Chloroquine inhibits autophagy and deteriorates the mitochondrial dysfunction and apoptosis in hypoxic rat neurons

Hypoxic-Ischemic Encephalopathy: Pathogenesis and Promising Therapies

Hypoxic-ischemic encephalopathy (HIE) is a brain lesion caused by inadequate blood supply and oxygen deprivation, often occurring in neonates. It has emerged as a grave complication of neonatal asphyxia, leading to chronic neurological damage. Nevertheless, the precise pathophysiological mechanisms underlying HIE are not entirely understood. This paper aims to comprehensively elucidate the contributions of hypoxia-ischemia, reperfusion injury, inflammation, oxidative stress, mitochondrial dysfunction, excitotoxicity, ferroptosis, endoplasmic reticulum stress, and apoptosis to the onset and progression of HIE. Currently, hypothermia therapy stands as the sole standard treatment for neonatal HIE, albeit providing only partial neuroprotection. Drug therapy and stem cell therapy have been explored in the treatment of HIE, exhibiting certain neuroprotective effects. Employing drug therapy or stem cell therapy as adjunctive treatments to hypothermia therapy holds great significance. This article presents a systematic review of the pathogenesis and treatment strategies of HIE, with the goal of enhancing the effect of treatment and improving the quality of life for HIE patients.

The underlying molecular mechanisms of Fyn in neonatal hypoxic-ischaemic encephalopathy

Fyn is a cytoplasmic tyrosine kinase (TK) that is a nonreceptor and a member of the Src family of kinases (SFKs). It is involved in several transduction pathways in the central nervous system (CNS), such as oligodendrocyte development, myelination, axon guidance, and synaptic transmission. Owing to its wide range of activities in the molecular signaling pathways that underpin both neuropathologic and neurodevelopmental events, Fyn has remained of great interest for more than a century. Accumulating preclinical data have highlighted the potential role of Fyn in the pathophysiology of neonatal hypoxic-ischaemic encephalopathy (HIE). By mediating important signaling pathways, Fyn may control glutamate excitotoxicity, promote neuroinflammation and facilitate the death of neurons caused by oxidative stress. In this review, we address new evidence regarding the role of Fyn in the pathogenesis of this condition, with the aim of providing a reference for the development of new strategies to improve the prognosis of neonatal HIE. In addition, we also offer insights into additional Fyn-related molecular mechanisms involved in HIE pathology.

The Hypoxia Response Pathway: A Potential Intervention Target in Parkinson's Disease?

Parkinson's disease (PD) is a progressive neurodegenerative disorder for which only symptomatic treatments are available. Both preclinical and clinical studies suggest that moderate hypoxia induces evolutionarily conserved adaptive mechanisms that enhance neuronal viability and survival. Therefore, targeting the hypoxia response pathway might provide neuroprotection by ameliorating the deleterious effects of mitochondrial dysfunction and oxidative stress, which underlie neurodegeneration in PD. Here, we review experimental studies regarding the link between PD pathophysiology and neurophysiological adaptations to hypoxia. We highlight the mechanistic differences between the rescuing effects of chronic hypoxia in neurodegeneration and short-term moderate hypoxia to improve neuronal resilience, termed "hypoxic conditioning". Moreover, we interpret these preclinical observations regarding the pharmacological targeting of the hypoxia response pathway. Finally, we discuss controversies with respect to the differential effects of hypoxia response pathway activation across the PD spectrum, as well as intervention dosing in hypoxic conditioning and potential harmful effects of such interventions. We recommend that initial clinical studies in PD should focus on the safety, physiological responses, and mechanisms of hypoxic conditioning, as well as on repurposing of existing pharmacological compounds. © 2023 International Parkinson and Movement Disorder Society.

Impact of Suramin on Key Pathological Features of Sporadic Alzheimer's Disease-Derived Forebrain Neurons

Background

Alzheimer's disease (AD) is characterized by disrupted proteostasis and macroautophagy (hereafter "autophagy"). The pharmacological agent suramin has known autophagy modulation properties with potential efficacy in mitigating AD neuronal pathology.

Objective

In the present work, we investigate the impact of forebrain neuron exposure to suramin on the Akt/mTOR signaling pathway, a major regulator of autophagy, in comparison with rapamycin and chloroquine. We further investigate the effect of suramin on several AD-related biomarkers in sporadic AD (sAD)-derived forebrain neurons.

Methods

Neurons differentiated from ReNcell neural progenitors were used to assess the impact of suramin on the Akt/mTOR signaling pathway relative to the autophagy inducer rapamycin and autophagy inhibitor chloroquine. Mature forebrain neurons were differentiated from induced pluripotent stem cells (iPSCs) sourced from a late-onset sAD patient and treated with 100μM suramin for 72 h, followed by assessments for amyloid-β, phosphorylated tau, oxidative/nitrosative stress, and synaptic puncta density.

Results

Suramin treatment of sAD-derived neurons partially ameliorated the increased p-Tau(S199)/Tau ratio, and fully remediated the increased glutathione to oxidized nitric oxide ratio, observed in untreated sAD-derived neurons relative to healthy controls. These positive results may be due in part to the distinct increases in Akt/mTOR pathway mediator p-p70S6K noted with suramin treatment of both ReNcell-derived and iPSC-derived neurons. Longer term neuronal markers, such as synaptic puncta density, were unaffected by suramin treatment.

Conclusions

These findings provide initial evidence supporting the potential of suramin to reduce the degree of dysregulation in sAD-derived forebrain neurons in part via the modulation of autophagy.

Enterovirus D68 capsid formation and stability requires acidic compartments

IMPORTANCE

The respiratory picornavirus enterovirus D68 is a causative agent of acute flaccid myelitis, a childhood paralysis disease identified in the last decade. Poliovirus, another picornavirus associated with paralytic disease, is a fecal-oral virus that survives acidic environments when passing from host to host. Here, we follow up on our previous work showing a requirement for acidic intracellular compartments for maturation cleavage of poliovirus particles. Enterovirus D68 requires acidic vesicles for an earlier step, assembly, and maintenance of viral particles themselves. These data have strong implications for the use of acidification blocking treatments to combat enterovirus diseases.

Transition Metal Complexes as Antimalarial Agents: A Review

In antimalarial drug development research, overcoming drug resistance has been a major challenge for researchers. Nowadays, several drugs like chloroquine, mefloquine, sulfadoxine, and artemisinin are used to treat malaria. But increment in drug resistance has pushed researchers to find novel drugs to tackle drug resistance problems. The idea of using transition metal complexes with pharmacophores as ligands/ligand pendants to show enhanced antimalarial activity with a novel mechanism of action has gained significant attention recently. The advantages of metal complexes include tunable chemical/physical properties, redox activity, avoiding resistance factors, etc. Several recent reports have successfully demonstrated that the metal complexation of known organic antimalarial drugs can overcome drug resistance by showing enhanced activities than the parent drugs. This review has discussed the fruitful research works done in the past few years falling into this criterion. Based on transition metal series (3d, 4d, or 5d), the antimalarial metal complexes have been divided into three broad categories (3d, 4d, or 5d metal-based), and their activities have been compared with the similar control complexes as well as the parent drugs. Furthermore, we have also commented on the potential issues and their possible solution for translating these metal-based antimalarial complexes into the clinic.

Enterovirus D68 capsid formation and stability requires acidic compartments

Enterovirus D68 (EV-D68), a picornavirus traditionally associated with respiratory infections, has recently been linked to a polio-like paralytic condition known as acute flaccid myelitis (AFM). EV-D68 is understudied, and much of the field's understanding of this virus is based on studies of poliovirus. For poliovirus, we previously showed that low pH promotes virus capsid maturation, but here we show that, for EV-D68, inhibition of compartment acidification during a specific window of infection causes a defect in capsid formation and maintenance. These phenotypes are accompanied by radical changes in the infected cell, with viral replication organelles clustering in a tight juxtanuclear grouping. Organelle acidification is critical during a narrow window from 3-4hpi, which we have termed the "transition point," separating translation and peak RNA replication from capsid formation, maturation and egress. Our findings highlight that acidification is crucial only when vesicles convert from RNA factories to virion crucibles.

Mechanisms of Xuefu Zhuyu Decoction in the treatment of coronary heart disease based on integrated metabolomics and network pharmacology approach

Coronary heart disease (CHD) has become the leading cause of mortality, morbidity, and disability worldwide. Though the therapeutic effect of Xuefu Zhuyu Decoction (XFZY) on CHD has been demonstrated in China, the active ingredients and molecular mechanisms of XFZY have not been elucidated. The purpose of the current study is to explore the molecular mechanisms of XFZY in the treatment of CHD via network pharmacology, metabolomics, and experimental validation. First, we established a CHD rat model by permanently ligating the left anterior descending coronary artery (LAD), and evaluated the therapeutic effect of XFZY by hemorheology and histopathology. Second, network pharmacology was employed to screen the active ingredients and potential targets of XFZY for the treatment of CHD. Metabolomic was applied to identify the molecules present in the serum after XFZY treatment. Third, the results of network pharmacology and metabolomics were further analyzed by Cytoscape to elucidate the core ingredients and pathways. Finally, the obtained key pathways were verified by transmission electron microscopy and immunofluorescence assay. The results showed that XFZY was effective in the treatment of CHD in the rat model, and the highest dose exerted the best effect. Network pharmacology analysis revealed 215 active ingredients and 129 key targets associated with XFZY treatment of CHD. These targets were enriched in pathways of cancer, lipid and atherosclerosis, fluid shear stress and atherosclerosis, proteoglycans in cancer, chemical carcinogenesis - receptor activation, HIF-1 signaling, et al. Serum metabolomic identified 1081 metabolites involved in the therapeutic effect of XFZY on CHD. These metabolites were enriched in taurine and hypotaurine metabolism, histidine metabolism, retrograde endocannabinoid signaling pathways, et al. Cytoscape analysis combining the data from serum metabolomic and network pharmacology revealed that energy metabolism as the core pathway for XFZY treatment of CHD. Electron microscope observation identified changes in the level of autophagy in the mitochondrial structure of cardiomyocytes. Immunofluorescence assay showed that the expression levels of autophagy-related proteins LC3-B and P62/SQSTM1 were consistent with the levels of autophagy observed in mitochondria. In conclusion, our findings suggest that the possible mechanisms of XFZY in the treatment of CHD are reducing the level of autophagy, improving energy metabolism, and maintaining mitochondrial homeostasis in cardiomyocytes. Our study also shows that the combined strategies of network pharmacology, metabolomics, and experimental validation may provide a powerful approach for TCM pharmacology study.

Pre-treatment or post-treatment with hydroxychloroquine demonstrates neuroprotective effects in cerebral ischemia/reperfusion

Stroke is a serious life-threatening medical condition and is one of the principal reasons for death and disabilities worldwide. The aim of the present study was to determine the neuroprotective effects of hydroxychloroquine (HCQ) and the timing of its administration in cerebral ischemia/reperfusion (I/R) in rats. A global I/R model was used, and HCQ was administered in either pre- or post-treatment doses of 25 and 50 mg/kg. Effects of HCQ on infarct size, histological changes, oxidative stress, and learning and memory were evaluated. Phospho-AMPK and SQSTM1/p62 protein levels were also measured to elucidate the possible mechanisms involved. HCQ in both pre- (at doses of 25 and 50 mg/kg) or post-treatment (at a dose of 50 mg/kg) protocols reduces brain infarct size and histopathological changes and improves learning and memory after cerebral I/R. Pre-treatment with HCQ reduced AMPK activity with no significant effect on SQSTM1/p62 increment. Post-treatment with HCQ increased AMPK activity and SQSTM1/p62 protein levels. Our results show the neuroprotective effects of HCQ on cerebral I/R through the reduction in infarct size, histopathological changes, and improvement in memory and learning functions. Moreover, AMPK and autophagy may play a role in this protective effect.

Neuroprotective Mechanism of Icariin on Hypoxic Ischemic Brain Damage in Neonatal Mice

Objective

Our previous results showed that icariin (ICA) could inhibit apoptosis and provide neuroprotection against hypoxic-ischemic brain damage (HIBD) in neonatal mice, but the specific mechanism of its neuroprotective effect remains unknown. This study aims at exploring whether ICA plays a neuroprotective role in apoptosis inhibition by regulating autophagy through the estrogen receptor α (ERα)/estrogen receptor β (ERβ) pathway in neonatal mice with HIBD.

Methods

A neonatal mouse model of HIBD was constructed in vivo, and an oxygen and glucose deprivation (OGD) model in HT22 cells from the hippocampal neuronal system was constructed in vitro. The effects of ICA pretreatment on autophagy and the expression of ERα and ERβ were detected in vitro and in vivo, respectively. ICA pretreatment was also supplemented with the autophagy inhibitor 3-methyladenine (3-MA), ERα inhibitor methylpiperidino pyrazole (MPP), and ERβ inhibitor 4-(2-phenyl-5,7-bis (trifluoromethyl) pyrazolo [1,5-a] pyramidin-3-yl) phenol (PHTPP) to further detect whether ICA pretreatment can activate the ERα/ERβ pathway to promote autophagy and reduce HIBD-induced apoptosis to play a neuroprotective role against HIBD in neonatal mice.

Results

ICA pretreatment significantly promoted autophagy in HIBD mice. Treatment with 3-MA significantly inhibited the increase in autophagy induced by ICA pretreatment, reversed the neuroprotective effect of ICA pretreatment, and promoted apoptosis. Moreover, ICA pretreatment significantly increased the expression levels of the ERα and ERβ proteins in HIBD newborn mice. Both MPP and PHTPP administration significantly inhibited the expression levels of the ERα and ERβ proteins activated by ICA pretreatment, reversed the neuroprotective effects of ICA pretreatment, inhibited the increase in autophagy induced by ICA pretreatment, and promoted apoptosis.

Conclusion

ICA pretreatment may promote autophagy by activating the ERα and ERβ pathways, thus reducing the apoptosis induced by HIBD and exerting a neuroprotective effect on neonatal mice with HIBD.

Astragaloside trigger autophagy: Implication a potential therapeutic strategy for pulmonary fibrosis

Pulmonary fibrosis is an abnormal wound-healing response to repeated alveolar injury, characterized by continuous inflammation and abnormal collagen deposition. Its treatment is problematic. Astragaloside (AST) is an active component of Astragalus membranaceus with anti-inflammatory and anti-tumor properties. Although the underlying mechanisms are unknown, AST is also used to treat fibrotic diseases. This study aimed to investigate the mechanisms of action of AST in pulmonary fibrosis treatment. We found that AST significantly improved restrictive ventilatory impairment, compliance, total lung capacity, and functional residual capacity. In mice with pulmonary fibrosis, extracellular matrix deposition in the pulmonary parenchyma and intemperate inflammation were reversed. This therapeutic effect can be attributed to autophagy, activating the genes for autophagy flux and autophagic vacuoles. Impaired autophagy increased susceptibility to pulmonary fibrosis by exacerbating collagen deposition in vitro and in vivo. Using a combination of molecular docking and network pharmacology, the Ras/Raf/MEK/ERK signaling pathway was identified as a possible candidate for the pharmacologic target of AST. Functional dephosphorylation of MEK and ERK inhibited the Ras/Raf/MEK/ERK signaling pathway, which converges at the rapamycin switch to initiate autophagy. Inhibitors of Ras and MEK regulated autophagy. These findings suggest that AST might treat pulmonary fibrosis by modulating the Ras/Raf/MEK/ERK signaling pathway mediated by depression.

Enhanced autophagy interacting proteins negatively correlated with the activation of apoptosis-related caspase family proteins after focal ischemic stroke of young rats

Background

Neuronal injury induced in young rats by cerebral ischemia reperfusion (CIR) is known to differ substantially from that in adult rats. In the present study, we investigated the specific differences in neuronal injury induced by focal CIR between young and adult rats.

Results

2, 3, 5-triphenyl tetrazolium chloride (TTC) staining revealed a gradual increase in the infarct volume of both young and adult rats in accordance with I/R times and was significantly lower in young rats than in adult rats under the same conditions. The number of cells in the cortex showing immunoreactivity for neuronal nuclei (NeuN) gradually decreased in both young and adult rats in accordance with I/R times; these numbers were significantly higher in young rats than in adult rats under the same conditions. Similarly, as the duration of I/R increased, the degree of glial activation in the cortex penumbra region became more severe in both young and adult groups; however, glial activation was significantly lower in the cortex penumbra region of young rats when compared with that in adult rats. In addition, the expression of Beclin-1 was significantly higher in the infarct penumbra of young rats than adult rats and was more frequently co-expressed with neurons. The levels of autophagy-related proteins increased significantly in the penumbra region after I/R in both young and adult groups, this increase was more pronounced in young rats than in adult rats. Following CIR, analysis revealed significantly lower levels of pro-apoptosis-related factors and significantly higher levels of anti-apoptosis-related proteins in the young rats than in adult rats.

Conclusions

Collectively, the present results suggest that the the reduced levels of neuronal death after CIR in young rats were closely related to enhanced levels of autophagy and reduced levels of pro-apoptosis in neurons.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12868-022-00740-w.

Apoptosis, rather than neurogenesis, induces significant hippocampal-dependent learning and memory impairment in chronic low Cd2+ exposure

Cadmium (Cd), a ubiquitous toxic heavy metal, with the intractable trait of low degradation, can induce multiple organ damage. Whereas, far less is known about its neurotoxicity and the specific mechanism in the chronic low Cd exposure. To investigate the chronic neurotoxicity of Cd²⁺ , we traced its effects for up to 30 months in mice which were exposed to Cd²⁺ by drinking the mimicking Cd-polluted water. We found the toxicity of chronic Cd exposure was a process associated with the transition from autophagy to apoptosis, and the switch of autophagy-apoptosis was Cd dose-dependent with the threshold of [Cd²⁺ ] 0.04 mg/L. Furthermore, JNK was found to be a hub molecule orchestrated the switch of autophagy-apoptosis by interacting with Sirt1 and p53. At last, the hippocampus-dependent learning and memory was damaged by continuous neuron apoptosis rather than deficit of neurogenesis. Therefore, elucidation of the effect, process, and potential molecular mechanism of the chronic low Cd²⁺ exposure is important for controlling of the environmental-pollutant Cd.

Heat shock transcription factor HSF2 modulates the autophagy response through the BTG2-SOD2 axis

The heat shock transcription factor HSF1 regulates the inducible Hsp gene transcription, whereas HSF2 is involved in the constitutive transcription. HSFs can work for the non-heat shock genes transcription in a case-specific manner to facilitate normal cellular functions. Here, we demonstrate that HSF2 acts as an upstream regulator of heat shock-induced autophagy response in a rat histiocytoma. The heat-induced HSF2 transactivates the B-cell translocation gene-2 (BTG2) transcription, and the latter acts as a transcriptional coactivator for superoxide dismutase (SOD2). The altered HSF2 promoter occupancy on the BTG2 promoter enhances BTG2 transcription. Since SOD2 regulation is linked to mitochondrial redox sensing, HSF2 appears to act as a redox sensor in deciding the cell fate. The HSF2 shRNA or NFE2L2/BTG2 siRNA treatments have interfered with the autophagy response. We demonstrate that HSF2 is an upstream activator of autophagy response, and the HSF2-BTG2-SOD2 axis acts as a switch between the non-selective (micro/macro) and selective (chaperone-mediated) autophagy.

CircCAMSAP1 promotes non-small cell lung cancer proliferation and inhibits cell apoptosis by sponging miR-1182 and regulating BIRC5

Recently, various studies have suggested that circular RNAs (circRNAs) are ubiquitous in various malignant events, including non-small cell lung cancer (NSCLC) and are closely related to cell proliferation and apoptosis. Unfortunately, the molecular functions involved in this action still have little overlap. Therefore, this study aimed to identify a novel circCAMSAP1 role in NSCLC. Overexpression of circCAMSAP1 has been demonstrated in NSCLC lung tissues and cell lines. Sequencing and RNase R experiments were planned to determine whether circCAMSAP1 is looped and exists in NSCLC. We also found that downregulated circCAMSAP1 repressed cell proliferation and increased apoptosis of NSCLC cells in vitro and suppressed xenograft tumor growth in vivo. Furthermore, a luciferase assay revealed that circCAMSAP1 could regulate baculoviral inhibitor of apoptosis protein (IAP) repeat containing 5 (BIRC5, also known as survivin) expression by directly binding to miR-1182. However, BIRC5 without 3ʹ untranslated regions (3ʹUTR) could reverse the influence of downregulated circCAMSAP1 on proliferation and apoptosis in NSCLC. Together, our findings reveal a novel mechanism by which the circCAMSAP1/miR-1182/BIRC5 axis promotes NSCLC progression.

Defective transcription elongation in human cancers imposes targetable proteotoxic vulnerability

Successful cancer therapy is contingent on identifying cancer-specific aberrant phenotypes and their associated vulnerabilities. We recently reported that a subset of almost every cancer type contains a genome-wide defect in RNA Polymerase II-mediated transcription elongation (TE^def), which impairs the expression of long genes and confers resistance to anti-tumor immune attack. Using a combination of computational analysis and laboratory experiments, we report that tumor cells with TE^def have widespread overexpression of the components of the protein homeostasis machinery (mostly composed of short genes), including protein folding and clearance. Accordingly, TE^def cells were characterized by abnormally high levels of insoluble protein aggregates in the cytoplasm and autophagy influx. We present evidence that TE^def cells exhibit impaired clearance of misfolded protein aggregates through the ubiquitin-proteasome system, and thus rely on autophagy for their degradation. As such, while these cells were highly resistant to proteasome inhibitors, they were acutely sensitive to inhibitors of autophagy in vitro and in vivo. This study reveals a major aberrant phenotype that is observed in ∼15-25% of all cancers and characterizes a unique cellular vulnerability that can be readily exploited in the clinic to improve treatment efficacy.

Hypoxia Signaling in Parkinson's Disease: There Is Use in Asking "What HIF?"

Hypoxia is a condition characterized by insufficient tissue oxygenation, which results in impaired oxidative energy production. A reduction in cellular oxygen levels induces the stabilization of hypoxia inducible factor α (HIF-1α), master regulator of the molecular response to hypoxia, involved in maintaining cellular homeostasis and driving hypoxic adaptation through the control of gene expression. Due to its high energy requirement, the brain is particularly vulnerable to oxygen shortage. Thus, hypoxic injury can cause significant metabolic changes in neural cell populations, which are associated with neurodegeneration. Recent evidence suggests that regulating HIF-1α may ameliorate the cellular damage in neurodegenerative diseases. Indeed, the hypoxia/HIF-1α signaling pathway has been associated to several processes linked to Parkinson's disease (PD) including gene mutations, risk factors and molecular pathways such as mitochondrial dysfunction, oxidative stress and protein degradation impairment. This review will explore the impact of hypoxia and HIF-1α signaling on these specific molecular pathways that influence PD development and will evaluate different novel neuroprotective strategies involving HIF-1α stabilization.

Behavioral disorders caused by nonylphenol and strategies for protection

Nonylphenol (NP) is widely used in daily production and life due to its good emulsification. In this review, we discuss toxicology studies that examined behavioral disorders caused by NP, the corresponding toxicological mechanisms in the central nervous system (CNS), and strategies for protection. Available in vitro and in vivo evidence suggests that exposure to NP during adulthood or early childhood is associated with cognitive dysfunction, including depression-like behaviors, anxiety-like behaviors, and impaired learning and memory. The main mechanisms underlying NP-related cognitive disorders include inflammation, destruction of synaptic plasticity, and destruction of important signaling pathways that affect the synthesis and secretion of neurotransmitters. The effects and mechanisms of NP exposure on CNS-mediated reproductive function, including interference with the expression of hormones, proteins, and enzymes, are discussed. Other abnormal behaviors such as locomotor activity and swimming behavior are also described. Several measures to prevent NP neurotoxicity are summarized. These measures are based on the toxicological mechanisms underlying NP exposure and include external protection and internal self-regulation of the nervous system. Finally, a new treatment idea is proposed based on the gut-brain axis. Characterizing the behavioral changes and underlying toxicity mechanisms associated with NP exposure and investigating the possible methods of treatment will help to expand the understanding of these mechanisms and could lead to more effective treatments.

AT1R/GSK-3β/mTOR Signaling Pathway Involved in Angiotensin II-Induced Neuronal Apoptosis after HIE Both In Vitro and In Vivo

Objective

The focus of the present study is to evaluate the effects of Angiotensin II (Ang II) on neuronal apoptosis after HIE and the potential underlying mechanisms.

Methods

Primary neonatal rat cortical neurons were used to study the oxygen-glucose deprivation (OGD) cell model. The expressions of Ang II, AT1R, GSK-3β, p-GSK-3β, mTOR, p-mTOR, Bax, Bcl-2, and cleaved caspase-3 were detected via western blot. IF and flow cytometry were used to evaluate neuronal apoptosis. Hypoxic-ischemic encephalopathy (HIE) was established to evaluate the therapeutic effects of Ang II in vivo. Cerebral infarction areas were detected by 2,3,5-Triphenyltetrazolium chloride staining. The righting and geotaxis reflexes were also recorded. In addition, Fluoro-Jade C staining and TUNEL staining were performed to evaluate neuronal degeneration and apoptosis.

Results

Ang II significantly increased the rate of neuronal apoptosis, upregulated the expression of cleaved caspase-3, and downregulated Bcl-2/Bax ratio after OGD insult. For vivo assay, the expressions of endogenous Ang II and AT1R gradually increased and peaked at 24 h after HIE. Ang II increased NeuN-positive AT1R cell expression. In addition, Ang II increased the area of cerebral infarction, promoted neuronal degeneration and apoptosis, aggravated neurological deficits on righting and geotaxis reflexes, and was accompanied by increased expressions of phosphorylated GSK-3β and mTOR. The application of valsartan (Ang II inhibitor) or SB216763 (GSK-3β inhibitor) reversed these phenomena triggered by Ang II following HIE.

Conclusion

Ang II increased neuronal apoptosis through the AT1R/GSK-3β/mTOR signaling pathway after experimental HIE both in vitro and in vivo, and Ang II may serve as a novel therapeutic target to ameliorate brain injury after HIE.

Chloroquine Downregulation of Intestinal Autophagy to Alleviate Biological Stress in Early-Weaned Piglets

Simple Summary

Weaning is one of the biggest challenges in a pig’s life. Autophagy is a catabolic process aimed at recycling cellular components and damaged organelles in response to diverse stress conditions. There are two autophagy-modifying agents, rapamycin (RAPA) and chloroquine (CQ), that are often used in vitro and in vivo to regulate this process. We speculated that the regulation of autophagy may have some effect on weaning pressure. In this study, we try to understand the role of autophagy in intestinal barrier function and inflammation during the first week after weaning. We examined the effects of modulation of autophagy via RAPA and CQ on growth performance, immunity, inflammation profile, and the intestinal barrier to find potential value for CQ as a feed additive agent for ameliorating weaning stress.

Abstract

Early weaning stress impairs the development of gastrointestinal barrier function, causing immune system dysfunctions, reduction in feed intake, and growth retardation. Autophagy was hypothesized to be a key underlying cellular process in these dysfunctions. We conjectured that rapamycin (RAPA) and chloroquine (CQ), as two autophagy-modifying agents, regulate the autophagy process and may produce deleterious or beneficial effects on intestinal health and growth. To explore the effect of autophagy on early weaning stress in piglets, 18 early-weaned piglets were assigned to three treatments (each treatment of six piglets) and treated with an equal volume of RAPA, CQ, or saline. The degree of autophagy and serum concentrations of immunoglobulins and cytokines, as well as intestinal morphology and tight junction protein expression, were evaluated. Compared with the control treatment, RAPA-treated piglets exhibited activated autophagy and had decreased final body weight (BW) and average daily gain (ADG) (p < 0.05), impaired intestinal morphology and tight junction function, and higher inflammatory responses. The CQ-treated piglets showed higher final BW, ADG, jejuna and ileal villus height, and lower autophagy and inflammation, compared with control piglets (p < 0.05). Throughout the experiment, CQ treatment was beneficial to alleviate early weaning stress and intestinal and immune system dysfunction.

Is a combination of progesterone and chloroquine more effective than either alone in the treatment of cerebral ischemic injury?

BACKGROUND

In this proof-of-concept paper, we investigated whether combination treatment with progesterone (P4) and chloroquine (CQ) would reduce ischemic injury more effectively than either agent alone in a transient middle cerebral artery occlusion (tMCAO) model in male rats.

METHODS

P4 (8 mg/kg) and CQ (25 mg/kg) were given alone or in combination beginning at different times during surgery and for 3 days post-occlusion. Locomotor activity and grip strength were evaluated as measures of impairment and recovery. Infarct size was assessed by TTC staining. Markers of autophagy (LC3 and SQSTM1/p62) and apoptosis (Bcl-2 and Bax) were evaluated with western blotting.

RESULTS

At the doses we employed, the combination was not more effective than either drug given separately on measures of grip strength or locomotor activity. However, combination therapy substantially reduced infarct size, and significantly increased Bcl-2 protein levels and suppressed Bax expression. Progesterone decreased the expression of LC3-II 24 h and SQSTM1/p62 after ischemia.

CONCLUSIONS

Our findings suggest that combination therapy with P4 and CQ is not detrimental and has a small-to-moderate additive neuroprotective effect on ischemic injury in rats without substantively affecting behavioral outcomes. CQ and P4 may help to regulate the expression of both autophagy-related and apoptosis-related proteins.