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Staphylococcus aureus generates extracellular membrane vesicles (MVs) during both in vitro culture and in vivo infection. S. aureus MVs are generated by either blebbing of the cytoplasmic membrane or explosive cell lysis. Proteins and nucleic acids encapsulated within S. aureus MVs are protected from degradation or neutralization by host factors. S. aureus MVs exhibit cytotoxicity to a variety of host cell types and induce both host innate and adaptive immune responses in animal infection models. MVs exploit different endocytic pathways for the delivery of their cargo into host cells. Deciphering the intracellular fate of S. aureus MVs after cellular entry may deepen our limited understanding of how MVs impact the host during staphylococcal infections. Staphylococcus aureus is an important bacterial pathogen that causes a wide variety of human diseases in community and hospital settings. S. aureus employs a diverse array of virulence factors, both surface-associated and secreted, to promote colonization, infection, and immune evasion. Over the past decade, a growing body of research has shown that S. aureus generates extracellular membrane vesicles (MVs) that package a variety of bacterial components, many of which are virulence factors. In this review, we summarize recent advances in our understanding of S. aureus MVs and highlight their biogenesis, cargo, and potential role in the pathogenesis of staphylococcal infections. Lastly, we present some emerging questions in the field. [ABSTRACT FROM AUTHOR]

Bacterial extracellular vesicles (BEVs) have emerged as pivotal mediators between bacteria and host. In addition to being crucial players in host homeostasis, they have recently been implicated in disease pathologies such as cancer. Hence, the study of BEVs represents an intriguing and rapidly evolving field with substantial translational potential. In this review, we briefly introduce the fundamentals of BEV characteristics, cargo and biogenesis. We emphatically summarize the current relationship between BEVs across various cancer types, illustrating their role in tumorigenesis, treatment responses and patient survival. We further discuss the inherent advantages of BEVs, such as stability, abundance and specific cargo profiles, that make them attractive candidates for non‐invasive diagnostic and prognostic approaches. The review also explores the potential of BEVs as a strategy for cancer therapy, considering their ability to deliver therapeutic agents, modulate the tumour microenvironment (TME) and elicit immunomodulatory responses. Understanding the clinical significance of BEVs may lead to the development of better‐targeted and personalized treatment strategies. This comprehensive review evaluates the current progress surrounding BEVs and poses questions to encourage further research in this emerging field to harness the benefits of BEVs for their full potential in clinical applications against cancer. [ABSTRACT FROM AUTHOR]

SUMMARY: The accessory proteins Hyponastic‐like 1 (HYL1) and Serrated (SE) enhance the precise and efficient processing of miRNAs by Dicer‐like 1 (DCL1), which is important for proper miRNA function. However, other factors determining the precision and efficiency of miRNA biogenesis are not well‐known. Here, we found that an asymmetric bulge (AB) at the 3′ end of miR‐5p (produced from the 5′ arm of the pre‐miRNA) reduced the precision of the second cleavage, whereas an AB at other sites of miR‐5p mainly affected the accumulation level of miR‐5p in transient expression in Nicotiana benthamiana. In contrast, many ABs in miR‐3p (produced from the 3′ arm of the pre‐miRNA) impose strong negative impact on the processing precision and the accumulation level of miR‐5p in N. benthamiana. Arabidopsis DCL1/SE/HYL1 complex‐mediated miRNA processing was reconstituted in Saccharomyces cerevisiae to further investigate AB‐mediated interference with DCL1 processing. With this system, the positional effect of AB on miRNA processing was tested. The results showed that ABs on the middle of miR‐5p have less of an impact on DCL1 cleavage efficiency and precision, whereas those on miR‐3p or near the ends of miR‐5p strongly reduce DCL1 cleavage activity, precision or both. Studies using the yeast miRNA processing system and transgenic Arabidopsis also revealed the importance of the interaction between the 2‐nt 3′ overhang of pre‐miRNA and the 3′ overhang binding pocket (3′BP) on the precision of the second cleavage reaction for many endogenous miRNAs. These findings provide new insights into the mechanism of miRNA biogenesis. Significance Statement: Factors determining the precision and efficiency of miRNA biogenesis are not well‐known. This study found that an asymmetric bulge at different positions of miR‐5p and miR‐3p had different impacts on miRNA levels and processing precision and revealed the importance of the interaction between the 2‐nt 3′ overhang of pre‐miRNA and the 3′ overhang binding pocket (3'BP) on the precision of the second cleavage reaction for many endogenous miRNAs. [ABSTRACT FROM AUTHOR]

Outer membrane vesicles (OMVs) are nano-sized vesicles actively released by Gram-negative bacteria, playing a crucial role in bacterial survival and interactions with phages. This review focuses on OMVs and succinctly delineates the stimuli instigating OMV formation, their functional repertoire, and their involvement in bacterial-phage interplays. Initially, the discussion centers on the drivers prompting OMV genesis, encompassing both extrinsic environmental pressures and intrinsic regulatory mechanisms within bacterial systems. Subsequently, a comprehensive examination of OMVs’ multifaceted functions in bacterial physiology ensues, spanning signaling cascades, nutrient transport, antibiotic resilience, and evasion of immune surveillance. Particular emphasis is placed on elucidating the paramount significance of OMVs in mediating bacterial-phage dynamics. OMVs function as decoys, providing protection to bacterial hosts against phages, and concurrently promoting the spread of phage receptors, thereby rendering phage-resistant strains susceptible to phage invasion. This comprehensive review deepens our comprehension of membrane vesicles biogenesis in bacteria and their pivotal role in microbial community dynamics. [ABSTRACT FROM AUTHOR]

Skeletal muscle hypertrophy is generally associated with a fast-to-slow phenotypic adaptation in both human and rodent models. Paradoxically, this phenotypic shift is not paralleled by a concomitant increase in mitochondrial content and aerobic markers that would be expected to accompany a slow muscle phenotype. To understand the temporal response of the mitochondrial life cycle (i.e., biogenesis, oxidative phosphorylation, fission/fusion, and mitophagy/autophagy) to hypertrophic stimuli, in this study, we used the functional overload (FO) model in adult female rats and examined the plantaris muscle responses at 1 and 10 weeks. As expected, the absolute plantaris muscle mass increased by ~12 and 26% at 1 and 10 weeks following the FO procedure, respectively. Myosin heavy-chain isoform types I and IIa significantly increased by 116% and 17%, respectively, in 10-week FO plantaris muscles. Although there was a general increase in protein markers associated with mitochondrial biogenesis in acute FO muscles, this response was unexpectedly sustained under 10-week FO conditions after muscle hypertrophy begins to plateau. Furthermore, the early increase in mito/autophagy markers observed under acute FO conditions was normalized by 10 weeks, suggesting a cellular environment favoring mitochondrial biogenesis to accommodate the aerobic demands of the plantaris muscle. We also observed a significant increase in the expression of mitochondrial-, but not nuclear-, encoded oxidative phosphorylation (OXPHOS) proteins and peptides (i.e., humanin and MOTS-c) under chronic, but not acute, FO conditions. Taken together, the temporal response of markers related to the mitochondrial life cycle indicates a pattern of promoting biogenesis and mitochondrial protein expression to support the energy demands and/or enhanced neural recruitment of chronically overloaded skeletal muscle. [ABSTRACT FROM AUTHOR]

Mitochondrial homeostasis is controlled by biogenesis, dynamics, and mitophagy. Mitochondrial dysfunction plays a central role in cardiovascular and renal disease and omega-3 fatty acids (FAs) are beneficial for cardiovascular disease. We investigated whether omega-3 fatty acids (FAs) regulate mitochondrial biogenesis, dynamics, and mitophagy in the kidney and heart of adenine-induced uremic rats. Eighteen male Sprague Dawley rats were divided into normal control, adenine control, and adenine with omega-3 FA groups. Using Western blot analysis, the kidney and heart expression of mitochondrial homeostasis-related molecules, including peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), dynamin-related protein 1 (Drp1), and phosphatase and tensin homolog-induced putative kinase 1 (PINK1) were investigated. Compared to normal, serum creatinine and heart weight/body weight in adenine control were increased and slightly improved in the omega-3 FA group. Compared to the normal controls, the expression of PGC-1α and PINK1 in the kidney and heart of the adenine group was downregulated, which was reversed after omega-3 FA supplementation. Drp1 was upregulated in the kidney but downregulated in the heart in the adenine group. Drp1 expression in the heart recovered in the omega-3 FA group. Mitochondrial DNA (mtDNA) was decreased in the kidney and heart of the adenine control group but the mtDNA of the heart was recovered in the omega-3 FA group. Drp1, which is related to mitochondrial fission, may function oppositely in the uremic kidney and heart. Omega-3 FAs may be beneficial for mitochondrial homeostasis by activating mitochondrial biogenesis and PINK1-dependent mitophagy in the kidney and heart of uremic rats. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are short endogenous non-coding RNAs that regulate gene expression at the post-transcriptional level in a broad range of eukaryotic species. In animals, it is estimated that more than 60% of mammalian genes are targets of miRNAs, with miRNAs regulating cellular processes such as differentiation and proliferation. In plants, miRNAs regulate gene expression and play essential roles in diverse biological processes, including growth, development, and stress responses. Arabidopsis mutants with defective miRNA biogenesis are embryo lethal, and abnormal expression of miRNAs can cause severe developmental phenotypes. It is therefore crucial that the homeostasis of miRNAs is tightly regulated. In this review, we summarize the key mechanisms of plant miRNA biogenesis and stabilization. We provide an update on nuclear proteins with functions in miRNA biogenesis and proteins linking miRNA biogenesis to environmental triggers.

Heart failure (HF), a syndrome of persistent development of cardiac insufficiency due to various heart diseases, is a serious and lethal disease for which specific curative therapies are lacking and poses a severe burden on all aspects of global public health. Extracellular vesicles (EVs) are essential mediators of intercellular and interorgan communication, and are enclosed nanoscale vesicles carrying biomolecules such as RNA, DNA, and proteins. Recent studies have showed, among other things, that non-coding RNAs (ncRNAs), especially microRNAs (miRNAs), long ncRNAs (lncRNA), and circular RNAs (circRNAs) can be selectively sorted into EVs and modulate the pathophysiological processes of HF in recipient cells, acting on both healthy and diseased hearts, which makes them promising targets for the diagnosis and therapy of HF. This review aims to explore the mechanism of action of EV-ncRNAs in heart failure, with emphasis on the potential use of differentially expressed miRNAs and circRNAs as biomarkers of cardiovascular disease, and recent research advances in the diagnosis and treatment of heart failure. Finally, we focus on summarising the latest advances and challenges in engineering EVs for HF, providing novel concepts for the diagnosis and treatment of heart failure.

Abstract Long noncoding RNAs (lncRNAs), which are more than 200 nucleotides in length and do not encode proteins, play crucial roles in governing gene expression at both the transcriptional and posttranscriptional levels. These molecules demonstrate specific expression patterns in various tissues and developmental stages, suggesting their involvement in numerous developmental processes and diseases, notably cancer. Despite their widespread acknowledgment and the growing enthusiasm surrounding their potential as diagnostic and prognostic biomarkers, the precise mechanisms through which lncRNAs function remain inadequately understood. A few lncRNAs have been studied in depth, providing valuable insights into their biological activities and suggesting emerging functional themes and mechanistic models. However, the extent to which the mammalian genome is transcribed into functional noncoding transcripts is still a matter of debate. This review synthesizes our current understanding of lncRNA biogenesis, their genomic contexts, and their multifaceted roles in tumorigenesis, highlighting their potential in cancer-targeted therapy. By exploring historical perspectives alongside recent breakthroughs, we aim to illuminate the diverse roles of lncRNA and reflect on the broader implications of their study for understanding genome evolution and function, as well as for advancing clinical applications.

Cardiovascular diseases pose a significant public health challenge globally, necessitating the development of effective treatments to mitigate the risk of cardiovascular diseases. Recently, circular RNAs (circRNAs), a novel class of non-coding RNAs, have been recognized for their role in cardiovascular disease. Aberrant expression of circRNAs is closely linked with changes in various cellular and pathophysiological processes within the cardiovascular system, including metabolism, proliferation, stress response, and cell death. Functionally, circRNAs serve multiple roles, such as acting as a microRNA sponge, providing scaffolds for proteins, and participating in protein translation. Owing to their unique properties, circRNAs may represent a promising biomarker for predicting disease progression and a potential target for cardiovascular drug development. This review comprehensively examines the properties, biogenesis, and potential mechanisms of circRNAs, enhancing understanding of their role in the pathophysiological processes impacting cardiovascular disease. Furthermore, the prospective clinical applications of circRNAs in the diagnosis, prognosis, and treatment of cardiovascular disease are addressed. [ABSTRACT FROM AUTHOR]

In multicellular tissues, the size and shape of cells are intricately linked with their physiological functions. In the vertebrate auditory organ, the neurosensory epithelium develops as a mosaic of sensory hair cells (HCs), and their glial-like supporting cells, which have distinct morphologies and functional properties at different frequency positions along its tonotopic long axis. In the chick cochlea, the basilar papilla (BP), proximal (high-frequency) HCs, are larger than their distal (low-frequency) counterparts, a morphological feature essential for sound perception. Mitochondrial dynamics, which constitute the equilibrium between fusion and fission, regulate differentiation and functional refinement across a variety of cell types. We investigate this as a potential mechanism for regulating the shape of developing HCs. Using live imaging in intact BP explants, we identify distinct remodelling of mitochondrial networks in proximal compared with distal HCs. Manipulating mitochondrial dynamics in developing HCs alters their normal morphology along the proximal-distal (tonotopic) axis. Inhibition of the mitochondrial fusion machinery decreased proximal HC surface area, whereas promotion of fusion increased the distal HC surface area. We identify mitochondrial dynamics as a key regulator of HC morphology in developing inner ear epithelia. [ABSTRACT FROM AUTHOR]

Introduction: Coronavirus (CoV) has become a public health crisis that causes numerous illnesses in humans and certain animals. Studies have identified the small, lipid-bound structures called extracellular vesicles (EVs) as the mechanism through which viruses can enter host cells, spread, and evade the host's immune defenses. EVs are able to package and carry numerous viral compounds, including proteins, genetic substances, lipids, and receptor proteins. We proposed that the coronavirus could alter EV production and content, as well as influence EV biogenesis and composition in host cells. Methods: In the current research, Crandell-Rees feline kidney (CRFK) cells were infected with feline coronavirus (FCoV) in an exosome-free media at a multiplicity of infection (MOI) of 2,500 infectious units (IFU) at 48 h and 72 h time points. Cell viability was analyzed and found to be significantly decreased by 9% (48 h) and 15% (72 h) due to FCoV infection. EVs were isolated by ultracentrifugation, and the surface morphology of isolated EVs was analyzed via Scanning Electron Microscope (SEM). Results: NanoSight particle tracking analysis (NTA) confirmed that the mean particle sizes of control EVs were 131.9 nm and 126.6 nm, while FCoV infectedderived EVs were 143.4 nm and 120.9 nm at 48 and 72 h, respectively. Total DNA, RNA, and protein levels were determined in isolated EVs at both incubation time points; however, total protein was significantly increased at 48 h. Expression of specific protein markers such as TMPRSS2, ACE2, Alix, TSG101, CDs (29, 47, 63), TLRs (3, 6, 7), TNF-α, and others were altered in infection-derived EVs when compared to control-derived EVs after FCoV infection. Discussion: Our findings suggested that FCoV infection could alter the EV production and composition in host cells, which affects the infection progression and disease evolution. One purpose of studying EVs in various animal coronaviruses that are in close contact with humans is to provide significant information about disease development, transmission, and adaptation. Hence, this study suggests that EVs could provide diagnostic and therapeutic applications in animal CoVs, and such understanding could provide information to prevent future coronavirus outbreaks. [ABSTRACT FROM AUTHOR]

Exosomes represent a type of extracellular vesicles derived from the endosomal pathway that transport diverse molecular cargoes such as proteins, lipids, and nucleic acids. These cargoes have emerged as crucial elements impacting disease diagnosis, treatment, and prognosis, and are integral to the process of exosome formation. This review delves into the essential molecular cargoes implicated in the phases of exosome production and release. Emphasis is placed on their significance as cancer biomarkers and potential therapeutic targets, accompanied by an exploration of the obstacles and feasible applications linked to these developments. [ABSTRACT FROM AUTHOR]

The vast regenerative potential of stem cells has laid the foundation for stem cell-based therapies. However, certain challenges limit the application of cell-based therapies. The therapeutic use of cell-free therapy can avoid limitations associated with cell-based therapies. Acellular stem cell-based therapies rely on the use of biological factors released by stem cells, including growth factors and extracellular vesicles such as exosomes. Due to their comparable regenerative potential, acellular therapies may provide a feasible and scalable alternative to stem cell-based therapies. Exosomes are small vesicles secreted by various types of cells, including stem cells. Exosomes contain parent cell-derived nucleic acids, proteins, lipids, and other bioactive molecules. They play an important role in intra-cellular communication and influence the biological characteristics of cells. Exosomes inherit the properties of their parent cells; therefore, stem cell-derived exosomes are of particular interest for applications of regenerative medicine. In comparison to stem cell-based therapy, exosome therapy offers several benefits, such as easy transport and storage, no risk of immunological rejection, and few ethical dilemmas. Unlike stem cells, exosomes can be lyophilized and stored off-the-shelf, making acellular therapies standardized and more accessible while reducing overall treatment costs. Exosome-based acellular treatments are therefore readily available for applications in patients at the time of care. The current review discusses the use of exosomes as an acellular therapy. The review explores the molecular mechanism of exosome biogenesis, various methods for exosome isolation, and characterization. In addition, the latest advancements in bioengineering techniques to enhance exosome potential for acellular therapies have been discussed. The challenges in the use of exosomes as well as their diverse applications for the diagnosis and treatment of diseases have been reviewed in detail. [ABSTRACT FROM AUTHOR]

Circular RNA (circRNA) is a type of non-coding RNA with multiple biological functions. Whole circRNA genomes in plants have been identified, and circRNAs have been demonstrated to be widely present and highly expressed in various plant tissues and organs. CircRNAs are highly stable and conserved in plants, and exhibit tissue specificity and developmental stage specificity. CircRNAs often interact with other biomolecules, such as miRNAs and proteins, thereby regulating gene expression, interfering with gene function, and affecting plant growth and development or response to environmental stress. CircRNAs are less studied in plants than in animals, and their regulatory mechanisms of biogenesis and molecular functions are not fully understood. A variety of circRNAs in plants are involved in regulating growth and development and responding to environmental stress. This review focuses on the biogenesis and regulatory mechanisms of circRNAs, as well as their biological functions during growth, development, and stress responses in plants, including a discussion of plant circRNA research prospects. Understanding the generation and regulatory mechanisms of circRNAs is a challenging but important topic in the field of circRNAs in plants, as it can provide insights into plant life activities and their response mechanisms to biotic or abiotic stresses as well as new strategies for plant molecular breeding and pest control. [ABSTRACT FROM AUTHOR]

Regenerative medicine represents a paradigm shift in healthcare, aiming to restore tissue and organ function through innovative therapeutic strategies. Among these, bioprinting and extracellular vesicles (EVs) have emerged as promising techniques for tissue rejuvenation. EVs are small lipid membrane particles secreted by cells, known for their role as potent mediators of intercellular communication through the exchange of proteins, genetic material, and other biological components. The integration of 3D bioprinting technology with EVs offers a novel approach to tissue engineering, enabling the precise deposition of EV-loaded bioinks to construct complex three-dimensional (3D) tissue architectures. Unlike traditional cell-based approaches, bioprinted EVs eliminate the need for live cells, thereby mitigating regulatory and financial obstacles associated with cell therapy. By leveraging the synergistic effects of EVs and bioprinting, researchers aim to enhance the therapeutic outcomes of skin regeneration while addressing current limitations in conventional treatments. This review explores the evolving landscape of bioprinted EVs as a transformative approach for skin regeneration. Furthermore, it discusses the challenges and future directions in harnessing this innovative therapy for clinical applications, emphasizing the need for interdisciplinary collaboration and continued scientific inquiry to unlock its full therapeutic potential. [ABSTRACT FROM AUTHOR]

Mango is a popular tropical fruit that requires quarantine hot water treatment (QHWT) for postharvest sanitation, which can cause abiotic stress. Plants have various defense mechanisms to cope with stress; miRNAs mainly regulate the expression of these defense responses. Proteins involved in the biogenesis of miRNAs include DICER-like (DCL), ARGONAUTE (AGO), HYPONASTIC LEAVES 1 (HYL1), SERRATE (SE), HUA ENHANCER1 (HEN1), HASTY (HST), and HEAT-SHOCK PROTEIN 90 (HSP90), among others. According to our analysis, the mango genome contains five DCL, thirteen AGO, six HYL, two SE, one HEN1, one HST, and five putative HSP90 genes. Gene structure prediction and domain identification indicate that sequences contain key domains for their respective gene families, including the RNase III domain in DCL and PAZ and PIWI domains for AGOs. In addition, phylogenetic analysis indicates the formation of clades that include the mango sequences and their respective orthologs in other flowering plant species, supporting the idea these are functional orthologs. The analysis of cis-regulatory elements of these genes allowed the identification of MYB, ABRE, GARE, MYC, and MeJA-responsive elements involved in stress responses. Gene expression analysis showed that most genes are induced between 3 to 6 h after QHWT, supporting the early role of miRNAs in stress response. Interestingly, our results suggest that mango rapidly induces the production of miRNAs after heat stress. This research will enable us to investigate further the regulation of gene expression and its effects on commercially cultivated fruits, such as mango, while maintaining sanitary standards. [ABSTRACT FROM AUTHOR]

Main Conclusion: A mutation was first found to cause the great generation of glutelin precursors (proglutelins) in rice (Oryza sativa L.) endosperm, and thus referred to as GPGG1. The GPGG1 was involved in synthesis and compartmentation of storage proteins. The PPR-like gene in GPGG1-mapped region was determined as its candidate gene. In the wild type rice, glutelins and prolamins are synthesized on respective subdomains of rough endoplasmic reticulum (ER) and intracellularly compartmentalized into different storage protein bodies. In this study, a storage protein mutant was obtained and characterized by the great generation of proglutelins combining with the lacking of 13 kD prolamins. A dominant genic-mutation, referred to as GPGG1, was clarified to result in the proteinous alteration. Novel saccular composite-ER was shown to act in the synthesis of proglutelins and 14 kD prolamins in the mutant. Additionally, a series of organelles including newly occurring several compartments were shown to function in the transfer, trans-plasmalemmal transport, delivery, deposition and degradation of storage proteins in the mutant. The GPGG1 gene was mapped to a 67.256 kb region of chromosome 12, the pentatricopeptide repeat (PPR)-like gene in this region was detected to contain mutational sites. [ABSTRACT FROM AUTHOR]

World Health Organisation data suggest that up to 99% of the global population are exposed to air pollutants above recommended levels. Impacts to health range from increased risk of stroke and cardiovascular disease to chronic respiratory conditions, and air pollution may contribute to over 7 million premature deaths a year. Additionally, mounting evidence suggests that in utero or early life exposure to particulate matter (PM) in ambient air pollution increases the risk of neurodevelopmental impairment with obvious lifelong consequences. Identifying brain‐specific cellular targets of PM is vital for determining its long‐term consequences. We previously established that microglial‐like BV2 cells were particularly sensitive to urban (U)PM‐induced damage including reactive oxygen species production, which was abrogated by a mitochondrially targeted antioxidant. Here we extend those studies to find that UPM treatment causes a rapid impairment of mitochondrial function and increased mitochondrial fragmentation. However, there is a subsequent restoration of mitochondrial and therefore cell health occurring concomitantly with upregulated measures of mitochondrial biogenesis and mitochondrial load. Our data highlight that protecting mitochondrial function may represent a valuable mechanism to offset the effects of UPM exposure in the neonatal brain. Key points: Air pollution represents a growing risk to long‐term health especially in early life, and the CNS is emerging a target for airborne particulate matter (PM).We previously showed that microglial‐like BV2 cells were vulnerable to urban (U)PM exposure, which impaired cell survival and promoted reactive oxygen species production.Here we find that, following UPM exposure, BV2 mitochondrial membrane potential is rapidly reduced, concomitant with decreased cellular bioenergetics and increased mitochondrial fission.However, markers of mitochondrial biogenesis and mitochondrial mass are subsequently induced, which may represent a cellular mitigation strategy.As mitochondria are more vulnerable in the developing brain, exposure to air pollution may represent a greater risk to lifelong health in this cohort; conversely, promoting mitochondrial integrity may offset these risks. [ABSTRACT FROM AUTHOR]

BACKGROUND: Aging is associated with increased susceptibility to cardiovascular disease, and mitochondrial dysfunction plays a key role in the pathogenesis of cardiovascular disease. Regular physical activity is beneficial to cardiovascular health and can prevent and treat chronic heart disease. However, the specific mechanism of mitochondria in the protective effect of exercise on the aging heart has not yet been clarified. OBJECTIVE: To explore the effect of aerobic exercise on cardiac pathological remodeling in aging rats and to investigate the possible mechanism of mitochondrial quality control system. METHODS: Sixty Wistar rats were randomly divided into young sedentary group (6 months old), old sedentary group (20 months old) and old exercise group (20 months old) with 20 rats in each group. Rats in the young sedentary and old sedentary groups were fed in cages for 12 weeks, while those in the old exercise group underwent moderate-intensity aerobic treadmill exercise (60% of the maximal running speed, slope 0°, 60 minute per day, 5 days per week) for 12 weeks. After the experiment, the heart was extracted for relevant indicator tests. RESULTS AND CONCLUSION: Cardiac morphology and myocardial histopathology: compared with the young sedentary group, the rats in the old sedentary group presented with concentric cardiac hypertrophy, myocardial fibrosis, myocardial cell apoptosis and loss, and cardiac diastolic dysfunction (P < 0.05); compared with the old sedentary group, animals in the old exercise group showed reduced myocardial fibrosis and apoptosis rates, increased cell numbers, improved cardiac function (P < 0.05), and a transition in cardiac phenotype from pathological to physiological hypertrophy. Mitochondrial function: compared with the young sedentary group, the generation rate of mitochondrial hydrogen peroxide increased (P < 0.05), respiration rate and respiratory control ratio of state 3 and state 4 decreased (P < 0.05), activities of respiratory chain complexes I, II and IV decreased (P < 0.05), mitochondrial calcium retention capacity decreased (P < 0.05), and mitochondrial permeability transition pore opening increased (P < 0.05) in the old sedentary group. Compared with the old sedentary group, all of the above indicators were significantly improved in the old exercise group (P < 0.05). Mitochondrial quality control: compared with the young sedentary group, mitochondrial biogenesis decreased (P < 0.05), mitophagy activity increased (P < 0.05), mitochondrial fusion reduced (P < 0.05), and fission raised (P < 0.05) in the old sedentary group; compared with the old sedentary group, mitochondrial biogenesis and mitophagy activity increased (P < 0.05), mitochondrial fusion raised (P < 0.05) and fission decreased (P < 0.05) in the old exercise group. To conclude, regular aerobic exercises exert cardioprotective effects in aging rats by regulating the mitochondrial quality control system, thus reversing pathological cardiac remodeling and improving cardiac function. [ABSTRACT FROM AUTHOR]

Long noncoding RNAs (lncRNAs), which are more than 200 nucleotides in length and do not encode proteins, play crucial roles in governing gene expression at both the transcriptional and posttranscriptional levels. These molecules demonstrate specific expression patterns in various tissues and developmental stages, suggesting their involvement in numerous developmental processes and diseases, notably cancer. Despite their widespread acknowledgment and the growing enthusiasm surrounding their potential as diagnostic and prognostic biomarkers, the precise mechanisms through which lncRNAs function remain inadequately understood. A few lncRNAs have been studied in depth, providing valuable insights into their biological activities and suggesting emerging functional themes and mechanistic models. However, the extent to which the mammalian genome is transcribed into functional noncoding transcripts is still a matter of debate. This review synthesizes our current understanding of lncRNA biogenesis, their genomic contexts, and their multifaceted roles in tumorigenesis, highlighting their potential in cancer-targeted therapy. By exploring historical perspectives alongside recent breakthroughs, we aim to illuminate the diverse roles of lncRNA and reflect on the broader implications of their study for understanding genome evolution and function, as well as for advancing clinical applications. [ABSTRACT FROM AUTHOR]

After an initial positive response to chemotherapy, cancer patients often acquire chemoresistance and tumor relapse, which makes cancer one of the most lethal diseases worldwide. Exosomes are essential mediators of cell-to-cell communication by delivering their cargo, such as proteins, RNAs and DNA, from cell to cell. They participate in cancer progression, metastasis, immune response and therapy resistance. Their ability to shuttle between cells makes them efficient drug delivery systems. As drug transporters, they provide novel strategies for cancer therapy by advancing targeted drug therapy and improving the therapeutic effects of anti-cancer medications. In this review, a comprehensive overview of the potential of exosomes as therapeutic agents and targeted molecules in the treatment of cancer patients is given. The current challenges of preparation of exosomes loaded with drugs and delivering them to the recipient tumor cells as well as a consequent exosome-mediated cancer therapy are also discussed. [ABSTRACT FROM AUTHOR]

Membrane proteins carrying redox cofactors are key subunits of respiratory chain complexes, yet the exact path of their folding and maturation remains poorly understood. Here, using cryo‐EM and structure prediction via Alphafold2, we generated models of early assembly intermediates of cytochrome b (Cytb), a central subunit of complex III. The predicted structure of the first assembly intermediate suggests how the binding of Cytb to the assembly factor Cbp3‐Cbp6 imposes an open configuration to facilitate the acquisition of its heme cofactors. Moreover, structure predictions of the second intermediate indicate how hemes get stabilized by binding of the assembly factor Cbp4, with a concomitant weakening of the contact between Cbp3‐Cbp6 and Cytb, preparing for the release of the fully hemylated protein from the assembly factors. [ABSTRACT FROM AUTHOR]

PIWI-interacting RNAs (piRNAs), a class of small non-coding RNAs (sncRNAs) with 24–32 nucleotides (nt), were initially identified in the reproductive system. Unlike microRNAs (miRNAs) or small interfering RNAs (siRNAs), piRNAs normally guide P-element-induced wimpy testis protein (PIWI) families to slice extensively complementary transposon transcripts without the seed pairing. Numerous studies have shown that piRNAs are abundantly expressed in the brain, and many of them are aberrantly regulated in central neural system (CNS) disorders. However, the role of piRNAs in the related developmental and pathological processes is unclear. The elucidation of piRNAs/PIWI would greatly improve the understanding of CNS development and ultimately lead to novel strategies to treat neural diseases. In this review, we summarized the relevant structure, properties, and databases of piRNAs and their functional roles in neural development and degenerative disorders. We hope that future studies of these piRNAs will facilitate the development of RNA-based therapeutics for CNS disorders. [ABSTRACT FROM AUTHOR]

The low-molecular-weight PsbM and PsbT proteins of Photosystem II (PS II) are both located at the monomer-monomer interface of the mature PS II dimer. Since the extrinsic proteins are associated with the final step of assembly of an active PS II monomer and, in the case of PsbO, are known to impact the stability of the PS II dimer, we have investigated the potential cooperativity between the PsbM and PsbT subunits and the PsbO, PsbU and PsbV extrinsic proteins. Blue-native polyacrylamide electrophoresis and western blotting detected stable PS II monomers in the ∆PsbM:∆PsbO and ∆PsbT:∆PsbO mutants that retained sufficient oxygen-evolving activity to support reduced photoautotrophic growth. In contrast, the ∆PsbM:∆PsbU and ∆PsbT:∆PsbU mutants assembled dimeric PS II at levels comparable to wild type and supported photoautotrophic growth at rates similar to those obtained with the corresponding ∆PsbM and ∆PsbT cells. Removal of PsbV was more detrimental than removal of PsbO. Only limited levels of dimeric PS II were observed in the ∆PsbM:∆PsbV mutant and the overall reduced level of assembled PS II in this mutant resulted in diminished rates of photoautotrophic growth and PS II activity below those obtained in the ∆PsbM:∆PsbO and ∆PsbT:∆PsbO strains. In addition, the ∆PsbT:∆PsbV mutant did not assemble active PS II centers although inactive monomers could be detected. The inability of the ∆PsbT:∆PsbV mutant to grow photoautotrophically, or to evolve oxygen, suggested a stable oxygen-evolving complex could not assemble in this mutant. [ABSTRACT FROM AUTHOR]

Abstract Bacterial extracellular vesicles (BEVs) have emerged as pivotal mediators between bacteria and host. In addition to being crucial players in host homeostasis, they have recently been implicated in disease pathologies such as cancer. Hence, the study of BEVs represents an intriguing and rapidly evolving field with substantial translational potential. In this review, we briefly introduce the fundamentals of BEV characteristics, cargo and biogenesis. We emphatically summarize the current relationship between BEVs across various cancer types, illustrating their role in tumorigenesis, treatment responses and patient survival. We further discuss the inherent advantages of BEVs, such as stability, abundance and specific cargo profiles, that make them attractive candidates for non‐invasive diagnostic and prognostic approaches. The review also explores the potential of BEVs as a strategy for cancer therapy, considering their ability to deliver therapeutic agents, modulate the tumour microenvironment (TME) and elicit immunomodulatory responses. Understanding the clinical significance of BEVs may lead to the development of better‐targeted and personalized treatment strategies. This comprehensive review evaluates the current progress surrounding BEVs and poses questions to encourage further research in this emerging field to harness the benefits of BEVs for their full potential in clinical applications against cancer.

The role of extracellular vesicles (EVs) as key players in the intercellular communication is a subject of growing interest in all areas of physiology and pathophysiology, and the field of viral infections is no exception to the rule. In this review, we focus on the current state of knowledge and remaining gaps regarding the entanglement of viruses and EVs during infections. These two entities share many similarities, mainly due to their intricated biogenesis pathways that are in constant interaction. EVs can promote the replication and dissemination of viruses within the organism, through the dysregulation of their cargo and the modulation of the innate and adaptive immune response that occurs upon infection, but they can also promote the mitigation of viral infections. Here, we examine how viruses hijack EV biogenesis pathways and describe the consequences of dysregulated EV secretion during viral infections, beneficial or not for viruses, revealing the duality of their possible effects.

After an initial positive response to chemotherapy, cancer patients often acquire chemoresistance and tumor relapse, which makes cancer one of the most lethal diseases worldwide. Exosomes are essential mediators of cell-to-cell communication by delivering their cargo, such as proteins, RNAs and DNA, from cell to cell. They participate in cancer progression, metastasis, immune response and therapy resistance. Their ability to shuttle between cells makes them efficient drug delivery systems. As drug transporters, they provide novel strategies for cancer therapy by advancing targeted drug therapy and improving the therapeutic effects of anti-cancer medications. In this review, a comprehensive overview of the potential of exosomes as therapeutic agents and targeted molecules in the treatment of cancer patients is given. The current challenges of preparation of exosomes loaded with drugs and delivering them to the recipient tumor cells as well as a consequent exosome-mediated cancer therapy are also discussed.

Circular RNAs (circRNAs) and small non-coding RNAs of the head-to-junction circle in the construct play critical roles in gene regulation and are significantly associated with breast cancer (BC). Numerous circRNAs are potential cancer biomarkers that may be used for diagnosis and prognosis. Widespread expression of circRNAs is regarded as a feature of gene expression in highly diverged eukaryotes. Recent studies show that circRNAs have two main biological modulation models: sponging and RNA-binding. This review explained the biogenesis of circRNAs and assessed emerging findings on their sponge function and role as RNA-binding proteins (RBPs) to better understand how their interaction alters cellular function in BC. We focused on how sponges significantly affect the phenotype and progression of BC. We described how circRNAs exercise the translation functions in ribosomes. Furthermore, we reviewed recent studies on RBPs, and post-protein modifications influencing BC and provided a perspective on future research directions for treating BC.

Conventional photodynamic therapy (PDT) approaches face challenges including limited light penetration, low uptake of photosensitizers by tumors, and lack of oxygen in tumor microenvironments. One promising solution is to internally generate light, photosensitizers, and oxygen. This can be accomplished through endogenous production, such as using bioluminescence as an endogenous light source, synthesizing genetically encodable photosensitizers in situ, and modifying cells genetically to express catalase enzymes. Furthermore, these strategies have been reinforced by the recent rapid advancements in synthetic biology. In this review, we summarize and discuss the approaches to overcome PDT obstacles by means of endogenous production of excitation light, photosensitizers, and oxygen. We envision that as synthetic biology advances, genetically engineered cells could act as precise and targeted “living factories” to produce PDT components, leading to enhanced performance of PDT.

Abstract Exosomes are nanoscale extracellular vesicles present in bodily fluids that mediate intercellular communication by transferring bioactive molecules, thereby regulating a range of physiological and pathological processes. Exosomes can be secreted from nearly all cell types, and the biological function of exosomes is heterogeneous and depends on the donor cell type and state. Recent research has revealed that the levels of exosomes released from the endosomal system increase in cells undergoing programmed cell death. These exosomes play crucial roles in diseases, such as inflammation, tumors, and autoimmune diseases. However, there is currently a lack of systematic research on the differences in the biogenesis, secretion mechanisms, and composition of exosomes under different programmed cell death modalities. This review underscores the potential of exosomes as vital mediators of programmed cell death processes, highlighting the interconnection between exosome biosynthesis and the regulatory mechanisms governing cell death processes. Furthermore, we accentuate the prospect of leveraging exosomes for the development of innovative biomarkers and therapeutic strategies across various diseases.

With the development of sequencing technology, transfer RNA (tRNA)-derived small RNAs (tsRNAs) have received extensive attention as a new type of small noncoding RNAs. Based on the differences in the cleavage sites of nucleases on tRNAs, tsRNAs can be divided into two categories, tRNA halves (tiRNAs) and tRNA-derived fragments (tRFs), each with specific subcellular localizations. Additionally, the biogenesis of tsRNAs is tissue-specific and can be regulated by tRNA modifications. In this review, we first elaborated on the classification and biogenesis of tsRNAs. After summarizing the latest mechanisms of tsRNAs, including transcriptional gene silencing, post-transcriptional gene silencing, nascent RNA silencing, translation regulation, rRNA regulation, and reverse transcription regulation, we explored the representative biological functions of tsRNAs in tumors. Furthermore, this review summarized the clinical value of tsRNAs in cancers, thus providing theoretical support for their potential as novel biomarkers and therapeutic targets.

Exploration and marketable exploitation of coalbed methane (CBM) as cleaner fuel has been started globally. In addition, incidence of methane in coal basins is an imperative fraction of global carbon cycle. Significantly, subsurface coal ecosystem contains methane forming archaea. There is a rising attention in optimizing microbial coal gasification to exploit the abundant or inexpensive coal reserves worldwide. Therefore, it is essential to understand the coalbeds in geo-microbial perspective. Current review provides an in-depth analysis of recent advances in our understanding of how methanoarchaea are distributed in coal deposits globally. Specially, we highlight the findings on coal-associated methanoarchaeal existence, abundance, diversity, metabolic activity, and biogeography in diverse coal basins worldwide. Growing evidences indicates that we have arrived an exciting era of archaeal research. Moreover, gasification of coal into methane by utilizing microbial methanogenesis is a considerable way to mitigate the energy crisis for the rising world population. [ABSTRACT FROM AUTHOR]

The RNA‐binding protein PNO1 plays an essential role in ribosome biogenesis. Recent studies have shown that it is involved in tumorigenesis; however, its role in hepatocellular carcinoma (HCC) is not well understood. The purpose of this study was to examine whether PNO1 can be used as a biomarker of HCC and also examine the therapeutic potential of PNO1 knockout for the treatment of HCC. PNO1 expression was upregulated in HCC and associated with poor prognosis. PNO1 expression was positively associated with tumour stage, lymph node metastasis and poor survival. PNO1 expression was significantly higher in HCC compared to that in fibrolamellar carcinoma or normal tissues. Furthermore, HCC tissues with mutant Tp53 expressed higher PNO1 than those with wild‐type Tp53. PNO1 knockout suppressed cell viability, colony formation and EMT of HCC cells. Since activation of Notch signalling pathway promotes HCC, we measured the effects of PNO1 knockout on the components of Notch pathway and its targets. PNO1 knockout suppressed Notch signalling by modulating the expression of Notch ligands and their receptors, and downstream targets. PNO1 knockout also inhibited genes involved in surface adhesion, cell cycle, inflammation and chemotaxis. PNO1 knockout also inhibited colony and spheroid formation, cell migration and invasion, and markers of stem cells, pluripotency and EMT in CSCs. Overall, our data suggest that PNO1 can be used as a diagnostic and prognostic biomarker of HCC, and knockout of PNO1 by CRISPR/Cas9 can be beneficial for the management of HCC by targeting CSCs. [ABSTRACT FROM AUTHOR]

Exosomes‐like nanoparticles (ELNs) (exosomes or extracellular vesicles) are vesicle‐like bodies secreted by cells. Plant ELNs (PENs) are membrane vesicles secreted by plant cells, with a lipid bilayer as the basic skeleton, enclosing various active substances such as proteins and nucleic acids, which have many physiological and pathological functions. Recent studies have found that the PENs are widespread within different plant species and their biological functions are increasingly recognized. The effective separation method is also necessary for its function and application. Ultracentrifugation, sucrose density gradient ultracentrifugation, ultrafiltration, polymer‐based precipitation methods, etc., are commonly used methods for plant exosome‐like nanoparticle extraction. In recent years, emerging methods such as size exclusion chromatography, immunoaffinity capture‐based technique, and microfluidic technology have shown advancements compared to traditional methods. The standardized separation process for PENs continues to evolve. In this review, we summarized the recent progress in the biogenesis, components, separation methods, and some functions of PENs. When the research on the separation method of PENs and their unique biological structure is further studied. A brand‐new idea for the efficient separation and utilization of PENs can be provided in the future, which has a very broad prospect. [ABSTRACT FROM AUTHOR]

The etiology of epilepsy is ascribed to the synchronized aberrant neuronal activity within the brain. Circular RNAs (circRNAs), a class of non‐coding RNAs characterized by their circular structures and covalent linkage, exert a substantial influence on this phenomenon. CircRNAs possess stereotyped replication, transience, repetitiveness, and paroxysm. Additionally, MicroRNA (miRNA) plays a crucial role in the regulation of diverse pathological processes, including epilepsy. CircRNA is of particular significance due to its ability to function as a competing endogenous RNA, thereby sequestering or inhibiting miRNA activity through binding to target mRNA. Our review primarily concentrates on elucidating the pathological and functional roles, as well as the underlying mechanisms, of circRNA–miRNA–mRNA networks in epilepsy. Additionally, it explores the potential utility of these networks for early detection and therapeutic intervention. [ABSTRACT FROM AUTHOR]

Mitochondria-Associated Endoplasmic Reticulum Membranes (MAMs) mediate the communication between the Endoplasmic Reticulum (ER) and the mitochondria, playing a fundamental role in steroidogenesis. This study aimed to understand how D-aspartate (D-Asp), a well-known stimulator of testosterone biosynthesis and spermatogenesis, affects the mechanism of steroidogenesis in rat testes. Our results suggested that D-Asp exerts this function through MAMs, affecting lipid trafficking, calcium signaling, ER stress, and mitochondrial dynamics. After 15 days of oral administration of D-Asp to rats, there was an increase in both antioxidant enzymes (SOD and Catalase) and in the protein expression levels of ATAD3A, FACL4, and SOAT1, which are markers of lipid transfer, as well as VDAC and GRP75, which are markers of calcium signaling. Additionally, there was a decrease in protein expression levels of GRP78, a marker of aging that counteracts ER stress. The effects of D-Asp on mitochondrial dynamics strongly suggested its active role as well. It induced the expression levels of proteins involved in fusion (MFN1, MFN2, and OPA1) and in biogenesis (NRF1 and TFAM), as well as in mitochondrial mass (TOMM20), and decreased the expression level of DRP1, a crucial mitochondrial fission marker. These findings suggested D-Asp involvement in the functional improvement of mitochondria during steroidogenesis. Immunofluorescent signals of ATAD3A, MFN1/2, TFAM, and TOMM20 confirmed their localization in Leydig cells showing an intensity upgrade in D-Asp-treated rat testes. Taken together, our results demonstrate the involvement of D-Asp in the steroidogenesis of rat testes, acting at multiple stages of both MAMs and mitochondrial dynamics, opening new opportunities for future investigation in other steroidogenic tissues. [ABSTRACT FROM AUTHOR]

Exosomes are nanoscale extracellular vesicles present in bodily fluids that mediate intercellular communication by transferring bioactive molecules, thereby regulating a range of physiological and pathological processes. Exosomes can be secreted from nearly all cell types, and the biological function of exosomes is heterogeneous and depends on the donor cell type and state. Recent research has revealed that the levels of exosomes released from the endosomal system increase in cells undergoing programmed cell death. These exosomes play crucial roles in diseases, such as inflammation, tumors, and autoimmune diseases. However, there is currently a lack of systematic research on the differences in the biogenesis, secretion mechanisms, and composition of exosomes under different programmed cell death modalities. This review underscores the potential of exosomes as vital mediators of programmed cell death processes, highlighting the interconnection between exosome biosynthesis and the regulatory mechanisms governing cell death processes. Furthermore, we accentuate the prospect of leveraging exosomes for the development of innovative biomarkers and therapeutic strategies across various diseases. [ABSTRACT FROM AUTHOR]

Conventional photodynamic therapy (PDT) approaches face challenges including limited light penetration, low uptake of photosensitizers by tumors, and lack of oxygen in tumor microenvironments. One promising solution is to internally generate light, photosensitizers, and oxygen. This can be accomplished through endogenous production, such as using bioluminescence as an endogenous light source, synthesizing genetically encodable photosensitizers in situ , and modifying cells genetically to express catalase enzymes. Furthermore, these strategies have been reinforced by the recent rapid advancements in synthetic biology. In this review, we summarize and discuss the approaches to overcome PDT obstacles by means of endogenous production of excitation light, photosensitizers, and oxygen. We envision that as synthetic biology advances, genetically engineered cells could act as precise and targeted "living factories" to produce PDT components, leading to enhanced performance of PDT. Targeted delivery of external light, photosensitizers, and oxygen to tumors is challenging, which hinders the efficacy of photodynamic treatments. Endogenous production of light, photosensitizers, and oxygen in-situ at tumor sites is a promising solution. [Display omitted] [ABSTRACT FROM AUTHOR]

Skeletal muscle hypertrophy is generally associated with a fast-to-slow phenotypic adaptation in both human and rodent models. Paradoxically, this phenotypic shift is not paralleled by a concomitant increase in mitochondrial content and aerobic markers that would be expected to accompany a slow muscle phenotype. To understand the temporal response of the mitochondrial life cycle (i.e., biogenesis, oxidative phosphorylation, fission/fusion, and mitophagy/autophagy) to hypertrophic stimuli, in this study, we used the functional overload (FO) model in adult female rats and examined the plantaris muscle responses at 1 and 10 weeks. As expected, the absolute plantaris muscle mass increased by ∼12 and 26% at 1 and 10 weeks following the FO procedure, respectively. Myosin heavy-chain isoform types I and IIa significantly increased by 116% and 17%, respectively, in 10-week FO plantaris muscles. Although there was a general increase in protein markers associated with mitochondrial biogenesis in acute FO muscles, this response was unexpectedly sustained under 10-week FO conditions after muscle hypertrophy begins to plateau. Furthermore, the early increase in mito/autophagy markers observed under acute FO conditions was normalized by 10 weeks, suggesting a cellular environment favoring mitochondrial biogenesis to accommodate the aerobic demands of the plantaris muscle. We also observed a significant increase in the expression of mitochondrial-, but not nuclear-, encoded oxidative phosphorylation (OXPHOS) proteins and peptides (i.e., humanin and MOTS-c) under chronic, but not acute, FO conditions. Taken together, the temporal response of markers related to the mitochondrial life cycle indicates a pattern of promoting biogenesis and mitochondrial protein expression to support the energy demands and/or enhanced neural recruitment of chronically overloaded skeletal muscle.

Mango is a popular tropical fruit that requires quarantine hot water treatment (QHWT) for postharvest sanitation, which can cause abiotic stress. Plants have various defense mechanisms to cope with stress; miRNAs mainly regulate the expression of these defense responses. Proteins involved in the biogenesis of miRNAs include DICER-like (DCL), ARGONAUTE (AGO), HYPONASTIC LEAVES 1 (HYL1), SERRATE (SE), HUA ENHANCER1 (HEN1), HASTY (HST), and HEAT-SHOCK PROTEIN 90 (HSP90), among others. According to our analysis, the mango genome contains five DCL, thirteen AGO, six HYL, two SE, one HEN1, one HST, and five putative HSP90 genes. Gene structure prediction and domain identification indicate that sequences contain key domains for their respective gene families, including the RNase III domain in DCL and PAZ and PIWI domains for AGOs. In addition, phylogenetic analysis indicates the formation of clades that include the mango sequences and their respective orthologs in other flowering plant species, supporting the idea these are functional orthologs. The analysis of cis-regulatory elements of these genes allowed the identification of MYB, ABRE, GARE, MYC, and MeJA-responsive elements involved in stress responses. Gene expression analysis showed that most genes are induced between 3 to 6 h after QHWT, supporting the early role of miRNAs in stress response. Interestingly, our results suggest that mango rapidly induces the production of miRNAs after heat stress. This research will enable us to investigate further the regulation of gene expression and its effects on commercially cultivated fruits, such as mango, while maintaining sanitary standards.

ABSTRACT Sweet orange (Citrus sinensis) is one of the most important fruit crops worldwide. Virus infections in this crop can interfere with cellular processes, causing dramatic economic losses. By performing RT-qPCR analyses, we demonstrated that citrus psorosis virus (CPsV)-infected orange plants exhibited higher levels of unprocessed microRNA (miRNA) precursors than healthy plants. This result correlated with the reported reduction of mature miRNAs species. The protein 24K, the CPsV suppressor of RNA silencing (VSR), interacts with miRNA precursors in vivo. Thus, this protein becomes a candidate responsible for the increased accumulation of unprocessed miRNAs. We analyzed 24K RNA-binding and protein-protein interaction domains and described patterns of its subcellular localization. We also showed that 24K colocalizes within nuclear D-bodies with the miRNA biogenesis proteins DICER-LIKE 1 (DCL1), HYPONASTIC LEAVES 1 (HYL1), and SERRATE (SE). According to the results of bimolecular fluorescence complementation and co-immunoprecipitation assays, the 24K protein interacts with HYL1 and SE. Thus, 24K may inhibit miRNA processing in CPsV-infected citrus plants by direct interaction with the miRNA processing complex. This work contributes to the understanding of how a virus can alter the regulatory mechanisms of the host, particularly miRNA biogenesis and function.IMPORTANCESweet oranges can suffer from disease symptoms induced by virus infections, thus resulting in drastic economic losses. In sweet orange plants, CPsV alters the accumulation of some precursors from the regulatory molecules called miRNAs. This alteration leads to a decreased level of mature miRNA species. This misregulation may be due to a direct association of one of the viral proteins (24K) with miRNA precursors. On the other hand, 24K may act with components of the cell miRNA processing machinery through a series of predicted RNA-binding and protein-protein interaction domains.

The article presents the hypothesis of the origin of life. All the basic ideas of the 20th century research program in this area can be found there: the extrapolation of Darwinism into the area of chemical evolution, the influence of solar energy, the large “chemical possibilities” of carbon compounds, early heterotrophy, the gradual increase of organic purpose as a result of natural selection.