Main Cations and Cellular Biology of Traumatic Spinal Cord Injury

Regulating Astrocytes via Short Fibers for Spinal Cord Repair

Reactive astrogliosis is the main cause of secondary injury to the central nerves. Biomaterials can effectively suppress astrocyte activation, but the mechanism remains unclear. Herein, Differentially Expressed Genes (DEGs) are identified through whole transcriptome sequencing in a mouse model of spinal cord injury, revealing the VIM gene as a pivotal regulator in the reactive astrocytes. Moreover, DEGs are predominantly concentrated in the extracellular matrix (ECM). Based on these, 3D injectable electrospun short fibers are constructed to inhibit reactive astrogliosis. Histological staining and functional analysis indicated that fibers with unique 3D network spatial structures can effectively constrain the reactive astrocytes. RNA sequencing and single-cell sequencing results reveal that short fibers downregulate the expression of the VIM gene in astrocytes by modulating the "ECM receptor interaction" pathway, inhibiting the transcription of downstream Vimentin protein, and thereby effectively suppressing reactive astrogliosis. Additionally, fibers block the binding of Vimentin protein with inflammation-related proteins, downregulate the NF-κB signaling pathway, inhibit neuron apoptosis, and consequently promote the recovery of spinal cord neural function. Through mechanism elucidation-material design-feedback regulation, this study provides a detailed analysis of the mechanism chain by which short fibers constrain the abnormal spatial expansion of astrocytes and promote spinal cord neural function.

Omega-3 polyunsaturated fatty acids alleviate endoplasmic reticulum stress-induced neuroinflammation by protecting against traumatic spinal cord injury through the histone deacetylase 3/ peroxisome proliferator-activated receptor-γ coactivator pathway

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) attenuate inflammatory responses in the central nervous system, leading to neuroprotective effects. Inhibition of histone deacetylase 3 (HDAC3) has neuroprotective effects after spinal cord injury (SCI) through the SIRT1 pathway, but the pathophysiological mechanisms of SCI are complex and the interactions between ω-3 PUFAs and organelles remain largely unknown. This study aimed to investigate the effect of ω-3 PUFAs on endoplasmic reticulum (ER) stress-induced neuroinflammation through the HDAC3/peroxisome proliferator-activated receptor-γ coactivator (PGC)-1ɑ pathway after SCI. To this end, a contusion-induced SCI rat model was established to evaluate the effects of ω-3 PUFAs on ER stress-mediated inflammation in SCI. ER stress was rapidly induced in spinal cord lesions after SCI and was significantly reduced after ω-3 PUFA treatment. Consistent with reduced ER stress, HDAC3 expression levels and inflammatory responses were decreased, and PGC-1ɑ expression levels were increased after SCI. We found that ω-3 PUFA treatment attenuated ER stress through HDAC3 inhibition, thereby reducing SCI-induced inflammation. Taken together, these results suggest a role for ω-3 PUFA in protecting against SCI-induced neuroinflammation and promoting neurological functional recovery by regulating the histone deacetylase 3/ peroxisome proliferator-activated receptor-γ coactivator pathway.

Luminescence Probes in Bio-Applications: From Principle to Practice

Bioanalysis based on optical imaging has gained significant progress in the last few decades. Luminescence probes are capable of detecting, monitoring, and tracing particular biomolecules in complex biological systems to figure out the roles of these molecules in organisms. Considering the rapid development of luminescence probes for bio-applications and their promising future, we have attempted to explore the working principles and recent advances in bio-applications of luminescence probes, in the hope of helping readers gain a detailed understanding of luminescence probes developed in recent years. In this review, we first focus on the current widely used luminescence probes, including fluorescence probes, bioluminescence probes, chemiluminescence probes, afterglow probes, photoacoustic probes, and Cerenkov luminescence probes. The working principles for each type of luminescence probe are concisely described and the bio-application of the luminescence probes is summarized by category, including metal ions detection, secretion detection, imaging, and therapy.

Hydrogen Sulfide: An Emerging Regulator of Oxidative Stress and Cellular Homeostasis-A Comprehensive One-Year Review

Hydrogen sulfide (H2S), traditionally recognized as a toxic gas, has emerged as a critical regulator in many biological processes, including oxidative stress and cellular homeostasis. This review presents an exhaustive overview of the current understanding of H2S and its multifaceted role in mammalian cellular functioning and oxidative stress management. We delve into the biological sources and function of H2S, mechanisms underlying oxidative stress and cellular homeostasis, and the intricate relationships between these processes. We explore evidence from recent experimental and clinical studies, unraveling the intricate biochemical and molecular mechanisms dictating H2S's roles in modulating oxidative stress responses and maintaining cellular homeostasis. The clinical implications and therapeutic potential of H2S in conditions characterized by oxidative stress dysregulation and disrupted homeostasis are discussed, highlighting the emerging significance of H2S in health and disease. Finally, this review underscores current challenges, controversies, and future directions in the field, emphasizing the need for further research to harness H2S's potential as a therapeutic agent for diseases associated with oxidative stress and homeostatic imbalance. Through this review, we aim to emphasize H2S's pivotal role in cellular function, encouraging further exploration into this burgeoning area of research.

Mesenchymal stem cell-derived extracellular vesicles: emerging concepts in the treatment of spinal cord injury

Spinal cord injury (SCI) is a prevalent central nervous system disease with a high disability rate, leading to the loss of motor and sensory nerve function. Due to the complex pathophysiology of SCI, more effective clinical treatment strategies are needed. Research has indicated the considerable potential of extracellular vesicles (EVs) derived from mesenchymal stem cells (MSC-EVs) as a cell-free therapy in SCI repair and regeneration due to their ability to regulate immune cell activity and stimulate damaged neuron regeneration. Moreover, applying MSCs and engineered EVs can fully exploit the potential of MSC-EVs in spinal cord repair. Here, we outline the pathological process of SCI and its current clinical treatment status, summarize the latest MSC-EVs research and its pretreatment and engineering strategies in SCI treatment, and explore MSC-EVs application prospects.

A dynamic nomogram for predicting the probability of irreversible neurological dysfunction after cervical spinal cord injury: research based on clinical features and MRI data

BACKGROUND

Irreversible neurological dysfunction (IND) is an adverse event after cervical spinal cord injury (CSCI). However, there is still a shortage of objective criteria for the early prediction of neurological function. We aimed to screen independent predictors of IND and use these findings to construct a nomogram that could predict the development of neurological function in CSCI patients.

METHODS

Patients with CSCI attending the Affiliated Hospital of Southwest Medical University between January 2014 and March 2021 were included in this study. We divided the patients into two groups: reversible neurological dysfunction (RND) and IND. The independent predictors of IND in CSCI patients were screened using the regularization technique to construct a nomogram, which was finally converted into an online calculator. Concordance index (C-index), calibration curves analysis and decision curve analysis (DCA) evaluated the model's discrimination, calibration, and clinical applicability. We tested the nomogram in an external validation cohort and performed internal validation using the bootstrap method.

RESULTS

We enrolled 193 individuals with CSCI in this study, including IND (n = 75) and RND (n = 118). Six features, including age, American spinal injury association Impairment Scale (AIS) grade, signal of spinal cord (SC), maximum canal compromise (MCC), intramedullary lesion length (IMLL), and specialized institution-based rehabilitation (SIBR), were included in the model. The C-index of 0.882 from the training set and its externally validated value of 0.827 demonstrated the model's prediction accuracy. Meanwhile, the model has satisfactory actual consistency and clinical applicability, verified in the calibration curve and DCA.

CONCLUSION

We constructed a prediction model based on six clinical and MRI features that can be used to assess the probability of developing IND in patients with CSCI.

Molecular Aspects of Hypoxic Stress Effects in Chronic Ethanol Exposure of Neuronal Cells

Experimental models of a clinical, pathophysiological context are used to understand molecular mechanisms and develop novel therapies. Previous studies revealed better outcomes for spinal cord injury chronic ethanol-consuming patients. This study evaluated cellular and molecular changes in a model mimicking spinal cord injury (hypoxic stress induced by treatment with deferoxamine or cobalt chloride) in chronic ethanol-consuming patients (ethanol-exposed neural cultures (SK-N-SH)) in order to explain the clinical paradigm of better outcomes for spinal cord injury chronic ethanol-consuming patients. The results show that long-term ethanol exposure has a cytotoxic effect, inducing apoptosis. At 24 h after the induction of hypoxic stress (by deferoxamine or cobalt chloride treatments), reduced ROS in long-term ethanol-exposed SK-N-SH cells was observed, which might be due to an adaptation to stressful conditions. In addition, the HIF-1α protein level was increased after hypoxic treatment of long-term ethanol-exposed cells, inducing fluctuations in its target metabolic enzymes proportionally with treatment intensity. The wound healing assay demonstrated that the cells recovered after stress conditions, showing that the ethanol-exposed cells that passed the acute step had the same proliferation profile as the cells unexposed to ethanol. Deferoxamine-treated cells displayed higher proliferative activity than the control cells in the proliferation-migration assay, emphasizing the neuroprotective effect. Cells have overcome the critical point of the alcohol-induced traumatic impact and adapted to ethanol (a chronic phenomenon), sustaining the regeneration process. However, further experiments are needed to ensure recovery efficiency is more effective in chronic ethanol exposure.

The role of immune cells and associated immunological factors in the immune response to spinal cord injury

Spinal cord injury (SCI) is a devastating neurological condition prevalent worldwide. Where the pathological mechanisms underlying SCI are concerned, we can distinguish between primary injury caused by initial mechanical damage and secondary injury characterized by a series of biological responses, such as vascular dysfunction, oxidative stress, neurotransmitter toxicity, lipid peroxidation, and immune-inflammatory response. Secondary injury causes further tissue loss and dysfunction, and the immune response appears to be the key molecular mechanism affecting injured tissue regeneration and functional recovery from SCI. Immune response after SCI involves the activation of different immune cells and the production of immunity-associated chemicals. With the development of new biological technologies, such as transcriptomics, the heterogeneity of immune cells and chemicals can be classified with greater precision. In this review, we focus on the current understanding of the heterogeneity of these immune components and the roles they play in SCI, including reactive astrogliosis and glial scar formation, neutrophil migration, macrophage transformation, resident microglia activation and proliferation, and the humoral immunity mediated by T and B cells. We also summarize findings from clinical trials of immunomodulatory therapies for SCI and briefly review promising therapeutic drugs currently being researched.

Lithium Biological Action Mechanisms after Ischemic Stroke

Lithium is a source of great scientific interest because although it has such a simple structure, relatively easy-to-analyze chemistry, and well-established physical properties, the plethora of effects on biological systems—which influence numerous cellular and molecular processes through not entirely explained mechanisms of action—generate a mystery that modern science is still trying to decipher. Lithium has multiple effects on neurotransmitter-mediated receptor signaling, ion transport, signaling cascades, hormonal regulation, circadian rhythm, and gene expression. The biochemical mechanisms of lithium action appear to be multifactorial and interrelated with the functioning of several enzymes, hormones, vitamins, and growth and transformation factors. The widespread and chaotic marketing of lithium salts in potions and mineral waters, always at inadequate concentrations for various diseases, has contributed to the general disillusionment with empirical medical hypotheses about the therapeutic role of lithium. Lithium salts were first used therapeutically in 1850 to relieve the symptoms of gout, rheumatism, and kidney stones. In 1949, Cade was credited with discovering the sedative effect of lithium salts in the state of manic agitation, but frequent cases of intoxication accompanied the therapy. In the 1960s, lithium was shown to prevent manic and also depressive recurrences. This prophylactic effect was first demonstrated in an open-label study using the “mirror” method and was later (after 1970) confirmed by several placebo-controlled double-blind studies. Lithium prophylaxis was similarly effective in bipolar and also unipolar patients. In 1967, the therapeutic value of lithemia was determined, included in the range of 0.5–1.5 mEq/L. Recently, new therapeutic perspectives on lithium are connected with improved neurological outcomes after ischemic stroke. The effects of lithium on the development and maintenance of neuroprotection can be divided into two categories: short-term effects and long-term effects. Unfortunately, the existing studies do not fully explain the lithium biological action mechanisms after ischemic stroke.