miR-182-5p promotes hepatocyte-stellate cell crosstalk to facilitate liver regeneration

RNAa: Mechanisms, therapeutic potential, and clinical progress

RNA activation (RNAa), a gene regulatory mechanism mediated by small activating RNAs (saRNAs) and microRNAs (miRNAs), has significant implications for therapeutic applications. Unlike small interfering RNA (siRNA), which is known for gene silencing in RNA interference (RNAi), synthetic saRNAs can stably upregulate target gene expression at the transcriptional level through the assembly of the RNA-induced transcriptional activation (RITA) complex. Moreover, the dual functionality of endogenous miRNAs in RNAa (hereafter referred to as mi-RNAa) reveals their complex role in cellular processes and disease pathology. Emerging studies suggest saRNAs' potential as a novel therapeutic modality for diseases such as metabolic disorders, hearing loss, tumors, and Alzheimer's. Notably, MTL-CEBPA, the first saRNA drug candidate, shows promise in hepatocellular carcinoma treatment, while RAG-01 is being explored for non-muscle-invasive bladder cancer, highlighting clinical advancements in RNAa. This review synthesizes our current understanding of the mechanisms of RNAa and highlights recent advancements in the study of mi-RNAa and the therapeutic development of saRNAs.

Molecular mechanisms in liver repair and regeneration: from physiology to therapeutics

Liver repair and regeneration are crucial physiological responses to hepatic injury and are orchestrated through intricate cellular and molecular networks. This review systematically delineates advancements in the field, emphasizing the essential roles played by diverse liver cell types. Their coordinated actions, supported by complex crosstalk within the liver microenvironment, are pivotal to enhancing regenerative outcomes. Recent molecular investigations have elucidated key signaling pathways involved in liver injury and regeneration. Viewed through the lens of metabolic reprogramming, these pathways highlight how shifts in glucose, lipid, and amino acid metabolism support the cellular functions essential for liver repair and regeneration. An analysis of regenerative variability across pathological states reveals how disease conditions influence these dynamics, guiding the development of novel therapeutic strategies and advanced techniques to enhance liver repair and regeneration. Bridging laboratory findings with practical applications, recent clinical trials highlight the potential of optimizing liver regeneration strategies. These trials offer valuable insights into the effectiveness of novel therapies and underscore significant progress in translational research. In conclusion, this review intricately links molecular insights to therapeutic frontiers, systematically charting the trajectory from fundamental physiological mechanisms to innovative clinical applications in liver repair and regeneration.

Tristetraprolin Family Members and Processing Bodies: A Complex Regulatory Network Involved in Fatty Liver Disease, Viral Hepatitis and Hepatocellular Carcinoma

Chronic liver diseases, such as those encountered with obesity, chronic/abusive alcohol consumption or viral infections, represent not only major public health concerns with limited therapeutic options but also important risk factors for the onset of hepatocellular carcinoma (HCC). Deciphering the molecular traits underlying these disorders is of high interest for designing new and effective treatments. The tristetraprolin (TTP) family members are of particular importance given their ability to control the expression of a wide range of genes involved in metabolism, inflammation and carcinogenesis at the post-transcriptional level. This regulation can occur within small cytoplasmic granules, namely, processing bodies (P-bodies), where the mRNA degradation occurs. Increasing evidence indicates that TTP family members and P-bodies are involved in the development of chronic liver diseases and cancers. In this review, we discuss the role of this regulatory mechanism in metabolic-dysfunction-associated steatotic liver disease (MASLD), alcohol-related liver disease (ALD), hepatic viral infections and HCC.

Inhibition of mmu_circ_0009303 improves metabolic dysfunction-associated steatotic liver disease by regulating lipid metabolism and oxidative stress

Circular RNAs (circRNAs) play an important role in regulating inflammation and oxidative stress during the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD); however, the underlying mechanism is unclear. This study aimed to determine the role of mmu_circ_0009303 in MASLD. We used a bioinformatics approach to identify potential targets and established an in vitro model of MASLD. Oil red O staining, cell transfection and dual-luciferase reporter assay were used to determine the role of mmu_circ_0009303. The results indicated that the mmu_circ_0009303 expression was significantly increased in the MASLD model both in vitro and in vivo and was associated with oxidative stress levels and inflammation. Moreover, bioinformatics analyses revealed that miRNA-182-5p and Foxo3 are targets of mmu_circ_0009303 and miRNA-182-5p, respectively. In the in vitro MASLD model, mmu_circ_0009303 promoted fat deposition in NCTC1469 cells, which was induced by free fatty acid (FFA) through the regulation of miRNA-182-5p/Foxo3. The expression of miRNA-182-5p and Forkhead box O3 (Foxo3) was associated with mmu_circ_0009303 expression in the liver of mice with MASLD, which was induced by a high-fat diet. Furthermore, mmu_circ_0009303 may be involved in regulating the expression of lipid metabolism-related regulatory proteins, such as CPT1A, SLC27A4, ACBD3, SREBP1, FAS, PPARα, and PPARγ. Taken together, mmu_circ_0009303 promotes oxidative stress, inflammation, and excessive fat accumulation in NCTC1469 cells induced by FFA through the regulation of miRNA-182-5p/Foxo3 and lipid metabolism-related regulatory proteins. These findings provide a potential target for the treatment of MASLD.

Epigenetic regulation in liver regeneration

The liver is considered unique in its enormous capacity for regeneration and self-repair. In contrast to other regenerative organs (i.e., skin, skeletal muscle, and intestine), whether the adult liver contains a defined department of stem cells is still controversial. In order to compensate for the massive loss of hepatocytes following liver injury, the liver processes a precisely controlled transcriptional reprogram that can trigger cell proliferation and cell-fate switch. Epigenetic events are thought to regulate the organization of chromatin architecture and gene transcription during the liver regenerative process. In this review, we will summarize how changes to the chromatin by epigenetic modifiers are translated into cell fate transitions to restore liver homeostasis during liver regeneration.

Exploring the roles of non-coding RNAs in liver regeneration

Liver regeneration (LR) is a complex process encompassing three distinct phases: priming, proliferation phase and restoration, all influenced by various regulatory factors. After liver damage or partial resection, the liver tissue demonstrates remarkable restorative capacity, driven by cellular proliferation and repair mechanisms. The essential roles of non-coding RNAs (ncRNAs), predominantly microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNA (circRNA), in regulating LR have been vastly studied. Additionally, the impact of ncRNAs on LR and their abnormal expression profiles during this process have been extensively documented. Mechanistic investigations have revealed that ncRNAs interact with genes involved in proliferation to regulate hepatocyte proliferation, apoptosis and differentiation, along with liver progenitor cell proliferation and migration. Given the significant role of ncRNAs in LR, an in-depth exploration of their involvement in the liver's self-repair capacity can reveal promising therapeutic strategies for LR and liver-related diseases. Moreover, understanding the unique regenerative potential of the adult liver and the mechanisms and regulatory factors of ncRNAs in LR are crucial for improving current treatment strategies and exploring new therapeutic approaches for various liver-related diseases. This review provides a brief overview of the LR process and the ncRNA expression profiles during this process. Furthermore, we also elaborate on the specific molecular mechanisms through which multiple key ncRNAs regulate the LR process. Finally, based on the expression characteristics of ncRNAs and their interactions with proliferation-associated genes, we explore their potential clinical application, such as developing predictive indicators reflecting liver regenerative activity and manipulating LR processes for therapeutic purposes.

Hepatocyte-derived tissue extracellular vesicles safeguard liver regeneration and support regenerative therapy

Tissue-derived extracellular vesicles (EVs) are emerging as pivotal players to maintain organ homeostasis, which show promise as a next-generation candidate for medical use with extensive source. However, the detailed function and therapeutic potential of tissue EVs remain insufficiently studied. Here, through bulk and single-cell RNA sequencing analyses combined with ultrastructural tissue examinations, we first reveal that in situ liver tissue EVs (LT-EVs) contribute to the intricate liver regenerative process after partial hepatectomy (PHx), and that hepatocytes are the primary source of tissue EVs in the regenerating liver. Nanoscale and proteomic profiling further identify that the hepatocyte-specific tissue EVs (Hep-EVs) are strengthened to release with carrying proliferative messages after PHx. Moreover, targeted inhibition of Hep-EV release via AAV-shRab27a in vivo confirms that Hep-EVs are required to orchestrate liver regeneration. Mechanistically, Hep-EVs from the regenerating liver reciprocally stimulate hepatocyte proliferation by promoting cell cycle progression through Cyclin-dependent kinase 1 (Cdk1) activity. Notably, supplementing with Hep-EVs from the regenerating liver demonstrates translational potential and ameliorates insufficient liver regeneration. This study provides a functional and mechanistic framework showing that the release of regenerative Hep-EVs governs rapid liver regeneration, thereby enriching our understanding of physiological and endogenous tissue EVs in organ regeneration and therapy.

The evidence-based multifaceted roles of hepatic stellate cells in liver diseases: A concise review

Hepatic stellate cells (HSCs) play central roles in liver disease pathogenesis, spanning steatosis to cirrhosis and hepatocellular carcinoma. These cells, located in the liver's sinusoidal space of Disse, transition from a quiescent, vitamin A-rich state to an activated, myofibroblast-like phenotype in response to liver injury. This activation results from a complex interplay of cytokines, growth factors, and oxidative stress, leading to excessive collagen deposition and liver fibrosis, a hallmark of chronic liver diseases. Recently, HSCs have gained recognition for their dynamic, multifaceted roles in liver health and disease. Attention has shifted toward their involvement in various liver conditions, including acute liver injury, alcoholic and non-alcoholic fatty liver disease, and liver regeneration. This review aims to explore diverse functions of HSCs in these acute or chronic liver pathologies, with a focus on their roles beyond fibrogenesis. HSCs exhibit a wide range of actions, including lipid storage, immunomodulation, and interactions with other hepatic and extrahepatic cells, making them pivotal in the hepatic microenvironment. Understanding HSC involvement in the progression of liver diseases can offer novel insights into pathogenic mechanisms and guide targeted therapeutic strategies for various liver conditions.

Bile Acid Application in Cell-Targeting for Molecular Receptors in Relation to Hearing: A Comprehensive Review

Bile acids play important roles in the human body, and changes in their pool can be used as markers for various liver pathologies. In addition to their functional effects in modulating inflammatory responses and cellular survivability, the unconjugated or conjugated, secondary, or primary nature of bile acids accounts for their various ligand effects. The common hydrophilic bile acids have been used successfully as local treatment to resolve drug-induced cell damage or to ameliorate hearing loss. From various literature references, bile acids show concentration and tissue-dependent effects. Some hydrophobic bile acids act as ligands modulating vitamin D receptors, muscarinic receptors, and calcium-activated potassium channels, important proteins in the inner ear system. Currently, there are limited resources investigating the therapeutic effects of bile acid on hearing loss and little to no information on detecting bile acids in the remote ear system, let alone baseline bile acid levels and their prevalence in healthy and disease conditions. This review presents both hydrophilic and hydrophobic human bile acids and their tissue-specific effects in modulating cellular integrity, thus considering the possible effects and extended therapeutic applicability of bile acids to the inner ear tissue.

Past, present, and future of chemically induced hepatocarcinogenesis rodent models: Perspectives concerning classic and new cancer hallmarks

Hepatocellular carcinoma (HCC), the main primary liver cancer, accounts for 5 % of all incident cases and 8.4 % of all cancer-related deaths worldwide. HCC displays a spectrum of environmental risk factors (viral chronic infections, aflatoxin exposure, alcoholic- and nonalcoholic fatty liver diseases) that result in molecular complexity and heterogeneity, contributing to a rising epidemiological burden, poor prognosis, and non-satisfactory treatment options. The emergence of HCC (i.e., hepatocarcinogenesis) is a multistep and complex process that addresses many (epi)genetic alterations and phenotypic traits, the so-called cancer hallmarks. "Polymorphic microbiomes", "epigenetic reprogramming", "senescent cells" and "unlocking phenotypic plasticity" are trending hallmarks/enabling features in cancer biology. As the main molecular drivers of HCC are still undruggable, chemically induced in vivo models of hepatocarcinogenesis are useful tools in preclinical research. Thus, this narrative review aimed at recapitulating the basic features of chemically induced rodent models of hepatocarcinogenesis, eliciting their permanent translational value regarding the "classic" and the "new" cancer hallmarks/enabling features. We gathered state-of-art preclinical evidence on non-cirrhotic, inflammation-, alcoholic liver disease- and nonalcoholic fatty liver-associated HCC models, demonstrating that these bioassays indeed express the recently added hallmarks, as well as reflect the interplay between classical and new cancer traits. Our review demonstrated that these protocols remain valuable for translational preclinical application, as they recapitulate trending features of cancer science. Further "omics-based" approaches are warranted while multimodel investigations are encouraged in order to avoid "model-biased" responses.

The role of microRNAs in the different phases of liver regeneration

INTRODUCTION

Since the first discovery of microRNAs (miRs) extensive evidence reveals their indispensable role in different patho-physiological processes. They are recognized as critical regulators of hepatic regeneration, as they modulate multiple complex signaling pathways affecting liver regeneration. MiR-related translational suppression and degradation of target mRNAs and proteins are not limited to one specific gene, but act on multiple targets.

AREAS COVERED

In this review, we are going to explore the role of miRs in the context of liver regeneration and discuss the regulatory effects attributed to specific miRs. Moreover, specific pathways crucial for liver regeneration will be discussed, with a particular emphasis on the involvement of miRs within the respective signaling cascades.

EXPERT OPINION

The considerable amount of studies exploring miR functions in a variety of diseases paved the way for the development of miR-directed therapeutics. Clinical implementation has already shown promising results, but additional research is warranted to assure safe and efficient delivery. Nevertheless, given the broad functional properties of miRs and their critical involvement during hepatic regeneration, they represent an attractive treatment target to promote liver recovery after hepatic resection.

Classification of Parkinson's disease and its stages using machine learning

As digital health technology becomes more pervasive, machine learning (ML) provides a robust way to analyze and interpret the myriad of collected features. The purpose of this preliminary work was to use ML classification to assess the benefits and relevance of neurocognitive features both tablet-based assessments and self-reported metrics, as they relate to Parkinson’s Disease (PD) and its stages [Hoehn and Yahr (H&Y) Stages 1–5]. Further, this work aims to compare perceived versus sensor-based neurocognitive abilities. In this study, 75 participants (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n = 50$$\end{document}n=50 PD; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n = 25$$\end{document}n=25 control) completed 14 tablet-based neurocognitive functional tests (e.g., motor, memory, speech, executive, and multifunction), functional movement assessments (e.g., Berg Balance Scale), and standardized health questionnaires (e.g., PDQ-39). Decision tree classification of sensor-based features allowed for the discrimination of PD from healthy controls with an accuracy of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$92.6\%$$\end{document}92.6%, and early and advanced stages of PD with an accuracy of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$73.7\%$$\end{document}73.7%; compared to the current gold standard tools [e.g., standardized health questionnaires (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$78.3\%$$\end{document}78.3% accuracy) and functional movement assessments (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$70\%$$\end{document}70% accuracy)]. Significant features were also identified using decision tree classification. Device magnitude of acceleration was significant in 12 of 14 tests (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$85.7\%$$\end{document}85.7%), regardless of test type. For classification between diagnosed and control populations, 17 motor (e.g., device magnitude of acceleration), 9 accuracy (e.g., number of correct/incorrect interactions), and 8 timing features (e.g., time to between interactions) were significant. For classification between early (H&Y Stages 1 and 2) and advanced (H&Y Stages 3, 4, and 5) stages of PD, 7 motor, 12 accuracy, and 14 timing features were significant. Finally, this work depicts that perceived functionality of individuals with PD differed from sensor-based functionalities. In early-stage PD was shown to be \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$21.6\%$$\end{document}21.6% lower than sensor-based scores with notable perceived deficits in memory and executive function. However, individuals in advanced stages had elevated perceptions (1.57x) for executive and behavioral functions compared to early-stage populations. Machine learning in digital health systems allows for a more comprehensive understanding of neurodegenerative diseases and their stages and may also depict new features that influence the ways digital health technology should be configured.