lnc-Rps4l-encoded peptide RPS4XL regulates RPS6 phosphorylation and inhibits the proliferation of PASMCs caused by hypoxia

Micropeptides derived from long non-coding RNAs: Computational analysis and functional roles in breast cancer and other diseases

Long non-coding RNAs (lncRNAs), once thought to be mere transcriptional noise, are now revealing a hidden code. Recent advancements like ribosome sequencing have unveiled that many lncRNAs harbor small open reading frames and can potentially encode functional micropeptides. Emerging research suggests these micropeptides, not the lncRNAs themselves, play crucial roles in regulating homeostasis, inflammation, metabolism, and especially in breast cancer progression. This review delves into the rapidly evolving computational tools used to predict and validate lncRNA-encoded micropeptides. We then explore the diverse functions and mechanisms of action of these micropeptides in breast cancer pathogenesis, with a focus on their roles in various species. Ultimately, this review aims to illuminate the functional landscape of lncRNA-encoded micropeptides and their potential as therapeutic targets in cancer.

Enhanced Discovery of Alternative Proteins (AltProts) in Mouse Cardiac Development Using Data-Independent Acquisition (DIA) Proteomics

Alternative proteins (AltProts) are a class of proteins encoded by DNA sequences previously classified as noncoding. Despite their historically being overlooked, recent studies have highlighted their widespread presence and distinctive biological roles. So far, direct detection of AltProt has been relying on data-dependent acquisition (DDA) mass spectrometry (MS). However, data-independent acquisition (DIA) MS, a method that is rapidly gaining popularity for the analysis of canonical proteins, has seen limited application in AltProt research, largely due to the complexities involved in constructing DIA libraries. In this study, we present a novel DIA workflow that leverages a fragmentation spectra predictor for the efficient construction of DIA libraries, significantly enhancing the detection of AltProts. Our method achieved a 2-fold increase in the identification of AltProts and a 50% reduction in missing values compared to DDA. We conducted a comprehensive comparison of four AltProt databases, four DIA-library construction strategies, and three analytical software tools to establish an optimal workflow for AltProt analysis. Utilizing this workflow, we investigated the mouse heart development process and identified over 50 AltProts with differential expression between embryonic and adult heart tissues. Over 30 unannotated mouse AltProts were validated, including ASDURF, which played a crucial role in cardiac development. Our findings not only provide a practical workflow for MS-based AltProt analysis but also reveal novel AltProts with potential significance in biological functions.

Long non-coding RNA-encoded micropeptides: functions, mechanisms and implications

Long non-coding RNAs (lncRNAs) are typically described as RNA transcripts exceeding 200 nucleotides in length, which do not code for proteins. Recent advancements in technology, including ribosome RNA sequencing and ribosome nascent-chain complex sequencing, have demonstrated that many lncRNAs retain small open reading frames and can potentially encode micropeptides. Emerging studies have revealed that these micropeptides, rather than lncRNAs themselves, are responsible for vital functions, including but not limited to regulating homeostasis, managing inflammation and the immune system, moderating metabolism, and influencing tumor progression. In this review, we initially outline the rapidly advancing computational analytical methods and public tools to predict and validate the potential encoding of lncRNAs. We then focus on the diverse functions of micropeptides and their underlying mechanisms in the pathogenesis of disease. This review aims to elucidate the functions of lncRNA-encoded micropeptides and explore their potential applications as therapeutic targets in cancer.

LncRNA MFRL regulates the phenotypic switch of vascular smooth muscle cells to attenuate arterial remodeling by encoding a novel micropeptide MFRLP

BACKGROUND

Arterial remodeling is a common pathophysiological change in the pathogenesis of cardiovascular diseases in which the phenotypic switch of vascular smooth muscle cells (VSMC) plays an important role. Recently, an increasing number of long non-coding RNAs(lncRNAs) have been shown to encode micropeptides that play biological roles and have great clinical transformation potential. However, the role of micropeptides encoded by lncRNAs in arterial remodeling has not been well studied and requires further exploration.

METHODS AND RESULTS

Through bioinformatic analysis and experimental verification, we found that a new lncRNA, the mitochondrial function-related lncRNA (MFRL), encodes a 64-amino acid micropeptide, MFRLP. MFRL and MFRLP play important roles in the phenotypic switch of VSMC. Further experiments showed that MFRLP interacts with mitochondrial cytochrome b to reduce accumulation of reactive oxygen species, suppress mitophagy and inhibit the VSMC switch from contractile to synthetic phenotype.

CONCLUSIONS

LncRNA MFRL encodes the micropeptide MFRLP, which interacts with mitochondrial cytochrome b to inhibit the VSMC switch from contractile to synthetic phenotype and improve arterial remodeling.

CircRNA and lncRNA-encoded peptide in diseases, an update review

Non-coding RNAs (ncRNAs), including circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs), are unique RNA molecules widely identified in the eukaryotic genome. Their dysregulation has been discovered and played key roles in the pathogenesis of numerous diseases, including various cancers. Previously considered devoid of protein-coding ability, recent research has revealed that a small number of open reading frames (ORFs) within these ncRNAs endow them with the potential for protein coding. These ncRNAs-derived peptides or proteins have been proven to regulate various physiological and pathological processes through diverse mechanisms. Their emerging roles in disease diagnosis and targeted therapy underscore their potential utility in clinical settings. This comprehensive review aims to provide a systematic overview of proteins or peptides encoded by lncRNAs and circRNAs, elucidate their production and functional mechanisms, and explore their promising applications in cancer diagnosis, disease prediction, and targeted therapy.

Microscale marvels: unveiling the macroscopic significance of micropeptides in human health

Non-coding RNA encodes micropeptides from small open reading frames located within the RNA. Interestingly, these micropeptides are involved in a variety of functions within the body. They are emerging as the resolving piece of the puzzle for complex biomolecular signaling pathways within the body. Recent studies highlight the pivotal role of small peptides in regulating important biological processes like DNA repair, gene expression, muscle regeneration, immune responses, etc. On the contrary, altered expression of micropeptides also plays a pivotal role in the progression of various diseases like cardiovascular diseases, neurological disorders and several types of cancer, including colorectal cancer, hepatocellular cancer, lung cancer, etc. This review delves into the dual impact of micropeptides on health and pathology, exploring their pivotal role in preserving normal physiological homeostasis and probing their involvement in the triggering and progression of diseases.

Non-Coding RNA Networks in Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary artery hypertension (PAH) is a severe cardiovascular disease marked by a persistent increase in pulmonary artery resistance and pressure, leading to right ventricular strain, hypertrophy, and eventually right heart failure and death. Despite numerous available targeted therapies, the clinical needs for treating PAH remain unmet. Current treatments primarily aim to dilate pulmonary vessels rather than reverse pulmonary vascular remodeling, failing to offer a fundamental solution for PAH. Therefore, developing new therapies for this condition is urgently required.

SUMMARY

Recent research has highlighted the crucial role of non-coding RNAs (ncRNAs) in the occurrence and development of PAH. NcRNAs, such as long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), microRNAs (miRNAs), and PIWI-interacting RNAs (piRNAs), are a class of transcripts that do not translate proteins but affect various diseases at different levels, including chromatin modification, transcription regulation, post-translational processes.

KEY MESSAGE

The current study delves into recent advancements in understanding how lncRNAs, circRNAs, miRNAs, and piRNAs contribute to the pathogenesis of PAH. This review addresses the existing research challenges and explores the potential of ncRNAs as both biomarkers and therapeutic targets, suggesting that ncRNAs may serve as valuable indicators and treatment options for the disease.

Transcriptomics-based analysis of Macrobrachium rosenbergii growth retardation

Macrobrachium rosenbergii is an economically important crustacean in many parts of the world, but in recent years, growth retardation has become an increasingly serious issue. While the underlying causes remain unclear, this has inevitably impacted on aquaculture and production outputs. In this study, gill, hepatopancreas, and muscle tissue samples from M. rosenbergii, with distinct growth differences, underwent transcriptome sequencing and bioinformatics analyses using high-throughput sequencing. In total, 59,796 unigenes were annotated. Differential expression analyses showed that the most differentially expressed genes (DEGs) were screened in gill tissue (1790 DEGs). In muscle and hepatopancreas tissues, 696 and 598 DEGs were screened, respectively. These DEGs were annotated to Kyoto Encyclopedia of Genes and Genomes pathways, which identified several significantly enriched pathways related to growth metabolism, such as PI3K-AKT, glycolysis/gluconeogenesis, and starch and sucrose metabolism. These results suggest that low growth metabolism levels may be one cause of M. rosenbergii growth retardation. Our data provide support for further investigations into the causes and molecular mechanisms underpinning growth retardation in M. rosenbergii.

Roles of LncRNAs in the Pathogenesis of Pulmonary Hypertension

Pulmonary hypertension (PH) is a persistently progressive, incurable, multifactorial associated fatal pulmonary vascular disease characterized by pulmonary vascular remodeling. Long noncoding RNAs (lncRNAs) are involved in regulating pathological processes such as pulmonary vasoconstriction, thickening, remodeling, and inflammatory cell infiltration in PH by acting on different cell types. Because of their differential expression in PH patients, as demonstrated by the observation that some lncRNAs are significantly upregulated while others are significantly downregulated in PH patients, lncRNAs are potentially useful biomarkers for assessing disease progression and diagnosis or prognosis in PH patients. This article provides an overview of the different mechanisms by which lncRNAs are involved in the pathogenesis of PH.

Administration of A. muciniphila ameliorates pulmonary arterial hypertension by targeting miR-208a-3p/NOVA1 axis

Pulmonary arterial hypertension (PH) is a chronic disease induced by a progressive increase in pulmonary vascular resistance and failure of the right heart function. A number of studies show that the development of PH is closely related to the gut microbiota, and lung-gut axis might be a potential therapeutic target in the PH treatment. A. muciniphila has been reported to play a critical role in treating cardiovascular disorders. In this study we evaluated the therapeutic effects of A. muciniphila against hypoxia-induced PH and the underlying mechanisms. Mice were pretreated with A. muciniphila suspension (2 × 108 CFU in 200 μL sterile anaerobic PBS, i.g.) every day for 3 weeks, and then exposed to hypoxia (9% O2) for another 4 weeks to induce PH. We showed that A. muciniphila pretreatment significantly facilitated the restoration of the hemodynamics and structure of the cardiopulmonary system, reversed the pathological progression of hypoxia-induced PH. Moreover, A. muciniphila pretreatment significantly modulated the gut microbiota in hypoxia-induced PH mice. miRNA sequencing analysis reveals that miR-208a-3p, a commensal gut bacteria-regulated miRNA, was markedly downregulated in lung tissues exposed to hypoxia, which was restored by A. muciniphila pretreatment. We showed that transfection with miR-208a-3p mimic reversed hypoxia-induced abnormal proliferation of human pulmonary artery smooth muscle cells (hPASMCs) via regulating the cell cycle, whereas knockdown of miR-208a-3p abolished the beneficial effects of A. muciniphila pretreatment in hypoxia-induced PH mice. We demonstrated that miR-208a-3p bound to the 3'-untranslated region of NOVA1 mRNA; the expression of NOVA1 was upregulated in lung tissues exposed to hypoxia, which was reversed by A. muciniphila pretreatment. Furthermore, silencing of NOVA1 reversed hypoxia-induced abnormal proliferation of hPASMCs through cell cycle modulation. Our results demonstrate that A. muciniphila could modulate PH through the miR-208a-3p/NOVA1 axis, providing a new theoretical basis for PH treatment.

Large-scale ORF screening based on LC-MS to discover novel lncRNA-encoded peptides responding to ionizing radiation and microgravity

In the human genome, 98% of genes can be transcribed into non-coding RNAs (ncRNAs), among which lncRNAs and their encoded peptides play important roles in regulating various aspects of cellular processes and may serve as crucial factors in modulating the biological effects induced by ionizing radiation and microgravity. Unfortunately, there are few reports in space radiation biology on lncRNA-encoded peptides below 10kD due to limitations in detection techniques. To fill this gap, we integrated a variety of methods based on genomics and peptidomics, and discovered 22 lncRNA-encoded small peptides that are sensitive to space radiation and microgravity, which have never been reported before. We concurrently validated the transmembrane helix, subcellular localization, and biological function of these small peptides using bioinformatics and molecular biology techniques. More importantly, we found that these small peptides function independently of the lncRNAs that encode them. Our findings have uncovered a previously unknown human proteome encoded by 'non-coding' genes in response to space conditions and elucidated their involvement in biological processes, providing valuable strategies for individual protection mechanisms for astronauts who carry out deep space exploration missions in space radiation environments.

LncRNA-encoded peptides: unveiling their significance in cardiovascular physiology and pathology-current research insights

Long non-coding RNAs (lncRNAs), which are RNA transcripts exceeding 200 nucleotides were believed to lack any protein-coding capacity. But advancements in -omics technology have revealed that some lncRNAs have small open reading frames (sORFs) that can be translated by ribosomes to encode peptides, some of which have important biological functions. These encoded peptides subserve important biological functions by interacting with their targets to modulate transcriptional or signalling axes, thereby enhancing or suppressing cardiovascular disease (CVD) occurrence and progression. In this review, we summarize what is known about the research strategy of lncRNA-encoded peptides, mainly comprising predictive websites/tools and experimental methods that have been widely used for prediction, identification, and validation. More importantly, we have compiled a list of lncRNA- encoded peptides, with a focus on those that play significant roles in cardiovascular physiology and pathology, including ENSRNOT (RNO)-sORF6/RNO-sORF7/RNO-sORF8, dwarf open reading frame (DOWRF), myoregulin (NLN), etc. Additionally, we have outlined the functions and mechanisms of these peptides in cardiovascular physiology and pathology, such as cardiomyocyte hypertrophy, myocardial contraction, myocardial infarction, and vascular remodelling. Finally, an overview of the existing challenges and potential future developments in the realm of lncRNA-encoded peptides was provided, with consideration given to prospective avenues for further research. Given that many lncRNA-encoded peptides have not been functionally annotated yet, their application in CVD diagnosis and treatment still requires further research.

Small Open Reading Frame-Encoded Micro-Peptides: An Emerging Protein World

Small open reading frames (sORFs) are often overlooked features in genomes. In the past, they were labeled as noncoding or "transcriptional noise". However, accumulating evidence from recent years suggests that sORFs may be transcribed and translated to produce sORF-encoded polypeptides (SEPs) with less than 100 amino acids. The vigorous development of computational algorithms, ribosome profiling, and peptidome has facilitated the prediction and identification of many new SEPs. These SEPs were revealed to be involved in a wide range of basic biological processes, such as gene expression regulation, embryonic development, cellular metabolism, inflammation, and even carcinogenesis. To effectively understand the potential biological functions of SEPs, we discuss the history and development of the newly emerging research on sORFs and SEPs. In particular, we review a range of recently discovered bioinformatics tools for identifying, predicting, and validating SEPs as well as a variety of biochemical experiments for characterizing SEP functions. Lastly, this review underlines the challenges and future directions in identifying and validating sORFs and their encoded micropeptides, providing a significant reference for upcoming research on sORF-encoded peptides.

LINC00493-encoded microprotein SMIM26 exerts anti-metastatic activity in renal cell carcinoma

Human microproteins encoded by long non-coding RNAs (lncRNA) have been increasingly discovered, however, complete functional characterization of these emerging proteins is scattered. Here, we show that LINC00493-encoded SMIM26, an understudied microprotein localized in mitochondria, is tendentiously downregulated in clear cell renal cell carcinoma (ccRCC) and correlated with poor overall survival. LINC00493 is recognized by RNA-binding protein PABPC4 and transferred to ribosomes for translation of a 95-amino-acid protein SMIM26. SMIM26, but not LINC00493, suppresses ccRCC growth and metastatic lung colonization by interacting with acylglycerol kinase (AGK) and glutathione transport regulator SLC25A11 via its N-terminus. This interaction increases the mitochondrial localization of AGK and subsequently inhibits AGK-mediated AKT phosphorylation. Moreover, the formation of the SMIM26-AGK-SCL25A11 complex maintains mitochondrial glutathione import and respiratory efficiency, which is abrogated by AGK overexpression or SLC25A11 knockdown. This study functionally characterizes the LINC00493-encoded microprotein SMIM26 and establishes its anti-metastatic role in ccRCC, and therefore illuminates the importance of hidden proteins in human cancers.

Long non-coding RNAs: The growth controller of vascular smooth muscle cells in cardiovascular diseases

The active proliferation and migration of vascular smooth muscle cells supports the healing of vessel damage while their abnormal aggression or destitution contribute to the aberrant intima-medial structure and function in various cardiovascular diseases, so the understanding of the proliferation disorders of vascular smooth muscle cell and the related mechanism is the basis of effective intervention and control for cardiovascular diseases. Recently, long non-coding RNAs have stood out as upstream switchers for multiple proliferative signaling pathways and molecules, and many of them have been shown to conduce to the dysregulated proliferation and apoptosis of vascular smooth muscle cells under various pathogenic stimuli. This article discusses the long non-coding RNAs disclosed and linked to atherosclerosis, pulmonary hypertension, and aneurysms, and focuses upon their modulation of vascular smooth muscle cell population affecting three deadly cardiovascular diseases.

Shiny transcriptional junk: lncRNA-derived peptides in cancers and immune responses

By interacting with DNA, RNA, and proteins, long noncoding RNAs (lncRNAs) have been linked to several pathological states. LncRNA-derived peptides, as a novel modality of action of lncRNAs, have recently become a research hotspot. An increasing body of evidence has demonstrated the important role of these peptides in carcinogenesis and cancer progression and immune response. This review first describes lncRNA-derived peptides, the regulators that control their translation, and the roles of these peptides in multiple biological processes and disease states including cancers. In the following section, we comprehensively analyzed the significant role lncRNA-derived peptide played in the immune response. This review provides fresh perspectives on the biological role of lncRNAs and their relationship with diseases, particularly with cancers and the immune response, providing a theoretical basis for these lncRNA-derived peptides as therapeutic and diagnostic targets in cancers and inflammatory diseases.

Hypoxia Inhibits Cell Cycle Progression and Cell Proliferation in Brain Microvascular Endothelial Cells via the miR-212-3p/MCM2 Axis

Hypoxia impairs blood-brain barrier (BBB) structure and function, causing pathophysiological changes in the context of stroke and high-altitude brain edema. Brain microvascular endothelial cells (BMECs) are major structural and functional elements of the BBB, and their exact role in hypoxia remains unknown. Here, we first deciphered the molecular events that occur in BMECs under 24 h hypoxia by whole-transcriptome sequencing assay. We found that hypoxia inhibited BMEC cell cycle progression and proliferation and downregulated minichromosome maintenance complex component 2 (Mcm2) expression. Mcm2 overexpression attenuated the inhibition of cell cycle progression and proliferation caused by hypoxia. Then, we predicted the upstream miRNAs of MCM2 through TargetScan and miRanDa and selected miR-212-3p, whose expression was significantly increased under hypoxia. Moreover, the miR-212-3p inhibitor attenuated the inhibition of cell cycle progression and cell proliferation caused by hypoxia by regulating MCM2. Taken together, these results suggest that the miR-212-3p/MCM2 axis plays an important role in BMECs under hypoxia and provide a potential target for the treatment of BBB disorder-related cerebrovascular disease.

Functional Micropeptides Encoded by Long Non-Coding RNAs: A Comprehensive Review

Long non-coding RNAs (lncRNAs) were originally defined as non-coding RNAs (ncRNAs) which lack protein-coding ability. However, with the emergence of technologies such as ribosome profiling sequencing and ribosome-nascent chain complex sequencing, it has been demonstrated that most lncRNAs have short open reading frames hence the potential to encode functional micropeptides. Such micropeptides have been described to be widely involved in life-sustaining activities in several organisms, such as homeostasis regulation, disease, and tumor occurrence, and development, and morphological development of animals, and plants. In this review, we focus on the latest developments in the field of lncRNA-encoded micropeptides, and describe the relevant computational tools and techniques for micropeptide prediction and identification. This review aims to serve as a reference for future research studies on lncRNA-encoded micropeptides.

The Landscape of Noncoding RNA in Pulmonary Hypertension

The transcriptome of pulmonary hypertension (PH) is complex and highly genetically heterogeneous, with noncoding RNA transcripts playing crucial roles. The majority of RNAs in the noncoding transcriptome are long noncoding RNAs (lncRNAs) with less circular RNAs (circRNAs), which are two characteristics gaining increasing attention in the forefront of RNA research field. These noncoding transcripts (especially lncRNAs and circRNAs) exert important regulatory functions in PH and emerge as potential disease biomarkers and therapeutic targets. Recent technological advancements have established great momentum for discovery and functional characterization of ncRNAs, which include broad transcriptome sequencing such as bulk RNA-sequence, single-cell and spatial transcriptomics, and RNA-protein/RNA interactions. In this review, we summarize the current research on the classification, biogenesis, and the biological functions and molecular mechanisms of these noncoding RNAs (ncRNAs) involved in the pulmonary vascular remodeling in PH. Furthermore, we highlight the utility and challenges of using these ncRNAs as biomarkers and therapeutics in PH.

Molecular cloning, characterization, and functional analysis of the uncharacterized C11orf96 gene

Background

The mammalian genome encodes millions of proteins. Although many proteins have been discovered and identified, a large part of proteins encoded by genes are yet to be discovered or fully characterized. In the present study, we successfully identified a host protein C11orf96 that was significantly upregulated after viral infection.

Results

First, we successfully cloned the coding sequence (CDS) region of the cat, human, and mouse C11orf96 gene. The CDS region of the C11orf96 gene is 372 bp long, encodes 124 amino acids, and is relatively conserved in different mammals. From bioinformatics analysis, we found that C11orf96 is rich in Ser and has multiple predicted phosphorylation sites. Moreover, protein interaction prediction analysis revealed that the protein is associated with several transmembrane family proteins and zinc finger proteins. Subsequently, we found that C11orf96 is strictly distributed in the cytoplasm. According to the tissue distribution characteristics, C11orf96 is distributed in all tissues and organs, with the highest expression levels in the kidney. These results indicate that C11orf96 may play a specific biological role in the kidney.

Conclusions

Summarizing, these data lay the foundation for studying the biological functions of C11orf96 and for exploring its role in viral replication.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03224-5.

The Emerging Landscape of Long Non-Coding RNAs in Wilms Tumor

Long noncoding RNAs (LncRNAs) are transcripts of nucleic acid sequences with a length of more than 200 bp, which have only partial coding capabilities. Recent studies have shown that lncRNAs located in the nucleus or cytoplasm can be used as gene expression regulatory elements due to their important regulatory effects in a variety of biological processes. Wilms tumor (WT) is a common abdominal tumor in children whose pathogenesis remains unclear. In recent years, many specifically expressed lncRNAs have been found in WT, which affect the occurrence and development of WT. At the same time, lncRNAs may have the capacity to become novel biomarkers for the diagnosis and prognosis of WT. This article reviews related research progress on the relationship between lncRNAs and WT, to provide a new direction for clinical diagnosis and treatment of WT.

Evaluating the Effect of Circ-Sirt1 on the Expression of SIRT1 and Its Role in Pathology of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a disease that plagues a major portion of the world's population, and there is currently no effective cure for this ailment. The proliferation and migration of pulmonary artery smooth muscle cells (PASMC) are known to be the pathological basis of pulmonary vascular remodeling in pulmonary hypertension. Studies in the past have shown involvement of CircRNA in the pathology of pulmonary as well as cardiovascular diseases. However, there are very few studies that have analyzed the relationship between CircRNA and PAH. The aim of this study was to explore this relationship by using rat PAH model. A hypoxic, PAH rat model was constructed for this study and the subsequently produced hypoxia-induced rat PASMC cells were utilized to demonstrate the reduction in expression of circular RNA of Silent information regulator factor 2-related enzyme 1 (circ-Sirt1) and SIRT1 mRNA in response to hypoxia, through cell function tests, cell rescue tests, and physical tests. We found that the expression of circ-Sirt1 and SIRT1 decreased in the PAH rat model induced by hypoxia. It was also revealed that the overexpression of circ-SIRT1 increased SIRT1 levels, but inhibited the expression of transforming growth factor (TGF)-β1, Smad3, and Smad7, and weakened PASMC cell vitality, proliferation, and migration ability. The findings of the present study indicate that circ-Sirt1 regulates the expression of SIRT1 mRNA and inhibits TGF-β1/Smad3/Smad7 mediated proliferation and migration of PASMC. This provides a new insight into the molecular mechanism of pulmonary artery vascular remodeling in PAH and may aid in the development of novel therapeutic options for management of PAH.

The Small Open Reading Frame-Encoded Peptides: Advances in Methodologies and Functional Studies

Small open reading frames (sORFs) are an important class of genes with less than 100 codons. They were historically annotated as noncoding or even junk sequences. In recent years, accumulating evidence suggests that sORFs could encode a considerable number of polypeptides, many of which play important roles in both physiology and disease pathology. However, it has been technically challenging to directly detect sORF-encoded peptides (SEPs). Here, we discuss the latest advances in methodologies for identifying SEPs with mass spectrometry, as well as the progress on functional studies of SEPs.

Long non-coding RNA NORAD promotes pancreatic cancer stem cell proliferation and self-renewal by blocking microRNA-202-5p-mediated ANP32E inhibition

Background

Cancer stem cells (CSCs) are key regulators in the processes of tumor initiation, progression, and recurrence. The mechanism that maintains their stemness remains enigmatic, although the role of several long noncoding RNAs (lncRNAs) has been highlighted in the pancreatic cancer stem cells (PCSCs). In this study, we first established that PCSCs overexpressing lncRNA NORAD, and then investigated the effects of NORAD on the maintenance of PCSC stemness.

Methods

Expression of lncRNA NORAD, miR-202-5p and ANP32E in PC tissues and cell lines was quantified after RNA isolation. Dual-luciferase reporter assay, RNA pull-down and RIP assays were performed to verify the interactions among NORAD, miR-202-5p and ANP32E. We then carried out gain- and loss-of function of miR-202-5p, ANP32E and NORAD in PANC-1 cell line, followed by measurement of the aldehyde dehydrogenase activity, cell viability, apoptosis, cell cycle distribution, colony formation, self-renewal ability and tumorigenicity of PC cells.

Results

LncRNA NORAD and ANP32E were upregulated in PC tissues and cells, whereas the miR-202-5p level was down-regulated. LncRNA NORAD competitively bound to miR-202-5p, and promoted the expression of the miR-202-5p target gene ANP32E thereby promoting PC cell viability, proliferation, and self-renewal ability in vitro, as well as facilitating tumorigenesis of PCSCs in vivo.

Conclusion

Overall, lncRNA NORAD upregulates ANP32E expression by competitively binding to miR-202-5, which accelerates the proliferation and self-renewal of PCSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03052-5.

Role of Long Non-Coding RNAs in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a debilitating condition of the pulmonary circulatory system that occurs in patients of all ages and if untreated, eventually leads to right heart failure and death. Despite existing medical treatment options that improve survival and quality of life, the disease remains incurable. Thus, there is an urgent need to develop novel therapies to treat this disease. Emerging evidence suggests that long non-coding RNAs (lncRNAs) play critical roles in pulmonary vascular remodeling and PAH. LncRNAs are implicated in pulmonary arterial endothelial dysfunction by modulating endothelial cell proliferation, angiogenesis, endothelial mesenchymal transition, and metabolism. LncRNAs are also involved in inducing different pulmonary arterial vascular smooth muscle cell phenotypes, such as cell proliferation, apoptosis, migration, regulation of the phenotypic switching, and cell cycle. LncRNAs are essential regulators of gene expression that affect various diseases at the chromatin, transcriptional, post-translational, and even post-translational levels. Here, we focus on the role of LncRNAs and their molecular mechanisms in the pathogenesis of PAH. We also discuss the current research challenge and potential biomarker and therapeutic potentials of lncRNAs in PAH.