Erythropoietin prevents LPS-induced preterm birth and increases offspring survival

Harnessing stem cell therapeutics in LPS-induced animal models: mechanisms, efficacies, and future directions

The severity and threat posed by inflammation are well documented, and lipopolysaccharides (LPS), as important inducers of inflammatory responses, are widely recognized for studying host immunity and the resulting tissue and organ damage. The LPS-induced disease model, triggers a remarkable release of inflammatory factors, immune and coagulation dysfunction, and damage to vital organs such as the brain, lungs, heart, liver, and kidneys. Recently, the role of mesenchymal stem cells (MSCs) in various clinical diseases has garnered significant attention due to their immunomodulatory, anti-inflammatory, tissue healing, anti-apoptotic, and antibacterial properties. Despite the common use of LPS models to induce disease models and simulate acute inflammation, the integration of stem cell therapy within these models remains underexplored. This article integrates the LPS induced animal model and reviews the current evidence regarding the therapeutic mechanisms of stem cells in LPS-induced disease models across various human body systems. Furthermore, this review predicts and hypothesizes the feasibility and potential of using stem cells in disease models that have not yet been extensively studied, based on existing animal inflammation models.

MiRNA-26a-5p inhibits preterm labor initiation by targeting and regulating TRPC3 ion channel protein expression

The incidence of preterm birth (PTB) is increasing annually worldwide, leading to various health problems or even fetal deaths. Our previous work demonstrated the activation of transient receptor potential cation channel subfamily C 3 (TRPC3) in mice with PTB, and its activation could promote inward flow of calcium ions and uterine smooth muscle (USM) contraction via regulation of Cav3.2, Cav3.1, and Cav1.2. However, the upstream regulators of TRPC3 and its mechanisms remain unknown. In the present study, the binding of miR-26a-5p to the 3' untranslated region of TRPC3 was predicted by bioinformatics databases (TargetScanHuman and starBase v3.0) and confirmed by a dual-luciferase assay. MiR-26a-5p was downregulated, while TRPC3 was upregulated in the USM tissues of patients with PTB compared to people without PTB. The results showed that miR-26a-5p mimic transfection markedly reduced TRPC3 expression in LPS-stimulated USM cells. Additionally, miR-26a-5p regulated intracellular Ca2+ levels in USM cells by targeting TRPC3. Furthermore, miR-26a-5p inhibited the CPI17/PKC/PLCγ signaling pathway and reduced the expression of Cav3.2, Cav3.1, and Cav1.2. In conclusion, miR-26a-5p regulated the initiation of PTB by targeting TRPC3 and regulating intracellular Ca2+ levels. This study provides a promising diagnostic biomarker and therapeutic target for PTB.

Single cell profiling at the maternal-fetal interface reveals a deficiency of PD-L1+ non-immune cells in human spontaneous preterm labor

The mechanisms that underlie the timing of labor in humans are largely unknown. In most pregnancies, labor is initiated at term (≥ 37 weeks gestation), but in a signifiicant number of women spontaneous labor occurs preterm and is associated with increased perinatal mortality and morbidity. The objective of this study was to characterize the cells at the maternal-fetal interface (MFI) in term and preterm pregnancies in both the laboring and non-laboring state in Black women, who have among the highest preterm birth rates in the U.S. Using mass cytometry to obtain high-dimensional single-cell resolution, we identified 31 cell populations at the MFI, including 25 immune cell types and six non-immune cell types. Among the immune cells, maternal PD1⁺ CD8 T cell subsets were less abundant in term laboring compared to term non-laboring women. Among the non-immune cells, PD-L1⁺ maternal (stromal) and fetal (extravillous trophoblast) cells were less abundant in preterm laboring compared to term laboring women. Consistent with these observations, the expression of CD274, the gene encoding PD-L1, was significantly depressed and less responsive to fetal signaling molecules in cultured mesenchymal stromal cells from the decidua of preterm compared to term women. Overall, these results suggest that the PD1/PD-L1 pathway at the MFI may perturb the delicate balance between immune tolerance and rejection and contribute to the onset of spontaneous preterm labor.

Interventions for Infection and Inflammation-Induced Preterm Birth: a Preclinical Systematic Review

Spontaneous preterm births (< 37 weeks gestation) are frequently associated with infection. Current treatment options are limited but new therapeutic interventions are being developed in animal models. In this PROSPERO-registered preclinical systematic review, we aimed to summarise promising interventions for infection/inflammation-induced preterm birth. Following PRISMA guidance, we searched PubMed, EMBASE, and Web of Science using the themes: "animal models", "preterm birth", "inflammation", and "therapeutics". We included original quantitative, peer-reviewed, and controlled studies applying prenatal interventions to prevent infection/inflammation-induced preterm birth in animal models. We employed two risk of bias tools. Of 4020 identified studies, 23 studies (24 interventions) met our inclusion criteria. All studies used mouse models. Preterm birth was most commonly induced by lipopolysaccharide (18 studies) or Escherichia coli (4 studies). Models varied according to infectious agent serotype, dose, and route of delivery. Gestational length was significantly prolonged in 20/24 interventions (83%) and markers of maternal inflammation were reduced in 20/23 interventions (87%). Interventions targeting interleukin-1, interleukin-6, and toll-like receptors show particular therapeutic potential. However, due to the heterogeneity of the methodology of the included studies, meta-analysis was impossible. All studies were assigned an unclear risk of bias using the SYRCLE risk of bias tool. Interventions targeting inflammation demonstrate therapeutic potential for the prevention of preterm birth. However, better standardisation of preterm birth models, including the dose, serotype, timing of administration and pathogenicity of infectious agent, and outcome reporting is urgently required to improve the reproducibility of preclinical studies, allow meaningful comparison of intervention efficacy, and aid clinical translation.

Signaling Pathways Regulating Human Cervical Ripening in Preterm and Term Delivery

At the end of gestation, the cervical tissue changes profoundly. As a result of these changes, the uterine cervix becomes soft and vulnerable to dilation. The process occurring in the cervical tissue can be described as cervical ripening. The ripening is a process derivative of enzymatic breakdown and inflammatory response. Therefore, it is apparent that cervical remodeling is a derivative of the reactions mediated by multiple factors such as hormones, prostaglandins, nitric oxide, and inflammatory cytokines. However, despite the research carried out over the years, the cellular pathways responsible for regulating this process are still poorly understood. A comprehensive understanding of the entire process of cervical ripening seems crucial in the context of labor induction. Greater knowledge could provide us with the means to help women who suffer from dysfunctional labor. The overall objective of this review is to present the current understanding of cervical ripening in terms of molecular regulation and cell signaling.

Recombinant human erythropoietin accelerated the proliferation of non-small cell lung cancer cell lines and reduced the expression of VEGF, HIF-1α, and PD-L1 under a simulated hypoxic environment in vitro

Background

As erythropoietin (EPO) has been used to treat anemia in cancer patients, negative controversy has continued. Unfortunately, its effects on non-small-cell lung carcinoma (NSCLC) cell lines are uncertain and the phenomenon of inducing immune escape of tumor cells remains to be explored. This study aimed to provide an important basis for the application of exogenous EPO in the treatment of tumor-associated anemia.

Methods

Cells were cultured in 1% O2, 5% CO2, and 94% N2 to simulate a hypoxic environment of the tumor. A549 cell line (lower expression EPOR) and NCI-H838 cell line (higher expression EPOR) were treated with 2 and 8 U/ml recombinant human EPO (rhEPO). CCK-8 method was used to determine the logarithmic growth phase of the cells and to detect cell proliferation. The expression levels of VEGF, HIF-1α, and PD-L1 were determined by western blot. One-way ANOVA was used for statistical analysis between groups, with p < 0.05 indicating a significant difference.

Results

Hypoxia itself could decrease the survival rate of NSCLC cells. Under the hypoxic condition, rhEPO induced tumor cells proliferation, especially in the NCI-H838 cell line, where 2 U/ml rhEPO increased the total number of surviving cells (Hypoxia + rhEPO 2 U/ml vs. Hypoxia, p < 0.05). Western blot analysis showed that hypoxia upregulated the expression of VEGF, HIF-1α, and PD-L1 in NSCLC cell lines (Normoxia vs. Hypoxia, p < 0.05), but may not be dependent on the expression levels of EPOR. RhEPO decreased the expression levels of VEGF and HIF-1α. In the A549 cell line, it depended on the concentration of rhEPO and was particularly obvious in HIF-1α (Hypoxia vs. Hypoxia + rhEPO 2 U/ml vs. Hypoxia + rhEPO 8 U/ml, p < 0.05). A low concentration of rhEPO may not reduce VEGF expression. In the NCI-H838 cell line, the effect of rhEPO on VEGF was more obvious, but it may be independent of rhEPO concentrations. The downregulation of PD-L1 expression by rhEPO was only presented in the A549 cell line and required higher rhEPO concentrations (Hypoxia + rhEPO 8 U/ml vs. Hypoxia&Hypoxia + rhEPO 2 U/ml, p < 0.05).

Conclusion

The effect of prolonged high concentrations of rhEPO under hypoxic conditions resulted in accelerated cells proliferation of non-small-cell lung cancer and was independent of EPOR expression levels on the cell lines surface. Hypoxia resulted in increased expression of VEGF, HIF-1α, and PD-L1 on the NSCLC cell lines. Under normoxic conditions, rhEPO did not affect the expression of VEGF, HIF-1α, and PD-L1; but under hypoxic conditions, the application of rhEPO reduced the expression of VEGF, HIF-1α, and PD-L1, producing an impact on the biological behavior of tumor cells.

Erythropoietin Improves Atrophy, Bleeding and Cognition in the Newborn Intraventricular Hemorrhage

The germinal matrix-intraventricular hemorrhage (GM-IVH) is one of the most devastating complications of prematurity. The short- and long-term neurodevelopmental consequences after severe GM-IVH are a major concern for neonatologists. These kids are at high risk of psychomotor alterations and cerebral palsy; however, therapeutic approaches are limited. Erythropoietin (EPO) has been previously used to treat several central nervous system complications due to its role in angiogenesis, neurogenesis and as growth factor. In addition, EPO is regularly used to reduce the number of transfusions in the preterm infant. Moreover, EPO crosses the blood-brain barrier and EPO receptors are expressed in the human brain throughout development. To analyze the role of EPO in the GM-IVH, we have administered intraventricular collagenase (Col) to P7 mice, as a model of GM-IVH of the preterm infant. After EPO treatment, we have characterized our animals in the short (14 days) and the long (70 days) term. In our hands, EPO treatment significantly limited brain atrophy and ventricle enlargement. EPO also restored neuronal density and ameliorated dendritic spine loss. Likewise, inflammation and small vessel bleeding were also reduced, resulting in the preservation of learning and memory abilities. Moreover, plasma gelsolin levels, as a feasible peripheral marker of GM-IVH-induced damage, recovered after EPO treatment. Altogether, our data support the positive effect of EPO treatment in our preclinical model of GM-IVH, both in the short and the long term.

Erythropoietin prevents LPS-induced preterm birth and increases offspring survival

PROBLEM

Preterm delivery is the leading cause of neonatal mortality and contributes to delayed physical and cognitive development in children. At present, there is no efficient therapy to prevent preterm labor. A large body of evidence suggests that infections might play a significant and potentially preventable cause of premature birth. This work assessed the effects of erythropoietin (EPO) in a murine model of inflammation-associated preterm delivery, which mimics central features of preterm infections in humans.

METHOD OF STUDY

BALB/c mice were injected i.p. with 20 000 IU/kg EPO or normal saline twice on gestational day (GD) 15, with a 3 hours time interval between injections. An hour after the first EPO or normal saline injection, all mice received two injections of 50 μg/kg LPS, also given 3 hours apart.

RESULTS

EPO significantly prevented preterm labor and increased offspring survival in an LPS induced preterm delivery model. EPO prevented LPS-induced leukocyte infiltration into the placenta. Moreover, EPO inhibited the expression of pro-inflammatory cytokines, interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α) in maternal serum and amniotic fluid. EPO also prevented LPS-induced increase in placental prostaglandin (PG)E2 and uterine inducible nitric oxide synthase (iNOS) production, while decreasing nuclear factor kappa-B (NF-κβ) activity in the myometrium. EPO also increased the gene expression of placental programmed cell death ligand 1 (PD-L1) in LPS-treated mice.

CONCLUSIONS

Our results suggest that EPO could be a potential novel therapeutic strategy to tackle infection-related preterm labor.