Roles and Molecular Mechanisms of Physical Exercise in Sepsis Treatment

Special Issue "Molecular Insights into the Role of Exercise in Disease and Health"

Regular physical activity is a fundamental determinant of overall health and a key factor in mitigating the risk of numerous pathological conditions [...].

Protective effect of exercise on animals with sepsis: a systematic review of the existing literature

BACKGROUND

Sepsis often led to multiple organ dysfunction (MODS) and even death. Although a variety of medicine were used to treat sepsis in clinic, there was still no specific and effective clinical medicine treatment. Exercise had been shown to work on MODS. However, in preclinical studies, there was no systematic evidence to summarize the effects of exercise training on sepsis.

OBJECTIVES

To investigate the effects of exercise training on sepsis in preclinical studies and explore possible mechanisms to provide reliable preclinical evidence for the use of exercise training in sepsis.

METHOD

Preclinical studies were retrieved from electronic databases (Pubmed, Embase, Cochrane Library, Scopus, Medline, Web of science) as of June 25, 2024. Our review included in vivo English studies evaluating the radioprotective effects of exercise training on sepsis. The quality of each study was assessed using the Center for Systematic Evaluation of Experimental Animal Studies (SYCLE) Animal Research Bias Risk Tool. All results were described comprehensively.

RESULTS

17 in vivo studies were included. Our comprehensive descriptive analysis showed that exercise could improve the general condition, lung injury, liver injury, kidney injury, heart and aortic injury, spleen and thymus injury, and other injuries in animals with sepsis. And its possible mechanisms were involved improving the general condition of sepsis animals, pathological and cell number of organs, anti-inflammation, anti-oxidative stress, anti-DNA damage, and so on.

CONCLUSION

Exercise training could protect sepsis by anti-inflammatory, anti-oxidative stress, increased antibacterial ability, reduced cell death, improved metabolism, vital signs and MODS.

Mechanisms of Sepsis-Induced Acute Lung Injury and Advancements of Natural Small Molecules in Its Treatment

Sepsis-induced acute lung injury (ALI), characterized by widespread lung dysfunction, is associated with significant morbidity and mortality due to the lack of effective pharmacological treatments available clinically. Small-molecule compounds derived from natural products represent an innovative source and have demonstrated therapeutic potential against sepsis-induced ALI. These natural small molecules may provide a promising alternative treatment option for sepsis-induced ALI. This review aims to summarize the pathogenesis of sepsis and potential therapeutic targets. It assembles critical updates (from 2014 to 2024) on natural small molecules with therapeutic potential against sepsis-induced ALI, detailing their sources, structures, effects, and mechanisms of action.

Vascular Responses to Acute Induced Inflammation With Aging: Does Fitness Matter?

Acute inflammation impairs vascular function in an age-dependent manner and affects cardiovascular event risk. Regular aerobic exercise preserves vascular function with aging and potentially modifies how acute inflammation affects the vasculature. We hypothesize high cardiorespiratory fitness may accompany greater arterial responsiveness post-acute inflammation in older adults.

Coptisine attenuates sepsis lung injury by suppressing LPS-induced lung epithelial cell inflammation and apoptosis

OBJECTIVE

This study aimed to investigate the functioning and mechanism of coptisine in acute lung injury (ALI).

METHODS

Murine Lung Epithelial 12 (MLE-12) cells were stimulated with lipopolysaccharide (LPS) to construct an in vitro pulmonary injury model to study the functioning of coptisine in sepsis-induced ALI. The viability of MLE-12 cells was assessed by the cell counting kit-8 assay. The cytokine release of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and IL-1β was measured by enzyme-linked-immunosorbent serologic assay. The relative expression levels of TNF-α, IL-6, and IL-1β mRNA were examined by reverse transcription-quantitative polymerase chain reaction. The cell apoptosis of MLE-12 cells was determined by Annexin V/propidium iodide staining and analyzed by flow cytometry. The expressions of apoptosis-related proteins Bax and cleaved Caspase-3 were observed by Western blot analysis. The activation of nuclear factor kappa B (NF-κB) signaling pathway was discovered by the determination of phospho-p65, p65, phospho-nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha (IκBα), and IκBα through Western blot analysis.

RESULTS

Coptisine treatment could significantly restore decrease in MLE-12 cell viability caused by LPS stimulation. The release of TNF-α, IL-6, and IL-1β was significantly inhibited by coptisine treatment. Coptisine treatment inhibited MLE-12 cell apoptosis induced by LPS, and also inhibited the expression levels of Bax and cleaved Caspase-3. Coptisine treatment along with LPS stimulation, significantly reduced the protein level of phospho-IκBα, increased the level of IκBα, and reduced phospho-p65-p65 ratio.

CONCLUSION

These results indicated that coptisine attenuated sepsis lung injury by suppressing lung epithelial cell inflammation and apoptosis through NF-κB pathway. Therefore, coptisine may have potential to treat sepsis-induced ALI.

Physical exercise as a friend not a foe in acute kidney diseases through immune system modulation

Regular and moderate exercise is being used for therapeutic purposes in treating several diseases, including cancer, cardiovascular diseases, arthritis, and even chronic kidney diseases (CKDs). Conversely, extenuating physical exercise has long been pointed out as one of the sources of acute kidney injury (AKI) due to its severe impact on the body's physiology. AKI development is associated with increased tubular necrosis, which initiates a cascade of inflammatory responses. The latter involves cytokine production, immune cell (macrophages, lymphocytes, and neutrophils, among others) activation, and increased oxidative stress. AKI can induce prolonged fibrosis stimulation, leading to CKD development. The need for therapeutic alternative treatments for AKI is still a relevant issue. In this context arises the question as to whether moderate, not extenuating, exercise could, on some level, prevent AKI. Several studies have shown that moderate exercise can help reduce tissue damage and increase the functional recovery of the kidneys after an acute injury. In particular, the immune system can be modulated by exercise, leading to a better recovery from different pathologies. In this review, we aimed to explore the role of exercise not as a trigger of AKI, but as a modulator of the inflammatory/immune system in the prevention or recovery from AKI in different scenarios. In AKI induced by ischemia and reperfusion, sepsis, diabetes, antibiotics, or chemotherapy, regular and/or moderate exercise could modulate the immune system toward a more regulatory immune response, presenting, in general, an anti-inflammatory profile. Exercise was shown to diminish oxidative stress, inflammatory markers (caspase-3, lactate dehydrogenase, and nitric oxide), inflammatory cytokines (interleukin (IL)-1b, IL-6, IL-8, and tumor necrosis factor-α (TNF-α)), modulate lymphocytes to an immune suppressive phenotype, and decrease tumor necrosis factor-β (TGF-β), a cytokine associated with fibrosis development. Thus, it creates an AKI recovery environment with less tissue damage, hypoxia, apoptosis, or fibrosis. In conclusion, the practice of regular moderate physical exercise has an impact on the immune system, favoring a regulatory and anti-inflammatory profile that prevents the occurrence of AKI and/or assists in the recovery from AKI. Moderate exercise should be considered for patients with AKI as a complementary therapy.

Role of Serum Inflammatory Cytokines in Sepsis Rats Following BMSCs Transplantation: Protein Microarray Analysis

Bone marrow stromal cells (BMSCs) have emerged as a potential therapy for sepsis, yet the underlying mechanisms remain unclear. In this study, we investigated the effects of BMSCs on serum inflammatory cytokines in a rat model of lipopolysaccharide (LPS)-induced sepsis. Sepsis was induced by intravenous injection of LPS, followed by transplantation of BMSCs. We monitored survival rates for 72 h and evaluated organ functions, histopathological changes, and cytokines expression. Sepsis rats showed decreased levels of white blood cells, platelets, lymphocyte ratio, and oxygen partial pressure, along with increased levels of neutrophil ratio, carbon dioxide partial pressure, lactic acid, alanine aminotransferase, and aspartate aminotransferase. Histologically, lung, intestine, and liver tissues exhibited congestion, edema, and infiltration of inflammatory cells. However, after BMSCs treatment, there was improvement in organ functions, histopathological injuries, and survival rates. Protein microarray analysis revealed significant changes in the expression of 12 out of 34 inflammatory cytokines. These findings were confirmed by enzyme-linked immunosorbent assay. Pro-inflammatory factors, such as interleukin-1β (IL-1β), IL-1α, tumor necrosis factor-α (TNF-α), tissue inhibitor of metal protease 1 (TIMP-1), matrix metalloproteinase 8 (MMP-8), Leptin, and L-selectin were upregulated in sepsis, whereas anti-inflammatory and growth factors, including IL-4, β-nerve growth factor (β-NGF), ciliary neurotrophic factor (CNTF), interferon γ (IFN-γ), and Activin A were downregulated. BMSCs transplantation led to a decrease in pro-inflammatory cytokines and an increase in anti-inflammatory and growth factors. We summarized relevant molecular signaling pathways that resulted from cytokines in BMSCs for treating sepsis. Our results illustrated that BMSCs could promote tissue repair and improve organ functions and survival rates in sepsis through modulating cytokine networks.

Non-Invasive Pulsatile Shear Stress Modifies Endothelial Activation; A Narrative Review

The monolayer of cells that line both the heart and the entire vasculature is the endothelial cell (EC). These cells respond to external and internal signals, producing a wide array of primary or secondary messengers involved in coagulation, vascular tone, inflammation, and cell-to-cell signaling. Endothelial cell activation is the process by which EC changes from a quiescent cell phenotype, which maintains cellular integrity, antithrombotic, and anti-inflammatory properties, to a phenotype that is prothrombotic, pro-inflammatory, and permeable, in addition to repair and leukocyte trafficking at the site of injury or infection. Pathological activation of EC leads to increased vascular permeability, thrombosis, and an uncontrolled inflammatory response that leads to endothelial dysfunction. This pathological activation can be observed during ischemia reperfusion injury (IRI) and sepsis. Shear stress (SS) and pulsatile shear stress (PSS) are produced by mechanical frictional forces of blood flow and contraction of the heart, respectively, and are well-known mechanical signals that affect EC function, morphology, and gene expression. PSS promotes EC homeostasis and cardiovascular health. The archetype of inducing PSS is exercise (i.e., jogging, which introduces pulsations to the body as a function of the foot striking the pavement), or mechanical devices which induce external pulsations to the body (Enhanced External Pulsation (EECP), Whole-body vibration (WBV), and Whole-body periodic acceleration (WBPA aka pGz)). The purpose of this narrative review is to focus on the aforementioned noninvasive methods to increase PSS, review how each of these modify specific diseases that have been shown to induce endothelial activation and microcirculatory dysfunction (Ischemia reperfusion injury-myocardial infarction and cardiac arrest and resuscitation), sepsis, and lipopolysaccharide-induced sepsis syndrome (LPS)), and review current evidence and insight into how each may modify endothelial activation and how these may be beneficial in the acute and chronic setting of endothelial activation and microvascular dysfunction.