Adipose-derived mesenchymal stem cells ameliorate acute liver injury in rat model of CLP induced-sepsis via sTNFR1

Mesenchymal stem cells and their extracellular vesicles in bone and joint diseases: targeting the NLRP3 inflammasome

The nucleotide-binding oligomerization domain-like-receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a cytosolic multi-subunit protein complex, and recent studies have demonstrated the vital role of the NLRP3 inflammasome in the pathological and physiological conditions, which cleaves gasdermin D to induce inflammatory cell death called pyroptosis and mediates the release of interleukin-1 beta and interleukin-18 in response to microbial infection or cellular injury. Over-activation of the NLRP3 inflammasome is associated with the pathogenesis of many disorders affecting bone and joints, including gouty arthritis, osteoarthritis, rheumatoid arthritis, osteoporosis, and periodontitis. Moreover, mesenchymal stem cells (MSCs) have been discovered to facilitate the inhibition of NLRP3 and maybe ideal for treating bone and joint diseases. In this review, we implicate the structure and activation of the NLRP3 inflammasome along with the detail on the involvement of NLRP3 inflammasome in bone and joint diseases pathology. In addition, we focused on MSCs and MSC-extracellular vesicles targeting NLRP3 inflammasomes in bone and joint diseases. Finally, the existing problems and future direction are also discussed.

Palmatine ameliorated lipopolysaccharide-induced sepsis-associated encephalopathy mice by regulating the microbiota-gut-brain axis

BACKGROUND

Sepsis-associated encephalopathy (SAE), a common neurological complication from sepsis, is widespread among patients in intensive care unit and is linked to substantial morbidity and mortality rates, thus posing a substantial menace to human health. Due to the intricate nature of SAE's pathogenesis, there remains a dearth of efficacious therapeutic protocols, encompassing pharmaceutical agents and treatment modalities, up until the present time. Palmatine exhibits distinctive benefits in the regulation of inflammation for the improvement of sepsis. Nevertheless, the precise functions of palmatine in treating SAE and its underlying mechanism have yet to be elucidated.

PURPOSE

This study aimed to evaluate efficiency of palmatine in SAE mice and its underlying mechanisms.

STUDY DESIGN AND METHODS

Behavioral experiments, percent survival rate analysis, histological analysis, immunofluorescence staining, ELISA analysis, were performed to evaluate the efficiency of palmatine in SAE mice. Quantibody® mouse inflammation array glass chip was performed to observe the effects of palmatine on inflammation storm in SAE mice. Real-time quantitative and western blotting analyzes were employed to examine the expression of relevant targets in the Notch1/nuclear factor-kappa B (NF-κB) pathway. Finally, brain tissues metabolomics-based analyzes were performed to detect the differentially expressed metabolites and metabolic pathways. The fecal samples were subjected to microbial 16S rRNA analysis and untargeted metabolomics analysis in order to identify the specific flora and metabolites associated with SAE, thereby further investigating the mechanism of palmatine in SAE mice.

RESULTS

Our results showed that palmatine significantly improved nerve function, reduced cell apoptosis in brain tissue, and decreased inflammatory cytokine levels in SAE induced-LPS mice. Meanwhile, our results demonstrate the potential of palmatine in modulating key components of the Notch1/NF-κB pathway, enhancing the expression of tight junction proteins, improving intestinal permeability, promoting the growth of beneficial bacteria (such as Lachnospiraceae_NK4A136_group), inhibiting the proliferation of harmful bacteria (such as Escherichia-Shigella), and mitigating metabolic disorders. Ultimately, these observed effects contribute to the therapeutic efficacy of palmatine in treating SAE.

CONCLUSION

The findings of our study have provided confirmation regarding the efficacy of palmatine in the treatment of SAE, thereby establishing a solid foundation for further exploration into SAE therapy and the advancement and investigation of palmatine.

Protective effect of omega-3 polyunsaturated fatty acids on sepsis via the AMPK/mTOR pathway

CONTEXT

Sepsis is a systemic inflammatory response caused by infection, with high morbidity and mortality. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have reported biological activities.

OBJECTIVE

This study explored the signaling pathways through which ω-3 PUFAs protect against sepsis-induced multiorgan failure.

MATERIALS AND METHODS

Septic Sprague-Dawley (SD) rat model was established by the cecum ligation perforation (CLP) method. Rats were divided into control, sham, model, parenteral ω-3 PUFAs (0.5 g/kg) treatment, ω-3 PUFAs (0.5 g/kg) + AMPK inhibitor Compound C (30 mg/kg) treatment, and ω-3 PUFAs (0.5 g/kg) + mTOR activator MHY1485 (10 mg/kg) treatment groups. The serum inflammatory cytokines were measured using ELISA. Organ damage-related markers cTnI, CK, CK-MB, Cr, BUN, ALT, and AST were measured using an automated chemical analyzer. The AMPK/mTOR pathway in liver, kidney, and myocardial tissues was detected using western blot and qRT-PCR methods.

RESULTS

CLP treatment enhanced the secretion of pro-inflammatory cytokines and multi-organ related markers, along with increased p-AMPK/AMPK ratio (from 0.47 to 0.87) and decreased p-mTOR/mTOR ratio (from 0.33 to 0.12) in rats. The inflammation response and multi-organ injury induced by CLP treatment could be partially counteracted by 0.5 g/kg parenteral ω-3 PUFA treatment. The activated AMPK/mTOR pathway in CLP-induced rats was further promoted. Finally, Compound C and MHY1485 could reverse the effects of parenteral ω-3 PUFA treatment on sepsis rats.

DISCUSSION AND CONCLUSION

ω-3 PUFAs ameliorated sepsis development by activating the AMPK/mTOR pathway, serving as a potent therapeutic agent for sepsis. Further in vivo studies may validate potential clinical use.

Advances in Mesenchymal stem cells regulating macrophage polarization and treatment of sepsis-induced liver injury

Sepsis is a syndrome of dysregulated host response caused by infection, which leads to life-threatening organ dysfunction. It is a familiar reason of death in critically ill patients. Liver injury frequently occurs in septic patients, yet the development of targeted and effective treatment strategies remains a pressing challenge. Macrophages are essential parts of immunity system. M1 macrophages drive inflammation, whereas M2 macrophages possess anti-inflammatory properties and contribute to tissue repair processes. Mesenchymal stem cells (MSCs), known for their remarkable attributes including homing capabilities, immunomodulation, anti-inflammatory effects, and tissue regeneration potential, hold promise in enhancing the prognosis of sepsis-induced liver injury by harmonizing the delicate balance of M1/M2 macrophage polarization. This review discusses the mechanisms by which MSCs regulate macrophage polarization, alongside the signaling pathways involved, providing an idea for innovative directions in the treatment of sepsis-induced liver injury.

LncRNA 220: A Novel Long Non-Coding RNA Regulates Autophagy and Apoptosis in Kupffer Cells via the miR-5101/PI3K/AKT/mTOR Axis in LPS-Induced Endotoxemic Liver Injury in Mice

Sepsis is a severe medical condition distinguished by immune systematic dysfunction and multiple organic injury, or even failure, resulting from an acute systemic inflammatory response. Acute liver injury (ALI) could be considered as a notable inflammatory outcome of sepsis. Studies have demonstrated the essential roles played by long non-coding RNAs (lncRNAs) in mediating the processes of various diseases, including their ability to engage in interactions with microRNAs (miRNAs) as complexes of competing endogenous RNA (ceRNA) to modulate signaling pathways. In this study, a newly discovered lncRNA, named 220, was identified to function in regulating autophagy and apoptosis in Kupffer cells treated with lipopolysaccharide (LPS). This was achieved through sponging miR-5101 as a ceRNA complex, as identified via high-throughput sequencing. The expression of 220 was found to be significantly different in the hepatic tissues of endotoxemic mice that were treated with LPS for 8 h, ultimately modulating the ALI process. Our studies have collectively demonstrated that 220 is a novel regulator that acts on LPS-induced autophagy and apoptosis in Kupffer cells, thereby mediating the ALI process induced by LPS. Furthermore, the validation of our findings using clinical databases suggests that 220 could potentially serve as a molecular target of clinical, diagnostic, and therapeutic significance in septic liver injury.

Anti-inflammatory Effect of Low-Intensity Ultrasound in Septic Rats

OBJECTIVE

Sepsis is a severe systemic inflammatory response caused by infection. Here, the spleen region of Sprague-Dawley (SD) rats with sepsis was irradiated with low-intensity ultrasound (LIUS) to explore the regulation of inflammation and its mechanism by LIUS.

METHODS

In this study, 30 rats used for survival analysis were randomly divided into the sham-operated group (Sham, n = 10), the group in which sepsis was induced by cecal ligation and puncture (CLP, n = 10) and the group treated with LIUS immediately after CLP (LIUS, n = 10). The other 120 rats were randomly divided into the aforementioned three groups for detection at each time point. The parameters used in the LIUS group were 200 mW/cm², 0.37 MHz, 20% duty cycle and 20 min, and no ultrasonic energy was produced in the Sham and CLP groups. Seven-day survival rate, histopathology and expression of inflammatory factors and proteins were evaluated in the three groups.

RESULTS

LIUS was able to improve the survival rate of septic SD rats (p < 0.05), significantly inhibit the expression of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6) and nuclear factor-κB p65 (NF-κB p65) (p < 0.05) and restore the ultrastructure of the spleen.

CONCLUSION

Our study determined that LIUS can relieve spleen damage and alleviate severe cytokine storm to improve survival outcomes in septic SD rats, and its mechanism may be related to the inhibition of the NF-κB signaling pathway by downregulation of IL-1β.

Attenuation of experimental osteoarthritis with human adipose-derived mesenchymal stem cell therapy: inhibition of the pyroptosis in chondrocytes

AIM

To explore the role and mechanism of human adipose-derived mesenchymal stem cells (hAD-MSCs) in the treatment of osteoarthritis (OA).

METHODS

OA hulth model of Sprague Dawley (SD) rats and 20 ng/ml TNF-α treated chondrocytes were used as models of OA in vivo and in vitro, respectively. hAD-MSCs were administrated in the articular cavity by injection in vivo and co-cultured with chondrocytes using transwell in vitro. Haematoxylin and eosin staining and Safranin-O/Fast green staining were performed to detect tissue destruction and histopathology. Scanning electron microscopy and transmission electron microscopy were used to observe the ultrastructure of chondrocytes. The pyroptosis signaling pathway-related proteins were detected by immunohistochemistry, immunofluorescence, qRT-PCR and Western blot. And small interference technology was used to study the mechanism in depth.

RESULTS

hAD-MSCs could delay the development of rat OA, improve the pathological changes of joints, inhibit the expression of NLRP3, Caspase1, GSDMD and TNFR1. In vitro, the expression of pyroptosis signal proteins in chondrocytes was significantly elevated when stimulated with TNF-α, the level of inflammatory factors such as IL-1β, IL-18 was increased, and the cell morphology was significantly destroyed. While co-cultured with hAD-MSCs, these syndromes were reversed. Knockout of TNFR1 also returned the upregulation of pyroptosis signals which caused by TNF-α.

CONCLUSION

These results demonstrated that hAD-MSCs could inhibit pyroptosis signaling pathway of chondrocytes induced by TNF-α, which have raised our understanding of the role of hAD-MSCs as promising therapy for the management of OA.

Effects of Gabexate Mesylate on the Gut Microbiota and Metabolomics in Rats with Sepsis

Background

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. However, there is still no single drug that could reduce septic mortality. Previous studies have reported gabexate mesylate (GM) significantly reduced serum inflammatory factors, alleviated sepsis-induced lung injury and improved clinical outcomes. This study aimed to combine with microbiome sequencing and metabolomics analysis to explore the effects of GM administration in septic rats.

Methods

Sixty SD rats were randomly divided into the sham control (SC), cecal ligation and puncture (CLP), and GM injection (GM) groups. The mortality was measured and colonic feces were collected to examine the gut microbiota and metabolism 24 h after the procedure. The lung tissues were collected for hematoxylin-eosin staining.

Results

We observed the relative abundance of Pygmaiobacter, which contributed to short-chain fatty acids (SCFAs) promotion, Lactobacillus and Erysipelotrichaceae UCG-003 increased in the GM-treated rats, while Escherichia-Shigella and Akkermansia decreased compared to the sepsis-induced lung injury group. Furthermore, these 3 metabolites including Palmitoylethanolamide, Deoxycholic acid and Chenodeoxycholic acid correlated significantly to CLP- and GM-rich genus (P < 0.05). Besides, the lung tissues of CLP group showed more severe inflammatory infiltration and edema, and the mortality rate in the CLP group (10/20) was significantly higher than in the SC group (0/20) (P < 0.001) and GM group (4/20) (P < 0.05).

Conclusion

Our findings showed that GM attenuated sepsis-induced lung injury rats and regulated metabolites related to gut microbiota, which may provide an effective treatment for sepsis patients.

Bioinformatics Analysis Identifies TNFRSF1A as a Biomarker of Liver Injury in Sepsis TNFRSF1A is a Biomarker for Septic Liver Injury

Sepsis is a severe disease with high mortality, and liver injury is an independent risk factor for sepsis morbidity and mortality. We analyzed co-differentially expressed genes (co-DEGs) to explore potential biomarkers and therapeutic targets for sepsis-related liver injury. Three gene expression datasets (GSE60088, GSE23767, and GSE71530) were downloaded from the Gene Expression Omnibus (GEO). DEGs were screened between sepsis and control samples using GEO2R. The association of these DEGs with infection and liver disease was analyzed by using the CTD database. GO functional analysis, KEGG pathway enrichment analysis, and protein-protein interaction (PPI) network analysis were performed to elucidate the potential molecular mechanism of DEGs. DEGs of different tissues in GSE60088 were analyzed again to obtain specific markers of septic liver injury. Mouse model of sepsis was also established by cecal ligation and puncture (CLP), and the expression of specific markers in liver, lung, and kidney tissues was analyzed using Western blot. Here, we identified 21 DEGs in three datasets with 8 hub genes, all of which showed higher inference scores in liver diseases than bacterial infections. Among them, only TNFRSF1A had a liver-specific differential expression. TNFRSF1A was also confirmed to be specifically reduced in septic liver tissues in mice. Therefore, TNFRSF1A may serve as a potential biomarker for septic liver injury.

Down-Regulation of CXCR4 in Mesenchymal Stem Cells by Septic Serum

Background

Sepsis is one of the main concerns of health and one of the leading causes of death in hospitals. It is essential to manage sepsis in hospitalized patients. In recent years, cell therapy has been considered as a new approach to treat sepsis. This study evaluated the effect of CXCR4 as one of the main proteins involved in the homing of mesenchymal stem cells in the sepsis serum in mice model.

Methods

Mouse sepsis model was induced by injection of E.coli and biochemical analyses was done to confirm the organ failure. Mesenchymal stem cells (MSCs) derived from bone marrow were separated into sepsis and control groups. In the sepsis serum group, MSCs were treated with sepsis serum at two time points: 24 and 48 h. Quantitative RT-PCR and flow cytometry were performed to determine the mRNA expression of CXCR4 in sepsis serum group compared to control group. Also, a migration assay was done to assess the migration capacity of bone marrow MSCs during inflammation and treatment in sepsis.

Results

Our result showed that treatment with sepsis serum can control migration by decrease in CXCR4 level (P ≤ 0.05) compared to control group. Moreover it was also reported that sepsis serum decreased mRNA expression of CXCR4 in MScs.

Conclusions

In our study, MSCs treated with septic serum were no longer able to migrate . Probably many variables such as source, dose, injection time, and injection route of MSCs after sepsis induction in the animal models are key factors for successful cell therapy.

Alpha-Chymotrypsin Protects Against Acute Lung, Kidney, and Liver Injuries and Increases Survival in CLP-Induced Sepsis in Rats Through Inhibition of TLR4/NF-κB Pathway

Abstract

Inflammation and oxidative stress play a major role in the development of sepsis and its associated complications, leading to multiple organ failure and death. The lungs, liver, and kidneys are among the early affected organs correlated with mortality in sepsis. Alpha-chymotrypsin (α-ch) is a serine protease that exerts anti-inflammatory, anti-edematous, and anti-oxidant properties.

Purpose

This study was undertaken to elucidate if the anti-inflammatory and anti-oxidant effects of α-ch observed in previous studies can alleviate lung, liver, and kidney injuries in a cecal ligation and puncture (CLP)-induced sepsis model, and thus decrease mortality.

Materials and Methods

Septic animals were given α-ch 2 h post CLP procedure. Sepsis outcomes were assessed in the lungs, liver, and kidneys. Separate animal groups were investigated for a survival study.

Results

CLP resulted in 0% survival, while α-chymotrypsin post-treatment led to 50% survival at the end of the study. Administration of α-chymotrypsin resulted in a significant attenuation of sepsis-induced elevated malonaldehyde (MDA) and total nitrite/nitrate (NOx) levels. In addition, there was a significant increase in reduced glutathione (GSH) content and superoxide dismutase (SOD) activity in the lungs, liver, and kidneys. Administration of α-ch reduced elevated tissue expression of toll-like receptor-4 (TLR4), nuclear factor kappa-B (NF-κB), myeloperoxidase (MPO), and inducible nitric oxide synthase (iNOS). Alpha-chymotrypsin resulted in a significant reduction in serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6). Alpha-chymotrypsin attenuated the rise in serum creatinine, cystatin C, blood urea nitrogen (BUN), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels that was observed in the septic group. In addition, α-ch significantly reduced the lung wet/dry weight ratio, total protein content, and leukocytic counts in bronchoalveolar lavage fluid (BALF). Histopathological examination of the lungs, liver, and kidneys confirmed the protective effects of α-ch on those organs.

Conclusion

α-ch has protective potential against sepsis through lowering tissue expression of TLR4, NF-κB, MPO, and iNOS leading to decreased oxidative stress and inflammatory signals induced by sepsis. This effect appeared to alleviate the damage to the lungs, liver, and kidneys and increase survival in rats subjected to sepsis.

Effect of Celecoxib and Infliximab against Multiple Organ Damage Induced by Sepsis in Rats: A Comparative Study

In cases of sepsis, the immune system responds with an uncontrolled release of proinflammatory cytokines and reactive oxygen species. The lungs, kidneys, and liver are among the early impacted organs during sepsis and are a direct cause of mortality. The aim of this study was to compare the effects of infliximab (IFX) and celecoxib (CLX) on septic rats that went through a cecal ligation and puncture (CLP) surgery to induce sepsis. This study included four groups: sham, CLP (untreated), and CLP-treated with CLX or IFX. The administration of “low dose” CLX or IFX was performed after 2 h following the induction of sepsis. Twenty-four hours following the induction of sepsis, the rats were sacrificed and blood samples were collected to evaluate kidney, liver, and lung injuries. MDA and NOx content, in addition to SOD activity and GSH levels, were evaluated in the tissue homogenates of each group. Tissue samples were also investigated histopathologically. In a separate experiment, the same groups were employed to evaluate the survival of septic rats in a 7-day observation period. The results of this study showed that treatment with either CLX or IFX ameliorated the three organs’ damage compared to septic-untreated rats, decreased oxidative stress, enhanced the antioxidant defense, and reduced serum cytokines. As a result, a higher survival rate resulted: 62.5% and 37.5% after the administration of CLX and IFX, respectively, compared to 0% in the CLP group after 7 days. No significant differences were observed between the two agents in all measured parameters. Histopathological examination confirmed the observed results. In conclusion, CLX and IFX ameliorated lung, kidney, and liver injuries associated with sepsis through anti-inflammatory and antioxidant actions, which correlated to the increase in survival observed with both of them.

Adipose-derived stem cells in the treatment of hepatobiliary diseases and sepsis

Determination of the mesenchymal stem cells is one of the greatest and most exciting achievements that tissue engineering and regenerative medicine have achieved. Adipose-derived mesenchymal stem cells (AD-MSC) are easily isolated and cultured for a long time before losing their stem cell characteristics, which are self-renewal and pluripotency. AD-MSC are mesenchymal stem cells that have pluripotent lineage characteristics. They are easily accessible, and the fraction of stem cells in the adipose tissue lysates is highest among all other sources of mesenchymal stem cells. It is also HLA-DR negative and can be transplanted allogenically without the need for immunosuppression. These advantages have popularized its use in many fields including plastic reconstructive surgery. However, in the field of hepatology and liver transplantation, the progress is slower. AD-MSC have the potential to modulate inflammation, ameliorate ischemia-reperfusion injury, and support liver and biliary tract regeneration. These are very important for the treatment of various hepatobiliary diseases. Furthermore, the anti-inflammatory potential of these cells has paramount importance in the treatment of sepsis. We need alternative therapeutic approaches to treat end-stage liver failure. AD-MSC can provide a means of therapy to bridge to definitive therapeutic alternatives such as liver transplantation. Here we propose to review theoretic applications of AD-MSC in the treatment of hepatobiliary diseases and sepsis.

Metformin attenuated sepsis-related liver injury by modulating gut microbiota

Increased evidence shows that gut microbiota acts as the primary regulator of the liver; however, its role in sepsis-related liver injury (SLI) in the elderly is unclear. This study assessed whether metformin could attenuate SLI by modulating gut microbiota in septic-aged rats. Cecal ligation and puncture (CLP) was used to induce SLI in aged rats. Fecal microbiota transplantation (FMT) was used to validate the roles of gut microbiota in these pathologies. The composition of gut microbiota was analysed by 16S rRNA sequencing. Moreover, the liver and colon tissues were analysed by histopathology, immunofluorescence, immunohistochemistry, and reverse transcription polymerase chain reaction (RT–PCR). Metformin improved liver damage, colon barrier dysfunction in aged SLI rats. Moreover, metformin improved sepsis-induced liver inflammation and damage under gut microbiota. Importantly, FMT assay showed that rats gavaged with faeces from metformin-treated SLI rats displayed less severe liver damage and colon barrier dysfunctions than those gavaged with faeces from SLI rats. The gut microbiota composition among the sham-operated, CLP-operated and metformin-treated SLI rats was different. In particular, the proportion of Klebsiella and Escherichia_Shigella was higher in SLI rats than sham-operated and metformin-treated SLI rats; while metformin could increase the proportion of Bifidobacterium, Muribaculaceae, Parabacteroides_distasonis and Alloprevitella in aged SLI rats. Additionally, Klebsiella and Escherichia_Shigella correlated positively with the inflammatory factors in the liver. Our findings suggest that metformin may improve liver injury by regulating the gut microbiota and alleviating colon barrier dysfunction in septic-aged rats, which may be an effective therapy for SLI.

Metformin attenuated sepsis-associated liver injury and inflammatory response in aged mice

Sepsis-associated liver injury is with poor survival in intensive care units. Metformin is well known for its therapeutic effects; however, its impact on treating liver injury due to sepsis remains poorly understood. This study investigated the therapeutic effects of metformin on aged mice suffering from sepsis-associated liver injury. Male C57BL/6 J mice aged (18–19 months) were divided into 3 groups: 1) intraperitoneal injection of sterile normal saline (C group), 12.5 mg/kg lipopolysaccharide (LPS) to induce sepsis-associated liver injury (LPS group), and 25 mg/kg metformin (MET) at 1 h after LPS injection (MET group). After 24 h, blood samples and liver tissue were collected for biochemical analysis. Histological assays revealed significantly elevated inflammatory infiltration and apoptosis in the liver, while metformin was found to relieve these aberrant features. The percentage of apoptotic cells decreased after metformin treatment (P < 0.05). Additionally, MET group had significantly reduced plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels compared to the LPS group (P < 0.05). Furthermore, in the MET group, the mRNA levels of chemokines and inflammatory factors, TNF-α, IL-6, caspase-1, decreased markedly (P < 0.05). Metformin notably reversed the decreased phosphorylated AMP-activated protein kinase (p-AMPK) and PGC-1α expressions in the liver of septic rats. Metformin also inhibited PDK1, HIF-1α expression, including downstream inflammatory mediators, HMGB1 and TNF-α. Metformin attenuated inflammation and liver injury in septic aged mice. Most importantly, we report the effect of metformin on liver injury via the AMPK–PGC1α axis in septic aged mice for the first time.

Exosomes from adipose-derived mesenchymal stem cells alleviate sepsis-induced lung injury in mice by inhibiting the secretion of IL-27 in macrophages

Acute lung injury (ALI) represents a frequent sepsis-induced inflammatory disorder. Mesenchymal stromal cells (MSCs) elicit anti-inflammatory effects in sepsis. This study investigated the mechanism of exosomes from adipose-derived MSCs (ADMSCs) in sepsis-induced ALI. The IL-27r^-/- (WSX-1 knockout) or wild-type mouse model of sepsis was established by cecal ligation and puncture (CLP). The model mice and lipopolysaccharide (LPS)-induced macrophages were treated with ADMSC-exosomes. The content of Dil-labeled exosomes in pulmonary macrophages, macrophages CD68⁺ F4/80⁺ in whole lung tissues, and IL-27 content in macrophages were detected. The mRNA expression and protein level of IL27 subunits P28 and EBI3 in lung tissue and the levels of IL-6, TNF-α, and IL-1β were measured. The pulmonary edema, tissue injury, and pulmonary vascular leakage were measured. In vitro, macrophages internalized ADMSC-exosomes, and ADMSC-exosomes inhibited IL-27 secretion in LPS-induced macrophages. In vivo, IL-27 knockout attenuated CLP-induced ALI. ADMSC-exosomes suppressed macrophage aggregation in lung tissues and inhibited IL-27 secretion. ADMSC-exosomes decreased the contents of IL-6, TNF-α, and IL-1β, reduced pulmonary edema and pulmonary vascular leakage, and improved the survival rate of mice. Injection of recombinant IL-27 reversed the protective effect of ADMSC-exosomes on sepsis mice. Collectively, ADMSC-exosomes inhibited IL-27 secretion in macrophages and alleviated sepsis-induced ALI in mice.

Elevated lncRNA-UCA1 upregulates EZH2 to promote inflammatory response in sepsis-induced pneumonia via inhibiting HOXA1

Sepsis is characterized by a dysregulated inflammatory response. We aimed to explore the role of the long non-coding RNA urothelial carcinoma associated 1 (lncRNA UCA1)/enhancer of zeste homolog 2 (EZH2)/homeobox A1 (HOXA1) axis in sepsis-induced pneumonia. The sepsis rat models and RLE-6TN cellular sepsis-induced pneumonia models were established using ligation and puncture (CLP) and lipopolysaccharide (LPS). The expression of UCA1, EZH2 and HOXA1 in rat lung tissues and RLE-6TN cells was detected. Then, the CLP rats were respectively treated with UCA1 up-regulation or UCA1 silencing, EZH2 overexpression to measure their roles in the pathology, apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in CLP rat lung tissues. The cells were subjected to same treatment to examine the effects of UCA1, EZH2 and HOXA1 on viability, apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in LPS-induced RLE-6TN cells. The interactions among UCA1, EZH2 and HOXA1 were identified. UCA1 and EZH2 were upregulated while HOXA1 was downregulated in CLP rat lung tissues and LPS-induced RLE-6TN cells. Elevated UCA1 or increased EZH2 aggravated pathology and promoted apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in CLP rat lung tissues, and inhibited viability while facilitated apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in LPS-induced RLE-6TN cells. UCA1 inhibition exerted contrary effects. Silenced EZH2 reversed the effects of UCA1 elevation on sepsis-induced pneumonia. UCA1 targeted EZH2 that interacted with HOXA1. UCA1 overexpression upregulates EZH2 to repress HOXA1 expression, thus aggravating the progression of sepsis-induced pneumonia, which could be alleviated by EZH2 inhibition.

Neuropeptide W Attenuates Oxidative Multi-Organ Injury in Rats Induced with Intra-Abdominal Sepsis

Sepsis leads to systemic hypotension, disturbed perfusion, inflammation, and tissue toxicity in vital organs. Neuropeptide W (NPW) has modulatory effects in the control of blood pressure and inflammatory processes, implicating a potential beneficial effect against sepsis-induced oxidative damage. Under anesthesia, male Sprague Dawley rats underwent cecal ligation and puncture. Immediately after surgery, either saline or TNF-alpha inhibitor (etanercept; 1 mg/kg) antibiotic (ceftriaxon; 10 mg/kg) combination or NPW (0.1, 1, or 3 μg/kg) was given subcutaneously, and injections were repeated on the 12th and 24th h. The sham-operated control group was treated with saline at the same time points. All rats were euthanized on the 25th h of surgery. Sepsis resulted in oxidative damage of the brain, heart, lung, liver, and kidney. Elevations in blood urea nitrogen and alkaline phosphatase, showing renal and hepatic dysfunction, were not evident when septic rats were treated with NPW. NPW reduced serum levels of C-reactive protein, corticosterone, and interleukin-6, while histopathologically verified tissue damage in all the studied tissues was ameliorated. NPW treatment suppressed lipid peroxidation in the heart, lung, and brain, and the depleted antioxidant GSH levels of the brain and heart were replenished by NPW. Moreover, sepsis-related neutrophil recruitment to the liver and lung was also suppressed by NPW. Although the survival rate of the rats was not significantly prolonged by NPW, most of these improvements in systemic and local inflammatory events were comparable with those reached by the etanercept and antibiotic combination, suggesting the therapeutic impact of NPW during the acute period of sepsis.

RETRACTED: Exosomal microRNA-16-5p from adipose mesenchymal stem cells promotes TLR4-mediated M2 macrophage polarization in septic lung injury

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). The authors have requested that this paper be retracted as they were unable to replicate the experimental data reported in Figure 1A. The authors posit that changes in reagents or experimental conditions might be the source of their inability to do so. Additional concerns were raised about the reliability of the Western blot results in Figure 1E, Figure 4B and F, Figure 5B, and Figure 6B, as regarding ‘morphology space’ similarities contained within a series of papers with distinctive eyebrow blots, tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0 [nam11.safelinks.protection.outlook.com] [nam11.safelinks.protection.outlook.com]). The journal requested the authors comment on these concerns and provide raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Bone marrow-mesenchymal stem cell-derived exosomal microRNA-141 targets PTEN and activates β-catenin to alleviate myocardial injury in septic mice

BACKGROUND

Mesenchymal stem cells (MSCs) and their derived exosomes have shown potentials in the control of myocardial dysfunction. This study aimed to reveal the function of bone marrow (BM)-MSC-derived exosomes in sepsis-induced myocardial injury and the molecular mechanism.

METHODS

BM-MSC-derived exosomes were obtained and identified. A mouse model with sepsis was induced by cecalligation puncture (CLP) and treated with exosomes. The myocardial function of mice, the production of creatine kinase MB (CK-MB) and lactate dehydrogenase (LDH) in serum, the phosphorylation of a key myocardial contractility-related protein phospholamban (PLB), and the pathological changes in the myocardial tissues were examined. A microRNA (miRNA) microarray analysis was performed to examine the candidate miRNAs carried by the exosomes. Rescue experiments were conducted to validate the involvement of miR-141.

RESULTS

CLP treatment led to sepsis and notably reduced the myocardial function in mice. Further treatment of BM-MSC-derived exosomes alleviated the CLP-induced myocardial impairment, production of CK-MB and LDH, and inflammatory infiltration and cell apoptosis in mouse myocardial tissues, and restored the PLB phosphorylation. miR-141 was the most upregulated miRNA in the myocardial tissues after exosome treatment. Downregulation of miR-141 blocked the myocardium-protective functions of the exosomes. miR-141 was found to bind to and suppress PTEN expression, which further enhanced the activity of β-catenin.

CONCLUSION

This study suggested that BM-MSC derived exosomes ameliorates myocardial injury in septic mice through conveying miRNA-141 and regulating the PTEN/β-catenin axis, and exosomes may serve as promising tools for the management of myocardial injury induced by sepsis or other factors.

Ferulic acid positively modulates the inflammatory response to septic liver injury through the GSK-3β/NF-κB/CREB pathway

AIMS

Ferulic acid (FA) is a component found in plants that has free radical scavenging and liver-protective properties. Acute liver injury (ALI) is a serious complication of sepsis and is closely associated with changes in the levels of inflammatory factors. This study was taken to examine the role of FA in cecal ligation and perforation (CLP)-induced murine ALI and lipopolysaccharide (LPS)-induced cellular ALI models.

MATERIALS AND METHODS

An in vivo ALI model was established by performing CLP surgery on C57BL/6 mice. After the ALI model was established, mice were examined for liver injury, including HE staining to observe tissue sections, the percentage of liver/body weight and inflammatory factor levels. Myeloperoxidase (MPO), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were measured in liver or serum using commercial kits. An in vitro ALI model was established using LPS-stimulated RAW264.7 cells. Cell viability was measured by MTT method and the intracellular levels of IL-10, IL-1β, IL-6, IL-12 and TNF-α inflammatory factors were measured using kits. The expression of GSK-3β, NF-κB and CREB was measured by western blot or immunofluorescence.

KEY FINDINGS

FA pretreatment significantly reduced liver/body weight ratio, decreased MPO, AST and ALT activity, alleviated the inflammatory responses and improved CLP-induced histopathological changes in liver. In addition, in vitro results showed that FA could dose-dependently increase the viability of RAW264.7 cells and decrease the levels of pro-inflammatory factors.

SIGNIFICANCE

In conclusion, our data suggest that FA can ameliorate ALI-induced inflammation via the GSK-3β/NF-κB/CREB pathway, suggesting that FA can be used to protect the liver against ALI.

Adipose-Derived Stem Cells: Current Applications and Future Directions in the Regeneration of Multiple Tissues

Adipose-derived stem cells (ADSCs) can maintain self-renewal and enhanced multidifferentiation potential through the release of a variety of paracrine factors and extracellular vesicles, allowing them to repair damaged organs and tissues. Consequently, considerable attention has increasingly been paid to their application in tissue engineering and organ regeneration. Here, we provide a comprehensive overview of the current status of ADSC preparation, including harvesting, isolation, and identification. The advances in preclinical and clinical evidence-based ADSC therapy for bone, cartilage, myocardium, liver, and nervous system regeneration as well as skin wound healing are also summarized. Notably, the perspectives, potential challenges, and future directions for ADSC-related researches are discussed. We hope that this review can provide comprehensive and standardized guidelines for the safe and effective application of ADSCs to achieve predictable and desired therapeutic effects.

Adipose-derived mesenchymal stem cells attenuate acute lung injury and improve the gut microbiota in septic rats

Background

We hypothesized that adipose-derived mesenchymal stem cells (ADMSCs) may ameliorate sepsis-induced acute lung injury (ALI) and change microorganism populations in the gut microbiota, such as that of Firmicutes and Bacteroidetes.

Methods

A total of 60 male adult Sprague-Dawley (SD) rats were separated into three groups: the sham control (SC) group, the sepsis induced by cecal ligation and puncture (CLP) group, and the ADMSC treatment (CLP-ADMSCs) group, in which rats underwent the CLP procedure and then received 1 × 10⁶ ADMSCs. Rats were sacrificed 24 h after the SC or CLP procedures. To study the role of ADMSCs during ALI caused by sepsis and examine the impact of ADMSCs on the gut microbiome composition, rat lungs were histologically evaluated using hematoxylin and eosin (H&E) staining, serum levels of pro-inflammatory factors were detected using enzyme-linked immunosorbent assay (ELISA), and fecal samples were collected and analyzed using 16S rDNA sequencing.

Results

The serum levels of inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-6, were significantly increased in rats after the CLP procedure, but were significantly decreased in rats treated with ADMSCs. Histological evaluation of the rat lungs yielded results consistent with the changes in IL-6 levels among all groups. Treatment with ADMSCs significantly increased the diversity of the gut microbiota in rats with sepsis. The principal coordinates analysis (PCoA) results showed that there was a significant difference between the gut microbiota of the CLP-ADMSCs group and that of the CLP group. In rats with sepsis, the proportion of Escherichia–Shigella (P = 0.01) related to lipopolysaccharide production increased, and the proportion of Akkermansia (P = 0.02) related to the regulation of intestinal mucosal thickness and the maintenance of intestinal barrier function decreased. These changes in the gut microbiota break the energy balance, aggravate inflammatory reactions, reduce intestinal barrier functions, and promote the translocation of intestinal bacteria. Intervention with ADMSCs increased the proportion of beneficial bacteria, reduced the proportion of harmful bacteria, and normalized the gut microbiota.

Conclusions

Therapeutically administered ADMSCs ameliorate CLP-induced ALI and improves gut microbiota, which provides a potential therapeutic mechanism for ADMSCs in the treatment of sepsis.

Immunomodulatory and Therapeutic Effects of Mesenchymal Stem Cells on Organ Dysfunction in Sepsis

ABSTRACT

Sepsis is a life-threatening disorder that is caused by a dysregulated inflammatory response during an infection. The disease mostly affects pregnant women, newborns, and patients in intensive care units. Sepsis treatment is a significant part of a country's health budgets. Delay in the therapy causes irreversible failure of various organs due to the lack of blood supply and reduction of oxygen in the tissues and eventually increased mortality. The involvement of four or five organs by sepsis has been attributed to an increased risk of death to over 90%. Although antibiotics are at the first line of sepsis treatment, they do not possess enough potency to control the disease and prevent subsequent organ failure. The immunomodulatory, anti-inflammatory, anti-apoptotic, and anti-microbial properties of mesenchymal stem cells (MSCs) have been reported in various studies. Therefore, the application of MSCs has been considered a potentially promising therapeutic strategy. In preclinical studies, the administration of MSCs has been associated with reduced bacterial load and decreased levels of pro-inflammatory factors as well as the improved function of the different vital organs, including heart, kidney, liver, and lungs. The current study provides a brief review of sepsis and its pathophysiology, and then highlights recent findings in the therapeutic effects of MSCs and MSC-derived secretome in improving sepsis-induced organ dysfunction. Besides, eligible sepsis candidates for MSC-therapy and the latest clinical findings in these areas have been reviewed.

LncRNA XIST silencing protects against sepsis-induced acute liver injury via inhibition of BRD4 expression

Sepsis is recognized as the acute systemic inflammatory response to severe infection. It is main cause of multiple organ system dysfunction and even organ failure. Long non-coding RNA X inactivate-specific transcript (XIST) is implicated in multiple inflammatory diseases. The aim of present work was to investigate the precise mechanism of XIST underlying sepsis-induced acute liver injury. Rats were underwent cecal ligation and puncture (CLP) to establish sepsis-induced the animal models of acute liver injury. Hematoxylin and eosin (H&E) staining was performed to observe pathological alterations. Corresponding commercial assay kits were employed to analyze the levels of inflammatory cytokines and oxidative stress. Western blot and reverse transcriptional quantitative PCR (RT-qPCR) were performed to determine the expression of proteins and target genes. Finally, TUNEL and CCK-8 assays were performed to test apoptosis rate and cell viability, respectively. In our study, XIST and BRD4 were highly expressed in serum of patients with sepsis-induced acute liver injury. XIST knockdown ameliorated sepsis-induced acute liver injury and inhibited inflammation, oxidative stress, and cell apoptosis in sepsis-induced acute liver injury rats. Interestingly, XIST knockdown downregulated the expression of BRD4, and BRD4 overexpression abolished the impacts of XIST knockdown on inflammation, oxidative stress, and apoptosis of that LPS-induced Kupffer cells. We conclude that lncRNA XIST silencing protects against sepsis-induced acute liver injury via inhibition of the BRD4 expression. Therefore, XIST may be a biomarker for sepsis diagnosis and treatment.

Efficacy of mesenchymal stem cell therapy for sepsis: a meta-analysis of preclinical studies

Background

Multiple studies have reported that mesenchymal stem cell (MSC) therapy has beneficial effects in experimental models of sepsis. However, this finding remains inconclusive. This study was performed to systematically determine the connection between MSC therapy and mortality in sepsis animal models by pooling and analyzing data from newly published studies.

Methods

A detailed search of related studies from 2009 to 2019 was conducted in four databases, including MEDLINE, EMBASE, Cochrane Library, and Web of Science. After browsing and filtering out articles that met the inclusion criteria for statistical analysis, the inverse variance method of the fixed effects model was used to calculate the pooled odds ratios (ORs) and their 95% confidence intervals (CIs).

Results

Twenty-nine animal studies, including 1266 animals, were identified. None of the studies was judged to have a low risk of bias. The meta-analysis demonstrated that MSC therapy was related to a significantly lower mortality rate (OR 0.29, 95% CI 0.22–0.38, P < 0.001). Subgroup analyses performed based on the MSC injection dose (< 1.0 × 10⁶ cells, OR = 0.33, 95% CI 0.20–0.56, P < 0.001; 1.0 × 10⁶ cells, OR = 0.24, 95% CI 0.16–0.35, P < 0.001) and injection time (< 1 h, OR = 0.24, 95% CI 0.13–0.45, P < 0.001; 1 h, OR = 0.28, 95% CI 0.17–0.46, P < 0.001) demonstrated that treatment with MSCs significantly reduced the mortality rate of animals with sepsis.

Conclusion

This up-to-date meta-analysis showed a connection between MSC therapy and lower mortality in sepsis animal models, supporting the potential therapeutic effect of MSC treatment in future clinical trials. The results in this study contradict a previous meta-analysis with regards to the ideal dose of MSC therapy. Thus, further research is required to support these findings.

Immunomodulatory and Tissue-preserving Effects of Human Dental Follicle Stem Cells in a Rat Cecal Ligation and Perforation Sepsis Model

BACKGROUND

Mesenchymal stem cells may be used for the treatment of sepsis. Dental follicle stem cells (DFSCs) are easily accessible but have not been studied in vivo or in clinical trials in sepsis models.

AIM OF THE STUDY

We aim to elucidate DFSC effects on host immunological functions in a rat cecal ligation and perforation (CLP) sepsis model.

METHODS

Adult male rats were categorized into group 1 (sham procedure SP), group 2 (SP + 1 × 10⁶ DFSCs administered 0 h after SP), group 3 (CLP + saline), group 4 (CLP + 1 × 10⁶ DFSCs administered 0 h after CLP), and group 5 (CLP + 1 × 10⁶ DFSCs administered 4 h after CLP). Green fluorescent protein-labeled cells were used for imaging. Histopathological examination of ileal tissues was performed.

RESULTS

A significant increase in the percentage of CD4+/CD25+/Foxp3+ Treg cells in groups 4 and 5 occurred compared with that in group 3. No significant changes in CD3+/CD4+ helper T-cells and CD3+/CD8+ cytotoxic T-cells were observed. Treatment with DFSCs at 4 h significantly decreased the level of TNF-α compared with that in group 3. No significant changes in IL-10 levels and lymphocyte proliferation suppression were observed. During histopathological examination, no high scoring (Chiu scores: 3 or 4) rats were observed in the curative treatment group (group 5).

CONCLUSIONS

Treatment with DFSC after 4 h of sepsis induction downregulates tissue inflammatory responses by decreasing TNF-α levels and increasing Treg cell ratio. This also has a protective effect on intestinal tissues during sepsis.