Turning 21: Induction of miR-21 as a Key Switch in the Inflammatory Response

miR-21 attenuated inflammation targeting MyD88 in human chondrocytes stimulated with Hyaluronan oligosaccharides

Inflammation is the body's response to injuries, which depends on numerous regulatory factors. Among them, miRNAs have gained much attention for their role in regulating inflammatory gene expression at multiple levels. In particular, miR-21 is up-regulated during the inflammatory response and reported to be involved in the resolution of inflammation by down-regulating pro-inflammatory mediators, including MyD88. Herein, we evaluated the regulatory effects of miR-21 on the TLR-4/MyD88 pathway in an in vitro model of 6-mer HA oligosaccharides-induced inflammation in human chondrocytes. The exposition of chondrocytes to 6-mer HA induced the activation of the TLR4/MyD88 pathway, which culminates in NF-kB activation. Changes in miR-21, TLR-4, MyD88, NLRP3 inflammasome, IL-29, Caspase1, MMP-9, iNOS, and COX-2 mRNA expression of 6-mer HA-stimulated chondrocytes were examined by qRT-PCR. Protein amounts of TLR-4, MyD88, NLRP3 inflammasome, p-ERK1/2, p-AKT, IL-29, caspase1, MMP-9, p-NK-kB p65 subunit, and IKB-a have been evaluated by ELISA kits. NO and PGE2 levels have been assayed by colorimetric and ELISA kits, respectively. HA oligosaccharides induced a significant increase in the expression of the above parameters, including NF-kB activity. The use of a miR-21 mimic attenuated MyD88 expression levels and the downstream effectors. On the contrary, treatment with a miR-21 inhibitor induced opposite effects. Interestingly, the use of a MyD88 siRNA confirmed MyD88 as the target of miR-21 action. Our results suggest that miR-21 expression could increase in an attempt to reduce the inflammatory response, targeting MyD88.

Inflammatory bowel disease and risk for hemorrhoids: a Mendelian randomization analysis

Observational studies have reported an association between inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), and hemorrhoids (HEM). However, the presence of a causal relationship within this observed association remains to be confirmed. Consequently, we utilized the Mendelian randomization (MR) method to assess the causal effects of IBD on hemorrhoids. We validated the association between IBD and hemorrhoids in humans based on genome-wide association studies (GWAS) data. To investigate the causal relationship between IBD and hemorrhoids, we performed a two-sample Mendelian randomization study using training and validation sets. The genetic variation data for IBD, CD, UC, and hemorrhoids were derived from published genome-wide association studies (GWAS) of individuals of European. Two-sample Mendelian randomization and Multivariable Mendelian randomization (MVMR) were employed to determine the causal relationship between IBD (CD or UC) and hemorrhoids. Genetically predicted overall IBD was positively associated with hemorrhoids risk, with ORs of 1.02 (95% CIs 1.01-1.03, P = 4.39 × 10-4) and 1.02 (95% CIs 1.01-1.03, P = 4.99 × 10-5) in the training and validation sets, respectively. Furthermore, we found that CD was positively associated with hemorrhoids risk, with ORs of 1.02 (95% CIs 1.01-1.03, P = 4.12 × 10-6) and 1.02 (95% CIs 1.01-1.02, P = 3.78 × 10-5) for CD in the training and validation sets, respectively. In addition, we found that UC in the training set was positively associated with hemorrhoids risk (ORs 1.02, 95% CIs 1.01-1.03, P = 4.65 × 10-3), while no significant causal relationship between UC and hemorrhoids was shown in the validation set (P > 0.05). However, after MVMR adjustment, UC in the training set was not associated with an increased risk of hemorrhoids. Our study showed that there is a causal relationship between CD and hemorrhoids, which may suggest that clinicians need to prevent the occurrence of hemorrhoids in CD patients.

HSV-1 and Cellular miRNAs in CSF-Derived Exosomes as Diagnostically Relevant Biomarkers for Neuroinflammation

Virus-associated chronic inflammation may contribute to autoimmunity in a number of diseases. In the brain, autoimmune encephalitis appears related to fluctuating reactivation states of neurotropic viruses. In addition, viral miRNAs and proteins can be transmitted via exosomes, which constitute novel but highly relevant mediators of cellular communication. The current study questioned the role of HSV-1-encoded and host-derived miRNAs in cerebrospinal fluid (CSF)-derived exosomes, enriched from stress-induced neuroinflammatory diseases, mainly subarachnoid hemorrhage (SAH), psychiatric disorders (AF and SZ), and various other neuroinflammatory diseases. The results were compared with CSF exosomes from control donors devoid of any neuroinflammatory pathology. Serology proved positive, but variable immunity against herpesviruses in the majority of patients, except controls. Selective ultrastructural examinations identified distinct, herpesvirus-like particles in CSF-derived lymphocytes and monocytes. The likely release of extracellular vesicles and exosomes was most frequently observed from CSF monocytes. The exosomes released were structurally similar to highly purified stem-cell-derived exosomes. Exosomal RNA was quantified for HSV-1-derived miR-H2-3p, miR-H3-3p, miR-H4-3p, miR-H4-5p, miR-H6-3p, miR-H27 and host-derived miR-21-5p, miR-146a-5p, miR-155-5p, and miR-138-5p and correlated with the oxidative stress chemokine IL-8 and the axonal damage marker neurofilament light chain (NfL). Replication-associated miR-H27 correlated with neuronal damage marker NfL, and cell-derived miR-155-5p correlated with oxidative stress marker IL-8. Elevated miR-138-5p targeting HSV-1 latency-associated ICP0 inversely correlated with lower HSV-1 antibodies in CSF. In summary, miR-H27 and miR-155-5p may constitute neuroinflammatory markers for delineating frequent and fluctuating HSV-1 replication and NfL-related axonal damage in addition to the oxidative stress cytokine IL-8 in the brain. Tentatively, HSV-1 remains a relevant pathogen conditioning autoimmune processes and a psychiatric clinical phenotype.

Targeted delivery of anti-miRNA21 sensitizes PD-L1high tumor to immunotherapy by promoting immunogenic cell death

Rationale: Growing evidence has demonstrated that miRNA-21 (miR-21) upregulation is closely associated with tumor pathogenesis. However, the mechanisms by which miR-21 inhibition modulates the immunosuppressive tumor microenvironment (TME) and improves tumor sensitivity to immune checkpoint blockade therapies remain largely unexplored. In this study, we demonstrate the precise delivery of anti-miR-21 using a PD-L1-targeting peptide conjugate (P21) to the PD-L1high TME. Methods: Investigating miR-21 inhibition mechanisms involved conducting quantitative real-time PCR, western blot, flow cytometry, and confocal microscopy analyses. The antitumor efficacy and immune profile of P21 monotherapy, or combined with anti-PD-L1 immune checkpoint inhibitors, were assessed in mouse models bearing CT26.CL25 tumors and 4T1 breast cancer. Results Inhibition of oncogenic miR-21 in cancer cells by P21 efficiently activates tumor suppressor genes, inducing autophagy and endoplasmic reticulum stress. Subsequent cell-death-associated immune activation (immunogenic cell death) is initiated via the release of damage-associated molecular patterns. The in vivo results also illustrated that the immunogenic cell death triggered by P21 could effectively sensitize the immunosuppressive TME. That is, P21 enhances CD8+ T cell infiltration in tumor tissues by conferring immunogenicity to dying cancer cells and promoting dendritic cell maturation. Meanwhile, combining P21 with an anti-PD-L1 immune checkpoint inhibitor elicits a highly potent antitumor effect in a CT26.CL25 tumor-bearing mouse model and 4T1 metastatic tumor model. Conclusions: Collectively, we have clarified a miR-21-related immunogenic cell death mechanism through the precise delivery of anti-miR-21 to the PD-L1high TME. These findings highlight the potential of miR-21 as a target for immunotherapeutic interventions.

Influence of Photodynamic Therapy with Subsequent Surgical Treatment of Experimental Breast Cancer on Quantitative Changes in miRNAs in a Mesenteric Lymph Node

In female Wistar rats with breast cancer, quantitative changes of pro-oncogenic miRNAs (miR-21, -27a, and -221) and tumor-suppressive miR-429 in the mesenteric lymph node were assessed after photodynamic therapy for breast cancer and after photodynamic therapy followed surgical treatment. The level of pro-oncogenic miR-221 in the mesenteric lymph node decreased, and the level of pro-oncogenic miR-21 increased after photodynamic therapy for breast cancer followed by surgical treatment in comparison with the corresponding parameters after photodynamic therapy alone. The content of tumor-suppressive miR-429 remained reduced, as in the group of animals receiving photodynamic therapy alone.

A miRNA-21-Mediated PTEN/Akt/NF-κB Axis Promotes Chronic Obstructive Pulmonary Disease Pathogenesis

Background

This study sought to explore the underlying mechanism of miR-21 mediated apoptosis and inflammation in chronic obstructive pulmonary disease (COPD) induced by cigarette smoke (CS).

Methods

We detected levels and PTEN/Akt/NF-κB axis protein levels in peripheral lung tissues of COPD patients and CS-exposed mice and HBE cells. Western blotting assay was used to determine the expression of cleaved caspase-3. IL-6 and IL-8 protein was detected in cell supernatant from cells by ELISA. HBE cells were transfected with a miR-21 inhibitor, and co-culture with A549.

Results

Increased miR-21 expression, reduced PTEN expression and following activation of Akt in in peripheral lung tissues of COPD patients and CS-exposed mice and HBE cells. Inhibition of miR-21 showed enhanced PTEN levels and reduced the expression of phosphorylated form of Akt and NF-κB. Decreased expression of cleaved caspase-3, IL-6 and IL-8 in A549 cells co cultured with HBE cells transfected with miR-21 inhibitor compared with transfected with miR-21 control inhibitor.

Conclusion

MiR-21 contributes to COPD pathogenesis by modulating apoptosis and inflammation through the PTEN/Akt/NF-κB pathway. Targeting miR-21 may increase PTEN expression and inhibit Akt/NF-κB pathway, offering potential diagnostic and therapeutic value in COPD management.

Restoration of epigenetic impairment in the skeletal muscle and chronic inflammation resolution as a therapeutic approach in sarcopenia

Sarcopenia is an age-associated loss of skeletal muscle mass, strength, and function, accompanied by severe adverse health outcomes, such as falls and fractures, functional decline, high health costs, and mortality. Hence, its prevention and treatment have become increasingly urgent. However, despite the wide prevalence and extensive research on sarcopenia, no FDA-approved disease-modifying drugs exist. This is probably due to a poor understanding of the mechanisms underlying its pathophysiology. Recent evidence demonstrate that sarcopenia development is characterized by two key elements: (i) epigenetic dysregulation of multiple molecular pathways associated with sarcopenia pathogenesis, such as protein remodeling, insulin resistance, mitochondria impairments, and (ii) the creation of a systemic, chronic, low-grade inflammation (SCLGI). In this review, we focus on the epigenetic regulators that have been implicated in skeletal muscle deterioration, their individual roles, and possible crosstalk. We also discuss epidrugs, which are the pharmaceuticals with the potential to restore the epigenetic mechanisms deregulated in sarcopenia. In addition, we discuss the mechanisms underlying failed SCLGI resolution in sarcopenia and the potential application of pro-resolving molecules, comprising specialized pro-resolving mediators (SPMs) and their stable mimetics and receptor agonists. These compounds, as well as epidrugs, reveal beneficial effects in preclinical studies related to sarcopenia. Based on these encouraging observations, we propose the combination of epidrugs with SCLI-resolving agents as a new therapeutic approach for sarcopenia that can effectively attenuate of its manifestations.

miR-21 Expressed by Dermal Fibroblasts Enhances Skin Wound Healing Through the Regulation of Inflammatory Cytokine Expression

The management of skin wound healing is still a challenge. MicroRNA-21 (miR-21) has been reported to play important roles in wound repair; however, the underlying mechanism needs to be further clarified. The present study aimed to study the direct role of miR-21 in skin wound healing in miR-21 KO mice and to investigate the role of miR-21 in controlling the migration and proliferation of primary human skin cells and its underlying mechanism(s). miR-21 KO and wild-type (WT) mice were used for in vivo wound healing assays, while mouse and human primary skin cells were used for in vitro assays. miR-21 inhibitors or mimics or negative control small RNAs were transfected to either inhibit or enhance miR-21 expression in the human primary dermal fibroblasts or epidermal cells. RNA sequencing analysis was performed to identify the potential molecular pathways involved. We found that the loss of miR-21 resulted in slower wound healing in miR-21 KO mouse skin and especially delayed the healing of dermal tissue. In vitro assays demonstrated that the reduced expression of miR-21 caused by its inhibitor inhibited the migration of human primary dermal fibroblasts, which could be enhanced by increased miR-21 expression caused by miR-21 mimics. RNA-sequence analysis revealed that the inhibition of miR-21 expression downregulated the inflammatory response pathways associated with the decreased expression of inflammatory cytokines, and the addition of IL-1β into the culture medium enhanced the migration and proliferation of dermal fibroblasts in vitro. In conclusion, miR-21 in dermal fibroblasts can promote the migration and growth of epidermal and dermal cells to enhance skin wound healing through controlling the expression of inflammatory cytokines.

Serum monocyte chemotactic protein 1 and soluble mannose receptor aid predictive diagnosis of pediatric sepsis

BACKGROUND

To investigate the value of serum monocyte chemotactic protein 1 (MCP-1) and soluble mannose receptor (sMR) for predictive diagnosis of pediatric sepsis.

METHODS

This study retrospectively analyzed the data of 82 children with acute and severe signs of inflammation. According to the diagnostic criteria of sepsis, these children were divided into a sepsis group (40 cases) and a non-sepsis group (42 cases). In addition, 50 children who received health examinations during the same time period in Cangzhou Central Hospital were selected as a control group. According to the prognosis of the children in the sepsis group, they were further divided into a survival group (33 cases) and a death group (7 cases). The levels of blood indicators, inflammatory markers, liver and kidney function indicators, MCP-1 level, and sMR were collected from the children. The efficacy of using sMR and MCP-1 levels in the predictive diagnosis of sepsis was analyzed by using the area under the ROC curve (AUC).

RESULTS

Serum levels of MCP-1 and sMR were (452.32±2.79) μg/ml and (97.23±.15) μg/ml, respectively, in the sepsis group, significantly higher than those in all controls (P<0.001). In the death group, the levels of white blood cells (WBC), C-reactive protein (CRP), procalcitonin (PCT), sMR, and MCP-1 were significantly higher compared to the survival group (P<0.05). The AUC for CRP in predictive diagnosis of sepsis was 0.9075; the AUC for PCT was 0.8759; the AUC for sMR was 0.9244; and the AUC for MCP-1 was 0.9406.

CONCLUSIONS

Serum sMR and MCP-1 levels can help predict the diagnosis of pediatric sepsis.

miRNA Regulation of Cell Phenotype and Parietal Remodeling in Atherosclerotic and Non-Atherosclerotic Aortic Aneurysms: Differences and Similarities

Aortic aneurysms are a serious health concern as their rupture leads to high morbidity and mortality. Abdominal aortic aneurysms (AAAs) and thoracic aortic aneurysms (TAAs) exhibit differences and similarities in their pathophysiological and pathogenetic features. AAA is a multifactorial disease, mainly associated with atherosclerosis, characterized by a relevant inflammatory response and calcification. TAA is rarely associated with atherosclerosis and in some cases is associated with genetic mutations such as Marfan syndrome (MFS) and bicuspid aortic valve (BAV). MFS-related and non-genetic or sporadic TAA share aortic degeneration with endothelial-to-mesenchymal transition (End-Mt) and fibrosis, whereas in BAV TAA, aortic degeneration with calcification prevails. microRNA (miRNAs) contribute to the regulation of aneurysmatic aortic remodeling. miRNAs are a class of non-coding RNAs, which post-transcriptionally regulate gene expression. In this review, we report the involvement of deregulated miRNAs in the different aortic remodeling characterizing AAAs and TAAs. In AAA, miRNA deregulation appears to be involved in parietal inflammatory response, smooth muscle cell (SMC) apoptosis and aortic wall calcification. In sporadic and MFS-related TAA, miRNA deregulation promotes End-Mt, SMC myofibroblastic phenotypic switching and fibrosis with glycosaminoglycan accumulation. In BAV TAA, miRNA deregulation sustains aortic calcification. Those differences may support the development of more personalized therapeutic approaches.

Mogroside V alleviates inflammation response by modulating miR-21-5P/SPRY1 axis

Mogroside V (MV) is a natural sweetener extracted from the edible plant Siraitia grosvenorii that possesses anti-inflammatory bioactivity. It has been reported that microRNAs (miRNAs) play an important role in the inflammation response suppression by natural agents. However, whether the anti-inflammation effect of mogroside V is related to miRNAs and the underlying mechanism remains unclear. Our study aimed to identify the key miRNAs important for the anti-inflammation effect of MV and reveal its underlying mechanisms. Our results showed that MV effectively alleviated lung inflammation in ovalbumin-induced (OVA-induced) asthmatic mice. miRNA-seq and mRNA-seq combined analysis identified miR-21-5p as an important miRNA for the inflammation inhibition effect of MV and it predicted SPRY1 to be a target gene of miR-21-5p. We found that MV significantly inhibited the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-2 (IL-2), interleukin-6 (IL-6), and nitric oxide (NO), as well as the protein expression of p-P65/P65, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in OVA-induced asthmatic mice and LPS-treated RAW 264.7 cells. Moreover, the release of ROS increased in LPS-stimulated RAW 264.7 cells but was mitigated by MV pretreatment. In the meantime, the expression of miR-21-5p was decreased by MV, leading to an increase in the expression of SPRY1 in RAW 264.7 cells. Furthermore, miR-21-5p overexpression or SPRY1 knockdown reversed MV's protective effect on inflammatory responses. Conversely, miR-21-5p inhibition or SPRY1 overexpression enhanced MV's effect on inflammatory responses in LPS-exposed RAW 264.7 cells. Therefore, the significant protective effect of mogroside V on inflammation response is related to the downregulation of miR-21-5p and upregulation of SPRY1 in vitro and in vivo, MiR-21-5p/SPRY1 may be novel therapeutic targets of MV for anti-inflammation treatment.

MiRNA in cervical cancer: Diagnosis to therapy: Systematic review

Cancers are one of the most public health problems worldwide. Among them, cervical cancer (CC) is the fourth most prevalent cancer with 604 000 new cases and 342 000 deaths. Mostly, it is associated with Human papillomavirus (HPV). It has been caused by the aggregation of genetic and epigenetic modifications in cervical epithelial cells. Although genetic mutations are given great attention for the carcinogenesis of CC, epigenetic changes have emerged as a hotspot area for CC biomarkers research with great implications for early diagnosis, prognosis, and treatment response prediction of the disease. Recently, there are several studies focused on miRNAs as biomarkers of cervical cancer. However, the precise function of miRNAs in the development of cervical cancer is not still completely understood, particularly when it comes to unconventional sampling materials like cervical mucus and plasma serum. Hence, this review article will give a summary of the miRNAs profiles that emerge at different stages of cervical cancer progression and their downstream effects on target genes and associated signaling pathways. Finally, these results may provide insight into the use of miRNAs as biomarkers for the prediction or diagnosis of cervical cancer or the development of miRNA-based therapeutics against cervical cancer.

MicroRNA transcriptome analysis reveals the immune regulatory mechanism of Crassostrea hongkongesis against Vibrio harveyi infection

MicroRNAs (miRNAs) are small non-coding RNA molecules that modulate target-genes expression and play crucial roles in post-transcriptional regulation and immune system regulation. The Hong Kong oyster (Crassostrea hongkongesis), as the main marine aquaculture shellfish in the South China Sea, not only has high economic and ecological value, but also is an ideal model for conducting research on pathogen host interaction. Vibrio harveyi, a Gram negative luminescent marine bacterium, is widely distributed in coastal water environments and can cause large-scale death of C. hongkongesis. However, little in formation is available on the immune regulatory mechanisms of C. hongkongesis infected with V. harveyi. Therefore, we performed microRNA transcriptome analysis for elucidating the immunoregulation mechanism of C. hongkongesis infected with V. harveyi. The results show that a total of 308468208 clean reads and 288371159 clean tags were obtained. 222 differentially expressed miRNAs were identified. A total of 388 target genes that were differentially expressed and negatively correlated with miRNA expression were predicted by 222 DEmiRs. GO enrichment analysis of 388 DETGs showed that they were mainly enriched in the immune-related term of membrane-bounded vesicle, endocytic vesicle lumen, antigen processing and presentation of exogenous peptide antigen via MHC class I, antigen processing and presentation of peptide antigen via MHC class I, and other immune-related term. KEGG enrichment analysis showed that DETGs were mainly enriched in the Complement and coagulation cascades, Herpes simplex virus 1 infection, Bacterial invasion of epithelial cells, Antigen processing and presentation and NOD-like receptor signaling pathway. The 16 key DEmiRs and their target genes form a regulatory network for seven immune-related pathways. These results suggest that V. harveyi infection induces a complex miRNA response with wide-ranging effects on immune gene expression in the C. hongkongesis. This study explored the immune response of C. hongkongesis to V. harveyi infection at the level of miRNAs, which provides new ideas for the healthy culture and selective breeding of C. hongkongesis.

Melatonin affects the expression of microRNA-21: A mini-review of current evidence

Melatonin (MLT) is an endogenous hormone produced by pineal gland which possess promising anti-tumor effects. Anti-inflammatory and anti-oxidant properties of MLT, along with its immunomodulatory, proapoptotic, and anti-angiogenic properties, are often referred to the main mechanisms of its anti-tumor effects. Recent evidence has suggested that epigenetic alterations are also involved in the anti-tumor properties of MLT. Among these MLT-induced epigenetic alterations is modulation of the expression of several oncogenic and tumor suppressor microRNAs(miRNAs). MiRNAs are among the most promising and potential therapeutic and diagnostic tools in different diseases and enhanced the development of better therapeutic drugs. Suppression of oncomicroRNAs such as microRNA-21, - 20a, and - 27a as well as, up-regulation of microRNA-34 a/c are among the most important effects of MLT on microRNAs homeostasis. Recently, miR-21 has attracted the attention of scientists due to the its wide range of effects on different cancers and diseases. Regulation of this RNA may be a key to the development of better therapeutic targets. The present review will summarize the findings of in vitro and experimental studies of MLT-induced impacts on the expression of microRNAs which are involved in different models and numerous stages of tumor initiation, growth, metastasis, and chemo-resistance.

Polyethylene microplastics induced inflammation via the miR-21/IRAK4/NF-κB axis resulting to endoplasmic reticulum stress and apoptosis in muscle of carp

As a widespread environmental pollutant, microplastics pose a great threat to the tissues and organs of aquatic animals. The carp's muscles are necessary for movement and survival. However, the mechanism of injury of polyethylene microplastics (PE-MPs) to carp muscle remains unclear. Therefore, in this study, PE-MPs with the diameter of 8 μm and the concentration of 1000 ng/L were used to feed carp for 21 days, and polyethylene microplastic treatment groups was established. The results showed that PE-MPs could cause structural abnormalities and disarrangement of muscle fibers, and aggravate oxidative stress in muscles. Exposure to PE-MPs reduced microRNA (miR-21) in muscle tissue, negatively regulated Interleukin-1 Receptor Associated Kinase 4 (IRAK4), activated Nuclear Factor Kappa-B (NF-κB) pathway, induced inflammation, and led to endoplasmic reticulum stress and apoptosis. The present study provides different targets for the prevention of muscle injury induced by polyethylene microplastics.

MicroRNAs-associated with FOXO3 in cellular senescence and other stress responses

FOXO3 is a member of the FOXO transcription factor family and is known for regulating cellular survival in response to stress caused by various external and biological stimuli. FOXO3 decides cell fate by modulating cellular senescence, apoptosis and autophagy by transcriptional regulation of genes involved in DNA damage response and oxidative stress resistance. These cellular processes are tightly regulated physiologically, with FOXO3 acting as the hub that integrates signalling networks controlling them. The activity of FOXO3 is influenced by post-translational modifications, altering its subcellular localisation. In addition, FOXO3 can also be regulated directly or indirectly by microRNAs (miRNAs) or vice versa. This review discusses the involvement of various miRNAs in FOXO3-driven cellular responses such as senescence, apoptosis, autophagy, redox and inflammation defence. Given that these responses are linked and influence cell fate, a thorough understanding of the complex regulation by miRNAs would provide key information for developing therapeutic strategy and avoid unintended consequences caused by off-site targeting of FOXO3.

Resolvin D1 (Rvd1) Attenuates In Vitro LPS-Stimulated Inflammation Through Downregulation of miR-155, miR -146, miR -148 and Krupple Like Factor 5

Background

Chronic inflammation is associated with many inflammatory diseases. Specialized pro-resolving mediators (SPMs) are well known for their crucial role in promoting the resolution phase of inflammation and restoring tissue homeostasis. Resolvin D1 (RvD1) is an endogenous omega-3-derived lipid mediator with pro-resolving activity. This study aimed to evaluate the effect of Resolvin D1 (RvD1) on some inflammatory miRNAs (mir-155-5p, miR146a-5p and miR148-3p) and Krüppel-like factors 5 (KLF5) in an LPS-stimulated THP-1 preclinical model of inflammation.

Methods

PMA-differentiated THP-1 cells (macrophages) were pre-incubated with or without various concentrations of RvD1 (10, 50, or 100 nM) for 2 h prior to stimulation by 1 μg/ml LPS. Un-stimulated PMA-differentiated THP-1 cells were as the control group. Then, the expression levels of target genes were evaluated by real-time PCR.

Results

Compared with untreated macrophages, stimulation with 1 µg/ml LPS increased mRNA expression levels of TNF-α, KLF5, miR-155-5p, miR-146-5p, and miR-148a-3p. When the cells were exposed to various concentrations (10, 50 and 100 nM) of RvD1 for 2 h prior to LPS stimulation, the TNF-α, KLF5, miR-155-5p, miR-146-5p, and miR-148a-3p mRNA expression levels were significantly downregulated in a dose-dependent manner, compared to the LPS group.

Conclusions

The results demonstrate that RvD1 can attenuate inflammatory response in LPS-stimulated macrophages. Our data also showed that RvD1 may exert anti-inflammatory effects by inhibiting miR-155-5p, miR-146a-5p, and miR-148-3p.

Immunomodulation in diabetic wounds healing: The intersection of macrophage reprogramming and immunotherapeutic hydrogels

Diabetic wound healing presents a significant clinical challenge due to the interplay of systemic metabolic disturbances and local inflammation, which hinder the healing process. Macrophages undergo a phenotypic shift from M1 to M2 during wound healing, a transition pivotal for effective tissue repair. However, in diabetic wounds, the microenvironment disrupts this phenotypic polarization, perpetuating inflammation, and impeding healing. Reprograming macrophages to restore their M2 phenotype offers a potential avenue for modulating the wound immune microenvironment and promoting healing. This review elucidates the mechanisms underlying impaired macrophage polarization toward the M2 phenotype in diabetic wounds and discusses novel strategies, including epigenetic and metabolic interventions, to promote macrophage conversion to M2. Hydrogels, with their hydrated 3D cross-linked structure, closely resemble the physiological extracellular matrix and offer advantageous properties such as biocompatibility, tunability, and versatility. These characteristics make hydrogels promising candidates for developing immunomodulatory materials aimed at addressing diabetic wounds. Understanding the role of hydrogels in immunotherapy, particularly in the context of macrophage reprograming, is essential for the development of advanced wound care solutions. This review also highlights recent advancements in immunotherapeutic hydrogels as a step toward precise and effective treatments for diabetic wounds.

Mature microRNA-binding protein QKI promotes microRNA-mediated gene silencing

Although Argonaute (AGO) proteins have been the focus of microRNA (miRNA) studies, we observed AGO-free mature miRNAs directly interacting with RNA-binding proteins, implying the sophisticated nature of fine-tuning gene regulation by miRNAs. To investigate microRNA-binding proteins (miRBPs) globally, we analyzed PAR-CLIP data sets to identify RBP quaking (QKI) as a novel miRBP for let-7b. Potential existence of AGO-free miRNAs were further verified by measuring miRNA levels in genetically engineered AGO-depleted human and mouse cells. We have shown that QKI regulates miRNA-mediated gene silencing at multiple steps, and collectively serves as an auxiliary factor empowering AGO2/let-7b-mediated gene silencing. Depletion of QKI decreases interaction of AGO2 with let-7b and target mRNA, consequently controlling target mRNA decay. This finding indicates that QKI is a complementary factor in miRNA-mediated mRNA decay. QKI, however, also suppresses the dissociation of let-7b from AGO2, and slows the assembly of AGO2/miRNA/target mRNA complexes at the single-molecule level. We also revealed that QKI overexpression suppresses cMYC expression at post-transcriptional level, and decreases proliferation and migration of HeLa cells, demonstrating that QKI is a tumour suppressor gene by in part augmenting let-7b activity. Our data show that QKI is a new type of RBP implicated in the versatile regulation of miRNA-mediated gene silencing.

Inhibitory effect of microRNA-21 on pathways and mechanisms involved in cardiac fibrosis development

Cardiac fibrosis is a pivotal cardiovascular disease (CVD) process and represents a notable health concern worldwide. While the complex mechanisms underlying CVD have been widely investigated, recent research has highlighted microRNA-21's (miR-21) role in cardiac fibrosis pathogenesis. In this narrative review, we explore the molecular interactions, focusing on the role of miR-21 in contributing to cardiac fibrosis. Various signaling pathways, such as the RAAS, TGF-β, IL-6, IL-1, ERK, PI3K-Akt, and PTEN pathways, besides dysregulation in fibroblast activity, matrix metalloproteinases (MMPs), and tissue inhibitors of MMPs cause cardiac fibrosis. Besides, miR-21 in growth factor secretion, apoptosis, and endothelial-to-mesenchymal transition play crucial roles. miR-21 capacity regulatory function presents promising insights for cardiac fibrosis. Moreover, this review discusses numerous approaches to control miR-21 expression, including antisense oligonucleotides, anti-miR-21 compounds, and Notch signaling modulation, all novel methods of cardiac fibrosis inhibition. In summary, this narrative review aims to assess the molecular mechanisms of cardiac fibrosis and its essential miR-21 function.

Extracellular vesicles from hiPSC-NSCs can prevent peripheral inflammation-induced cognitive dysfunction with inflammasome inhibition and improved neurogenesis in the hippocampus

Extracellular vesicles (EVs) released by human induced pluripotent stem cell-derived neural stem cells (hiPSC-NSCs) are enriched with miRNAs and proteins capable of mediating robust antiinflammatory activity. The lack of tumorigenic and immunogenic properties and ability to permeate the entire brain to incorporate into microglia following intranasal (IN) administrations makes them an attractive biologic for curtailing chronic neuroinflammation in neurodegenerative disorders. We tested the hypothesis that IN administrations of hiPSC-NSC-EVs can alleviate chronic neuroinflammation and cognitive impairments induced by the peripheral lipopolysaccharide (LPS) challenge. Adult male, C57BL/6J mice received intraperitoneal injections of LPS (0.75 mg/kg) for seven consecutive days. Then, the mice received either vehicle (VEH) or hiPSC-NSC-EVs (~ 10 × 109 EVs/administration, thrice over 6 days). A month later, mice in all groups were investigated for cognitive function with behavioral tests and euthanized for histological and biochemical studies. Mice receiving VEH after LPS displayed deficits in associative recognition memory, temporal pattern processing, and pattern separation. Such impairments were associated with an increased incidence of activated microglia presenting NOD-, LRR-, and pyrin domain containing 3 (NLRP3) inflammasomes, elevated levels of NLRP3 inflammasome mediators and end products, and decreased neurogenesis in the hippocampus. In contrast, the various cognitive measures in mice receiving hiPSC-NSC-EVs after LPS were closer to naive mice. Significantly, these mice displayed diminished microglial activation, NLRP3 inflammasomes, proinflammatory cytokines, and a level of neurogenesis matching age-matched naïve controls. Thus, IN administrations of hiPSC-NSC-EVs are an efficacious approach to reducing chronic neuroinflammation-induced cognitive impairments.

MicroRNAs as Potential Biomarkers of Environmental Exposure to Polycyclic Aromatic Hydrocarbons and Their Link with Inflammation and Lung Cancer

Exposure to atmospheric air pollution containing volatile organic compounds such as polycyclic aromatic hydrocarbons (PAHs) has been shown to be a risk factor in the induction of lung inflammation and the initiation and progression of lung cancer. MicroRNAs (miRNAs) are small single-stranded non-coding RNA molecules of ~20-22 nucleotides that regulate different physiological processes, and their altered expression is implicated in various pathophysiological conditions. Recent studies have shown that the regulation of gene expression of miRNAs can be affected in diseases associated with outdoor air pollution, meaning they could also be useful as biomarkers of exposure to environmental pollution. In this article, we review the published evidence on miRNAs in relation to exposure to PAH pollution and discuss the possible mechanisms that may link these compounds with the expression of miRNAs.

Anti-atherosclerosis mechanisms associated with regulation of non-coding RNAs by active monomers of traditional Chinese medicine

Atherosclerosis is the leading cause of numerous cardiovascular diseases with a high mortality rate. Non-coding RNAs (ncRNAs), RNA molecules that do not encode proteins in human genome transcripts, are known to play crucial roles in various physiological and pathological processes. Recently, researches on the regulation of atherosclerosis by ncRNAs, mainly including microRNAs, long non-coding RNAs, and circular RNAs, have gradually become a hot topic. Traditional Chinese medicine has been proved to be effective in treating cardiovascular diseases in China for a long time, and its active monomers have been found to target a variety of atherosclerosis-related ncRNAs. These active monomers of traditional Chinese medicine hold great potential as drugs for the treatment of atherosclerosis. Here, we summarized current advancement of the molecular pathways by which ncRNAs regulate atherosclerosis and mainly highlighted the mechanisms of traditional Chinese medicine monomers in regulating atherosclerosis through targeting ncRNAs.

Targeted delivery of budesonide in acetic acid induced colitis: impact on miR-21 and E-cadherin expression

Inflammatory bowel disease (IBD) is characterized by chronic inflammation along the gastrointestinal tract. For IBD effective treatment, developing an orally administered stable drug delivery system capable of targeting inflammation sites is a key challenge. Herein, we report pH responsive hyaluronic (HA) coated Eudragit S100 (ES) nanoparticles (NPs) for the targeted delivery of budesonide (BUD) (HA-BUD-ES-NPs). HA-BUD-ES-NPs showed good colloidal properties (274.8 ± 2.9 nm and - 24.6 ± 2.8 mV) with high entrapment efficiency (98.3 ± 3.41%) and pH-dependent release profile. The negative potential following incubation in simulated gastrointestinal fluids reflected the stability of HA coat. In vitro studies on Caco-2 cells showed HA-BUD-ES-NPs biocompatibility and enhanced cellular uptake and anti-inflammatory effects as shown by the significant reduction in IL-8 and TNF-α. The oral administration of HA-BUD-ES-NPs in an acetic acid induced colitis rat model significantly mitigated the symptoms of IBD, and improved BUD therapeutic efficacy compared to drug suspension. This was proved via the improvement in disease activity index and ulcer score in addition to refined histopathological findings. Also, the assessment of inflammatory markers, epithelial cadherin, and mi-R21 all reflected the higher efficiency of HA-BUD-ES-NPs compared to free drug and uncoated formulation. We thus suggest that HA-BUD-ES-NPs provide a promising drug delivery platform for the management and site specific treatment of IBD.

The potential role of miRNA in regulating macrophage polarization

Macrophage polarization is a dynamic process determining the outcome of various physiological and pathological situations through inducing pro-inflammatory responses or resolving inflammation via exerting anti-inflammatory effects. The miRNAs are epigenetic regulators of different biologic pathways that target transcription factors and signaling molecules to promote macrophage phenotype transition and regulate immune responses. Modulating the macrophage activation, differentiation, and polarization by miRNAs is crucial for immune responses in response to microenvironmental signals and under various physiological and pathological conditions. In term of clinical significance, regulating macrophage polarization via miRNAs could be utilized for inflammation control. Also, understanding the role of miRNAs in macrophage polarization can provide insights into diagnostic strategies associated with dysregulated miRNAs and for developing macrophage-centered therapeutic methods. In this case, targeting miRNAs to further regulate of macrophage polarization may become an efficient strategy for treating immune-associated disorders. The current review investigated and categorized various miRNAs directly or indirectly involved in macrophage polarization by targeting different transcription factors and signaling pathways. In addition, prospects for regulating macrophage polarization via miRNA as a therapeutic choice that could be implicated in various pathological conditions, including cancer or inflammation-mediated injuries, were discussed.

MicroRNAs as Potential Biomarkers of Post-Traumatic Epileptogenesis: A Systematic Review

Structural or post-traumatic epilepsy often develops after brain tissue damage caused by traumatic brain injury, stroke, infectious diseases of the brain, etc. Most often, between the initiating event and epilepsy, there is a period without seizures-a latent period. At this time, the process of restructuring of neural networks begins, leading to the formation of epileptiform activity, called epileptogenesis. The prediction of the development of the epileptogenic process is currently an urgent and difficult task. MicroRNAs are inexpensive and minimally invasive biomarkers of biological and pathological processes. The aim of this study is to evaluate the predictive ability of microRNAs to detect the risk of epileptogenesis. In this study, we conducted a systematic search on the MDPI, PubMed, ScienceDirect, and Web of Science platforms. We analyzed publications that studied the aberrant expression of circulating microRNAs in epilepsy, traumatic brain injury, and ischemic stroke in order to search for microRNAs-potential biomarkers for predicting epileptogenesis. Thus, 31 manuscripts examining biomarkers of epilepsy, 19 manuscripts examining biomarkers of traumatic brain injury, and 48 manuscripts examining biomarkers of ischemic stroke based on circulating miRNAs were analyzed. Three miRNAs were studied: miR-21, miR-181a, and miR-155. The findings showed that miR-21 and miR-155 are associated with cell proliferation and apoptosis, and miR-181a is associated with protein modifications. These miRNAs are not strictly specific, but they are involved in processes that may be indirectly associated with epileptogenesis. Also, these microRNAs may be of interest when they are studied in a cohort with each other and with other microRNAs. To further study the microRNA-based biomarkers of epileptogenesis, many factors must be taken into account: the time of sampling, the type of biological fluid, and other nuances. Currently, there is a need for more in-depth and prolonged studies of epileptogenesis.

A cellular regulator of the niche: telocyte

Interstitial cells are present in the environment of stem cells in order to increase stem cell proliferation and differentiation and they are important to increase the efficiency of their transplantation. Telocytes (TCs) play an important role both in the preservation of tissue organ integrity and in the pathophysiology of many diseases, especially cancer. They make homo- or heterocellular contacts to form the structure of 3D network through their telopodes and deliver signaling molecules via a juxtacrine and/or paracrine association by budding shed vesicles into the vascular, nervous and endocrine systems. During this interaction, along with organelles, mRNA, microRNA, long non-coding RNA, and genomic DNA are transferred. This review article not only specifies the properties of TCs and their roles in the tissue organ microenvironment but also gives information about the factors that play a role in the transport of epigenetic information by TCs.

The macrophage polarization by miRNAs and its potential role in the treatment of tumor and inflammation (Review)

The characteristics of monocyte/macrophage lineage are diversity and plasticity, mainly manifested by M1 and M2 subtypes in the body tissues, and playing different roles in the immunity. In the polarization process of macrophages, the classic molecular mechanism is related to sequential transcription factors. Whether in tumor or inflammatory local microenvironment, the pathological factors of the local microenvironment often affect the polarization of M1 and M2 macrophages, and participate in the occurrence and development of these pathological processes. In recent years, a growing number of research results demonstrated that non‑coding RNA (ncRNA) also participates in the polarization process of macrophages, in addition to traditional cytokines and transcriptional regulation signal pathway molecules. Among numerous ncRNAs, microRNAs (miRNAs) have attracted more attention from scholars both domestically and internationally, and significant progress has been made in basic and clinical research. Therefore, for improved understanding of the molecular mechanism of miRNAs in macrophage polarization and analysis of the potential value of this regulatory pathway in tumor and inflammatory intervention therapy, a comprehensive review of the progress of relevant literature research was conducted and some viewpoints and perspectives were proposed.

Leishmania mexicana centrin knockout parasites promote M1-polarizing metabolic changes

Leishmaniasis is a tropical disease prevalent in 90 countries. Presently, there is no approved vaccine for human use. We developed a live attenuated L. mexicana Cen-/-(LmexCen-/-) strain as a vaccine candidate that showed excellent efficacy, characterized by reduced Th2 and enhanced Th1 responses in C57BL/6 and BALB/c mice, respectively, compared to wild-type L. mexicana (LmexWT) infection. Toward understanding the immune mechanisms of protection, we applied untargeted mass spectrometric analysis to LmexCen-/- and LmexWT infections. Data showed enrichment of the pentose phosphate pathway (PPP) in ears immunized with LmexCen-/-versus naive and LmexWT infection. PPP promotes M1 polarization in macrophages, suggesting a switch to a pro-inflammatory phenotype following LmexCen-/- inoculation. Accordingly, PPP inhibition in macrophages infected with LmexCen-/- reduced the production of nitric oxide and interleukin (IL)-1β, hallmarks of classical activation. Overall, our study revealed the immune regulatory mechanisms that may be critical for the induction of protective immunity.

Effect of Low Testosterone Levels on the Expression of Proliferator-Activated Receptor Alpha in Female Patients with Primary Biliary Cholangitis

Sex-dependent patterns in chronic immune-mediated cholangiopathies, like primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), remain poorly understood. Peroxisome proliferator-activated receptor alpha (PPAR-α), expressed in immune cells, plays a key role in innate defence. In this study, the relationship between PPAR-α expression in peripheral blood mononuclear cells (PBMCs), serum androgen levels, IFNγ production, and sex-dependent tendencies during the development of PBC and PSC was investigated. We confirmed that normal cholangiocytes respond to PPAR-α and inhibit the lipopolysaccharide-induced expression of IL-6, IL-1b, and TNFα. Compared with PSC patients, PPAR-α was downregulated, while IFNγ was upregulated, in the PBMCs of PBC patients. When the analysis was conducted on females only, there was no difference in PPAR-α, but IFNγ was elevated in females with PBC compared with those with PSC. Serum testosterone concentrations in females with PBC were below the normal range (regardless of age) and correlated positively with PPAR-α and negatively with IFNγ. While PPAR-α has been reported to be a target of miR-155 and miR-21, no correlations with these microRNAs were observed in the PBMCs. However, a positive correlation between miR-21 and IFNγ was observed. Our results showed suppressed PPAR-α expression accompanied by reduced testosterone levels in women with PBC, which should elicit interest in the role of testosterone in PBC development.

Stabilizing the neural barrier - A novel approach in pain therapy

Chronic and neuropathic pain are a widespread burden. Incomplete understanding of underlying pathomechanisms is one crucial factor for insufficient treatment. Recently, impairment of the blood nerve barrier (BNB) has emerged as one key aspect of pain initiation and maintenance. In this narrative review, we discuss several mechanisms and putative targets for novel treatment strategies. Cells such as pericytes, local mediators like netrin-1 and specialized proresolving mediators (SPMs), will be covered as well as circulating factors including the hormones cortisol and oestrogen and microRNAs. They are crucial in either the BNB or similar barriers and associated with pain. While clinical studies are still scarce, these findings might provide valuable insight into mechanisms and nurture development of therapeutic approaches.

Relationship between miRNA-21, miRNA-155, and miRNA-182 expression and inflammatory factors in cerebrospinal fluid from patients with multiple sclerosis

BACKGROUND

The impact of microRNAs (miRNAs) on the differentiation and function of inflammatory cells is well-established. MiRNAs play a crucial role in modulating the expression of pro-inflammatory genes in neuronal cells as well. With this knowledge in mind, our study aimed to explore the relationship between the expression of miRNAs and inflammatory markers in the cerebrospinal fluid (CSF) of patients diagnosed with multiple sclerosis (MS). By investigating this relationship, we aimed to gain insights into the potential involvement of miRNAs in the regulation of inflammation in the context of MS.

MATERIALS AND METHODS

The expression levels of miRNA-21, miRNA-155, and miRNA-182 in cerebrospinal fluid (CSF) samples from multiple sclerosis (MS) patients and controls were determined by RT-PCR. CSF levels of the inflammatory cytokines IL-1β, IL-6, and TNF-α were measured by enzyme-linked immunosorbent assay (ELISA). In addition, high-sensitivity C-reactive protein (hs-CRP) levels were measured by quantitative turbidimetry.

RESULTS

The expression levels of microRNAs and inflammatory factors were found to be significantly higher in the CSF of MS patients compared to controls (P < 0.05). Receiver operating characteristics (ROC) analysis revealed that miRNA-21, miRNA-182, and miRNA-155 had a high area under the curve (AUC) in discriminating MS patients, with AUC values of 0.97 (P < 0.0001) for miRNA-21, 0.97 (P < 0.0001) for miRNA-182, and 0.96 (P < 0.0001) for miRNA-155. Notably, CSF miRNA-155 showed the highest accuracy in correctly diagnosing MS. Furthermore, a statistically significant relationship was observed between inflammatory cytokines and miRNA-21, miRNA-155 and miRNA-182.

CONCLUSION

Our results demonstrated that cerebrospinal fluid (CSF) levels of IL-1β, IL-6, TNF-α, hs-CRP and specific miRNAs serve as biomarkers for assessing central nervous system (CNS) inflammation and neurodegenerative processes in patients with multiple sclerosis (MS).

Exosomal miR-17-5p, miR-146a-3p, and miR-223-3p Correlate with Radiologic Sequelae in Survivors of COVID-19-Related Acute Respiratory Distress Syndrome

We investigated the association between circulating microRNAs (miRNAs) potentially involved in the lung inflammatory process and fibrosis development among COVID-19-related acute respiratory distress syndrome (ARDS) survivors. At 4 ± 2 months from clinical recovery, COVID-19-related ARDS survivors matched for age, sex, and clinical characteristics underwent chest high-resolution computerized tomography (HRCT) and were selected based on imaging pattern evolution into fully recovered (N = normal), pulmonary opacities (PO) and fibrosis-like lesions (FL). Based on the previous literature, we performed plasma miRNA profiling of exosomal miRNAs belonging to the NLRP3-inflammasome platform with validated (miR-17-5p, miR-223-3p) and putative targets (miR-146a-5p), miRNAs involved in the post-transcriptional regulation of acute phase cytokines (miR128-3p, miR3168, miR125b-2-3p, miR106a-5p), miRNAs belonging to the NLRP4-inflammasome platform (miR-141-3p) and miRNAs related to post-transcriptional regulation of the fibrosis process (miR-21-5p). miR-17-5p, miR-223-3p, and miR-146a-5p were significantly down-regulated in patients with FL when compared to patients with PO. miR-146a-5p was also down-regulated in patients with FL than in N. The expression of the remaining miRNAs did not differ by group. In patients with long-term pulmonary radiological sequelae following COVID-19-related ARDS, a down-regulation of miR-17-5p, miR-146a-3p, and miR-223-3p correlated to fibrosis development in patients showing persistent hyper-reactivity to inflammatory stimulation. Our results support the hypothesis that NLRP3-Inflammasome could be implicated in the process of fibrotic evolution of COVID-19-associated ARDS.

The regulation of lncRNAs and miRNAs in SARS-CoV-2 infection

The coronavirus disease 2019 (COVID-19) was a global endemic that continues to cause a large number of severe illnesses and fatalities. There is increasing evidence that non-coding RNAs (ncRNAs) are crucial regulators of viral infection and antiviral immune response and the role of non-coding RNAs in SARS-CoV-2 infection has now become the focus of scholarly inquiry. After SARS-CoV-2 infection, some ncRNAs' expression levels are regulated to indirectly control the expression of antiviral genes and viral gene replication. However, some other ncRNAs are hijacked by SARS-CoV-2 in order to help the virus evade the immune system by suppressing the expression of type I interferon (IFN-1) and controlling cytokine levels. In this review, we summarize the recent findings of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) among non-coding RNAs in SARS-CoV-2 infection and antiviral response, discuss the potential mechanisms of actions, and prospects for the detection, treatment, prevention and future directions of SARS-CoV-2 infection research.

Variation of Tetrahydrofurans in Thyclotides Enhances Oligonucleotide Binding and Cellular Uptake of Peptide Nucleic Acids

Selective incorporation of conformational constraints into thyclotides can be used to modulate their binding to complementary oligonucleotides, increase polarity, and optimize uptake into HCT116 cells without assistance from moieties known to promote cell uptake. The X-ray structure and biophysical studies of a thyclotide-DNA duplex reveal that incorporation of tetrahydrofurans into an aegPNA backbone promotes a helical conformation that enhances binding to complementary DNA and RNA. Selective incorporation of tetrahydrofurans into the aegPNA backbone allows polarity to be increased incrementally so that uptake into HCT116 cells can be optimized. The enhanced binding, polarity, and cellular uptake properties of thyclotides were used to demonstrate effective inhibition of microRNA-21 in HCT116 cells.

Persistent and transient olfactory deficits in COVID-19 are associated to inflammation and zinc homeostasis

Introduction

The Coronavirus Disease 2019 (COVID-19) is mainly a respiratory syndrome that can affect multiple organ systems, causing a variety of symptoms. Among the most common and characteristic symptoms are deficits in smell and taste perception, which may last for weeks/months after COVID-19 diagnosis owing to mechanisms that are not fully elucidated.

Methods

In order to identify the determinants of olfactory symptom persistence, we obtained olfactory mucosa (OM) from 21 subjects, grouped according to clinical criteria: i) with persistent olfactory symptoms; ii) with transient olfactory symptoms; iii) without olfactory symptoms; and iv) non-COVID-19 controls. Cells from the olfactory mucosa were harvested for transcriptome analyses.

Results and discussion

RNA-Seq assays showed that gene expression levels are altered for a long time after infection. The expression profile of micro RNAs appeared significantly altered after infection, but no relationship with olfactory symptoms was found. On the other hand, patients with persistent olfactory deficits displayed increased levels of expression of genes involved in the inflammatory response and zinc homeostasis, suggesting an association with persistent or transient olfactory deficits in individuals who experienced SARS-CoV-2 infection.

The Role and Mechanism of MicroRNA 21 in Osteogenesis: An Update

MicroRNAs are short, single-stranded ribonucleic acids expressed endogenously in the body to regulate gene expression at the post-translational level, with exogenous microRNA offering an attractive approach to therapy. Among the myriad microRNA candidates involved in controlling bone homeostasis and remodeling, microRNA 21 (miR21) is the most abundant. This paper discusses the studies conducted on the role and mechanism of human miR21 (hsa-miR21) in the regulation of bones and the various pathways mediated by miR21, and explores the feasibility of employing exogenous miR21 as a strategy for promoting osteogenesis. From the literature review, it was clear that miR21 plays a dual role in bone metabolism by regulating both bone formation and bone resorption. There is substantial evidence to date from both in vitro and in vivo studies that exogenous miR21 can successfully accelerate new bone synthesis in the context of bone loss due to injury or osteoporosis. This supports the exploration of applications of exogenous miR21 in bone regenerative therapy in the future.

miRNAs in Neurological Manifestation in Patients Co-Infected with SARS-CoV-2 and Herpesvírus 6 (HHV-6)

Human herpesviruses (HHVs) can establish latency and be reactivated, also are neurotropic viruses that can trigger neurological disorders. HHV-6 is a herpesvirus that is associated with neurological disorders. Studies have reported the detection of HHV-6 in patients with COVID-19 and neurological manifestations. However, specific diagnoses of the neurological disorders caused by these viruses tend to be invasive or difficult to interpret. This study aimed to establish a relationship between miRNA and neurological manifestations in patients co-infected with COVID-19 and HHV-6 and evaluate miRNAs as potential biomarkers. Serum samples from COVID-19 patients in the three cohorts were analyzed. miRNA analysis by real-time polymerase chain reaction (qPCR) revealed miRNAs associated with neuroinflammation were highly expressed in patients with neurological disorders and HHV-6 detection. When compared with the group of patients without detection of HHVs DNA and without neurological alterations, the group with detection of HHV-6 DNA and neurological alteration, displayed significant differences in the expression of mir-21, mir-146a, miR-155 and miR-let-7b (p < 0.01). Our results reinforce the involvement of miRNAs in neurological disorders and provide insights into their use as biomarkers for neurological disorders triggered by HHV-6. Furthermore, understanding the expression of miRNAs may contribute to therapeutic strategies.

Canine Mesenchymal-Stem-Cell-Derived Extracellular Vesicles Attenuate Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is associated with systemic inflammation and immune modulation. Previously, we have shown that extracellular vesicles resulting from human adipose-tissue-derived mesenchymal stem cells (ASC-EVs) attenuated AD-like symptoms by reducing the levels of multiple inflammatory cytokines. Here, we aimed to investigate the improvement of canine AD upon using canine ASC-exosomes in a Biostir-induced AD mouse model. Additionally, we conducted in vivo toxicity studies to determine whether they targeted organs and their potential toxicity. Firstly, we isolated canine ASCs (cASCs) from the adipose tissue of a canine and characterized the cASCs-EVs. Interestingly, we found that cASC-EVs improved AD-like dermatitis and markedly decreased the levels of serum IgE, ear thickness, inflammatory cytokines, and chemokines such as IL-4 and IFN-γ in a dose-dependent manner. Moreover, there was no systemic toxicity in single- or repeat-dose toxicity studies using ICR mice. In addition, we analyzed miRNA arrays from cASC-EVs using next-generation sequencing (NGS) to investigate the role of miRNAs in improving inflammatory responses. Collectively, our results suggest that cASC-EVs effectively attenuate AD by transporting anti-inflammatory miRNAs to atopic lesions alongside no toxicological findings, resulting in a promising cell-free therapeutic option for treating canine AD.

High Expression Levels of miR-21-5p in Younger Hospitalized COVID-19 Patients Are Associated with Mortality and Critical Disease

In COVID-19, critical disease and invasive mechanical ventilation (IMV) increase the risk of death, mainly in patients over 60 years of age.

OBJECTIVES

To find the relationship between miR-21-5p and miR-146a-5p in terms of the severity, IMV, and mortality in hospitalized COVID-19 patients younger than 55 years of age.

METHODS

The patients were stratified according to disease severity using the IDSA/WHO criteria for severe and critical COVID-19 and subclassified into critical non-survivors and critical survivors.

RESULTS

Ninety-seven severe/critical COVID-19 patients were included; 81.3% of the deceased were male and 18.8% were female. Higher expression miR-21-5p levels were associated as follows: severe vs. critical disease (p = 0.007, FC = 0.498), PaO₂/FiO₂ index, mild vs. severe (p = 0.027, FC = 0.558), and survivors vs. non-survivors (p = 0.03, FC = 0.463). Moreover, we identified correlations with clinical variables: CRP (rho = -0.54, p < 0.001), D-dimer (rho = -0.47, p < 0.05), related to damage in the kidney (rho = 0.60, p < 0.001), liver (rho = 0.41, p < 0.05), and lung (rho = 0.54, p < 0.001). Finally, miR-21-5p thresholds were calculated according to severity (8.191), IMV (8.191), and mortality (8.237); these values increased the risk of developing a critical disease (OR = 4.19), the need for IMV (OR = 5.63), and death (OR = 6.00).

CONCLUSION

Increased expression levels of miR-21-5p are related to worse outcome of COVID-19 in younger hospitalized patients.

Inflammation Modifies miR-21 Expression Within Neuronal Extracellular Vesicles to Regulate Remyelination Following Spinal Cord Injury

Cell‒cell communication following spinal cord injury (SCI) plays a key role in remyelination and neurological recovery. Although communication between neuron-neural stem cells (NSCs) affects remyelination, its precise mechanism remains unclear. The present study investigated the biological effects of extracellular vesicles (EVs) derived from neurons on the differentiation of NSCs and the remyelination of axons in a rat model for SCI. We found that that EVs derived from neurons promoted the differentiation of NSCs into oligodendrocytes and the remyelination of axons in SCI rats. However, neuron-derived EVs lost their biological effects after inflammatory stimulation of these neurons from which they originate. Further analysis demonstrated that the inflammatory stimulation on neurons upregulated miR-21 within EVs, which targeted SMAD 7 and upregulated the TGF-β/SMAD2 signaling pathway, resulting in an excess of astrocytic scar boundaries and in remyelination failure. Moreover, these effects could be abolished by miR-21 inhibitors/antagomirs. Considered together, these results indicate that inflammatory stimulation of neurons prevents remyelination following SCI via the upregulation of miR-21 expression within neuron-derived EVs, and this takes place through SMAD 7-mediated activation of the TGF-β/SMAD2 signaling pathway. Graphical Astract.

Inflammatory microRNAs in cardiovascular pathology: another brick in the wall

The regulatory role of microRNAs (miRNAs) is mainly mediated by their effect on protein expression and is recognized in a multitude of pathophysiological processes. In recent decades, accumulating evidence has interest in these factors as modulatory elements of cardiovascular pathophysiology. Furthermore, additional biological processes have been identified as new components of cardiovascular disease etiology. In particular, inflammation is now considered an important cardiovascular risk factor. Thus, in the present review, we will focus on the role of a subset of miRNAs called inflamma-miRs that may regulate inflammatory status in the development of cardiovascular pathology. According to published data, the most representative candidates that play functional roles in thromboinflammation are miR-21, miR-33, miR-34a, miR-146a, miR-155, and miR-223. We will describe the functions of these miRNAs in several cardiovascular pathologies in depth, with specific emphasis on the molecular mechanisms related to atherogenesis. We will also discuss the latest findings on the role of miRNAs as regulators of neutrophil extracellular traps and their impact on cardiovascular diseases. Overall, the data suggest that the use of miRNAs as therapeutic tools or biomarkers may improve the diagnosis or prognosis of adverse cardiovascular events in inflammatory diseases. Thus, targeting or increasing the levels of adequate inflamma-miRs at different stages of disease could help mitigate or avoid the development of cardiovascular morbidities.

Nitrogen and copper-doped saffron-based carbon dots: Synthesis, characterization, and cytotoxic effects on human colorectal cancer cells

AIM

Doped carbon dots (CDs) have attracted tremendous attention in cancer therapy. We aimed to synthesize copper, nitrogen-doped carbon dots (Cu, N-CDs) from saffron and investigated their effects on HCT-116 and HT-29 colorectal cancer (CRC) cells.

MAIN METHODS

CDs were synthesized by hydrothermal method and characterized by transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-Vis) absorption spectroscopy, and fluorescence spectroscopy. HCT-116 and HT-29 cells were incubated with saffron, N-CDs, and Cu, N-CDs for 24 and 48 h for cell viability. Cellular uptake and intracellular reactive oxygen species (ROS) were evaluated by immunofluorescence microscopy. Oil Red O staining was used to monitor lipid accumulation. Apoptosis was evaluated using acridine orange/propidium iodide (AO/PI) staining and quantitative real-time polymerase chain reaction (Q-PCR) assay. The expression of miRNA-182 and miRNA-21 was measured by Q-PCR, while the generation of nitric oxide (NO) and lysyl oxidase (LOX) activity was calculated by colorimetric methods.

KEY FINDINGS

CDs were successfully prepared and characterized. Cell viability decreased in the treated cells dose- and time-dependently. HCT-116 and HT-29 cells uptook Cu, N-CDs with a high level of ROS generation. The Oil Red O staining showed lipid accumulation. Concomitant with an up-regulation of apoptotic genes (p < 0.05), AO/PI staining showed increased apoptosis in the treated cells. In comparison to control cells, NO generation, and miRNA-182 and miRNA-21 expression significantly changed in the Cu, N-CDs treated cells (p < 0.05).

SIGNIFICANCE

The results indicated that Cu, N-CDs could inhibit CRC cells through the induction of ROS generation and apoptosis.

A single session of EMS training induces long-lasting changes in circulating muscle but not cardiovascular miRNA levels: a randomized crossover study

Electromyostimulation (EMS) is used to maintain or build skeletal muscle and to increase cardiopulmonary fitness. Only limited data on the molecular mechanisms induced by EMS are available and effects on circulating microRNAs (c-miRNAs) have not been reported. This study aimed to evaluate whether EMS induces long-term changes in muscle- and cardiovascular-specific c-miRNA levels. Twelve healthy participants (33.0 ± 12.0 yr, 7 women) performed a 20-min whole body EMS training and a time- and intensity-matched whole body circuit training (CT) in random order. Blood samples were drawn pre-/posttraining and at 1.5, 3, 24, 48, and 72 h to determine creatine kinase (CK) and miRNA-21-5p, -126-3p, -133a-3p, -146a-5p, -206-3p, -222-3p, and -499a-5p levels. Muscular exertion was determined using an isometric strength test, and muscle soreness/pain was assessed by questionnaire. EMS participants reported higher muscle soreness 48 and 72 h postexercise and mean CK levels after EMS increased compared with CT at 48 and 72 h (time × group P ≤ 0.01). The EMS session induced a significant elevation of myomiR-206 and -133a levels starting at 1.5 and 3 h after exercise. Both miRNAs remained elevated for 72 h with significant differences between 24 and 72 h (time × group P ≤ 0.0254). EMS did not induce changes in cardiovascular miRNAs and no elevation in any miRNA was detected following CT. Time-course analysis of muscle damage marker CK and c-miR-133a and -206 levels did not suggest a common scheme (P ≥ 0.277). We conclude that a single EMS session induces specific long-lasting changes of miR-206 and miR-133 involved in muscle proliferation and differentiation. A single EMS session does not affect primary cardiovascular miRNA-21-5p, -126-3p, -146a-5p, and -222-3p levels.NEW & NOTEWORTHY Our study describes the long-term effects of electromyostimulation (EMS) on circulating miRNA levels. The observed increase of functional myomiR-206 and -133a levels over 72 h suggests long-lasting effects on muscle proliferation and differentiation, whereas cardiovascular miRNAs appear unaffected. Our findings suggest that circulating miRNAs provide useful insight into muscle regeneration processes after EMS and may thus be used to optimize EMS training effects.

Droplet Digital PCR Quantification of Selected Intracellular and Extracellular microRNAs Reveals Changes in Their Expression Pattern during Porcine In Vitro Adipogenesis

Extracellular miRNAs have attracted considerable interest because of their role in intercellular communication, as well as because of their potential use as diagnostic and prognostic biomarkers for many diseases. It has been shown that miRNAs secreted by adipose tissue can contribute to the pathophysiology of obesity. Detailed knowledge of the expression of intracellular and extracellular microRNAs in adipocytes is thus urgently required. The system of in vitro differentiation of mesenchymal stem cells (MSCs) into adipocytes offers a good model for such an analysis. The aim of this study was to quantify eight intracellular and extracellular miRNAs (miR-21a, miR-26b, miR-30a, miR-92a, miR-146a, miR-148a, miR-199, and miR-383a) during porcine in vitro adipogenesis using droplet digital PCR (ddPCR), a highly sensitive method. It was found that only some miRNAs associated with the inflammatory process (miR-21a, miR-92a) were highly expressed in differentiated adipocytes and were also secreted by cells. All miRNAs associated with adipocyte differentiation were highly abundant in both the studied cells and in the cell culture medium. Those miRNAs showed a characteristic expression profile with upregulation during differentiation.

MiRNA-Based Therapies for the Treatment of Inflammatory Bowel Disease: What Are We Still Missing?

Micro-RNAs (miRNAs) are noncoding RNAs usually 24-30 nucleotides long that play a central role in epigenetic mechanisms of inflammatory diseases and cancers. Recently, several studies have assessed the involvement of miRNAs in the pathogenesis of inflammatory bowel disease (IBD) and colitis-associated neoplasia. Particularly, it has been shown that many members of miRNAs family are involved in the pathways of inflammation and fibrogenesis of IBD; therefore, their use as inflammatory and fibrosis biomarkers has been postulated. In light of these results, the role of miRNAs in IBD therapy has been proposed and is currently under investigation with many in vitro and in vivo studies, murine models, and a phase 2a trial. The accumulating data have pushed miRNA-based therapy closer to clinical practice, although many open questions remain. With this systematic review, we discuss the current knowledge about the therapeutic effects of miRNAs mimicking and inhibition, and we explore the new potential targets of miRNA family for the treatment of inflammation and fibrosis in IBD.

The role of microRNAs in regulating inflammation and exercise-induced adaptations in rheumatoid arthritis

MicroRNAs (miRNAs) are endogenously generated single-stranded RNAs that play crucial roles in numerous biological processes, such as cell development, proliferation, differentiation, metabolism and apoptosis. They negatively regulate target gene expression by repressing translation of messenger RNA into a functional protein. Several miRNAs have been implicated in the development and progression of RA. They are involved in inflammatory and immune processes and are associated with susceptibility to RA and disease activity. They are also considered to be potential markers of disease activity or even therapeutic targets. Likewise, several miRNAs are affected acutely by exercise and regulate exercise-related adaptations in the skeletal muscle and cardiovascular system and aerobic fitness. Interestingly, some miRNAs affected by exercise are also important in the context of RA. Investigating these might increase our understanding of the effects of exercise in RA and improve exercise prescription and, potentially, disease management. In this review, we focus on the miRNAs that are associated with both RA and exercise and discuss their roles in (and potential interactions between) RA and exercise-induced adaptations.

Insights into intricacies of the Latent Membrane Protein-1 (LMP-1) in EBV-associated cancers

Numerous lymphomas, carcinomas, and other disorders have been associated with Epstein-Barr Virus (EBV) infection. EBV's carcinogenic potential can be correlated to latent membrane protein 1 (LMP1), which is essential for fibroblast and primary lymphocyte transformation. LMP1, a transmembrane protein with constitutive activity, belongs to the tumour necrosis factor receptor (TNFR) superfamily. LMP1 performs number of role in the life cycle of EBV and the pathogenesis by interfering with, reprogramming, and influencing a vast range of host cellular activities and functions that are getting well-known but still poorly understood. LMP1, pleiotropically perturbs, reprograms and balances a wide range of various processes of cell such as extracellular vesicles, epigenetics, ubiquitin machinery, metabolism, cell proliferation and survival, and also promotes oncogenic transformation, angiogenesis, anchorage-independent cell growth, metastasis and invasion, tumour microenvironment. By the help of various experiments, it is proven that EBV-encoded LMP1 activates multiple cell signalling pathways which affect antigen presentation, cell-cell interactions, chemokine and cytokine production. Therefore, it is assumed that LMP1 may perform majorly in EBV associated malignancies. For the development of novel techniques toward targeted therapeutic applications, it is essential to have a complete understanding of the LMP1 signalling landscape in order to identify potential targets. The focus of this review is on LMP1-interacting proteins and related signalling processes. We further discuss tactics for using the LMP1 protein as a potential therapeutic for cancers caused by the EBV.

Evaluation of Arterial Histopathology and microRNA Expression That Underlie Ultrasonography Findings in Temporal Arteries of Patients with Giant Cell Arteritis

The aim of this study was to assess the interrelation between vascular ultrasonography (US) findings, histopathological data, and the expression of selected dysregulated microRNAs (miRNAs) in giant cell arteritis (GCA). The study included data on the clinical parameters, US measurements, and temporal artery biopsies (TABs) of 46 treatment-naïve patients diagnosed with GCA and 22 age-matched non-GCA patient controls. We performed a comprehensive comparative and correlation analysis along with generation of receiver operating characteristic (ROC) curves to ascertain the diagnostic performance of US examination parameters and selected miRNAs for GCA diagnosis. We showed significant differences in the US-measured intima-media thickness of the temporal arteries, the presence of a halo sign, and the presence of luminal stenosis between GCA-positive/TAB-positive, GCA-positive/TAB-negative, and non-GCA patients. Correlation analysis revealed significant associations between several histopathological parameters, US-measured intima-media thickness, and the halo sign. We found that the significant overexpression of miR-146b-5p, miR-155-5p, miR-511-5p, and miR-21-5p, and the under-expression of the miR-143/145 cluster, miR-30a-5p, and miR-125a-5p, coincides and is associated with the presence of a halo sign in patients with GCA. Notably, we determined a high diagnostic performance of miR-146b-5p, miR-21-3p, and miR-21-5p expression profiles in discriminating GCA patients from non-GCA controls, suggesting their potential utilization as putative biomarkers of GCA. Taken together, our study provides an insight into the US-based diagnostic evaluation of GCA by revealing the complex interrelation of clearly defined image findings with underlying vascular immunopathology and altered arterial tissue-specific miRNA profiles.

The emerging role of noncoding RNAs in systemic lupus erythematosus: new insights into the master regulators of disease pathogenesis

Auto-immune diseases are a form of chronic disorders in which the immune system destroys the body's cells due to a loss of tolerance to self-antigens. Systemic lupus erythematosus (SLE), identified by the production of autoantibodies in different body parts, is one of the most well-known examples of these diseases. Although the etiology of SLE is unclear, the disease's progression may be affected by genetic and environmental factors. As studies in twins provide adequate evidence for genetic involvement in the SLE, other phenomena such as metallization, histone modifications, and alterations in the expression of noncoding RNAs (ncRNAs) also indicate the involvement of epigenetic factors in this disease. Among all the epigenetic alterations, ncRNAs appear to have the most crucial contribution to the pathogenesis of SLE. The ncRNAs' length and size are divided into three main classes: micro RNAs, long noncoding RNAs (LncRNA), and circular RNAs (circRNAs). Accumulating evidence suggests that dysregulations in these ncRNAs contributed to the pathogenesis of SLE. Hence, clarifying the function of these groups of ncRNAs in the pathophysiology of SLE provides a deeper understanding of the disease. It also opens up new opportunities to develop targeted therapies for this disease.