A systemic cell stress signal confers neuronal resilience toward oxidative stress in a Hedgehog-dependent manner

Implications of liquid-liquid phase separation and ferroptosis in Alzheimer's disease

Neuronal cell demise represents a prevalent occurrence throughout the advancement of Alzheimer's disease (AD). However, the mechanism of triggering the death of neuronal cells remains unclear. Its potential mechanisms include aggregation of soluble amyloid-beta (Aβ) to form insoluble amyloid plaques, abnormal phosphorylation of tau protein and formation of intracellular neurofibrillary tangles (NFTs), neuroinflammation, ferroptosis, oxidative stress, liquid-liquid phase separation (LLPS) and metal ion disorders. Among them, ferroptosis is an iron-dependent lipid peroxidation-driven cell death and emerging evidences have demonstrated the involvement of ferroptosis in the pathological process of AD. The sensitivity to ferroptosis is tightly linked to numerous biological processes. Moreover, emerging evidences indicate that LLPS has great impacts on regulating human health and diseases, especially AD. Soluble Aβ can undergo LLPS to form liquid-like droplets, which can lead to the formation of insoluble amyloid plaques. Meanwhile, tau has a high propensity to condensate via the mechanism of LLPS, which can lead to the formation of NFTs. In this review, we summarize the most recent advancements pertaining to LLPS and ferroptosis in AD. Our primary focus is on expounding the influence of Aβ, tau protein, iron ions, and lipid oxidation on the intricate mechanisms underlying ferroptosis and LLPS within the domain of AD pathology. Additionally, we delve into the intricate cross-interactions that occur between LLPS and ferroptosis in the context of AD. Our findings are expected to serve as a theoretical and experimental foundation for clinical research and targeted therapy for AD.

Enteric neuroprotection-A matter of balancing redox potentials, limiting inflammation, and boosting resilience

The enteric nervous system (ENS) orchestrates intricate and autonomous functions throughout the gastrointestinal (GI) tract. Disruptions in ENS function are associated GI disorders. This mini review focuses on the past decade's research, utilizing rodent models, with an emphasis on protecting enteric neurons from loss. The review specifically looks at efforts to reduce oxidative stress, limit inflammation, and enhance neuronal resilience. Protective interventions including administration of antioxidants and compounds targeting cellular redox buffer systems, are evaluated for their effectiveness in preventing loss of enteric neurons in the ischemia-reperfusion model and streptozotocin-induced diabetes model. Interventions such as engrafting mesenchymal stem cells and targeting inflammatory signaling pathways in enteric neurons and glial cells are evaluated in inflammatory bowel disease models including the Winnie mouse, DSS-, and DNBS/TNBS-induced colitis models. The review also touches upon neuronal resilience, particularly in the context of Parkinson's disease models. Including estrogen's neuroprotective role, and the influence of metal ions on enteric neuronal protection. Understanding the dynamic interplay within the ENS and its role in disease pathogenesis holds promise for developing targeted therapies to effectively manage and treat various GI ailments.

Oxidised rice bran oil induced oxidative stress and apoptosis in IPEC-J2 cells via the Nrf2 signalling pathway

Rice bran oil is a type of rice oil made by leaching or pressing during rice processing and has a high absorption rate after consumption. When oxidative rancidity occurs, it may cause oxidative stress (OS) and affect intestinal function. Meanwhile, the toxic effects of oxidised rice bran oil have been less well studied in pigs. Therefore, the IPEC-J2 cells model was chosen to explore the regulatory mechanisms of oxidised rice bran oil on OS and apoptosis. Oxidised rice bran oil extract treatment (OR) significantly decreased the viability of IPEC-J2 cells. The results showed that OR significantly elevated apoptosis and reactive oxygen species levels and promoted the expression of pro-apoptotic gene Caspase-3 messenger RNA levels. The activation of Nrf2 signalling pathway by OR decreased the cellular antioxidant capacity. This was further evidenced by the expression of kelch-like ECH-associated protein 1, heme oxygenase 1, NADH: quinone oxidoreductase 1, superoxide dismutase 2 and heat shock 70 kDa protein genes and proteins were all downregulated. In conclusion, our results suggested that oxidised rice bran oil induced damage in IPEC-J2 cells through the Nrf2 signalling pathway.

Biological resilience in health and disease

All living organisms - from single-celled prokaryotes through to invertebrates and humans - are frequently exposed to numerous challenges during their lifetime, which could damage their molecular and cellular contents and threaten their survival. Nevertheless, these diverse organisms are, on the whole, remarkably resilient to potential threats. Recent years have seen rapid advances in our mechanistic understanding of this emerging phenomenon of biological resilience, which enables cells, tissues and whole organisms to bounce back from challenges or stress. In this At a Glance article, I discuss current knowledge on the diverse molecular mechanisms driving biological resilience across scales, with particular focus on its dynamic and adaptive nature. I highlight emerging evidence that loss of biological resilience could underly numerous pathologies, including age-related frailty and degenerative disease. Finally, I present the multi-disciplinary experimental approaches that are helping to unravel the causal mechanisms of resilience and how this emerging knowledge could be harnessed therapeutically in the clinic.

Plasma membrane calcium ATPase powered by glycolysis is the main mechanism for calcium clearance in the hippocampal pyramidal neuron

AIMS

This study sought to elucidate the primary ATP-dependent mechanisms involved in clearing cytosolic Ca2+ in neurons and determine the predominant ATP-generating pathway-glycolysis or tricarboxylic acid cycle/oxidative phosphorylation (TCA/OxPhos)-associated with these mechanisms in hippocampal pyramidal neurons.

MAIN METHODS

Our investigation involved evaluating basal Ca2+ levels and analyzing the kinetic characteristics of evoked neuronal Ca2+ transients after selectively combined the inhibition/blockade of key ATP-dependent mechanisms with the suppression of either TCA/OxPhos or glycolytic ATP sources.

KEY FINDINGS

Our findings unveiled that the plasma membrane Ca2+ ATPase (PMCA) serves as the principal ATP-dependent mechanism for clearance cytosolic Ca2+ in hippocampal pyramidal neurons, both during rest and neuronal activity. Remarkably, during cellular activity, PMCA relies on ATP derived from glycolysis, challenging the traditional notion of neuronal reliance on TCA/OxPhos for ATP. Other mechanisms for Ca2+ clearance in pyramidal neurons, such as SERCA and NCX, appear to be dependent on TCA/OxPhos. Interestingly, at rest, the ATP required to fuel PMCA and SERCA, the two main mechanisms to keep resting Ca2+, seems to originate from a source other than glycolysis or the TCA/OxPhos.

SIGNIFICANCE

These findings underscore the vital role of glycolysis in bolstering PMCA neuronal function to uphold Ca2+ homeostasis. Moreover, they elucidate the varying dependencies of cytoplasmic Ca2+ clearance mechanisms on distinct energy sources for their operation.

Protocol for establishing a global ischemia model using a 4-vessel occlusion in rats

Global cerebral ischemia occurs when blood flow to the entire brain is transiently blocked, which results in delayed neurologic deficits. Here, we present a protocol for performing the four-vessel occlusion rat model to study the neurodegeneration and cognitive deficits associated with global ischemia. We describe steps for carrying out the vertebral and common carotid artery occlusion which enables sufficient blockage of cerebral blood flow. We then detail expected outcomes using histology assays and behavioral tests. For complete details on the use and execution of this protocol, please refer to Chung et al. (2022).1.

Regulatory mechanisms of the cAMP-responsive element binding protein 3 (CREB3) family in cancers

The CREB3 family of proteins, encompassing CREB3 and its four homologs (CREB3L1, CREB3L2, CREB3L3, and CREB3L4), exerts pivotal control over cellular protein metabolism in response to unfolded protein reactions. Under conditions of endoplasmic reticulum stress, activation of the CREB3 family occurs through regulated intramembrane proteolysis within the endoplasmic reticulum membrane. Perturbations in the function and expression of the CREB3 family have been closely associated with the development of diverse diseases, with a particular emphasis on cancer. Recent investigations have shed light on the indispensable role played by CREB3 family members in modulating the onset and progression of various human cancers. This comprehensive review endeavors to provide an in-depth examination of the involvement of CREB3 family members in distinct human cancer types, accentuating their significance in the pathogenesis of cancer and the manifestation of malignant phenotypes.