Identification of a Circulating miRNA Signature to Stratify Acute Respiratory Distress Syndrome Patients

Engineered extracellular vesicles carrying let-7a-5p for alleviating inflammation in acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening respiratory condition characterized by severe inflammation and lung tissue damage, frequently causing rapid respiratory failure and long-term complications. The microRNA let-7a-5p is involved in the progression of lung injury, inflammation, and fibrosis by regulating immune cell activation and cytokine production. This study aims to use an innovative cellular electroporation platform to generate extracellular vesicles (EVs) carring let-7a-5p (EV-let-7a-5p) derived from transfected Wharton's jelly-mesenchymal stem cells (WJ-MSCs) as a potential gene therapy for ALI.

METHODS

A cellular nanoporation (CNP) method was used to induce the production and release of EV-let-7a-5p from WJ-MSCs transfected with the relevant plasmid DNA. EV-let-7a-5p in the conditioned medium were isolated using a tangential flow filtration (TFF) system. EV characterization followed the minimal consensus guidelines outlined by the International Society for Extracellular Vesicles. We conducted a thorough set of therapeutic assessments, including the antifibrotic effects using a transforming growth factor beta (TGF-β)-induced cell model, the modulation effects on macrophage polarization, and the influence of EV-let-7a-5p in a rat model of hyperoxia-induced ALI.

RESULTS

The CNP platform significantly increased EV secretion from transfected WJ-MSCs, and the encapsulated let-7a-5p in engineered EVs was markedly higher than that in untreated WJ-MSCs. These EV-let-7a-5p did not influence cell proliferation and effectively mitigated the TGF-β-induced fibrotic phenotype by downregulating SMAD2/3 phosphorylation in LL29 cells. Furthermore, EV-let-7a-5p regulated M2-like macrophage activation in an inflammatory microenvironment and significantly induced interleukin (IL)-10 secretion, demonstrating their modulatory effect on inflammation. Administering EVs from untreated WJ-MSCs slightly improved lung function and increased let-7a-5p expression in plasma in the hyperoxia-induced ALI rat model. In comparison, EV-let-7a-5p significantly reduced macrophage infiltration and collagen deposition while increasing IL-10 expression, causing a substantial improvement in lung function.

CONCLUSION

This study reveals that the use of the CNP platform to stimulate and transfect WJ-MSCs could generate an abundance of let-7a-5p-enriched EVs, which underscores the therapeutic potential in countering inflammatory responses, fibrotic activation, and hyperoxia-induced lung injury. These results provide potential avenues for developing innovative therapeutic approaches for more effective interventions in ALI.

Plasma biomarkers for brain injury in extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a life-saving intervention for patients with refractory cardiorespiratory failure. Despite its benefits, ECMO carries a significant risk of neurological complications, including acute brain injury (ABI). Although standardized neuromonitoring and neurological care have been shown to improve early detection of ABI, the inability to perform neuroimaging in a timely manner is a major limitation in the accurate diagnosis of neurological complications. Therefore, blood-based biomarkers capable of detecting ongoing brain injury at the bedside are of great clinical significance. This review aims to provide a concise review of the current literature on plasma biomarkers for ABI in patients on ECMO support.

MicroRNAs and cytokines as potential predictive biomarkers for COVID-19 disease progression

Host microRNAs can influence the cytokine storm associated SARS-CoV-2 infection and proposed as biomarkers for COVID-19 disease. In the present study, serum MiRNA-106a and miRNA-20a were quantified by real time-PCR in 50 COVID-19 patients hospitalized at Minia university hospital and 30 healthy volunteers. Profiles of serum inflammatory cytokines (TNF-α, IFN-γ, and IL-10) and TLR4 were analyzed by Eliza in patients and controls. A highly significant decrease (P value = 0.0001) in the expressions of miRNA-106a and miRNA-20a was reported in COVID-19 patients compared to controls. A significant decrease in the levels of miRNA-20a was also reported in patients with lymphopenia, patients having chest CT severity score (CSS) > 19 and in patients having O₂ saturation less than 90%. Significantly higher levels of TNF-α, IFN-γ, IL-10 and TLR4 were reported in patients compared to controls. IL-10 and TLR4 levels were significantly higher in patients having lymphopenia. TLR-4 level was higher in patients with CSS > 19 and in patients with hypoxia. Using univariate logistic regression analysis, miRNA-106a, miRNA-20a, TNF-α, IFN-γ, IL-10 and TLR4 were identified as good predictors of disease. Receiver operating curve showed that the downregulation of miRNA-20a in patients having lymphopenia, patients with CSS > 19 and patients with hypoxia could be a potential biomarker with AUC = 0.68 ± 0.08, AUC = 0.73 ± 0.07 and AUC = 0.68 ± 0.07 respectively. Also, ROC curve showed accurate association between the increase of serum IL-10 and TLR-4 and lymphopenia among COVID-19 patients with AUC = 0.66 ± 0.08 and AUC = 0.73 ± 0.07 respectively. ROC curve showed also that serum TLR-4 could be a potential marker for high CSS with AUC = 0.78 ± 0.06. A negative correlation was detected between miRNA-20a with TLR-4 (r = - 0.30, P value = 0.03). We concluded that, miR-20a, is a potential biomarker of COVID-19 severity and blockade of IL-10 and TLR4 may constitute a novel therapy for COVID-19 patients.

Stem cell therapy in the treatment of organic and dysfunctional endometrial pathology

BACKGROUND

Intrauterine adhesions caused by postpartum curettage, spontaneous abortions, interrupted pregnancies, endometrial ablations, infections and inflammations, can lead to a loss of endometrial function, with consequent hypomenorrhea and infertility in women of reproductive age. In a non-negligible percentage of cases, the available surgical methods and hormone therapy, with sequential administration of estrogen and progesterone, are ineffective. In fact, severe damage to the basal layer of the endometrium causes the loss of endometrial cell precursors and leads to the failure of regeneration of the functional layer to which the endometrium is cyclically exposed. Today, many researchers are evaluating the use of stem cells of different origins as a potential therapy to restore endometrial function.

METHODS

Our interest has been focused on adipose-derived stromal/stem cells (ADSCs) obtained by collecting subcutaneous adipose tissue and subsequently treating it with the MilliGraft^® method. This procedure produces a cell suspension, the stromal vascular fraction (SVF), which includes ADSCs and soluble factors such as proteins and extracellular vesicles (exosomes). The SVF thus obtained was characterized in its cellular composition and its functional factors. Our clinical protocol for the future use of adipose tissue in endometrial regeneration in its different phases is presented.

RESULTS

The data obtained, even though they still require further support and implementation, show the regenerative properties of SVF obtained from adipose tissue using a mechanical method.

CONCLUSIONS

These findings can contribute to the development of cell therapies using stem cells of different derivations which are increasingly being utilized in the treatment of endometrial lesions from adherent or dysfunctional pathologies.

Increased Serum Mir-150-3p Expression Is Associated with Radiological Lung Injury Improvement in Patients with COVID-19

Coronavirus disease 2019 (COVID-19) is caused by the SARS-CoV-2 virus, responsible for an atypical pneumonia that can progress to acute lung injury. MicroRNAs are small non-coding RNAs that control specific genes and pathways. This study evaluated the association between circulating miRNAs and lung injury associated with COVID-19. Methods: We evaluated lung injury by computed tomography at hospital admission and discharge and the serum expression of 754 miRNAs using the TaqMan OpenArray after hospital discharge in 27 patients with COVID-19. In addition, miR-150-3p was validated by qRT-PCR on serum samples collected at admission and after hospital discharge. Results: OpenArray analysis revealed that seven miRNAs were differentially expressed between groups of patients without radiological lung improvement compared to those with lung improvement at hospital discharge, with three miRNAs being upregulated (miR-548c-3p, miR-212-3p, and miR-548a-3p) and four downregulated (miR-191-5p, miR-151a-3p, miR-92a-3p, and miR-150-3p). Bioinformatics analysis revealed that five of these miRNAs had binding sites in the SARS-CoV-2 genome. Validation of miR-150-3p by qRT-PCR confirmed the OpenArray results. Conclusions: The present study shows the potential association between the serum expression of seven miRNAs and lung injury in patients with COVID-19. Furthermore, increased expression of miR-150 was associated with pulmonary improvement at hospital discharge.

Comprehensive Analysis of Potential ceRNA Network and Different Degrees of Immune Cell Infiltration in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a leading cause of death in critically ill patients due to hypoxemic respiratory failure. The specific pathogenesis underlying ARDS has not been fully elucidated. In this study, we constructed a triple regulatory network involving competing endogenous RNA (ceRNA) to investigate the potential mechanism of ARDS and evaluated the immune cell infiltration patterns in ARDS patients. Overall, we downloaded three microarray datasets that included 60 patients with sepsis-induced ARDS and 79 patients with sepsis alone from the public Gene Expression Omnibus (GEO) database and identified differentially expressed genes (DEGs, including 9 DElncRNAs, 9 DEmiRNAs, and 269 DEmRNAs) by R software. The DEGs were subjected to the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for functional enrichment analysis, and a protein–protein interaction (PPI) network was generated for uncovering interactive relationships among DEmRNAs. Then, a ceRNA network that contained 5 DElncRNAs, 7 DEmiRNAs, and 71 DEmRNAs was established according to the overlapping genes in both DEGs and predicted genes by public databases. Finally, we identified the TUG1/miR-140-5p/NFE2L2 pathway as the hub pathway in the whole network through Cytoscape. In addition, we evaluated the distribution of 22 subtypes of immune cells and recognized three differentially expressed immune cells in patients with sepsis-induced ARDS by “Cell Type Identification by Estimating Relative Subsets of Known RNA Transcripts (CIBERSORT)” algorithm, namely, naive B cells, regulatory T cells, and eosinophils. Correlations between differentially expressed immune cells and hub genes in the ceRNA network were also performed. In conclusion, we demonstrated a new potential regulatory mechanism underlying ARDS (the TUG1/miR-140-5p/NFE2L2 ceRNA regulatory pathway), which may help in further exploring the pathogenesis of ARDS.

The role of microRNAs in solving COVID-19 puzzle from infection to therapeutics: A mini-review

Nowadays, one of the major global health concerns is coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Even though numerous treatments and vaccines to combat this virus are currently under development, the detailed molecular mechanisms underlying the pathogenesis of this disease are yet to be elucidated to design future therapeutic tools against SARS-CoV-2 variants. MicroRNAs (miRNAs) are small (20-24 nucleotides), non-coding RNA molecules that regulate post-transcriptional gene expression. Recently, it has been demonstrated that both host and viral-encoded miRNAs are crucial for the successful infection of SARS-CoV-2. For instance, dysregulation of miRNAs that modulate multiple genes expressed in COVID-19 patients with comorbidities (e.g., type 2 diabetes, lung adenocarcinoma, and cerebrovascular disorders) could affect the severity of the disease. Thus, altered expression levels of circulating miRNAs might be helpful to diagnose this illness and forecast whether a COVID-19 patient could develop a severe state of the disease. Besides, researchers have found a number of miRNAs could inhibit the expression of proteins, such as ACE2, TMPRSS2, spike, and Nsp12, involved in the life cycle of SARS-CoV-2. Accordingly, miRNAs represent potential biomarkers and therapeutic targets for this devastating viral disease. Therefore, in this current review, we present the recent discoveries regarding the clinical relevance and biological roles of miRNAs in COVID-19.

A novel miRNA-762/NFIX pathway modulates LPS-induced acute lung injury

Severe acute lung injury (ALI) cause significant morbidity and mortality worldwide. MicroRNAs (miRNAs) are possible biomarkers and therapeutic targets for ALI. We aimed to explore the role of miR-762, a known oncogenic factor, in the pathogenesis of ALI. Levels of miR-762 in lung tissues of LPS-treated ALI mice and blood cells of patients with lung injury were measured. Injury of human lung epithelial cell line A549 was induced by LPS stimulation. A downstream target of miR-762, NFIX, was predicted using online tools. Their interactions were validated by luciferase reporter assay. Effects of targeted regulation of the miR-762/NFIX axis on cell proliferation, apoptosis, and inflammatory responses were tested in vitro in A549 cells in vivo with an ALI mouse model. We found that upregulation of miR-762 expression and downregulation of NFIX expression were associated with lung injury. Either miR-762 inhibition or NFIX overexpression in A549 lung cells significantly attenuated LPS-mediated impairment of cell proliferation and viability. Notably, increasing expressions of miR-762 inhibitor or NFIX in vivo via airway lentivirus infection alleviated the LPS-induced ALI in mice. Further, targeted downregulation of miR-762 expression or upregulation of NFIX expression in A549 cells markedly down-regulates NF-κB/IRF3 activation, and substantially reduces the production of inflammatory factors, including TNF-α, IL-6, and IL-8. This study reveals a novel role for the miR-762/NFIX pathway in ALI pathogenesis and sheds new light on targeting this pathway for diagnosis, prevention, and therapy.

Circulating miRNAs as Promising Biomarkers to Evaluate ECMO Treatment Responses in ARDS Patients

The use of extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) has increased in the last decade. However, mortality remains high, and the complexity of ECMO requires individualized treatment. There are some biomarkers to monitor progression and predict clinical outcomes of ARDS. This project aims to advance the management of ARDS patients treated with ECMO by exploring miRNA expression in whole blood. The analysis was conducted on two groups with different length of ECMO: Group A (longer runs) and group B (shorter runs). We analyzed miRNAs before ECMO cannulation, and at 7 and 14 days of ECMO support. Our results showed that in the group B patients, 11 deregulated miRNAs were identified, and showed an opposite trend of expression compared to the group A patients. In silico analysis revealed that these 11 miRNAs were related to processes involved in the pathogenesis and evolution of ARDS. This scenario could represent homeostatic mechanisms by which, in ECMO responsive patients, pathways activated during ARDS progression are switched-off. Circulating miRNAs could represent promising biomarkers to monitor the evolution of ARDS under ECMO support. Further studies may shed light on this topic to improve a personalized approach in such a complex setting of patients.