameliorative Effect of Pioglitazone against Neuroinflammation Caused by Doxorubicin in Rats

Doxorubicin (DOX) is a chemotherapeutic agent that is linked with complications such as cardiotoxicity and cognitive dysfunction, known as chemobrain. Chemobrain affects up to 75% of cancer survivors, and there are no known therapeutic options for its treatment. This study aimed to determine the protective effect of pioglitazone (PIO) against DOX-induced cognitive impairment. Forty Wistar female rats were equally divided into four groups: control, DOX-treated, PIO-treated, and DOX + PIO-treated. DOX was administered at a dose of 5 mg/kg, i.p., twice a week for two weeks (cumulative dose, 20 mg/kg). PIO was dissolved in drinking water at a concentration of 2 mg/kg in the PIO and DOX-PIO groups. The survival rates, change in body weight, and behavioral assessment were performed using Y-maze, novel object recognition (NOR), and elevated plus maze (EPM), followed by estimation of neuroinflammatory cytokines IL-6, IL-1β, and TNF-α in brain homogenate and RT-PCR of a brain sample. Our results showed a survival rate of 40% and 65% in the DOX and DOX + PIO groups, respectively, compared with a 100% survival rate in the control and PIO treatment groups at the end of day 14. There was an insignificant increase in body weight in the PIO group and a significant reduction in the DOX and DOX + PIO groups as compared with the control groups. DOX-treated animals exhibited impairment of cognitive function, and the combination PIO showed reversal of DOX-induced cognitive impairment. This was evidenced by changes in IL-1β, TNF-α, and IL-6 levels and also by mRNA expression of TNF- α, and IL-6. In conclusion, PIO treatment produced a reversal of DOX-induced memory impairment by alleviating neuronal inflammation by modulating the expression of inflammatory cytokines.

Structural Biology Inspired Development of a Series of Human Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) Ligands: From Agonist to Antagonist

Recent progress in the structural and molecular pharmacological understanding of the nuclear receptor, peroxisome proliferator-activated receptor gamma (hPPARγ)-a transcription factor with pleiotropic effects on biological responses-has enabled the investigation of various graded hPPARγ ligands (full agonist, partial agonist, and antagonist). Such ligands are useful tools to investigate the functions of hPPARγ in detail and are also candidate drugs for the treatment of hPPARγ-mediated diseases, such as metabolic syndrome and cancer. This review summarizes our medicinal chemistry research on the design, synthesis, and pharmacological evaluation of a covalent-binding and non-covalent-binding hPPARγ antagonist, both of which have been created based on our working hypothesis of the helix 12 (H12) holding induction/inhibition concept. X-ray crystallographic analyses of our representative antagonists complexed with an hPPARγ ligand binding domain (LBD) indicated the unique binding modes of hPPARγ LBD, which are quite different from the binding modes observed for hPPARγ agonists and partial agonists.

8-O-acetyl shanzhiside methylester protects against sleep deprivation-induced cognitive deficits and anxiety-like behaviors by regulating NLRP3 and Nrf2 pathways in mice

Sleep deprivation (SD) is prevalent throughout the world, which has negative effects on cognitive abilities, and causing mood alterations. 8-O-acetyl shanzhiside methylester (8-OaS), a chief component in Lamiophlomis rotata (L. rotata) Kudo, possesses potent neuroprotective properties and analgesic effects. Here, we evaluated the alleviative effects of 8-OaS on memory impairment and anxiety in mice subjected to SD (for 72-h). Our results demonstrated that 8-OaS (0.2, 2, 20 mg/kg) administration dose-dependently ameliorated behavioral abnormalities in SD mice, accompanied with restored synaptic plasticity and reduced shrinkage and loss of hippocampal neurons. 8-OaS reduced the inflammatory response and oxidative stress injury in hippocampus caused by SD, which may be related to inhibition of NLRP3 inflammasome-mediated inflammatory process and activation of the Nrf2/HO-1 pathway. SD also led to increases in the expressions of TLR-4/MyD88, active NF-κB, pro-IL-1β, TNFα and MDA, as well as a decrease in the level of SOD in mice hippocampus, which were reversed by 8-OaS administration. Moreover, our molecular docking analyses showed that 8-OaS also has good affinity for NLRP3 and Nrf2 signaling pathways. These results suggested that 8-OaS could be used as a novel herbal medicine for the treatment of sleep loss and for use as a structural base for developing new drugs.

Influence of Guanine-Based Purines on the Oxidoreductive Reactions Involved in Normal or Altered Brain Functions

The production of reactive oxygen species (ROS) in the brain is homeostatically controlled and contributes to normal neural functions. Inefficiency of control mechanisms in brain aging or pathological conditions leads to ROS overproduction with oxidative neural cell damage and degeneration. Among the compounds showing therapeutic potential against neuro-dysfunctions induced by oxidative stress are the guanine-based purines (GBPs), of which the most characterized are the nucleoside guanosine (GUO) and the nucleobase guanine (GUA), which act differently. Indeed, the administration of GUO to in vitro or in vivo models of acute brain injury (ischemia/hypoxia or trauma) or chronic neurological/neurodegenerative disorders, exerts neuroprotective and anti-inflammatory effects, decreasing the production of reactive radicals and improving mitochondrial function via multiple molecular signals. However, GUO administration to rodents also causes an amnesic effect. In contrast, the metabolite, GUA, could be effective in memory-related disorders by transiently increasing ROS production and stimulating the nitric oxide/soluble guanylate cyclase/cGMP/protein kinase G cascade, which has long been recognized as beneficial for cognitive function. Thus, it is worth pursuing further studies to ascertain the therapeutic role of GUO and GUA and to evaluate the pathological brain conditions in which these compounds could be more usefully used.