The oncogenic microRNA miR-21 promotes regulated necrosis in mice

The role of mitochondrial damage-associated molecular patterns in acute pancreatitis

Acute pancreatitis (AP) is one of the most common gastrointestinal tract diseases with significant morbidity and mortality. Current treatments remain unspecific and supportive due to the severity and clinical course of AP, which can fluctuate rapidly and unpredictably. Mitochondria, cellular power plant to produce energy, are involved in a variety of physiological or pathological activities in human body. There is a growing evidence indicating that mitochondria damage-associated molecular patterns (mtDAMPs) play an important role in pathogenesis and progression of AP. With the pro-inflammatory properties, released mtDAMPs may damage pancreatic cells by binding with receptors, activating downstream molecules and releasing inflammatory factors. This review focuses on the possible interaction between AP and mtDAMPs, which include cytochrome c (Cyt c), mitochondrial transcription factor A (TFAM), mitochondrial DNA (mtDNA), cardiolipin (CL), adenosine triphosphate (ATP) and succinate, with focus on experimental research and potential therapeutic targets in clinical practice. Preventing or diminishing the release of mtDAMPs or targeting the mtDAMPs receptors might have a role in AP progression.

Quantitative proteomics of the miR-301a/SOCS3/STAT3 axis reveals underlying autism and anxiety-like behavior

Autism is a widespread neurodevelopmental disorder. Although the research on autism spectrum disorders has been increasing in the past decade, there is still no specific answer to its mechanism of action and treatment. As a pro-inflammatory microRNA, miR-301a is abnormally expressed in various psychiatric diseases including autism. Here, we show that miR-301a deletion and inhibition exhibited two distinct abnormal behavioral phenotypes in mice. We observed that miR-301a deletion in mice impaired learning/memory, and enhanced anxiety. On the contrary, miR-301a inhibition effectively reduced the maternal immune activation (MIA)-induced autism-like behaviors in mice. We further demonstrated that miR-301a bound to the 3'UTR region of the SOCS3, and that inhibition of miR-301a led to the upregulation of SOCS3 in hippocampus. The last result in the reduction of the inflammatory response by inhibiting phosphorylation of AKT and STAT3, and the expression level of IL-17A in poly(I:C)-induced autism-like features in mice. The obtained data revealed the miR-301a as a critical participant in partial behavior phenotypes, which may exhibit a divergent role between gene knockout and knockdown. Our findings ascertain that miR-301a negatively regulates SOCS3 in MIA-induced autism in mice and could present a new therapeutic target for ameliorating the behavioral abnormalities of autism.

Necroptosis-related genes allow novel insights into predicting graft loss and diagnosing delayed graft function in renal transplantation

Ischemia-reperfusion injury (IRI) is an inevitable pathophysiological phenomenon in kidney transplantation. Necroptosis is an undoubtedly important contributing mechanism in renal IRI. We first screened differentially expressed necroptosis-related genes (DENRGs) from public databases. Eight DENRGs were validated by independent datasets and verified by qRT-PCR in a rat IRI model. We used univariate and multivariate Cox regression analyses to establish a prognostic signature, and graft survival analysis was performed. Immune infiltrating landscape analysis and gene set enrichment analysis (GSEA) were performed to understand the underlying mechanisms of graft loss, which suggested that necroptosis may aggravate the immune response, resulting in graft loss. Subsequently, a delayed graft function (DGF) diagnostic signature was constructed using the Least Absolute Shrinkage and Selection Operator (LASSO) and exhibited robust efficacy in validation datasets. After comprehensively analyzing DENRGs during IRI, we successfully constructed a prognostic signature and DGF predictive signature, which may provide clinical insights for kidney transplant.

The role of microRNAs involved in the disorder of blood-brain barrier in the pathogenesis of multiple sclerosis

miRNAs are involved in various vital processes, including cell growth, development, apoptosis, cellular differentiation, and pathological cellular activities. Circulating miRNAs can be detected in various body fluids including serum, plasma, saliva, and urine. It is worth mentioning that miRNAs remain stable in the circulation in biological fluids and are released from membrane-bound vesicles called exosomes, which protect them from RNase activity. It has been shown that miRNAs regulate blood-brain barrier integrity by targeting both tight junction and adherens junction molecules and can also influence the expression of inflammatory cytokines. Some recent studies have examined the impact of certain commonly used drugs in Multiple Sclerosis on miRNA levels. In this review, we will focus on the recent findings on the role of miRNAs in multiple sclerosis, including their role in the cause of MS and molecular mechanisms of the disease, utilizing miRNAs as diagnostic and clinical biomarkers, using miRNAs as a therapeutic modality or target for Multiple Sclerosis and drug responses in patients, elucidating their importance as prognosticators of disease progression, and highlighting their potential as a future treatment for MS.

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.

p53 at the crossroad between mitochondrial reactive oxygen species and necroptosis

p53 is a redox-sensitive transcription factor that can regulate multiple cell death programs through different signaling pathways. In this review, we assess the role of p53 in the regulation of necroptosis, a programmed form of lytic cell death highly involved in the pathophysiology of multiple diseases. In particular, we focus on the role of mitochondrial reactive oxygen species (mtROS) as essential contributors to modulate necroptosis execution through p53. The enhanced generation of mtROS during necroptosis is critical for the correct interaction between receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and 3 (RIPK3), two key components of the functional necrosome. p53 controls the occurrence of necroptosis by modulating the levels of mitochondrial H2O2 via peroxiredoxin 3 and sulfiredoxin. Furthermore, in response to increased levels of H2O2, p53 upregulates the long non-coding RNA necrosis-related factor, favoring the translation of RIPK1 and RIPK3. In parallel, a fraction of cytosolic p53 migrates into mitochondria, a process notably involved in necroptosis execution via its interaction with the mitochondrial permeability transition pore. In conclusion, p53 is located at the intersection between mtROS and the necroptosis machinery, making it a key protein to orchestrate redox signaling during necroptosis.

miR-455-3p ameliorates pancreatic acinar cell injury by targeting Slc2a1

Objective

With the number of patients with acute pancreatitis (AP) increasing year by year, it is pressing to explore new key genes and markers for the treatment of AP. miR-455-3p/solute carrier family 2 member 1 (Slc2a1) obtained through bioinformatics analysis may participate in the progression of AP.

Materials and Methods

The C57BL/6 mouse model of AP was constructed for subsequent studies. Through bioinformatics analysis, the differentially expressed genes related to AP were screened and hub genes were identified. A caerulein-induced AP animal model was constructed to detect the pathological changes of mouse pancreas by HE staining. The concentrations of amylase and lipase were measured. Primary mouse pancreatic acinar cells were isolated and subjected to microscopy to observe their morphology. The enzymatic activities of trypsin and amylase were detected. The secretion of inflammatory cytokines in mouse were measured with the ELISA kits of TNF-α, IL-6 and IL-1β to determine pancreatic acinar cell damage. A binding site between the Slc2a1 3' UTR region and the miR-455-3p sequence was verified by dual-luciferase reporter assay. The expression of miR-455-3p was quantified by qRT-PCR, and Slc2a1 were detected by western blot.

Results

A total of five (Fyn, Gadd45a, Sdc1, Slc2a1, and Src) were identified by bioinformatics analysis, and miR-455-3p/Slc2a1 were further studied. HE staining results showed that the AP models were successfully established by caerulein induction. In mice with AP, the expression of miR-455-3p was reduced, while that of Slc2a1 was increased. In the caerulein-induced cell model, the expression of Slc2a1 was significantly reduced after intervention of miR-455-3p mimics, whereas increased after miR-455-3p inhibitor treatment. miR-455-3p decreased the secretion of inflammatory cytokines in the cell supernatant, reduced the activity of trypsin and amylase, and alleviated the cell damage induced by caerulein. In addition, Slc2a1 3'UTR region was bound by miR-455-3p, and its protein expression was also regulated.

Conclusion

miR-455-3p alleviated caerulein-induced mouse pancreatic acinar cell damage by regulating the expression of Slc2a1.

The Role of MicroRNAs in Pancreatitis Development and Progression

Pancreatitis (acute and chronic) is an inflammatory disease associated with significant morbidity, including a high rate of hospitalization and mortality. MicroRNAs (miRs) are essential post-transcriptional modulators of gene expression. They are crucial in many diseases' development and progression. Recent studies have demonstrated aberrant miRs expression patterns in pancreatic tissues obtained from patients experiencing acute and chronic pancreatitis compared to tissues from unaffected individuals. Increasing evidence showed that miRs regulate multiple aspects of pancreatic acinar biology, such as autophagy, mitophagy, and migration, impact local and systemic inflammation and, thus, are involved in the disease development and progression. Notably, multiple miRs act on pancreatic acinar cells and regulate the transduction of signals between pancreatic acinar cells, pancreatic stellate cells, and immune cells, and provide a complex interaction network between these cells. Importantly, recent studies from various animal models and patients' data combined with advanced detection techniques support their importance in diagnosing and treating pancreatitis. In this review, we plan to provide an up-to-date summary of the role of miRs in the development and progression of pancreatitis.

Mn2+ modified black phosphorus nanosheets with enhanced DNA adsorption and affinity for robust sensing

To develop various biosensors, several 2D nanomaterials adsorb DNA probes (aptamers) via π-π stacking interactions. However, interference from DNA displacement by external non-targeted ligands has precluded their practical applications for specific detection and imaging at high protein concentrations. Metal coordination is an attractive strategy for biomolecular crosslinking and functional molecular self-assembly. Herein, a robust 2D biosensor nanoplatform was developed to enhance DNA adsorption and affinity using Mn²⁺-modified black phosphorus nanosheets (BPNS@Mn²⁺) via metal coordination. The Mn²⁺ can simultaneously coordinate with the lone pair electrons (π bonds) of the BPNS and nucleotide bases to provide binding sites for DNA nucleobases on the BPNS surface, which greatly enhances the stability of the inner BPNS and improves DNA adsorption and affinity. The DNA adsorption mechanism of BPNS@Mn²⁺ was also characterized, and is extensively discussed. Without any further modification, this BPNS@Mn²⁺/DNA biosensor specifically detected single-stranded DNA (linear range: 10-200 nM, detection limit: 5.76 nM) and thrombin (linear range: 20-180 nM, detection limit: 2.39 nM) in 100 nM bovine serum albumin solution. The nonspecific ligands in the environment did not affect the detection performance of the robust biosensor. In addition, the expression levels of microRNA-21 can be imaged and analyzed in living cells using this biosensor, which is consistent with the results of the polymerase chain reaction. This study highlights the potential of metal coordination in surface modification and provides new opportunities for biomedical applications of 2D nanomaterials with superior DNA-adsorption capacity, facilitating the development of biosensor design and nucleic acid/drug delivery.

Downregulation of miR-146a-5p Promotes Acute Pancreatitis through Activating the TLR9/NLRP3 Signaling Pathway by Targeting TRAF6 In Vitro Rat Model

Acute pancreatitis (AP) is mainly caused by acinar cells releasing various inflammatory factors, causing inflammatory storms and leading to severe pancreatitis. Detection methods and treatment targets for pancreatitis are lacking, raising the urgency of identifying diagnostic markers and therapeutic targets for AP. MicroRNAs (miRNAs) have recently been identified as molecular markers for various biological processes such as tumors, immunity, and metabolism, and the involvement of miRNAs in inflammatory responses has been increasingly studied. To explore the role of miRNAs in AP is the primary objective of this study. By using qPCR on our cerulein-induced pancreatitis cell model, it is worth noting that the change of miR-146a-5p expression in inflammation-related miRNAs in AP was predominant. Next, ELISA, CCK8, and flow cytometry were used to inspect the impact of miR-146a-5p on pancreatitis. BiBiServ bioinformatics anticipated binding ability of miR-146a-5p and 3′-untranslated region (3′UTR) of TNF receptor-associated factor 6 (TRAF6), and the dual-luciferase assay verified the combination of the two. TRAF6 knockdown verified the effect of TRAF6 on the progression of pancreatitis. Finally, rescue experiments verified the capability of miR-146a-5p and TRAF6 interaction on the Toll-like receptor 9 (TLR9)/NOD-like receptor protein 3 (NLRP3) signaling pathway and cell function. The expression of miR-146a-5p decreased in cerulein-induced AR42J pancreatic acinar cells. Functional experiments verified that miR-146a-5p facilitated the proliferation of AR42J pancreatic acinar cells and inhibited their apoptosis. Bioinformatic predictions and dual-luciferase experiments verified the actual binding efficiency between miR-146a-5p and 3′UTR of TRAF6. Our study confirmed that knockdown of TRAF6 restrained the progression of pancreatitis, and knockdown of TRAF6 rescued pancreatitis caused by miR-146a-5p downregulation by the TLR9/NLRP3 signaling pathway. Therefore, downregulation of miR-146a-5p in the induced pancreatitis cell model promotes the progression of pancreatitis via the TLR9/TRAF6/NLRP3 signaling pathway. There is potential for miR-146a-5p to serve as a diagnostic marker and therapeutic nucleic acid drug for AP.

From Molecular Mechanisms to Therapeutics: Understanding MicroRNA-21 in Cancer

MicroRNAs (miRNAs) are small noncoding RNAs that play an important role in regulating gene expression at a posttranscriptional level. As one of the first discovered oncogenic miRNAs, microRNA-21 (miR-21) has been highlighted for its critical role in cancers, such as glioblastoma, pancreatic adenocarcinoma, non-small cell lung cancer, and many others. MiR-21 targets many vital components in a wide range of cancers and acts on various cellular processes ranging from cancer stemness to cell death. Expression of miR-21 is elevated within cancer tissues and circulating miR-21 is readily detectable in biofluids, making it valuable as a cancer biomarker with significant potential for use in diagnosis and prognosis. Advances in RNA-based therapeutics have revealed additional avenues by which miR-21 can be utilized as a promising target in cancer. The purpose of this review is to outline the roles of miR-21 as a key modulator in various cancers and its potential as a therapeutic target.

Osteoclast-like stromal giant cells in breast cancer likely belong to the spectrum of immunosuppressive tumor-associated macrophages

Background: Breast cancer with osteoclast-like stromal giant cells (OSGC) is an exceedingly rare morphological pattern of invasive breast carcinoma. The tumor immune microenvironment (TIME) of these tumors is populated by OSGC, which resemble osteoclasts and show a histiocytic-like immunophenotype. Their role in breast cancer is unknown. The osteoclast maturation in the bone is regulated by the expression of cytokines that are also present in the TIME of tumors and in breast cancer tumor-associated macrophages (TAMs). TAMs-mediated anti-tumor immune pathways are regulated by miRNAs akin to osteoclast homeostasis. Here, we sought to characterize the different cellular compartments of breast cancers with OSGC and investigate the similarities of OSGC with tumor and TIME in terms of morphology, protein, and miRNA expression, specifically emphasizing on monocytic signatures.

Methods and Results: Six breast cancers with OSGC were included. Tumor-infiltrating lymphocytes (TILs) and TAMs were separately quantified. The different cellular populations (i.e., normal epithelium, cancer cells, and OSGC) were isolated from tissue sections by laser-assisted microdissection. After RNA purification, 752 miRNAs were analyzed using a TaqMan Advanced miRNA Low-Density Array for all samples. Differentially expressed miRNAs were identified by computing the fold change (log2Ratio) using the Kolmogorov-Smirnov test and p values were corrected for multiple comparisons using the false discovery rate (FDR) approach. As a similarity analysis among samples, we used the Pearson test. The association between pairs of variables was investigated using Fisher exact test. Classical and non-classical monocyte miRNA signatures were finally applied. All OSGC displayed CD68 expression, TILs (range, 45–85%) and high TAMs (range, 35–75%). Regarding the global miRNAs profile, OSGC was more similar to cancer cells than to non-neoplastic ones. Shared deregulation of miR-143-3p, miR-195-5p, miR-181a-5p, and miR-181b-5p was observed between OSGC and cancer cells. The monocyte-associated miR-29a-3p and miR-21-3p were dysregulated in OSGCs compared with non-neoplastic or breast cancer tissues.

Conclusion: Breast cancers with OSGC have an activated TIME. Shared epigenetic events occur during the ontogenesis of breast cancer cells and OSGC but the innumophenotype and miRNA profiles of the different cellular compartmens suggest that OSGC likely belong to the spectrum of M2 TAMs.

p53 drives necroptosis via downregulation of sulfiredoxin and peroxiredoxin 3

Mitochondrial dysfunction is a key contributor to necroptosis. We have investigated the contribution of p53, sulfiredoxin, and mitochondrial peroxiredoxin 3 to necroptosis in acute pancreatitis. Late during the course of pancreatitis, p53 was localized in mitochondria of pancreatic cells undergoing necroptosis. In mice lacking p53, necroptosis was absent, and levels of PGC-1α, peroxiredoxin 3 and sulfiredoxin were upregulated. During the early stage of pancreatitis, prior to necroptosis, sulfiredoxin was upregulated and localized into mitochondria. In mice lacking sulfiredoxin with pancreatitis, peroxiredoxin 3 was hyperoxidized, p53 localized in mitochondria, and necroptosis occurred faster; which was prevented by Mito-TEMPO. In obese mice, necroptosis occurred in pancreas and adipose tissue. The lack of p53 up-regulated sulfiredoxin and abrogated necroptosis in pancreas and adipose tissue from obese mice. We describe here a positive feedback between mitochondrial H₂O₂ and p53 that downregulates sulfiredoxin and peroxiredoxin 3 leading to necroptosis in inflammation and obesity.

Interferon‐mediated repression of miR ‐324‐5p potentiates necroptosis to facilitate antiviral defense

Mixed lineage kinase domain‐like protein (MLKL) is the terminal effector of necroptosis, a form of regulated necrosis. Optimal activation of necroptosis, which eliminates infected cells, is critical for antiviral host defense. MicroRNAs (miRNAs) regulate the expression of genes involved in various biological and pathological processes. However, the roles of miRNAs in necroptosis‐associated host defense remain largely unknown. We screened a library of miRNAs and identified miR‐324‐5p as the most effective suppressor of necroptosis. MiR‐324‐5p downregulates human MLKL expression by specifically targeting the 3′UTR in a seed region‐independent manner. In response to interferons (IFNs), miR‐324‐5p is downregulated via the JAK/STAT signaling pathway, which removes the posttranscriptional suppression of MLKL mRNA and facilitates the activation of necroptosis. In influenza A virus (IAV)‐infected human primary macrophages, IFNs are induced, leading to the downregulation of miR‐324‐5p. MiR‐324‐5p overexpression attenuates IAV‐associated necroptosis and enhances viral replication, whereas deletion of miR‐324‐5p potentiates necroptosis and suppresses viral replication. Hence, miR‐324‐5p negatively regulates necroptosis by manipulating MLKL expression, and its downregulation by IFNs orchestrates optimal activation of necroptosis in host antiviral defense.

An Integrative Transcriptomic Analysis Reveals EGFR Exon-19 E746-A750 Fragment Deletion Regulated miRNA, circRNA, mRNA and lncRNA Networks in Lung Carcinoma

Introduction

Competing endogenous RNA (ceRNA) appears to be an important post-transcriptional manner that regulates gene expression through a miRNA-mediated mechanism. Mutations in exon-19 of EGFR were frequently observed in lung cancer genes, which were associated with EGFR activity and EGFR-targeted therapies.

Methods

We explored the transcriptome regulated by mutation in EGFR exon-19 E746-A750 fragment via using a network modeling strategy. We applied transcriptome sequencing to detect the deletion process of EGFR exon-19 E746-A750 fragment. Bio-informatics analyses were used to predict the gene target pairs and explain their potential roles in tumorigenesis and progression of lung cancer.

Results

We conducted an explorative lncRNA/miRNA/circRNA and mRNA expression study with two groups of lung adenocarcinoma tissues, including EGFR exon-19 E746-A750 deletion group and EGFR exon-19 wild-type group. Meanwhile, we screen out the hub genes related to the EGFR-19-D patient. Significant pathways and biological functions potentially regulated by the deregulated 128 non-coding genes were enriched.

Conclusion

Our work provides an important theoretical, experimental and clinical foundation for further research on more effective targets for the diagnosis, therapy and prognosis of lung cancer.

MicroRNA-21 promotes pancreatic β cell function through modulating glucose uptake

Pancreatic β cell dysfunction contributes to the pathogenesis of type 2 diabetes. MiR-21 has been shown to be induced in the islets of glucose intolerant patients and type 2 diabetic mice. However, the role of miR-21 in the regulation of pancreatic β cell function remains largely elusive. In the current study, we identify the pathway by which miR-21 regulates glucose-stimulated insulin secretion utilizing mice lacking miR-21 in their β cells (miR-21βKO). We find that miR-21βKO mice develop glucose intolerance due to impaired glucose-stimulated insulin secretion. Mechanistic studies reveal that miR-21 enhances glucose uptake and subsequently promotes insulin secretion by up-regulating Glut2 expression in a miR-21-Pdcd4-AP-1 dependent pathway. Over-expression of Glut2 in knockout islets results in rescue of the impaired glucose-stimulated insulin secretion. Furthermore, we demonstrate that delivery of miR-21 into the pancreas of type 2 diabetic db/db male mice is able to promote Glut2 expression and reduce blood glucose level. Taking together, our results reveal that miR-21 in islet β cell promotes insulin secretion and support a role for miR-21 in the regulation of pancreatic β cell function in type 2 diabetes.

Understanding Necroptosis in Pancreatic Diseases

Intermediate between apoptosis and necrosis, necroptosis is a regulated caspase-independent programmed cell death that induces an inflammatory response and mediates cancer development. As our understanding improves, its role in the physiopathology of numerous diseases, including pancreatic diseases, has been reconsidered, and especially in pancreatitis and pancreatic cancer. However, the exact pathogenesis remains elusive, even though some studies have been conducted on these diseases. Its unique mechanisms of action in diseases are expected to bring prospects for the treatment of pancreatic diseases. Therefore, it is imperative to further explore its molecular mechanism in pancreatic diseases in order to identify novel therapeutic options. This article introduces recent related research on necroptosis and pancreatic diseases, explores necroptosis-related molecular pathways, and provides a theoretical foundation for new therapeutic targets for pancreatic diseases.

New challenges for microRNAs in acute pancreatitis: progress and treatment

Acute pancreatitis (AP) is a common clinical abdominal emergency, with a high and increasing incidence each year. Severe AP can easily cause systemic inflammatory response syndrome, multiple organ dysfunction and other complications, leading to higher hospitalization rates and mortality. Currently, there is no specific treatment for AP. Thus, we still need to understand the exact AP pathogenesis to effectively cure AP. With the rise of transcriptomics, RNA molecules, such as microRNAs (miRNAs) transcribed from nonprotein-coding regions of biological genomes, have been found to be of great significance in the regulation of gene expression and to be involved in the occurrence and development of many diseases. Increasing evidence has shown that miRNAs, as regulatory RNAs, can regulate pancreatic acinar necrosis and apoptosis and local and systemic inflammation and play an important role in the development and thus potentially the diagnosis and treatment of AP. Therefore, here, the current research on the relationship between miRNAs and AP is reviewed.

A microRNA checkpoint for Ca2+ signaling and overload in acute pancreatitis

Acute pancreatitis (AP) is a common digestive disease without specific treatment, and its pathogenesis features multiple deleterious amplification loops dependent on translation, triggered by cytosolic Ca2+ ([Ca2+]i) overload; however, the underlying mechanisms in Ca2+ overload of AP remains incompletely understood. Here we show that microRNA-26a (miR-26a) inhibits pancreatic acinar cell (PAC) store-operated Ca2+ entry (SOCE) channel expression, Ca2+ overload, and AP. We find that major SOCE channels are post-transcriptionally induced in PACs during AP, whereas miR-26a expression is reduced in experimental and human AP and correlated with AP severity. Mechanistically, miR-26a simultaneously targets Trpc3 and Trpc6 SOCE channels and attenuates physiological oscillations and pathological elevations of [Ca2+]i in PACs. MiR-26a deficiency increases SOCE channel expression and [Ca2+]i overload, and significantly exacerbates AP. Conversely, global or PAC-specific overexpression of miR-26a in mice ameliorates pancreatic edema, neutrophil infiltration, acinar necrosis, and systemic inflammation, accompanied with remarkable improvements on pathological determinants related with [Ca2+]i overload. Moreover, pancreatic or systemic administration of an miR-26a mimic to mice significantly alleviates experimental AP. These findings reveal a previously unknown mechanism underlying AP pathogenesis, establish a critical role for miR-26a in Ca2+ signaling in the exocrine pancreas, and identify a potential target for the treatment of AP.

Circulating Blood miR-155 and miR-21 Promote the Development of Acute Pancreatitis and Can Be Used to Assess the Risk Stratification of Pancreatitis

To explore the role of circulating blood miR-155 and miR-21 in promoting acute pancreatitis (AP) and evaluating the risk stratification of pancreatitis. In this experiment, 70 patients with AP treated in our hospital from October 2019 to December 2020 were included in the research group (RG), and the blood of 52 healthy cases was collected and they were included in the control group (CG). The expression of miR-155 and miR-21 in circulating blood was observed in the two groups. The diagnostic efficacy of miR-155 and miR-21 in AP was observed. The risk factors of patients with AP were observed. The expression of serum gastrointestinal hormones was observed in the two groups. The GAS and VIP in RG were higher than those in CG, while MTL and CCK were lower than those in CG. Moreover, the detection level of mild, moderate, severe, and critical patients was also significantly different (P < 0.05). The expression of miR-155 and miR-21 in circulating blood of RG was significantly lower than that of CG (P < 0.05), and the area under the miR-155 curve was 0.775 and the area under the miR-21 curve was 0.832. Alcoholism, GAS, VIP, MTL, CCK, miR-155, and miR-21 were the risk factors of patients. miR-155 and miR-21 show low expression in the serum of patients. The lower the expression, the more serious the disease. They are closely related to the development of AP. miR-155 and miR-21 have good diagnostic efficacy by ROC analysis, and they are expected to become effective indicators for the diagnosis and treatment of AP in the future.

microRNA-based diagnostic and therapeutic applications in cancer medicine

It has been almost two decades since the first link between microRNAs and cancer was established. In the ensuing years, this abundant class of short noncoding regulatory RNAs has been studied in virtually all cancer types. This tremendously large body of research has generated innovative technological advances for detection of microRNAs in tissue and bodily fluids, identified the diagnostic, prognostic, and/or predictive value of individual microRNAs or microRNA signatures as potential biomarkers for patient management, shed light on regulatory mechanisms of RNA-RNA interactions that modulate gene expression, uncovered cell-autonomous and cell-to-cell communication roles of specific microRNAs, and developed a battery of viral and nonviral delivery approaches for therapeutic intervention. Despite these intense and prolific research efforts in preclinical and clinical settings, there are a limited number of microRNA-based applications that have been incorporated into clinical practice. We review recent literature and ongoing clinical trials that highlight most promising approaches and standing challenges to translate these findings into viable microRNA-based clinical tools for cancer medicine. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Dysregulation of microRNA and Intracerebral Hemorrhage: Roles in Neuroinflammation

Intracerebral hemorrhage (ICH) is a major public health problem and devastating subtype of stroke with high morbidity and mortality. Notably, there is no effective treatment for ICH. Neuroinflammation, a pathological hallmark of ICH, contributes to both brain injury and repair and hence, it is regarded as a potential target for therapeutic intervention. Recent studies document that microRNAs, small non-coding RNA molecules, can regulate inflammatory brain response after ICH and are viable molecular targets to alter brain function. Therefore, there is an escalating interest in studying the role of microRNAs in the pathophysiology of ICH. Herein, we provide, for the first time, an overview of the microRNAs that play roles in ICH-induced neuroinflammation and identify the critical knowledge gap in the field, as it would help design future studies.

Necroptosis protects against exacerbation of acute pancreatitis

The sensing of various extrinsic stimuli triggers the receptor-interacting protein kinase-3 (RIPK3)-mediated signaling pathway, which leads to mixed-lineage kinase-like (MLKL) phosphorylation followed by necroptosis. Although necroptosis is a form of cell death and is involved in inflammatory conditions, the roles of necroptosis in acute pancreatitis (AP) remain unclear. In the current study, we administered caerulein to Ripk3- or Mlkl-deficient mice (Ripk3^−/− or Mlkl^−/− mice, respectively) and assessed the roles of necroptosis in AP. We found that Ripk3^−/− mice had significantly more severe pancreatic edema and inflammation associated with macrophage and neutrophil infiltration than control mice. Consistently, Mlkl^−/− mice were more susceptible to caerulein-induced AP, which occurred in a time- and dose-dependent manner, than control mice. Mlkl^−/− mice exhibit weight loss, edematous pancreatitis, necrotizing pancreatitis, and acinar cell dedifferentiation in response to tissue damage. Genetic deletion of Mlkl resulted in downregulation of the antiapoptotic genes Bclxl and Cflar in association with increases in the numbers of apoptotic cells, as detected by TUNEL assay. These findings suggest that RIPK3 and MLKL-mediated necroptosis exerts protective effects in AP and caution against the use of necroptosis inhibitors for AP treatment.

The role of microRNAs in cell death pathways

MicroRNAs (miRNAs) are a class of noncoding RNAs that negatively regulate target messenger RNAs. In multicellular eukaryotes, numerous miRNAs perform basic cellular functions, including cell proliferation, differentiation, and death. Abnormal expression of miRNAs weakens or modifies various apoptosis pathways, leading to the development of human cancer. Cell death occurs in an active manner that maintains tissue homeostasis and eliminates potentially harmful cells through regulated cell death processes, including apoptosis, autophagic cell death, and necroptosis. In this review, we discuss the involvement of miRNAs in regulating cell death pathways in cancers and the potential therapeutic functions of miRNAs in cancer treatment.

Effect of emodin on long non-coding RNA-mRNA networks in rats with severe acute pancreatitis-induced acute lung injury

Long non-coding RNAs (lncRNAs) contribute to disease pathogenesis and drug treatment effects. Both emodin and dexamethasone (DEX) have been used for treating severe acute pancreatitis-associated acute lung injury (SAP-ALI). However, lncRNA regulation networks related to SAP-ALI pathogenesis and drug treatment are unreported. In this study, lncRNAs and mRNAs in the lung tissue of SAP-ALI and control rats, with or without drug treatment (emodin or DEX), were assessed by RNA sequencing. Results showed both emodin and DEX were therapeutic for SAP-ALI and that mRNA and lncRNA levels differed between untreated and treated SAP-ALI rats. Gene expression profile relationships for emodin-treated and control rats were higher than DEX-treated and -untreated animals. By comparison of control and SAP-ALI animals, more up-regulated than down-regulated mRNAs and lncRNAs were observed with emodin treatment. For DEX treatment, more down-regulated than up-regulated mRNAs and lncRNAs were observed. Functional analysis demonstrated both up-regulated mRNA and co-expressed genes with up-regulated lncRNAs were enriched in inflammatory and immune response pathways. Further, emodin-associated lncRNAs and mRNAs co-expressed modules were different from those associated with DEX. Quantitative polymerase chain reaction demonstrates selected lncRNA and mRNA co-expressed modules were different in the lung tissue of emodin- and DEX-treated rats. Also, emodin had different effects compared with DEX on co-expression network of lncRNAs Rn60_7_1164.1 and AABR07062477.2 for the blue lncRNA module and Nrp1 for the green mRNA module. In conclusion, this study provides evidence that emodin may be a suitable alternative or complementary medicine for treating SAP-ALI.

miR-339-3p regulated acute pancreatitis induced by caerulein through targeting TNF receptor-associated factor 3 in AR42J cells

Acute pancreatitis (AP) is an inflammatory disease with high morbidity and mortality. The regulation mechanism of miRNA is involved in the production and development of various diseases, but the regulation mechanism of miRNA in AP is still not fully elucidated. The expression of miR-339-3p was detected using quantitative real-time PCR. The levels of TNF-α, IL-1β, and IL-6 were detected using enzyme-linked immunosorbent assay. Cell apoptosis was measured using flow cytometry. The protein expressions of TNF receptor-associated factor 3 (TRAF3), Bcl-2, C-caspase 3, Bax, p-p38, and p38 were measured using western blot. Luciferase reporter assay and RNA immunoprecipitation assay were applied to ensure that miR-399-3p targeted TRAF3. Caerulein promoted the expression of TNF-α, IL-1β, and IL-6, enhanced the expression of C-caspase 3 and Bax while inhibited Bcl-2 protein expression. Meanwhile, caerulein also reduced the expression of miR-339-3p and induced the expression of TRAF3 in rat pancreatic acinar cells. miR-399-3p transfection inhibited the levels of TNF-α, IL-1β, and IL-6 and C-caspase 3 and Bax protein expression as well as suppressed cell apoptosis, while increased Bcl-2 protein expression in caerulein-induced AP. TRAF3 has been verified as a target of miR-339-3p. Interestingly, the reduction of miR-399-3p inhibited the p38 pathway, which was impaired by the upregulation of TRAF3. In addition, the suppression effects of miR-339-3p on cell inflammation and apoptosis in caerulein-induced AP were reversed by enhancing TRAF3 expression. In this study, in vitro model of AP was characterized by strong inflammation and cell apoptosis. We have first demonstrated the regulatory network of miR-339-3p and TRAF3. Overexpression of miR-339-3p inhibited cell inflammation and cell apoptosis in caerulein-induced AP through modulating TRAF3 expression via the p38 pathway, providing a new therapeutic target in the treatment of AP.

Inhibition of CHRM3 Alleviates Necrosis Via the MAPK-p38/miR-31-5p/RIP3 Axis in L-Arginine-Induced Severe Acute Pancreatitis

OBJECTIVES

Pancreatic acinar necrosis is a typical feature in the early phase of severe acute pancreatitis (SAP). Muscarinic acetylcholine receptor M3 (CHRM3) has been reported to play important roles in promoting insulin secretion and tumor cell proliferation, but its effect on necrosis remains unknown. This study revealed the important role of CHRM3 in regulating L-arginine-induced SAP and the molecular mechanisms.

METHODS

To verify the function of CHRM3, pancreatic tissues and primary acinar cells of CRISPR/Cas9-mediated Chrm3 knockout mice were used in CHRM3 knockdown experiments, and to ascertain the CHRM3 overexpression, PLV-EGFP-Chrm3 plasmids were transfected in acinar cells in vitro.

RESULTS

In L-arginine-induced SAP, CHRM3 is activated and regulates SAP through the mitogen-activated protein kinase/p38 pathway. Moreover, the expression of miR-31-5p decreased in the SAP model both in vitro and in vivo. Mir-31-5p effects the necrosis of acinar cells in SAP by upregulating the target gene RIP3, and miR-31-5p is a downstream miRNA of CHRM3.

CONCLUSIONS

Necrosis in L-arginine-induced SAP is promoted by CHRM3 through the mitogen-activated protein kinase-p38/miR-31-5p/RIP3 axis.

Loss of microRNA-21 leads to profound stromal remodeling and short survival in K-Ras-driven mouse models of pancreatic cancer

The microenvironment of pancreatic cancer adenocarcinoma (PDAC) is highly desmoplastic with distinct tumor-restraining and tumor-promoting fibroblast subpopulations. Re-education rather than indiscriminate elimination of these fibroblasts has emerged as a new strategy for combination therapy. Here, we studied the effects of global loss of profibrotic noncoding regulatory microRNA-21 (miR-21) in K-Ras-driven p53-deleted genetically engineered mouse models of PDAC. Strikingly, loss of miR-21 accelerated tumor initiation via mucinous cystic neoplastic lesions and progression to locally advanced invasive carcinoma from which animals precipitously succumbed at an early age. The absence of tumor-restraining myofibroblasts and a massive infiltrate of immune cells were salient phenotypic features of global miR-21 loss. Stromal miR-21 activity was required for induction of tumor-restraining myofibroblasts in in vivo isograft transplantation experiments. Low miR-21 expression negatively correlated with a fibroblast gene expression signature and positively with an immune cell gene expression signature in The Cancer Genome Atlas PDAC data set (n = 156) mirroring findings in the mouse models. Our results exposed an overall tumor-suppressive function of miR-21 in in vivo PDAC models. These results have important clinical implications for anti-miR-21-based inhibitory therapeutic approaches under consideration for PDAC and other cancer types. Mechanistic dissection of the cell-intrinsic role of miR-21 in cancer-associated fibroblasts and other cell types will be needed to inform best strategies for pharmacological modulation of miR-21 activity to remodel the tumor microenvironment and enhance treatment response in PDAC.

Processes exacerbating apoptosis in non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is a significant public health concern, owing to its high prevalence, progressive nature and lack of effective medical therapies. NAFLD is a complex and multifactorial disease involving the progressive and concerted action of factors that contribute to the development of liver inflammation and eventually fibrosis. Here, we summarize fundamental molecular mechanisms underlying the pathogenesis of non-alcoholic steatohepatitis (NASH), how they are interrelated and possible translation to clinical applications. We focus on processes triggering and exacerbating apoptotic signalling in the liver of NAFLD patients and their metabolic and pathological implications. Indeed, liver injury and inflammation are cardinal histopathological features of NASH, a duo in which derailment of apoptosis is of paramount importance. In turn, the liver houses a very high number of mitochondria, crucial metabolic unifiers of both extrinsic and intrinsic signals that converge in apoptosis activation. The role of lifestyle options is also dissected, highlighting the management of modifiable risk factors, such as obesity and harmful alcohol consumption, influencing apoptosis signalling in the liver and ultimately NAFLD progression. Integrating NAFLD-associated pathologic mechanisms in the cell death context could provide clues for a more profound understating of the disease and pave the way for novel rational therapies.

Micro-RNA-21 rs1292037 A>G polymorphism can predict hepatocellular carcinoma prognosis (HCC), and plays a key role in cell proliferation and ischemia-reperfusion injury (IRI) in HCC cell model of IRI

OBJECTIVES

To assess the predictive function of miR-21 rs1292037 A greater than G polymorphism in survival and ischemia-reperfusion injury (IRI) in hepatocellular carcinoma (HCC) patients.

METHODS

The experiment was carried out between July 2018 and July 2019, whereas the prospective clinical study was carried out between January 2014 and January 2019. In this study, 62 HCC patients with hepatitis B virus (HBV), 17 HCC patients without HBV, and 13 healthy controls were investigated. Micro-RNA-21 levels in the blood were identified using quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and allele specific PCR for miR-21 rs1292037. Partial hepatectomy was performed in all patients, and the tumor development indicators and survival time were evaluated in a subsequent follow-up. Cell-based simulated IRI model of HCC huh7 cell line was used to determine the functions of miR-21 with respect to IRI and proliferation.

RESULTS

Micro-RNA-21 levels were significantly increased in HCC patients. Furthermore, an miR- 21 rs1292037 A greater than G polymorphism was found to be significantly associated with HCC prognosis and severity of liver injury after hepatectomy. In vitro study revealed that miR-21 might prevent IRI from occurring, and can induce proliferation in HCC huh7 cells. These functions of miR-21 were demonstrated to be triggered by IL-12A inhibition.

CONCLUSION

Micro-RNA-21 rs1292037 A greater than G polymorphism can predict IRI and tumor progression by regulating the miR-21/IL-12A.axis.

CircRNA Expression Profiles and the Potential Role of CircZFP644 in Mice With Severe Acute Pancreatitis via Sponging miR-21-3p

Severe acute pancreatitis (SAP) is the most serious type of pancreatitis with high morbidity and mortality. The underlying mechanism behind SAP pathogenesis is complex and remains elusive. Circular RNAs (circRNAs) are emerging as vital regulators of gene expression in various diseases by sponging microRNAs (miRNAs). However, the roles of circRNAs in the pathophysiology of SAP remain unknown. In the present study, next-generation RNA sequencing was utilized to identify circRNA transcripts in the pancreatic tissues from three SAP mice and three matched normal tissues. The differentially expressed circRNAs were confirmed by real-time PCR, and the biological functions of their interaction with miRNAs and mRNAs were analyzed. Our results demonstrate that 56 circRNAs were differentially expressed in SAP mice compared with normal controls. Six differentially expressed circRNAs were confirmed with the sequencing data. Importantly, we characterized a significantly downregulated circRNA derived from the ZFP664 gene in SAP. CircZFP644 was found to be negatively correlated with miR-21-3p, with a perfectly matched binding sequence to miR-21-3p. In conclusion, CircZFP644 may play an important role in the pathogenesis of SAP through sponging miR-21-3p. Our findings may provide novel insights regarding the workings of the pathophysiological mechanism of SAP and offer novel targets for SAP.

Osteocytic miR21 deficiency improves bone strength independent of sex despite having sex divergent effects on osteocyte viability and bone turnover

Osteocytes play a critical role in mediating cell-cell communication and regulating bone homeostasis, and osteocyte apoptosis is associated with increased bone resorption. miR21, an oncogenic microRNA, regulates bone metabolism by acting directly on osteoblasts and osteoclasts, but its role in osteocytes is not clear. Here, we show that osteocytic miR21 deletion has sex-divergent effects in bone. In females, miR21 deletion reduces osteocyte viability, but suppresses bone turnover. Conversely, in males, miR21 deletion increases osteocyte viability, but stimulates bone turnover and enhances bone structure. Further, miR21 deletion differentially alters osteocyte cytokine production in the two sexes. Interestingly, despite these changes, miR21 deletion increases bone mechanical properties in both sexes, albeit to a greater extent in males. Collectively, our findings suggest that miR21 exerts both sex-divergent and sex-equivalent roles in osteocytes, regulating osteocyte viability and altering bone metabolism through paracrine actions on osteoblasts and osteoclasts differentially in males vs females, whereas, influencing bone mechanical properties independent of sex.

A smart ATP-responsive chemotherapy drug-free delivery system using a DNA nanostructure for synergistic treatment of breast cancer in vitro and in vivo

This study demonstrated a chemotherapy drug-free delivery system for breast cancer treatment based on a simple DNA nanostructure composed of sequence 1 containing ATP and AS1411 aptamers and sequence 2 containing antimiR-21. The DNA nanostructure was used for co-delivery of KLA peptide and antimiR-21 as antiapoptotic agents. These therapeutic agents could not be internalised into eukaryotic cells freely which is one of the great features of this targeting platform. The presented delivery system was ATP-responsive, leading to disassembly of the DNA nanostructure in high ATP concentration of cancer cells and restoration of the function of antimiR-21 in these cells. The DNA nanostructure was associated with high cellular uptake by MCF-7 and 4T1 cells due to expression of nucleolin as target of AS1411 on their plasma membranes, while the developed targeting platform could not be internalised into CHO cells because of lack of the active targeting moiety on their surfaces. Furthermore, the results showed that co-delivery of antimiR-21 and KLA peptide using the DNA nanostructure could efficiently prohibit tumour growth in vitro and in vivo and induce a synergistic anticancer activity. Thus, this work provides a new ATP-responsive nanotargeting delivery system and synergistic chemotherapy drug-free regimen for cancer treatment.

Low‑intensity ultrasound enhances the antitumor effects of doxorubicin on hepatocellular carcinoma cells through the ROS‑miR‑21‑PTEN axis

Hepatocellular carcinoma (HCC) is a type of liver cancer and is a leading cause of cancer-associated mortality. In China, ~466,000 patients are diagnosed with HCC and it is responsible for ~422,000 cases of mortality each year. Surgery is the most effective treatment available; however it is only suitable for patients with early-stage HCC. Chemotherapy has been confirmed as a necessary treatment for patients with advanced HCC, although drug resistance may limit its clinical outcome. Low intensity ultrasound (LIUS) represents a novel therapeutic approach to treat patients with HCC; however, its underlying molecular mechanism remains unclear. In the present study, cell viability, apoptosis and reactive oxygen species (ROS) generation were determined via Cell Counting Kit-8, flow cytometry and 2′,7′-dichlorofluorescein diacetate assays, respectively. The expression of miRNA in HCC cells following exposure to LIUS and doxorubicin (Dox) was analyzed using a microarray and reverse transcription-quantitative polymerase chain reaction analysis. It was revealed treatment with LIUS in combination with Dox was able to induce apoptosis of Huh7 cells, increasing the intracellular levels of reactive oxygen species (ROS) and malondialdehyde. Glutathione peroxidase and superoxide dismutase 1 are ROS-scavenging enzymes, which serve important roles in the oxidative balance, preventing oxidative stress. The protein expression levels of these two enzymes were significantly decreased following treatment with LIUS combined with Dox. The present results suggested that LIUS may decrease Dox resistance in HCC cells and that LIUS may be combined with chemotherapy to treat HCC. By performing microarray analysis, the expression levels of microRNA-21 (miR-21) were decreased following treatment with LIUS combined with Dox. Functional experiments showed that knockdown of miR-21 enhanced the antitumor activity of Dox, whereas overexpression of miR-21 reversed these effects. Phosphatase and tensin homolog (PTEN), a well-known tumor suppressor, was revealed to be a direct target of miR-21, and its translation was suppressed by miR-21. Finally, it was determined that combined treatment of LIUS and Dox induced anticancer effects by blocking the activation of the AKT/mTOR pathway, as demonstrated by the downregulation of phosphorylated (p-)AKT and p-mTOR; N-acetylcysteine, a general ROS inhibitor reversed the suppressive effects on the AKT/mTOR pathway mediated by LIUS and Dox. Collectively, the present results suggested that LIUS increased cell sensitivity to Dox via the ROS/miR-21/PTEN pathway. Chemotherapy combined with LIUS may represent a novel effective therapeutic strategy to treat patients with advanced HCC.

UTX/KDM6A Deletion Promotes Recovery of Spinal Cord Injury by Epigenetically Regulating Vascular Regeneration

The regeneration of the blood vessel system post spinal cord injury (SCI) is essential for the repair of neurological function. As a significant means to regulate gene expression, epigenetic regulation of angiogenesis in SCI is still largely unknown. Here, we found that Ubiquitously Transcribed tetratricopeptide repeat on chromosome X (UTX), the histone H3K27 demethylase, increased significantly in endothelial cells post SCI. Knockdown of UTX can promote the migration and tube formation of endothelial cells. The specific knockout of UTX in endothelial cells enhanced angiogenesis post SCI accompanied with improved neurological function. In addition, we found regulation of UTX expression can change the level of microRNA 24 (miR-24) in vitro. The physical binding of UTX to the promotor of miR-24 was indicated by chromatin immunoprecipitation (ChIP) assay. Meanwhile, methylation sequencing of endothelial cells demonstrated that UTX could significantly decrease the level of methylation in the miR-24 promotor. Furthermore, miR-24 significantly abolished the promoting effect of UTX deletion on angiogenesis in vitro and in vivo. Finally, we predicted the potential target mRNAs of miR-24 related to angiogenesis. We indicate that UTX deletion can epigenetically promote the vascular regeneration and functional recovery post SCI by forming a regulatory network with miR-24.

Chrm3 protects against acinar cell necrosis by stabilizing caspase-8 expression in severe acute pancreatitis mice model

Acinar cells in acute pancreatitis (AP) die through apoptosis and necrosis, the impacts of which are quite different. Early clinical interference strategies on preventing the progress of AP to severe acute pancreatitis (SAP) are the elimination of inflammation response and inhibition of necrosis. Muscarinic acetylcholine receptor M3 was encoded by Chrm3 gene. It is one of the best-characterized receptors of pancreatic β cells and regulates insulin secretion, but its function in AP remains unclear. In this study, we explored the function of Chrm3 gene in the regulation of cell death in l-arginine-induced SAP animal models. We found that Chrm3 was upregulated in pancreatitis, and we further confirmed the localization of Chrm3 resided in both pancreatic islets and acinar cell membranes. The reduction of Chrm3 decreased the pathological lesion of SAP and reduced amylase activities in serum. Consistently, Chrm3 can suppress acinar cells necrosis markedly, but has no effect on regulating apoptosis after l-arginine treatment. It was shown that Chrm3 attenuated acinar cells necrosis at least in part by stabilizing caspase-8. Thus, this study indicates that Chrm3 is critical participants in SAP, and regulation of Chrm3 expression might be a useful therapeutic strategy for preventing pathologic necrosis.

MicroRNAs in acute pancreatitis: From pathogenesis to novel diagnosis and therapy

Acute pancreatitis (AP) is an inflammatory disorder initiated by activation of pancreatic zymogens, leading to pancreatic injury and systemic inflammatory response. MicroRNAs (miRNAs) have emerged as important regulators of gene expression and key players in human physiological and pathological processes. Discoveries over the past decade have confirmed that altered expression of miRNAs is implicated in the pathogenesis of AP. Indeed, a number of miRNAs have been found to be dysregulated in various cell types involved in AP such as acinar cells, macrophages, and lymphocytes. These aberrant miRNAs can regulate acinar cell necrosis and apoptosis, local and systemic inflammatory response, thereby contributing to the initiation and progression of AP. Moreover, patients with AP possess unique miRNA signatures when compared with healthy individuals or those with other diseases. In view of their stability and easy detection, therefore, miRNAs have the potential to act as biomarkers for the diagnosis and assessment of patients with AP. In this review, we provide an overview of the novel cellular and molecular mechanisms underlying the roles of miRNAs during the disease processes of AP, as well as the potential diagnosis and therapeutic biomarkers of miRNAs in patients with AP.

MicroRNAs derived from urinary exosomes act as novel biomarkers in the diagnosis of intrahepatic cholestasis of pregnancy

We aimed to investigate the value of cholestasis-related miRNAs in the diagnosis of intra-hepatic cholestasis of pregnancy (ICP) as well as the molecular mechanisms underlying the role of these miRNAs in the pathogenesis of ICP. In this study, electron microscopy was utilized to observe the exosomes present in the urine samples collected from both ICP patients and healthy pregnant women. Real-time PCR and area under curve (AUC) analysis were performed to predict the values of several miRNAs in the diagnosis of ICP. Bioinformatics analysis and luciferase assays were conducted to identify the target genes of miR-21, miR-29a and miR-590-3p, whose regulatory relationships were then established using real-time PCR, immunohistochemistry (IHC) assay and Western Blot. In the exosomes isolated from urine samples, several miRNAs, including miR-21, miR-29a and miR-590-3p, were differentially expressed between ICP patients and healthy pregnant women. In addition, the gene of intercellular adhesion molecule 1 (ICAM1) was identified as a shared target of miR-21, miR-29a and miR-590-3p, all of which inhibited ICAM1 expression. Therefore, up-regulated expression of miR-21, miR-29a and miR-590-3p in urinary exosomes reduced the expression of ICAM1, which in turn increased the incidence of ICP.

Inhibition of RIPK1-dependent regulated acinar cell necrosis provides protection against acute pancreatitis via the RIPK1/NF-κB/AQP8 pathway

Currently, preliminary results have confirmed the existence of receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL)-dependent necroptosis of pancreatic acinar cells during early acute pancreatitis (AP), which might be a potential target for the effective regulation of necroinflammatory injury. However, the exact effect of receptor-interacting protein kinase 1 (RIPK1)-dependent regulated acinar cell necrosis on AP is still uncertain. In our study, we first explored the changes in the degree of local and systemic inflammation in AP rats when the activation of acinar cell RIPK1 was inhibited. The RIPK1 inhibitor Nec-1 was used to treat rats, and the levels of related inflammatory markers, necrosis indicators and apoptotic indicators were measured. Changes in pancreatic nuclear factor κB (NF-κB) and aquaporin 8 (AQP8) expression were noted. Next, the expression of AQP8 in AR42J cells was inhibited, and the degree of cell necrosis and inflammatory damage was found to be significantly reduced. Most importantly, we demonstrated that the RIPK1/NF-ĸB/AQP8 axis might be a potential regulatory pathway mediating RIPK1-dependent regulated acinar cell necrosis in early AP. Finally, we used the NF-κB inhibitor PDTC and Nec-1 to treat rats in different groups and measured the degree of pathological pancreatic injury, the activation of RIPK1, and the expression of NF-κB and AQP8. In summary, we hypothesized that there might be a RIPK1/NF-ĸB/AQP8 pathway controlling RIPK1-dependent regulated necrosis of acinar cells in AP, which might be a promising therapeutic target against AP-related injury.

Exosomes and pancreatic diseases: status, challenges, and hopes

Pancreatic disease, including pathologies such as acute pancreatitis (AP), chronic pancreatitis (CP), and pancreatic cancer (PC), is a complicated and dangerous clinical condition involving the disruption of exocrine or endocrine function. PC has one of the highest mortality rates among cancers due to insufficient diagnosis in early stages. Furthermore, efficient treatment options for the disease etiologies of AP and CP are lacking. Thus, the identification of new therapeutic targets and reliable biomarkers is required. As essential couriers in intercellular communication, exosomes have recently been confirmed to play an important role in pancreatic disease, but the specific underlying mechanisms are unknown. Herein, we summarize the current knowledge of exosomes in pancreatic disease with respect to diagnosis, molecular mechanisms, and treatment, proposing new ideas for the study of pancreatic disease.

Down-regulated miR-21 promotes learning-memory recovery after brain injury

BACKGROUND

MicroRNA is anendogenous non-coding single strand RNA which consists of 22 nt. It post-transcriptionally regulates gene expression and development. MicroRNA 21 plays an important role in repairing injured brain tissues. Thus, in this research, we explored the function of miR-21 in learning-memory recovery after brain injury.

METHOD

3 days old newborn SD rats were separated into three groups: Sham operation group (Sham), inflammation-sensitized hypoxic-ischemic brain injury (LPS+HI) group and miR-21 inhibitor group. 28 days later, the learning and memory capability was assayed by water maze. H&E staining and Nissl's staining were used to assay pathologic changes and TUNEL was used to assay neuron apoptosis in brain tissue.

RESULTS

Water maze assay showed that the capability of positioning navigation in the IH-HI group was worse than in the Sham group and miR-21 inhibition group, and the Sham group wass better than miR-21 group. Both of the comparisons had statistical significance (P < 0.05). H&E staining in the sham group showed that the neurons were arranged well in hippocampus. In LPS+HI group, some neurons in hippocampus had vacuolar degeneration and the neurons were not well arranged well. In the hippocampus of miR-21 inhibitor group, the neuron cell layers were decreased but the neurons were arranged better than in the LPS+HI group. Nissl's staining in LPS+HI group showed neuronal edema, neurons decreased, and Nissl's bodies decreased in the cytoplasm compared with the sham group. However, compared with the LPS+HI group, Nissl's staining in miR-21 inhibitor group showed that the neuronal edema was alleviated and neurons were better arranged. TUNEL assay showed that the apoptosis rate of LPS+HI group was higher than in the miR-21 inhibitor group and miR-21 inhibitor group was higher than the sham group.

CONCLUSION

Down-regulated miR-21 can alleviate LPS+HI injury in the brain.

RNA Micelles for the Systemic Delivery of Anti-miRNA for Cancer Targeting and Inhibition without Ligand

Displaying the advantage of nanoparticles in cancer targeting and drug delivery, micelles have shown great potential in cancer therapy. The mechanism for micelle targeting to cancer without the need for ligands is due to the size advantage of micelles within the lower end of the nanometer scale that is the optimal size for favoring the enhanced permeability and retention (EPR) effect while escaping trapping by macrophages. MicroRNAs are ubiquitous and play critical roles in regulating gene expression, cell growth, and cancer development. However, their in vivo delivery in medical applications is still challenging. Here, we report the targeted delivery of anti-miRNA to cancers via RNA micelles. The phi29 packaging RNA three-way junction (pRNA-3WJ) was used as a scaffold to construct micelles. An oligo with 8nt locked nucleic acid (LNA) complementary to the seed region of microRNA21(miR21) was included in the micelles as an interference molecule for cancer inhibition. These RNA micelles carrying anti-miR21 exhibited strong binding and internalization to cancer cells, inhibited the function of oncogenic miR21, enhanced the expression of the pro-apoptotic factor, and induced cell apoptosis. Animal trials revealed effective tumor targeting and inhibition in xenograft models. The inclusion of folate as a targeting ligand in the micelles did not show significant improvement of the therapeutic efficacy in vivo, suggesting that micelles can carry therapeutics to a target tumor and inhibit its growth without ligands.

A new perspective of triptolide-associated hepatotoxicity: Liver hypersensitivity upon LPS stimulation

OBJECTIVE

This study was designed to investigate whether the mice treated with triptolide (TP) could disrupt the liver immune homeostasis, resulting in the inability of the liver to eliminate the harmful response induced by lipopolysaccharide (LPS). In addition, we explored whether apoptosis and necroptosis played a critical role in the progression of the hepatotoxicity induced by TP-LPS co-treatment.

METHODS

Female C57BL/6 mice were continuously administrated with two different doses of TP (250 μg/kg and 500 μg/kg) intragastrically for 7 days. Subsequently, a single dose of LPS (0.1 mg/kg) was injected intraperitoneally to testify whether the liver possesses the normal immune function to detoxicate the exogenous pathogen's stimulation. To prove the involvement of apoptosis and necroptosis in the liver damage induced by TP-LPS co-treatment, apoptosis inhibitor Z-VAD-FMK (FMK) and necroptosis inhibitor necrostatin (Nec-1) were applied before the stimulation of LPS to diminish the apoptosis and necroptosis respectively.

RESULTS

TP or LPS alone did not induce significant liver damage. However, compared with TP or LPS treated mice, TP-LPS co-treatment mice showed obvious hepatotoxicity with a remarkable elevation of serum ALT and AST accompanied by abnormal bile acid metabolism, a depletion of liver glycogen storage, aberrant glucose metabolism, an up-regulation of inflammatory cell infiltration, and an increase of apoptosis and necroptosis. Intraperitoneal injection of FMK or Nec-1 could counteract the toxic reactions induced by TP-LPS co-treatment.

CONCLUSION

TP could disrupt the immune response, resulting in hypersensitivity of the liver upon LPS stimulation, ultimately leading to abnormal liver function and cell death. Additionally, apoptosis and necroptosis played a vital role in the development of liver damage induced by TP-LPS co-treatment.

miR-148a-3p exhaustion inhibits necrosis by regulating PTEN in acute pancreatitis

BACKGROUND

Acute pancreatitis (AP) is a necro-inflammatory disorder with high mortality rate. With advances in understanding the pathogenesis of AP, microRNAs (miRNAs) have been reported to play an essential role in AP progression. However, the mechanism that allows miR-148a-3p to regulate necrosis in AP remains unclear.

METHODS

Caerulein treatment was used to induce AP in mice or cells. miR-148a-3p-/- mice or miR-148a-3p inhibition in wild type mice were used to investigate the effect of miR-148a-3p on AP. The expression of miR-148a-3p was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The abundances of phosphatase and tensin homolog (PTEN) and hallmarks of necrosis or apoptosis were measured by qRT-PCR or western blots (WB). Cell necrosis, apoptosis, serum amylase or lipase activity and inflammatory cytokines levels were investigated by commercial assay kit. Inflammatory infiltration was analyzed by immunohistochemistry (IHC). The interaction between miR-148a-3p and PTEN was probed by luciferase activity.

RESULTS

miR-148a-3p was highly expressed in AP and knockout of miR-148a-3p inhibited water content, cell necrosis, amylase and lipase activity while inducing PTEN expression. Moreover, miR-148a-3p deletion attenuated inflammatory infiltration and necrosis by promoting apoptosis. In addition, miR-148a-3p knockdown protected against cell necrosis, amylase, and lipase activity in AP. Intriguingly, PTEN was a target of miR-148a-3p and interference of PTEN reversed the effect of miR-148a-3p deficiency on AP in vitro.

CONCLUSION

miR-148a-3p inhibition repressed necrosis by regulating PTEN expression in AP, providing a novel biomarker of therapeutics for AP treatment.

MiR-21-3p aggravates injury in rats with acute hemorrhagic necrotizing pancreatitis by activating TRP signaling pathway

To evaluate the expression and effect of miR-21-3p in pancreas and lung injury of acute hemorrhagic necrotizing pancreatitis (AHNP) rats. AHNP rat model was constructed via retrograde injection of 5% sodium taurocholate into biliary pancreatic duct. Then rats were divided into normal, sham, AHNP, mimics negative control (NC), miR-21-3p mimics, inhibitors NC, miR-21-3p inhibitors, miR-21-3p mimics + phosphate buffer saline and miR-21-3p mimics + Gd³⁺ groups (N = 10 in each group). The expression of miR-21-3p, TRP signaling pathway factor, apoptosis related protein and histology were studied in pancreatic and lung tissues. Apoptosis of pancreatic acinar cells was detected. Oxidative stress indexes were detected in lung tissues. The level of PaO₂ and PaCO₂ and the expression of amylase, lipase and inflammatory factors were detected in blood. Compared with normal and sham groups, the miR-21-3p expression was increased in pancreatic and lung tissues of AHNP rats. MiR-21-3p expression was successfully regulated. Down-regulated miR-21-3p promoted apoptosis of pancreatic acinar cells and restored its function in AHNP rats. Up-regulated miR-21-3p reduced the lung oxygenation function, promoted pathological damage, and aggravated oxidative stress injury in AHNP rats. Meanwhile, up-regulated miR-21-3p also promoted the expression of serum enzymes and inflammatory factors, and activated TRP signaling pathway in AHNP rats. And miR-21-3p aggravated pancreatitis and lung injury by activating transient receptor potential (TRP) signaling pathway in AHNP rats. miR-21-3p promoted the pancreatic injury, inhibited apoptosis of necrotic acinar cells and aggravated lung oxidative stress injury by activating TRP signaling pathway in AHNP rats.

Regulation of PTEN expression by noncoding RNAs

Phosphatase and tensin homologue (PTEN) triggers a battery of intracellular signaling pathways, especially PI3K/Akt, playing important roles in the pathogenesis of multiple diseases, such as cancer, neurodevelopmental disorders, cardiovascular dysfunction and so on. Therefore PTEN might be a biomarker for various diseases, and targeting the abnormal expression level of PTEN is anticipated to offer novel therapeutic avenues. Recently, noncoding RNAs (ncRNAs) have been reported to regulate protein expression, and it is definite that PTEN expression is controlled by ncRNAs epigenetically or posttranscriptionally as well. Herein, we provide a review on current understandings of the regulation of PTEN by ncRNAs, which could contribute to the development of novel approaches to the diseases with abnormal expression of PTEN.