Effect of Hypoxia Preconditioned Adipose-Derived Mesenchymal Stem Cell Conditioned Medium on Cerulein-Induced Acute Pancreatitis in Mice

Mesenchymal stem cell-conditioned medium prevents inflammation-induced liver and lung damage in septic mice

AIM

Sepsis is a life-threatening condition caused by a dysregulated immune response to infection. Broad-spectrum antibiotics are used to treat it. However, due to antibiotic resistance, alternative treatments are needed. Mesenchymal stem cells (MSCs) have become a promising therapeutic tool for sepsis due to their immunomodulatory properties. The limitations of MSC therapy have led to increased attention to cell derivatives such as conditioned medium (CM). This study investigates the immunomodulatory effects of young and old MSC-CM during the inflammatory phase of sepsis.

MAIN METHODS

The cecal ligation and puncture (CLP) model was used to induce sepsis in mice. The mice were divided into four groups: sham, CLP, CLP treated with young MSC-CM, and CLP treated with old MSC-CM. The CM was injected intraperitoneally at 2-, 12-, and 24-hours post-surgery. After 72 h, blood was collected and white blood cells (WBCs) were counted. In addition, serum and tissue were isolated, and the levels of alanine transaminase (ALT) and aspartate transaminase (AST) in serum, bacterial load in the spleen, concentration of pro- and anti-inflammatory cytokines, and histopathology of liver and lung were investigated.

KEY FINDINGS

MSC-CM decreased serum AST and ALT levels, bacterial load in the spleen, and pro-inflammatory cytokines in serum. In addition, tissue damage was reduced, and the survival rate and WBC count increased. There was no significant difference between the young and old MSC-CM.

SIGNIFICANCE

MSC-CM effectively reduced inflammation-induced tissue damage in the liver and lungs during sepsis. Although young MSC-CM had better immunomodulatory effects than old MSC-CM, the difference was not significant.

The impact of hypoxia preconditioning on mesenchymal stem cells performance in hypertensive kidney disease

BACKGROUND

Autologous mesenchymal stem cells (MSCs) have emerged as a therapeutic option for many diseases. Hypertensive kidney disease (HKD) might impair MSCs' reparative ability by altering the biomolecular properties, but the characteristics of this impairment are unclear. In our previous pre-clinical studies, we found hypoxic preconditioning (HPC) enhanced angiogenesis and suppressed senescence gene expression. Thus, we hypothesize that HPC would improve human MSCs by enhancing their functionality and angiogenesis, creating an anti-inflammatory and anti-senescence environment.

METHODS

MSC samples (n = 12 each) were collected from the abdominal fat of healthy kidney donors (HC), hypertensive patients (HTN), and patients with hypertensive kidney disease (HKD). MSCs were harvested and cultured in Normoxic (20% O2) or Hypoxic (1% O2) conditions. MSC functionality was measured by proliferation assays and cytokine released in conditioned media. Senescence was evaluated by senescence-associated beta-galactosidase (SA-beta-gal) activity. Additionally, transcriptome analysis using RNA-sequencing and quantitative PCR (qPCR) were performed.

RESULTS

At baseline, normoxic HTN-MSCs had higher proliferation capacity compared to HC. However, HPC augmented proliferation in HC. HPC did not affect the release of pro-angiogenic protein VEGF, but increased EGF in HC-MSC, and decreased HGF in HC and HKD MSCs. Under HPC, SA-β-gal activity tended to decrease, particularly in HC group. HPC upregulated mostly the pro-angiogenic and inflammatory genes in HC and HKD and a few senescence genes in HKD.

CONCLUSIONS

HPC has a more favorable functional effect on HC- than on HKD-MSC, reflected in increased proliferation and EGF release, and modest decrease in senescence, whereas it has little effect on HTN or HKD MSCs.

The effect of adipose-derived mesenchymal stem cell transplantation on ovarian mitochondrial dysfunction in letrozole-induced polycystic ovary syndrome in rats: the role of PI3K-AKT signaling pathway

OBJECTIVE

The present study aimed to elucidate how mesenchymal stem cells (MSCs) application could efficiently attenuate pathological changes of letrozole-induced poly cystic ovary syndrome (PCOS) by modulating mitochondrial dynamic via PI3K-AKT pathway.

METHODS

Thirty-two female rats were randomly divided into four experimental groups: Sham, PCOS, PCOS + MSCs, and PCOS + MSCs + LY294002. The Sham group received 0.5% w/v carboxymethyl cellulose (CMC); the PCOS group received letrozole (1 mg/kg, daily) in 0.5% CMC for 21 days. Animals in the PCOS + MSCs group received 1 × 106 MSCs/rat (i.p,) on the 22th day of the study. In the PCOS + MSCs + LY294002 group, rats received LY294002 (PI3K-AKT inhibitor) 40 min before MSC transplantation. Mitochondrial dynamic gene expression, mitochondrial membrane potential (MMP), citrate synthase (CS) activity, oxidative stress, inflammation, ovarian histological parameters, serum hormone levels, homeostatic model assessment for insulin resistance (HOMA-IR), insulin and glucose concentrations, p-PI3K and p-AKT protein levels were evaluated at the end of the experiment.

RESULTS

PCOS rats showed a significant disruption of mitochondrial dynamics and histological changes, lower MMP, CS, ovary super oxide dismutase (SOD) and estrogen level. They also had a notable rise in insulin and glucose concentrations, HOMA-IR, testosterone level, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels, ovarian malondialdehyde (MDA) content as well as a notable decrease in p-PI3K and p-AKT protein levels compared to the Sham group. In the PCOS + MSCs group, the transplantation of MSCs could improve the above parameters. Administration of LY294002 (PI3K-AKT pathway inhibitor) deteriorated mitochondrial dynamic markers, oxidative stress status, inflammation markers, hormonal levels, glucose, and insulin levels and follicular development compared to the PCOS + MSCs group.

CONCLUSIONS

This study demonstrated that the protective effects of MSC transplantation in regulating mitochondrial dynamics, promoting mitochondrial biogenesis, competing with redox status and inflammation response were mainly mediated through the PI3K-AKT pathway in the PCOS model.

A literature review of bioactive substances for the treatment of periodontitis: In vitro, in vivo and clinical studies

Periodontitis is a common chronic inflammatory disease of the supporting tissues of the tooth that involves a complex interaction of microorganisms and various cell lines around the infected site. To prevent and treat this disease, several options are available, such as scaling, root planning, antibiotic treatment, and dental surgeries, depending on the stage of the disease. However, these treatments can have various side effects, including additional inflammatory responses, chronic wounds, and the need for secondary surgery. Consequently, numerous studies have focused on developing new therapeutic agents for more effective periodontitis treatment. This review explores the latest trends in bioactive substances with therapeutic effects for periodontitis using various search engines. Therefore, this study aimed to suggest effective directions for therapeutic approaches. Additionally, we provide a summary of the current applications and underlying mechanisms of bioactive substances, which can serve as a reference for the development of periodontitis treatments.

Prospect of Mesenchymal Stem-Cell-Conditioned Medium in the Treatment of Acute Pancreatitis: A Systematic Review

Mesenchymal stem cells (MSCs) have demonstrated potential in both clinical and pre-clinical research for mitigating tissue damage and inflammation associated with acute pancreatitis (AP) via paracrine mechanisms. Hence, there has been a recent surge of interest among researchers in utilizing MSC cultured medium (CM) and its components for the treatment of AP, which is recognized as the primary cause of hospitalization for gastrointestinal disorders globally. A systematic review was conducted by searching the MEDLINE, EMBASE, and Web of Science databases. Studies that involve the administration of MSC-CM, extracellular vesicles/microvesicles (EVs/MVs), or exosomes to AP animal models are included. A total of six research studies, including eight experiments, were identified as relevant. The findings of this study provide evidence in favor of a beneficial impact of MSC-CM on both clinical and immunological outcomes. Nevertheless, prior to clinical trials, large animal models should be used and prolonged observation periods conducted in pre-clinical research. Challenges arise due to the lack of standardization and consensus on isolation processes, quantifications, and purity testing, making it difficult to compare reports and conduct meta-analyses in MSC-CM-based therapies.

Effect of stem cell treatment on burn wounds: A systemic review and a meta-analysis

A meta-analysis was performed to evaluate the effect of stem cells treatment in managing burn wounds. A systematic literature search up to March 2022 incorporated 24 studies reported between 2013 and 2021 including 400 animals with burn wounds at the beginning of the study; 211 were using stem cells treatment, and 189 controlled. Statistical tools like the contentious method were used within a random or fixed-influence model to establish the mean difference (MD) with 95% confidence intervals (CIs) to evaluate the influence of stem cells treatment in managing burn wounds. Stem cells treatment had a significantly higher burn wound healing rate (MD, 15.18; 95% CI, 11.29-19.07, P < .001), higher blood vessel number (MD, 12.28; 95% CI, 10.06-14.51, P < .001), higher vascular endothelial growth factor (MD, 10.24; 95% CI, 7.19-13.29, P < .001), lower interleukin-1 level (MD, -98.48; 95% CI, -155.33 to -41.63, P < .001), and lower tumour necrosis factor α level (MD, -28.71; 95% CI, -46.65 to -10.76, P < .002) compared with control in animals' models with burn wounds. Stem cells treatment had a significantly higher burn wound healing rate, higher blood vessel number, higher vascular endothelial growth factor, lower interleukin-1 level, and lower tumour necrosis factor α level compared with control in animals' models with burn wounds. Further studies are required to validate these findings.

Mesenchymal stem cell-based therapy as a new therapeutic approach for acute inflammation

Acute inflammatory diseases such as acute colitis, kidney injury, liver failure, lung injury, myocardial infarction, pancreatitis, septic shock, and spinal cord injury are significant causes of death worldwide. Despite advances in the understanding of its pathophysiology, there are many restrictions in the treatment of these diseases, and new therapeutic approaches are required. Mesenchymal stem cell-based therapy due to immunomodulatory and regenerative properties is a promising candidate for acute inflammatory disease management. Based on preclinical results, mesenchymal stem cells and their-derived secretome improved immunological and clinical parameters. Furthermore, many clinical trials of acute kidney, liver, lung, myocardial, and spinal cord injury have yielded promising results. In this review, we try to provide a comprehensive view of mesenchymal stem cell-based therapy in acute inflammatory diseases as a new treatment approach.

Mesenchymal stem cells and their conditioned medium as potential therapeutic strategies in managing comorbid anxiety in rat sepsis induced by cecal ligation and puncture

OBJECTIVES

Sepsis-associated encephalopathy (SAE) is a common brain dysfunction following sepsis. Due to the beneficial effects of mesenchymal stem cells (MSCs) therapy on anxiety, an extreme and early manifestation of SAE, we hypothesized that MSCs-derived conditioned medium (CM) may be able to attenuate anxiety in cecal ligation and puncture (CLP)-induced sepsis.

MATERIALS AND METHODS

Rats were assigned into 4 groups: sham, CLP, MSC, and CM. All animals, except in the sham group, underwent the CLP procedure to induce sepsis. Two hours after sepsis induction, the rats in MSC and CM groups, received 1×10⁶ MSCs and CM derived from the same number of cells, respectively. 48 hr after the treatments, anxiety-related behaviors were assessed, and brain and right hippocampal tissues were collected.

RESULTS

MSCs and CM enhanced the percentages of open arm entries and time spent in the open arms of the elevated plus-maze and the time spent in the light side of the light-dark box. MSCs and CM decreased the Evans blue content and decreased the IL-6 and TNF-α levels in the brain tissue samples. Reductions in the expression of 5-HT2A receptors and phosphorylation of ERK1/2 and an increase in the expression of 5-HT1A receptors in the hippocampal tissue samples were observed in the MSC and CM groups.

CONCLUSION

MSCs and MSCs-derived CM attenuated anxiety-related behaviors to an equal extent by reducing inflammation, modifying 5-HT receptor expression changes, and inhibiting the ERK pathway. Therefore, MSCs-derived CM may be considered a promising therapy for comorbid anxiety in septic patients.

COVID-19 immunotherapy: Treatment based on the immune cell-mediated approaches

Multiple efforts are currently underway to control and treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing coronavirus disease 2019 (COVID-19) worldwide. Despite all efforts, the virus that emerged in Wuhan city has rapidly spread globally and led to a public health emergency of international concern (PHEIC) due to the lack of approved antiviral therapy. Nevertheless, SARS-CoV-2 has had a significant influence on the evolution of cellular therapeutic approaches. Adoptive immune cell therapy is innovative and offers either promising prophylactic or therapy for patients with moderate-to-severe COVID-19. This approach is aimed at developing safety and providing secure and effective therapy in combination with standard therapy for all COVID-19 infected individuals. Based on the effective results of previous studies on both inflammatory and autoimmune diseases, various immune cell therapies against COVID-19 have been reviewed and discussed. It must be considered that the application of cell therapy for treatment and to eliminate infected respiratory cells could result in excessive inflammation, so this treatment must be used in combination with other treatments, despite its many beneficial efforts.

Induction of pancreatitis in mice with susceptibility to pancreatic cancer

Chronic inflammation is known to be associated with pancreatic cancer, however a complete picture regarding how these pathologies intersect is still being characterized. In vivo model systems are critical for the study of mechanisms underlying how inflammation accelerates neoplasia. Repeat injection of cerulein, a cholecystokinin (CCK) analog, is widely used to experimentally induce acute and chronic pancreatitis in vivo. Chronic cerulein administration into genetically engineered mouse models (GEMMs) with predisposition to pancreatic cancer can induce a pro-inflammatory immune response, pancreatic acinar cell damage, pancreatic stellate cell activation, and accelerate the onset of neoplasia. Here we provide a detailed protocol and insights into using cerulein to induce pancreatitis in GEMMs, and methods to experimentally assess inflammation and pancreatic neoplasia.

Hypoxia, Serum Starvation, and TNF-α Can Modify the Immunomodulation Potency of Human Adipose-Derived Stem Cells

INTRODUCTION

Adipose-derived stem cells (ADSCs) are mesenchymal stem cells (MSCs) that are found in adipose tissues, which are easily obtained from liposuction procedures using an enzyme mixture. The adhering cells are then selectively cultivated. ADSCs have great potential in regenerative medicine because they are plentiful, easily accessible, and less invasive. They also have an impressive proliferation ability and can be differentiated into mesenchymal lineages and trans-differentiating into many other cell types. In particular, they have extraordinary abilities in immunomodulation. This study aimed to investigate the effects of culture conditions (hypoxia, starvation, and TNF-α treatment) on the immunomodulation of human ADSCs.

METHODS

Human ADSCs were expanded in vitro in the standard condition before they were cultured in different stress conditions. ADSCs from passages fifth were confirmed as MSCs by some standard assays suggested by the International Society for Cell and Gene Therapy. These MSCs were used to culture in four different stress conditions: hypoxia, serum starvation, and TNF-α treatment in 48 h. After treatments, MSCs were used to evaluate their immunomodulation capacity using MSCs mixed lymphocyte reaction assay, and the concentrations of IDO, PGE2, IL-6, and IL-10 were secreted in the culture medium.

RESULTS

In different stress conditions, ADSCs exhibited different responses related to their immunomodulation. In serum starvation, ADSCs exerted a strong secretion of IDO and PGE2, whereas they showed strong IL-6 secretion in the TNF-α-supplemented medium. When exposed to lymphocytes, ADSCs caused an increase in the ratio of regulatory T cells (Tregs), and co-culture lymphocytes with ADSCs induced in hypoxic malnutrition conditions increased the IL-10 level the most. In addition, when exposed to dendritic cells (DCs), ADSCs inhibited the mature marker expressions of the DCs.

CONCLUSION

The current research showed that ADSCs change their immunomodulation properties to survive in in vitro culture environments. Treatment of ADSCs in the starvation medium for 48 h can increase the immunomodulation of ADSCs.

Preconditioning of Hypoxic Culture Increases The Therapeutic Potential of Adipose Derived Mesenchymal Stem Cells

Various in vitro preconditioning strategies have been implemented to increase the regenerative capacity of MSCs. Among them are modulation of culture atmosphere (hypoxia or anoxia), three-dimensional culture (3D), addition of trophic factors (in the form of growth factors, cytokines or hormones), lipopolysaccharides, and pharmacological agents. Preconditioning mesenchymal stem cells by culturing them in a hypoxic environment, which resembles the natural oxygen environment of the tissues (1% –7%) and not with standard culture conditions (21%), increases the survival of these cells via Hypoxia Inducible Factor-1α (HIF-1a) and via Akt-dependent mechanisms. In addition, the hypoxic precondition stimulates the secretion of pro-angiogenic growth factors, increases the expression of chemokines SDF-1 (stromal cell-derived factor-1) and its receptor CXCR4 (chemokine receptor type 4) - CXCR7 (chemokine receptor type 7) and increases engraftment of stem cell. This review aims to provide an overview of the preconditioned hypoxic treatment to increase the therapeutic potential of adipose-derived mesenchymal stem cells.  

Efficacy of stem cell therapy for burn wounds: a systematic review and meta-analysis of preclinical studies

BACKGROUND

Burns remain a serious public health problem with high morbidity and mortality rates worldwide. Although there are various treatment options available, there is no consensus on the best treatment for severe burns as of yet. Stem cell therapy has a bright prospect in many preclinical studies of burn wounds. The systematic review was performed for these preclinical studies to assess the efficacy and possible mechanisms of stem cells in treating burn wounds.

METHODS

Twenty-two studies with 595 animals were identified by searching PubMed, EMBASE, Web of Science, and Cochrane Library databases from inception to 13 May 2020. In addition, a manual search of references of studies was performed to obtain potential studies. No language or time restrictions were enforced. RevMan 5.3 was used for all data analysis.

RESULTS

The overall meta-analysis showed that stem cell therapy significantly improved burn healing rate (SMD 3.06, 95% CI 1.98 to 4.14), irrespective of transplant type, burn area, and treatment method in the control group. Subgroup analyses indicated that hair follicle stem cells seemed to exert more beneficial effects on animals with burn wounds (SMD 7.53, 95% CI 3.11 to 11.95) compared with other stem cells. Furthermore, stem cell therapy seemed to exert more beneficial effects on burn wounds with second-degree (SMD 7.53, 95% CI 3.11 to 11.95) compared with third-degree (SMD 2.65, 95% CI 1.31 to 4.00).

CONCLUSIONS

Meta-analysis showed that stem cell therapy exerts a healing function for burn wounds, mainly through angiogenesis and anti-inflammatory actions. These findings also demonstrate the need for considering variations in future clinical studies using stem cells to treat a burn wound in order to maximize the effectiveness. In general, stem cells can potentially become a novel therapy candidate for burn wounds.

In Vitro Anti-cancer Activity of Adipose-Derived Mesenchymal Stem Cells Increased after Infection with Oncolytic Reovirus

Purpose: Reovirus type 3 Dearing (ReoT3D), a wild type oncolytic virus (OV) from the Reoviridae family, kills KRAS mutant cancer cells. However, the use of OVs has faced with some limitations such as immune responses, and delivery of OVs to the tumor sites in systemic therapy. To solve this, and also to increase the anti-cancer effects of these OVs, mesenchymal stem cells (MSCs) might be used as an effective vehicle for OVs delivery. In this study, we examined the anti-cancer effects of human adipose derived-MSCs (AD-MSCs) as a vehicle of ReoT3D against human glioblastoma cells.

Methods: Here, AD-MSCs were characterized and toxicity of ReoT3D on them was determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Then, capability of AD-MSCs for virus production was assessed by real-time polymerase chain reaction (PCR), and different in vitro anti-cancer experiments were applied for our anti-cancer purposes.

Results: Our results from toxicity assay revealed that the isolated and provoked AD-MSCs were resistant to nontoxic concentration multiplicity of infection (MOI) >1 pfu/cells of ReoT3D. In addition, the results indicated that AD-MSCs were susceptible for virus life cycle complementation and were capable for production of virus progenies. Furthermore, our results showed that AD-MSCs had oncolysis effects and increased the anti-cancer effects of ReoT3D.

Conclusion: AD-MSCs as a susceptible host for oncolytic reovirus could increase the anti-cancer activity of this OV against glioblastoma multiforme (GBM) cell line.