miR-132 suppresses transcription of ribosomal proteins to promote protective Th1 immunity

miRNA-132-5p mediates a negative feedback regulation of IL-8 secretion through S100A8/A9 downregulation in neutrophil-like HL-60 cells

Background

Neutrophils are an important source of pro-inflammatory and immunomodulatory cytokines. This makes neutrophils efficient drivers of interactions with immune and non-immune cells to maintain homeostasis and modulate the inflammatory process by notably regulating the release of cytokines. Ca2+-dependent regulatory mechanism encompassing cytokine secretion by neutrophils are not still identified. In this context, we propose to define new insights on the role of Ca2+-binding proteins S100A8/A9 and on the regulatory role of miRNA-132-5p, which was identified as a regulator of S100A8/A9 expression, on IL-8 secretion.

Methods

Differentiated HL-60 cells, a human promyelocytic leukemia cell line that can be induced to differentiate into neutrophil-like cells, were used as a model of human neutrophils and treated with N- formyl-methionyl-leucyl-phenylalanine (fMLF), a bacterial peptide that activates neutrophils. shRNA knockdown was used to define the role of selected targets (S100A8/A9 and miRNA-132-5p) on IL-8 secretion.

Results and discussion

Different types of cytokines engage different signaling pathways in the secretion process. IL-8 release is tightly regulated by Ca2+ binding proteins S100A8/A9. miRNA-132-5p is up-regulated over time upon fMLF stimulation and decreases S100A8/A9 expression and IL-8 secretion.

Conclusion

These findings reveal a novel regulatory loop involving S100A8/A9 and miRNA-132-5p that modulates IL-8 secretion by neutrophils in inflammatory conditions. This loop could be a potential target for therapeutic intervention in inflammatory diseases.

Promotion of Th1 and Th2 responses over Th17 in Riemerella anatipestifer stimulation in chicken splenocytes: Correlation of gga-miR-456-3p and gga-miR-16-5p with NOS2 and CCL5 expression

Riemerella (R.) anatipestifer poses a significant threat to ducks, resulting in mortality rates ranging from 5-75%. This disease is highly infectious and economically consequential for domestic ducks. Although other avian species, such as chickens, also display susceptibility, the impact is comparatively less severe than in ducks. IL-17A has a pronounced correlation with R. anatipestifer infection in ducks, which is less in chickens. This study performed an in vitro transcriptome analysis using chicken splenic lymphocytes collected at 4-, 8-, and 24-hour intervals following R. anatipestifer stimulation. The primary objective was to discern the differentially expressed genes, with a specific focus on IL-17A and IL-17F expression. Moreover, an association between specific miRNAs with NOS2 and CCL5 was identified. The manifestation of riemerellosis in chickens was linked to heightened expression of Th1- and Th2-associated cells, while Th17 cells exhibited minimal involvement. This study elucidated the mechanism behind the absence of a Th17 immune response, shedding light on its role throughout disease progression. Additionally, through small RNA sequencing, we identified a connection between miRNAs, specifically miR-456-3p and miR-16-5p, and their respective target genes NOS2 and CCL5. These miRNAs are potential regulators of the inflammatory process during riemerellosis in chickens.

microRNA-132 regulates gene expression programs involved in microglial homeostasis

microRNA-132 (miR-132), a known neuronal regulator, is one of the most robustly downregulated microRNAs (miRNAs) in the brain of Alzheimer's disease (AD) patients. Increasing miR-132 in AD mouse brain ameliorates amyloid and Tau pathologies, and also restores adult hippocampal neurogenesis and memory deficits. However, the functional pleiotropy of miRNAs requires in-depth analysis of the effects of miR-132 supplementation before it can be moved forward for AD therapy. We employ here miR-132 loss- and gain-of-function approaches using single-cell transcriptomics, proteomics, and in silico AGO-CLIP datasets to identify molecular pathways targeted by miR-132 in mouse hippocampus. We find that miR-132 modulation significantly affects the transition of microglia from a disease-associated to a homeostatic cell state. We confirm the regulatory role of miR-132 in shifting microglial cell states using human microglial cultures derived from induced pluripotent stem cells.

Small Extracellular Vesicles in Milk Cross the Blood-Brain Barrier in Murine Cerebral Cortex Endothelial Cells and Promote Dendritic Complexity in the Hippocampus and Brain Function in C57BL/6J Mice

Human milk contains large amounts of small extracellular vesicles (sEVs) and their microRNA cargos, whereas infant formulas contain only trace amounts of sEVs and microRNAs. We assessed the transport of sEVs across the blood-brain barrier (BBB) and sEV accumulation in distinct regions of the brain in brain endothelial cells and suckling mice. We further assessed sEV-dependent gene expression profiles and effects on the dendritic complexity of hippocampal granule cells and phenotypes of EV depletion in neonate, juvenile and adult mice. The transfer of sEVs across the BBB was assessed by using fluorophore-labeled bovine sEVs in brain endothelial bEnd.3 monolayers and dual chamber systems, and in wild-type newborn pups fostered to sEV and cargo tracking (ECT) dams that express sEVs labeled with a CD63-eGFP fusion protein for subsequent analysis by serial two-photon tomography and staining with anti-eGFP antibodies. Effects of EVs on gene expression and dendritic architecture of granule cells was analyzed in hippocampi from juvenile mice fed sEV and RNA-depleted (ERD) and sEV and RNA-sufficient (ERS) diets by using RNA-sequencing analysis and Golgi-Cox staining followed by integrated neuronal tracing and morphological analysis of neuronal dendrites, respectively. Spatial learning and severity of kainic acid-induced seizures were assessed in mice fed ERD and ERS diets. bEnd.3 cells internalized sEVs by using a saturable transport mechanism and secreted miR-34a across the basal membrane. sEVs penetrated the entire brain in fostering experiments; major regions of accumulation included the hippocampus, cortex and cerebellum. Two hundred ninety-five genes were differentially expressed in hippocampi from mice fed ERD and ERS diets; high-confidence gene networks included pathways implicated in axon guidance and calcium signaling. Juvenile pups fed the ERD diet had reduced dendritic complexity of dentate granule cells in the hippocampus, scored nine-fold lower in the Barnes maze test of spatial learning and memory, and the severity of seizures was 5-fold higher following kainic acid administration in adult mice fed the ERD diet compared to mice fed the ERS diet. We conclude that sEVs cross the BBB and contribute toward optimal neuronal development, spatial learning and memory, and resistance to kainic acid-induced seizures in mice.

Analysis of microRNA Expression after Glutamine Intervention in Acute Renal Ischemia-Reperfusion Injury

Background

Ischemia-reperfusion acute kidney injury (I/R AKI) is a severe kidney disease with high mortality and morbidity. This study aimed to explore the protective mechanism of glutamine (GLN) against I/R AKI.

Methods

The I/R AKI rat model was established, and HE staining of kidney tissue and serum creatinine (SCr) and blood urea nitrogen (BUN) detection were performed. The miRNAs were sequenced by high throughput in rat kidney tissue samples. Differentially expressed miRNAs (DEmiRs) between the I/R group and I/R + GLN group were screened, and enrichment analysis for target genes of DEmiRs was performed. Meanwhile, human HK-2 cells were cultured, and an I/R model was established to verify the expression of DEmiRs.

Results

Compared with the I/R group, the SCr and BUN levels at each time point were lower in the I/R + GLN group. Vacuolar degeneration of renal tubules in the I/R + GLN group was significantly reduced. In the 104 DEmiRs, we selected miR-132-5p, miR-205, and miR-615 as key miRNAs. KEGG analysis showed that the Notch signaling pathway, PI3K-Akt signaling pathway, and cGMP signaling pathway were mainly related to the GLN against I/R. qRT-PCR verified the downregulation of miR-205 in the I/R group, compared to the sham and I/R + GLN group. The I/R model was established with HK-2 cells, and the expression of miR-132-5p and miR-205 was decreased.

Conclusion

GLN reduced I/R-induced AKI. There were significant differences between miRNAs expression in I/R after GLN treatment. The process of GLN against I/R-induced AKI may be related to the Notch and PI3K-Akt signaling pathway.

Deciphering the Molecular Mechanisms of Chilling Tolerance in Lsi1-Overexpressing Rice

Improving tolerance to low-temperature stress during the rice seedling stage is of great significance in agricultural science. In this study, using the low silicon gene 1 (Lsi1)-overexpressing (Dular-OE) and wild-type rice (Dular-WT), we showed that Lsi1 overexpression enhances chilling tolerance in Dular-OE. The overexpression of the Lsi1 increases silicon absorption, but it was not the main reason for chilling tolerance in Dular-OE. Instead, our data suggest that the overexpression of a Lsi1-encoding NIP and its interaction with key proteins lead to chilling tolerance in Dular-OE. Additionally, we show that the high-mobility group protein (HMG1) binds to the promoter of Lsi1, positively regulating its expression. Moreover, Nod26-like major intrinsic protein (NIP)’s interaction with α and β subunits of ATP synthase and the 14-3-3f protein was validated by co-immunoprecipitation (Co-IP), bimolecular fluorescent complementary (BiFC), and GST-pulldown assays. Western blotting revealed that the overexpression of NIP positively regulates the ATP-synthase subunits that subsequently upregulate calcineurin B-like interacting protein kinases (CIPK) negatively regulating 14-3-3f. Overall, these NIP-mediated changes trigger corresponding pathways in an orderly manner, enhancing chilling tolerance in Dular-OE.

Association of microRNAs With Embryo Development and Fertilization in Women Undergoing Subfertility Treatments: A Pilot Study

Objective: Small non-coding RNAs, known as microRNAs (miRNAs), have emerging regulatory functions within the ovary that have been related to fertility. This study was undertaken to determine if circulating miRNAs reflect the changes associated with the parameters of embryo development and fertilization.

Methods: In this cross-sectional pilot study. Plasma miRNAs were collected from 48 sequentially presenting women in the follicular phase prior to commencing in vitro fertilization (IVF). Circulating miRNAs were measured using locked nucleic acid (LNA)-based quantitative PCR (qPCR), while an updated miRNA data set was used to determine their level of expression.

Results: Body mass index and weight were associated with the miRNAs let7b-3p and miR-375, respectively (p < 0.05), with the same relationship being found between endometrium thickness at oocyte retrieval and miR-885-5p and miR-34a-5p (p < 0.05). In contrast, miR-1260a was found to be inversely associated with anti-Mullerian hormone (AMH; p = 0.007), while miR-365a-3p, miR122-5p, and miR-34a-5p correlated with embryo fertilization rates (p < 0.05). However, when omitting cases of male infertility (n = 15), miR122-5p remained significant (p < 0.05), while miR-365a-3p and miR-34a-5p no longer differed; interestingly, however, miR1260a and mir93.3p became significant (p = 0.0087/0.02, respectively). Furthermore, age was negatively associated with miR-335-3p, miR-28-5p, miR-155-5p, miR-501-3p, and miR-497-5p (p < 0.05). Live birth rate was negatively associated with miR-335-3p, miR-100-5p, miR-497-5p, let-7d, and miR-574-3p (p < 0.05), but these were not significant when age was accounted for.However, with the exclusion of male factor infertility, all those miRNAs were no longer significant, though miR.150.5p emerged as significant (p = 0.042). A beta-regression model identified miR-1260a, miR-486-5p, and miR-132-3p (p < 0.03, p = 0.0003, p < 0.00001, respectively) as the most predictive for fertilization rate. Notably, changes in detectable miRNAs were not linked to cleavage rate, top quality embryos (G3D3), and blastocyst or antral follicle count. An ingenuity pathway analysis showed that miRNAs associated with age were also associated with the variables found in reproductive system diseases.

Conclusion: Plasma miRNAs prior to the IVF cycle were associated with differing demographic and IVF parameters, including age, and may be predictive biomarkers of fertilization rate.

Assessment of cytokines, microRNA and patient related outcome measures in conversion disorder/functional neurological disorder (CD/FND): The CANDO clinical feasibility study

BACKGROUND

Conversion disorder/functional neurological disorder (CD/FND) occurs often in neurological settings and can lead to long-term distress, disability and demand on health care services. Systemic low-grade inflammation might play a role, however, the pathogenic mechanism is still unknown.

AIM

1) To explore the feasibility to establish and assess a cohort of CD/FND with motor symptoms, involving persons with lived experience (PPI). 2) To generate proof of concept regarding a possible role for cytokines, microRNA, cortisol levels and neurocognitive symptoms in patients with motor CD/FND.

METHOD

Feasibility study.

RESULTS

The study showed active involvement of patients despite high clinical illness burden and disability, neurocognitive symptoms, childhood adverse experiences (ACE) and current life events. The study provided valuable knowledge regarding the feasibility of conducting a study in these patients that will inform future study phases. In the sample there were elevated levels of IL6, IL12, IL17A, IFNg, TNFa and VEGF-a, suggesting systemic low-grade inflammation. Also, microRNAs involved in inflammation and vascular inflammation were correlated with TNFa and VEGFa respectively, suggesting proof of concept for an epigenetic mechanism. Owing to the COVID-19 outbreak, the patient sample was limited to 15 patients.

CONCLUSION

It is a novelty that this study is conducted in the clinical setting. This innovative, translational study explores stress-related SLI in CD/FND patients and the feasibility of a larger project aiming to develop new treatments for this vulnerable population. Given the positive findings, there is scope to conduct further research into the mechanism of disease in CD/FND.

Upregulated microRNA-132 in T helper 17 cells activates hepatic stellate cells to promote hepatocellular carcinoma cell migration in vitro

MicroRNAs play an important role in the modulation of the immune system. T helper 17 (Th17) cells are involved in the modulation of the tumour microenvironment. However, the function of miRNA in Th17 cells in the tumour microenvironment is unclear. In this study, we analysed miR-132 expression in Th17 cells and assessed the function of miR-132 on Th17 cell differentiation. In addition, the effect of miR-132 on Th17 cells in the tumour microenvironment, especially hepatic stellate cells (HSCs), was confirmed. CD4+ IL-17 ∓ cells were isolated from hepatocellular carcinoma (HCC) tumour tissues. The expression of miR-132 was higher in CD4+ IL-17 + cells than in CD4+ IL-17- cells. Human primary CD4+ T cells were used for Th17 cell differentiation. Compared with primary CD4+ T cells, Th17 cells expressed high levels of miR-132. During Th17 cell differentiation, a miR-132 mimic and inhibition were applied. After treatment with the miR-132 mimic, the differentiation of Th17 cells accelerated, showing a a higher percentage of Th17 cells and the expression and secretion of IL-17 and IL-22. Smad nuclear interacting protein 1 (SNIP1), as one of the targets of miR-132, decreased during Th17 cell differentiation-related Th17 differentiation and IL-17 expression. The conditioned medium of miR-132-overexpressing Th17 cells could increase the activation of the HSCs, which strongly promoted HCC cell migration and epithelial-mesenchymal transition (EMT). In summary, miR-132 positively regulates Th17 cell differentiation and improves the function of Th17 on HSCs for their tumour-promoting effects.

Hypoxic naked mole-rat brains use microRNA to coordinate hypometabolic fuels and neuroprotective defenses

Naked mole-rats are among the mammalian champions of hypoxia tolerance. They evolved adaptations centered around reducing metabolic rate to overcome the challenges experienced in their underground burrows. In this study, we used next-generation sequencing to investigate one of the factors likely supporting hypoxia tolerance in naked mole-rat brains, posttranscriptional microRNAs (miRNAs). Of the 212 conserved miRNAs identified using small RNA sequencing, 18 displayed significant differential expression during hypoxia. Bioinformatic enrichment revealed that hypoxia-mediated miRNAs were suppressing energy expensive processes including de novo protein translation and cellular proliferation. This suppression occurred alongside the activation of neuroprotective and neuroinflammatory pathways, and the induction of central signal transduction pathways including HIF-1α and NFκB via miR-335, miR-101, and miR-155. MiRNAs also coordinated anaerobic glycolytic fuel sources, where hypoxia-upregulated miR-365 likely suppressed protein levels of ketohexokinase, the enzyme responsible for catalyzing the first committed step of fructose catabolism. This was further supported by a hypoxia-mediated reduction in glucose transporter 5 proteins that import fructose into the cell. Yet, messenger RNA and protein levels of lactate dehydrogenase, which converts pyruvate to lactate in the absence of oxygen, were elevated during hypoxia. Together, this demonstrated the induction of anaerobic glycolysis despite a lack of reliance on fructose as the primary fuel source, suggesting that hypoxic brains are metabolically different than anoxic naked mole-rat brains that were previously found to shift to fructose-based glycolysis. Our findings contribute to the growing body of oxygen-responsive miRNAs "OxymiRs" that facilitate natural miRNA-mediated mechanisms for successful hypoxic exposures.

Malat1 Suppresses Immunity to Infection through Promoting Expression of Maf and IL-10 in Th Cells

Malat1 is suppressed during Th1 and Th2 differentiation.

Malat1 loss suppresses IL-10 and Maf expression in effector Th cells.

Malat1^−/− mice mount enhanced immune responses in leishmaniasis and malaria models.

Despite extensive mapping of long noncoding RNAs in immune cells, their function in vivo remains poorly understood. In this study, we identify over 100 long noncoding RNAs that are differentially expressed within 24 h of Th1 cell activation. Among those, we show that suppression of Malat1 is a hallmark of CD4⁺ T cell activation, but its complete deletion results in more potent immune responses to infection. This is because Malat1^−/− Th1 and Th2 cells express lower levels of the immunosuppressive cytokine IL-10. In vivo, the reduced CD4⁺ T cell IL-10 expression in Malat1^−/−mice underpins enhanced immunity and pathogen clearance in experimental visceral leishmaniasis (Leishmania donovani) but more severe disease in a model of malaria (Plasmodium chabaudi chabaudi AS). Mechanistically, Malat1 regulates IL-10 through enhancing expression of Maf, a key transcriptional regulator of IL-10. Maf expression correlates with Malat1 in single Ag-specific Th cells from P. chabaudi chabaudi AS–infected mice and is downregulated in Malat1^−/− Th1 and Th2 cells. The Malat1 RNA is responsible for these effects, as antisense oligonucleotide-mediated inhibition of Malat1 also suppresses Maf and IL-10 levels. Our results reveal that through promoting expression of the Maf/IL-10 axis in effector Th cells, Malat1 is a nonredundant regulator of mammalian immunity.