Combined signaling of NF-kappaB and IL-17 contributes to Mesenchymal stem cells-mediated protection for Paraquat-induced acute lung injury

Inhibition of SMYD2 attenuates paraquat-induced pulmonary fibrosis by inhibiting the epithelial-mesenchymal transition through the GLIPR2/ERK/p38 axis

Paraquat (PQ) poisoning leads to irreversible fibrosis in the lungs with high mortality and no known antidote. In this study, we investigated the effect of the SET and MYND domain containing 2 (SMYD2) on PQ-induced pulmonary fibrosis (PF) and its potential mechanisms. We established an in vivo PQ-induced PF mouse model by intraperitoneal injection of PQ (20 mg/kg) and in vitro PQ (25 μM)-injured MLE-12 cell model. On the 15th day of administration, tissue injury, inflammation, and fibrosis in mice were evaluated using various methods including routine blood counts, blood biochemistry, blood gas analysis, western blotting, H&E staining, ELISA, Masson staining, and immunofluorescence. The findings indicated that AZ505 administration mitigated tissue damage, inflammation, and collagen deposition in PQ-poisoned mice. Mechanistically, both in vivo and in vitro experiments revealed that AZ505 treatment suppressed the PQ-induced epithelial-mesenchymal transition (EMT) process by downregulating GLI pathogenesis related 2 (GLIPR2) and ERK/p38 pathway. Further investigations demonstrated that SMYD2 inhibition decreased GLIPR2 methylation and facilitated GLIPR2 ubiquitination, leading to GLIPR2 destabilization in PQ-exposed MLE-12 cells. Moreover, rescue experiments conducted in vitro demonstrated that GLIPR2 overexpression eliminated the inhibitory effect of AZ505 on the ERK/p38 pathway and EMT. Our results reveal that the SMYD2 inhibitor AZ505 may act as a novel therapeutic candidate to suppress the EMT process by modulating the GLIPR2/ERK/p38 axis in PQ-induced PF.

Nutrient supplementation of beef female calves at pre-weaning enhances the commitment of fibro-adipogenic progenitor cells to preadipocytes

We aimed to evaluate the impact of nutrient supplementation of beef female calves at pre-weaning on adipogenic determination. Thirty-four female calves were assigned to two experimental treatments: Control (CON, n = 17), where animals were supplemented only with mineral mixture; Supplemented (SUP, n = 17), where animals received energy-protein supplement containing minerals (5 g/kg of BW per day) of their body weight. Animals were supplemented from 100 to 250 days of age, and muscle samples were biopsied at the end of the supplementation period. Regarding the performance variables, there were no differences between treatments for initial body weight (P = 0.75). The final body weight (P = 0.07), average daily gain (P = 0.07), rib eye area (P = 0.03), and rib fat thickness (P = 0.08) were greater in SUP female calves compared with CON treatment. The number of fibro-adipogenic progenitor cells (P = 0.69) did not differ between treatments, while a greater number of intramuscular pre-adipocytes were observed in SUP than CON female calves (P = 0.01). The expression of miRNA-4429 (P = 0.20) did not differ between treatments, while the expression of miRNA-129-5p (P = 0.09) and miRNA-129-2-3p (P = 0.05) was greater in CON than SUP female calves. Our results suggest that nutrient supplementation at early postnatal stages of development enhances the commitment of fibro-adipogenic progenitor cells into the adipogenic lineages allowing to an increase in intramuscular fat deposition potential of the animals later in life.

Human amnion-derived mesenchymal stem cells attenuate acute lung injury in two different acute lung injury mice models

Acute lung injury (ALI) is one of the most common clinical emergencies with limited effective pharmaceutical treatment in the clinic, especially when it progresses to acute respiratory distress syndrome (ARDS). Currently, mesenchymal stem cells (MSCs) exhibit specific superiority for ALI/ARDS treatment. However, stem cells from different sources may result in controversial effects on similar disease conditions. This study aimed to determine the effects of human amnion-derived mesenchymal stem cells (hAMSCs) on two different ALI mice model. The administered hAMSCs effectively accumulated in the lung tissues in all hAMSC-treated groups. Compared with the model and 1% human serum albumin (HSA) groups, high-dose hAMSCs (1.0 × 10⁶ cells) group significantly alleviated alveolar-capillary permeability, oxidative stress, inflammatory factors level and histopathological damage. In addition, the NF-κB signaling pathway is one of the key pathways activated during lipopolysaccharide (LPS) or paraquat (PQ)-induced lung injury. Our results indicated that hAMSCs (1.0 × 10⁶ cells) obviously inhibited the expression of p-IKKα/β, p-IκBα, and p-p65 in the lung tissue (p < 0.05). The high-dose (HD) hAMSC treatment exerted beneficial therapeutic effects on ALI mice models without detectable adverse reactions. The therapeutic effect of hAMSCs might involve NF-κB signaling pathway inhibition. hAMSC treatment is a potential candidate therapy for ALI.

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.

Human Amnion-Derived MSCs Alleviate Acute Lung Injury and Hinder Pulmonary Fibrosis Caused by Paraquat in Rats

Methods

First, the purity of hAD-MSCs was determined by morphological observation and FCM, and the effects on the survival of paraquat-poisoned Sprague-Dawley rats were observed. All rats were randomly divided into three groups, defined as the sham control group (n = 8), model group (n = 15), and hAD-MSC-transplanted group (n = 17). Pneumonocyte damage and inflammatory cell infiltration were investigated in the three groups of rats, untreated control, paraquat only, and paraquat+hAD-MSC transplanted, using H&E staining. Fibrosis was investigated in three groups of rats using Masson's trichrome staining and Sirius red staining. The profibrotic factor TGF-β1, the composition of fibrotic collagen HYP, and the hAD-MSC-secreted immunosuppressive factor HLA-G5 in serum were investigated in the three groups of rats using ELISA. Furthermore, the distribution of hAD-MSCs was investigated in the three groups of rats using immunohistochemistry and hematoxylin staining.

Results

The hAD-MSCs exhibited typical hallmarks of MSCs, improved the state of being and survival of paraquat-poisoned rats, reduced both lung injury and inflammation, and inhibited the progression of pulmonary fibrosis by decreasing the deposition of collagen and the secretion of both TGF-β1 and HYP. The hAD-MSCs could survive in damaged lungs and secreted appropriate amounts of HLA-G5 into the serum.

Conclusion

The obtained results indicate that hAD-MSCs used to treat paraquat-induced lung injury may work through anti-inflammatory and immunosuppressive pathways and the downregulation of profibrotic elements. This study suggests that the transplantation of hAD-MSCs is a promising therapeutic approach for the treatment of paraquat-intoxicated patients.

Cytokine changes in fatal cases of paraquat poisoning

Cytokine-mediated inflammation is involved in the pathophysiology of paraquat toxicity. Nevertheless, few human studies have examined fluctuations in circulating cytokine levels. Blood samples were obtained from 21 patients with paraquat poisoning and compared to those of 18 healthy controls. All paraquat patients received a standard detoxification protocol composed of hemoperfusion, pulse therapies of methylprednisolone and cyclophosphamide, followed by dexamethasone therapy. Nonsurvivors not only had higher scores for the severity index of paraquat poisoning (P=0.004) but also presented with higher white blood cell counts (P=0.046) than survivors. Multiplex immunoassays revealed higher circulating levels of interleukin 2 (IL-2), interleukin 9 (IL-9), interleukin 10 (IL-10) and macrophage inflammatory protein-1 beta (MIP-1β) in survivors than in healthy controls. Furthermore, the circulating levels of interleukin 1 beta (IL-1β), IL-2, interleukin 5 (IL-5), interleukin 8 (IL-8), IL-9, IL-10, interleukin 12 (IL-12 p70), interleukin 17A (IL-17A), eotaxin, granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein-1 (MCP-1), interferon gamma-induced protein 10 (IP-10) and MIP-1β were higher in nonsurvivors than in healthy controls. Finally, the circulating levels of IL-1β and MCP-1 were higher in nonsurvivors than in survivors. Therefore, the observation of cytokine-mediated inflammation is in line with the detoxification protocol because glucocorticoids and cyclophosphamide are potent anti-inflammatory agents. Additionally, circulating levels of IL-1β and MCP-1 could serve as promising prognostic markers for patients with paraquat poisoning.

HGF-Modified Dental Pulp Stem Cells Mitigate the Inflammatory and Fibrotic Responses in Paraquat-Induced Acute Respiratory Distress Syndrome

Paraquat (PQ) poisoning can cause acute lung injury and progress to pulmonary fibrosis and eventually death without effective therapy. Mesenchymal stem cells (MSCs) and hepatocyte growth factor (HGF) have been shown to partially reverse this damage. MSCs can be derived from bone marrow (BM-MSCs), adipose tissue (AD-MSCs), umbilical cord (UC-MSCs), dental pulp (DPSCs), and other sources. The biological characteristics of MSCs are specific to the tissue source. To develop an effective treatment for PQ poisoning, we compared the anti-inflammatory and antifibrotic effects of UC-MSCs and DPSCs and chose and modified a suitable source with HGF to investigate their therapeutic effects in vitro and in vivo. In this study, MSCs' supernatant was beneficial to the viability and proliferation of human lung epithelial cell BEAS-2B. Inflammatory and fibrosis-related cytokines were analyzed by real-time PCR. The results showed that MSCs' supernatant could suppress the expression of proinflammatory and profibrotic cytokines and increase the expression of anti-inflammatory and antifibrotic cytokines in BEAS-2B cells and human pulmonary fibroblast MRC-5. Extracellular vesicles (EVs) derived from MSCs performed more effectively than MSCs' supernatant. The effect of DPSCs was stronger than that of UC-MSCs and was further strengthened by HGF modification. PQ-poisoned mice were established, and UC-MSCs, DPSCs, and DPSCs-HGF were administered. Histopathological assessments revealed that DPSCs-HGF mitigated lung inflammation and collagen accumulation more effectively than the other treatments. DPSCs-HGF reduced lung permeability and increased the survival rate of PQ mice from 20% to 50%. Taken together, these results indicated that DPSCs can suppress inflammation and fibrosis in human lung cells better than UC-MSCs. The anti-inflammatory and antifibrotic effects were significantly enhanced by HGF modification. DPSCs-HGF ameliorated pulmonitis and pulmonary fibrosis in PQ mice, effectively improving the survival rate, which might be mediated by paracrine mechanisms. The results suggested that DPSCs-HGF transplantation was a potential therapeutic approach for PQ poisoning.

The herbicide paraquat-induced molecular mechanisms in the development of acute lung injury and lung fibrosis

The herbicide paraquat (PQ; 1,1'-dimethyl-4,4'-bipyridylium dichloride) is a highly toxic organic heterocyclic herbicide that has been widely used in agricultural settings. Since its commercial introduction in the early 1960s, numerous cases of fatal PQ poisonings attributed to accidental and/or intentional ingestion of PQ concentrated formulations have been reported. The clinical manifestations of the respiratory system during the acute phase of PQ poisoning mainly include acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), followed by pulmonary fibrosis in a later phase. The focus of this review is to summarize the most recent publications related to PQ-induced lung toxicity as well as the underlying molecular mechanisms for PQ-mediated pathologic processes. Growing sets of data from in vitro and in vivo models have demonstrated the involvement of the PQ in regulating lung oxidative stress, inflammatory response, epigenetics, apoptosis, autophagy, and the progression of lung fibrosis. The article also summarizes novel therapeutic avenues based on a literature review, which can be explored as potential means to combat PQ-induced lung toxicity. Finally, we also presented clinical studies on the association of PQ exposure with the incidence of lung injury and pulmonary fibrosis.