Lactadherin immunoblockade in small extracellular vesicles inhibits sEV-mediated increase of pro-metastatic capacities

BACKGROUND: Tumor-derived small extracellular vesicles (sEVs) can promote tumorigenic and metastatic capacities in less aggressive recipient cells mainly through the biomolecules in their cargo. However, despite recent advances, the specific molecules orchestrating these changes are not completely defined. Lactadherin is a secreted 0protein typically found in the milk fat globule membrane. Its overexpression has been associated with increased tumorigenesis and metastasis in breast cancer (BC) and other tumors. However, neither its presence in sEVs secreted by BC cells, nor its role in sEV-mediated intercellular communication have been described. The present study focused on the role of lactadherin-containing sEVs from metastatic MDA-MB-231 triple-negative BC (TNBC) cells (sEV-MDA231) in the promotion of pro-metastatic capacities in non-tumorigenic and non-metastatic recipient cells in vitro, as well as their pro-metastatic role in a murine model of peritoneal carcinomatosis. RESULTS: We show that lactadherin is present in sEVs secreted by BC cells and it is higher in sEV-MDA231 compared with the other BC cell-secreted sEVs measured through ELISA. Incubation of non-metastatic recipient cells with sEV- MDA231 increases their migration and, to some extent, their tumoroid formation capacity but not their anchorage-independent growth. Remarkably, lactadherin blockade in sEV-MDA231 results in a significant decrease of those sEV-mediated changes in vitro. Similarly, intraperitoneally treatment of mice with MDA-MB-231 BC cells and sEV-MDA231 greatly increase the formation of malignant ascites and tumor micronodules, effects that were significantly inhibited when lactadherin was previously blocked in those sEV-MDA231. CONCLUSIONS: As to our knowledge, our study provides the first evidence on the role of lactadherin in metastatic BC cell-secreted sEVs as promoter of: (i) metastatic capacities in less aggressive recipient cells, and ii) the formation of malignant ascites and metastatic tumor nodules. These results increase our understanding on the role of lactadherin in sEVs as promoter of metastatic capacities which can be used as a therapeutic option for BC and other malignancies.

Emerging roles of exosomes in oral diseases progression / 国际口腔科学杂志·英文版

Oral diseases, such as periodontitis, salivary gland diseases, and oral cancers, significantly challenge health conditions due to their detrimental effects on patient's digestive functions, pronunciation, and esthetic demands. Delayed diagnosis and non-targeted treatment profoundly influence patients' prognosis and quality of life. The exploration of innovative approaches for early detection and precise treatment represents a promising frontier in oral medicine. Exosomes, which are characterized as nanometer-sized extracellular vesicles, are secreted by virtually all types of cells. As the research continues, the complex roles of these intracellular-derived extracellular vesicles in biological processes have gradually unfolded. Exosomes have attracted attention as valuable diagnostic and therapeutic tools for their ability to transfer abundant biological cargos and their intricate involvement in multiple cellular functions. In this review, we provide an overview of the recent applications of exosomes within the field of oral diseases, focusing on inflammation-related bone diseases and oral squamous cell carcinomas. We characterize the exosome alterations and demonstrate their potential applications as biomarkers for early diagnosis, highlighting their roles as indicators in multiple oral diseases. We also summarize the promising applications of exosomes in targeted therapy and proposed future directions for the use of exosomes in clinical treatment.

A invenção de um setting on-line para atendimento psicológico remoto / The invention of an online environment for remote psychological care / La invención de un entorno en línea para la atención psicológica remota

Com o advento da covid-19, foi declarado estado de emergência de saúde pública e decretadas medidas de isolamento e distanciamento social para conter a propagação da doença. O Conselho Federal de Psicologia, considerando a importância do acolhimento seguro durante a pandemia, publicou a Resolução CFP nº 4/2020, permitindo que serviços psicológicos aconteçam de maneira remota. O presente estudo visa, através do Método da Cartografia, apresentar a construção de um setting on-line para intervenções grupais e os desafios na oferta de acolhimento e atendimento remoto. Foram ofertados grupos terapêuticos, por meio da plataforma Google Meet, para estudantes da Universidade Federal Rural do Rio de Janeiro. Um diário de bordo foi produzido para acompanhar as forças que atravessavam e constituíam o território e a experiência grupal remota. Compreendemos que o território-espaço-grupal-on-line era composto pelo espaço virtual em que nos reuníamos, pelos espaços individuais de cada integrante e pelas forças que os atravessavam. Observamos que nem sempre os participantes dispunham de um lugar privado, mas estiveram presentes no encontro com câmeras e áudios abertos e/ou fechados e/ou através do chat da videochamada. A participação no grupo funcionou como alternativa no momento de distanciamento social, sendo uma possibilidade para o atendimento psicológico em situações de dificuldade de encontros presenciais; entretanto, se mostrou dificultada em diversos momentos, pela falta de equipamentos adequados e instabilidade na internet, fatores que interferiram nas reuniões e impactaram na possibilidade de falar e escutar o que era desejado.(AU)

With the advent of COVID-19, a state of public health was declared, and measures of isolation and social distance to contain the spread of the disease was decreed. The Federal Council of Psychology, considering the importance of safe reception during the pandemic, published CFP Resolution No. 4/2020, allowing psychological services to happen remotely. This study narrates, via the Cartography Method, the experience of inventing an Online Setting for group reception. Therapeutic groups were offered, via Google Meet Platform, to students at the Federal Rural University of Rio de Janeiro. A logbook was produced to accompany the forces that crossed and constituted the territory and the remote group experience. We understand that the territoryspace-group-online was composed by the virtual-space that we gathered, by the individualspaces of each member and by the forces that crossed them. We observed that the participants did not always have a private place, but they were present at the meeting with open and/or closed cameras and audio and/or through the video call chat. Participation in the group worked as an alternative at the time of social distancing, being a possibility for psychological care in situations of difficulty in face-to-face meetings, however, it proved to be difficult at various times, due to the lack of adequate equipment and instability on the internet, factors that interfered in meetings and impacted the possibility of speaking and listening to what was desired.(AU)

La llegada de la COVID-19 produjo un estado de emergencia de salud pública, en el que se decretaron medidas de confinamiento y distanciamiento físico para contener la propagación de la enfermedad. El Consejo Federal de Psicología, considerando la importancia de la acogida segura durante la pandemia, publicó la Resolución CFP nº 4/2020, por la que se permite la atención psicológica remota. Este estudio tiene por objetivo presentar, mediante el método de la Cartografía, la elaboración de un escenario en línea para la intervención grupal y los desafíos en la oferta de acogida y atención remota. Grupos terapéuticos se ofrecieron, en la plataforma Google Meet, a estudiantes de la Universidad Federal Rural de Río de Janeiro. Se elaboró un diario para acompañar a las fuerzas que atravesaron y constituyeron el territorio y la experiencia remota del grupo. Entendemos que el territorio-espacio-grupo-en línea estaba compuesto por el espacio-virtual que reunimos, por los espacios individuales de cada integrante y por las fuerzas que los atravesaban. Observamos que los participantes no siempre tenían un lugar privado y que estaban presentes en la reunión con cámaras y audio abiertos y/o cerrados y/o por el chat de la videollamada. La participación en el grupo funcionó como una alternativa en el momento del distanciamiento físico y revela ser una posibilidad de atención psicológica en situaciones de dificultad en los encuentros presenciales, sin embargo, se mostró difícil en varios momentos, ya sea por la falta de medios adecuados o por inestabilidad en Internet, factores que interferían en las reuniones e impactaban en la posibilidad de hablar y escuchar lo que se deseaba.(AU)

Connexin 43-modified bone marrow stromal cells reverse the imatinib resistance of K562 cells via Ca 2+ -dependent gap junction intercellular communication / 中华医学杂志(英文版)

BACKGROUND@#Imatinib mesylate (IM) resistance is an emerging problem for chronic myeloid leukemia (CML). Previous studies found that connexin 43 (Cx43) deficiency in the hematopoietic microenvironment (HM) protects minimal residual disease (MRD), but the mechanism remains unknown.@*METHODS@#Immunohistochemistry assays were employed to compare the expression of Cx43 and hypoxia-inducible factor 1α (HIF-1α) in bone marrow (BM) biopsies of CML patients and healthy donors. A coculture system of K562 cells and several Cx43-modified bone marrow stromal cells (BMSCs) was established under IM treatment. Proliferation, cell cycle, apoptosis, and other indicators of K562 cells in different groups were detected to investigate the function and possible mechanism of Cx43. We assessed the Ca 2+ -related pathway by Western blotting. Tumor-bearing models were also established to validate the causal role of Cx43 in reversing IM resistance.@*RESULTS@#Low levels of Cx43 in BMs were observed in CML patients, and Cx43 expression was negatively correlated with HIF-1α. We also observed that K562 cells cocultured with BMSCs transfected with adenovirus-short hairpin RNA of Cx43 (BMSCs-shCx43) had a lower apoptosis rate and that their cell cycle was blocked in G0/G1 phase, while the result was the opposite in the Cx43-overexpression setting. Cx43 mediates gap junction intercellular communication (GJIC) through direct contact, and Ca 2+ is the key factor mediating the downstream apoptotic pathway. In animal experiments, mice bearing K562, and BMSCs-Cx43 had the smallest tumor volume and spleen, which was consistent with the in vitro experiments.@*CONCLUSIONS@#Cx43 deficiency exists in CML patients, promoting the generation of MRD and inducing drug resistance. Enhancing Cx43 expression and GJIC function in the HM may be a novel strategy to reverse drug resistance and promote IM efficacy.

Advances in the Regulation of Follicular Development by Extracellular Vesicles and Non-Coding RNAs / 中国医学科学院学报

Extracellular vesicles (EV),nanoscale vesicles encapsulated by phospholipid bilayers,are rich in biological molecules such as nucleic acids,metabolites,proteins,and lipids derived from parental cells.They are mainly involved in intercellular communication,signal transmission,and material transport and affect the functions of target cells.Ovulation disorders account for a higher proportion in the factors causing infertility which demonstrates increasing incidence year by year.Non-coding RNAs participate in a series of physiological and pathological processes of follicular development,playing a key role in female infertility.This review systematically introduces the types and biological roles of EV and elaborates on the regulation of follicular development from the effects of EV and non-coding RNAs on granulosa cell function,oocyte maturation,ovulation,luteal formation,and steroid hormone synthesis,providing a new idea and a breakthrough point for the diagnosis and treatment of infertility.

Pathophysiological implications of cellular senescence and prospects for novel anti-aging drugs / 生理学报

Chronological aging is the leading risk factor for human diseases, while aging at the cellular level, namely cellular senescence, is the fundamental driving force of organismal aging. The impact of cellular senescence on various life processes, including normal physiology, organismal aging and the progress of various age-related pathologies, has been largely ignored for a long time. However, with recent advancement in relevant fields, cellular senescence has become the core of aging biology and geriatric medicine. Although senescent cells play important roles in physiological processes including tissue repair, wound healing, and embryonic development, they can also contribute to tissue dysfunction, organ degeneration and various pathological conditions during adulthood. Senescent cells exert paracrine effects on neighboring cells in tissue microenvironments by developing a senescence-associated secretory phenotype, thus maintaining long-term and active intercellular communications that ultimately results in multiple pathophysiological effects. This is regarded as one of the most important discoveries in life science of this century. Notably, selective elimination of senescent cells through inducing their apoptosis or specifically inhibiting the senescence-associated secretory phenotype has shown remarkable potential in preclinical and clinical interventions of aging and age-related diseases. This reinforces the belief that senescent cells are the key drug target to alleviate various aging syndromes. However, senescent cells exhibit heterogeneity in terms of form, function and tissue distribution, and even differ among species, which presents a challenge for the translation of significant research achievements to clinical practice in future. This article reviews and discusses the characteristics of senescent cells, current targeting strategies and future trends, providing useful and valuable references for the rapidly blooming aging biology and geriatric medicine.

Distinct mononuclear diploid cardiac subpopulation with minimal cell-cell communications persists in embryonic and adult mammalian heart / 医学前沿

A small proportion of mononuclear diploid cardiomyocytes (MNDCMs), with regeneration potential, could persist in adult mammalian heart. However, the heterogeneity of MNDCMs and changes during development remains to be illuminated. To this end, 12 645 cardiac cells were generated from embryonic day 17.5 and postnatal days 2 and 8 mice by single-cell RNA sequencing. Three cardiac developmental paths were identified: two switching to cardiomyocytes (CM) maturation with close CM-fibroblast (FB) communications and one maintaining MNDCM status with least CM-FB communications. Proliferative MNDCMs having interactions with macrophages and non-proliferative MNDCMs (non-pMNDCMs) with minimal cell-cell communications were identified in the third path. The non-pMNDCMs possessed distinct properties: the lowest mitochondrial metabolisms, the highest glycolysis, and high expression of Myl4 and Tnni1. Single-nucleus RNA sequencing and immunohistochemical staining further proved that the Myl4+Tnni1+ MNDCMs persisted in embryonic and adult hearts. These MNDCMs were mapped to the heart by integrating the spatial and single-cell transcriptomic data. In conclusion, a novel non-pMNDCM subpopulation with minimal cell-cell communications was unveiled, highlighting the importance of microenvironment contribution to CM fate during maturation. These findings could improve the understanding of MNDCM heterogeneity and cardiac development, thus providing new clues for approaches to effective cardiac regeneration.

Single-cell profiling reveals Müller glia coordinate retinal intercellular communication during light/dark adaptation via thyroid hormone signaling

Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination. Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation. However, various types of neurons and glial cells exist in the retina, and whether and how all retinal cells interact to adapt to light/dark conditions at the cellular and molecular levels requires systematic investigation. Therefore, we utilized single-cell RNA sequencing to dissect retinal cell-type-specific transcriptomes during light/dark adaptation in mice. The results demonstrated that, in addition to photoreceptors, other retinal cell types also showed dynamic molecular changes and specifically enriched signaling pathways under light/dark adaptation. Importantly, Müller glial cells (MGs) were identified as hub cells for intercellular interactions, displaying complex cell‒cell communication with other retinal cells. Furthermore, light increased the transcription of the deiodinase Dio2 in MGs, which converted thyroxine (T4) to active triiodothyronine (T3). Subsequently, light increased T3 levels and regulated mitochondrial respiration in retinal cells in response to light conditions. As cones specifically express the thyroid hormone receptor Thrb, they responded to the increase in T3 by adjusting light responsiveness. Loss of the expression of Dio2 specifically in MGs decreased the light responsive ability of cones. These results suggest that retinal cells display global transcriptional changes under light/dark adaptation and that MGs coordinate intercellular communication during light/dark adaptation via thyroid hormone signaling.

Exosome-mediated regulatory mechanisms in skeletal muscle: a narrative review / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Skeletal muscle plays a paramount role in physical activity, metabolism, and energy balance, while its homeostasis is being challenged by multiple unfavorable factors such as injury, aging, or obesity. Exosomes, a subset of extracellular vesicles, are now recognized as essential mediators of intercellular communication, holding great clinical potential in the treatment of skeletal muscle diseases. Herein, we outline the recent research progress in exosomal isolation, characterization, and mechanism of action, and emphatically discuss current advances in exosomes derived from multiple organs and tissues, and engineered exosomes regarding the regulation of physiological and pathological development of skeletal muscle. These remarkable advances expand our understanding of myogenesis and muscle diseases. Meanwhile, the engineered exosome, as an endogenous nanocarrier combined with advanced design methodologies of biomolecules, will help to open up innovative therapeutic perspectives for the treatment of muscle diseases.

Research progress of tunneling nanotube in bone biology / 中华口腔医学杂志

Tunneling nanotube (TNT) is a newly discovered communication mode between animal cells in recent years, which have important physiological and pathological significance. However, the role of TNT in bone biology is still unclear. At present, there are many reports about tunneling nanotubes in bone marrow mesenchymal stem cells, osteoclast precursor cells, osteoblasts and immune cells. This review describes the research advances of TNT and its research progress in bone biology. It looks forward to the research direction of TNT in oral and maxillofacial bone development and bone biology, to provide new strategies for the maintenance of bone homeostasis and the treatment of bone diseases.

Neuronal guidance genes in health and diseases

Neurons migrate from their birthplaces to the destinations, and extending axons navigate to their synaptic targets by sensing various extracellular cues in spatiotemporally controlled manners. These evolutionally conserved guidance cues and their receptors regulate multiple aspects of neural development to establish the highly complex nervous system by mediating both short- and long-range cell-cell communications. Neuronal guidance genes (encoding cues, receptors, or downstream signal transducers) are critical not only for development of the nervous system but also for synaptic maintenance, remodeling, and function in the adult brain. One emerging theme is the combinatorial and complementary functions of relatively limited classes of neuronal guidance genes in multiple processes, including neuronal migration, axonal guidance, synaptogenesis, and circuit formation. Importantly, neuronal guidance genes also regulate cell migration and cell-cell communications outside the nervous system. We are just beginning to understand how cells integrate multiple guidance and adhesion signaling inputs to determine overall cellular/subcellular behavior and how aberrant guidance signaling in various cell types contributes to diverse human diseases, ranging from developmental, neuropsychiatric, and neurodegenerative disorders to cancer metastasis. We review classic studies and recent advances in understanding signaling mechanisms of the guidance genes as well as their roles in human diseases. Furthermore, we discuss the remaining challenges and therapeutic potentials of modulating neuronal guidance pathways in neural repair.

Extracellular signals regulate the biogenesis of extracellular vesicles

Extracellular vesicles (EVs) are naturally released membrane vesicles that act as carriers of proteins and RNAs for intercellular communication. With various biomolecules and specific ligands, EV has represented a novel form of information transfer, which possesses extremely outstanding efficiency and specificity compared to the classical signal transduction. In addition, EV has extended the concept of signal transduction to intercellular aspect by working as the collection of extracellular information. Therefore, the functions of EVs have been extensively characterized and EVs exhibit an exciting prospect for clinical applications. However, the biogenesis of EVs and, in particular, the regulation of this process by extracellular signals, which are essential to conduct further studies and support optimal utility, remain unclear. Here, we review the current understanding of the biogenesis of EVs, focus on the regulation of this process by extracellular signals and discuss their therapeutic value.

Research progress of extracellular vesicles in the treatment of renal disease / 生理学报

Extracellular vesicles (EVs) are lipid bilayer-enclosed structures containing diverse bioactive cargoes that play a major role in intercellular communication in both physiological and pathological conditions. Currently, the field of EV-based therapy has been rapidly growing, and two main therapeutic uses of EVs can be surmised: (i) exploiting stem cell-derived EVs as therapeutic agents; and (ii) employing EVs as natural therapeutic vectors for drug delivery. This review will discuss the recent advances in EV-based therapy in the treatment of renal disease.

MicroRNAs and exosomes: promising new biomarkers in acute myeloid leukemias?

ABSTRACT Despite advances in understanding of carcinogenesis and of treatment of acute myeloid leukemia, this neoplasm still has a lethality of at least 30%. The search for biomarkers that can predict the response to treatment in the early stages of the disease is still necessary. In recent years, a new form of cellular communication between tumor and non-neoplastic cells has been discovered: the exchange of information through extracellular vesicles. These are small vesicles released by membrane-coated cells that carry proteins, lipids, messenger RNAs, microRNA and DNA, which can be internalized and promote biological changes in target cells. Exosomes are qualified as a type of extracellular vesicle and, in tumors, carry immunoinhibitory signals that promote the escape of immune control. Recent studies have showed their involvement in communication with the cells of the tumor microenvironment and with chemoresistance in several tumors. To date, there is no information about immunoregulatory microRNAs transported by exosomes and their correlation with clinical evolution during chemotherapy for acute myeloid leukemia. Knowledge about immunomodulatory microRNAs obtained by leukemic cells and transported by exosomes can direct us towards the design of new diagnostic and treatment tools in this type of leukemia.

Effect of the Connexin 43 Coupling to the Biobehavior of Multiple Myeloma Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of gap junction intercellular communication (GJIC) combined by connexin43 (Cx43) and its signal to the biobehavior of multiple myeloma (MM) cells, and its possible mechanism.@*METHODS@#The mesenchymal stem cell (MSC) cells were isolated and cultured from patients with MM and normal donors. The expression of connexin43 (Cx43) in MSC cells from different sources was detected by RT-PCR and Western blot. The side population (SP) cells were sorted by flow cytometry (FCM). The effect of MSC cells from different sources to the cell cycle, Cx43 expression, colony formation in vitro, stem cell related genes expression, cytokines secretion and chemoresistance in MM SP cells as well as with or without Cx43 inhibitor 18α-glycyrrhetinic acid (18α-GA) was observed.@*RESULTS@#There was no significantly difference between the MSC isolated from normal donor and MM patients. Western blot showed that Cx43 expression in SP cells was up-regulated when the cells were incubated with MSC, and medium containing 18α-GA could partially inhibit it, moreover, it was more significant in MSC cells of MM patients. The ability of colony formation of SP cells in vitro was higher than those of MM cells and MM-MSC could promote the colony formation in a co-culture manner. The effect of MM-MSC to SP cells was down-regulated after 18α-GA was added. RT-PCR showed that there was several important stem cell-related genes including c-myc, Oct-4 Klf-4, and Sox-2 were found in RPMI 8226 cells, but those cells were up-regulated in SP cells (P0.05). Cytometry bead array assays showed that MM-MSCs could secrete high level of IL-6, but the levels of IL-6, IL-10 and TGF-β increased significantly when the MM-MSCs were co-cultured with SP cells (P<0.05), especially the levels of IL-6 and IL-10 were significantly higher than cultured alone. There was no significant change in the levels of bFGF and IL-17 before and after co-cultured. The levels of IL-6, IL-10 and TGF-β in supernatant decreased significantly after GJ inhibitor 18α-GA was added. PI/Annexin V assay showed that MM cells were sensitive to bortezomib (BTZ)-induced apoptosis, but the sensitivity for SP cells was weaker. The ratio of cell apoptosis was 75.2%±0.77% and 8.12%±0.86% (P<0.001), respectively. MM-MSC could down-regulate the cell apoptosis induced by BTZ, while the sensitivity of MM cells to BTZ could be partially recovered after GJ inhibitor was added.@*CONCLUSION@#MSC derived from MM patients can enhance GJIC to maintain its "hematopoiesis" by up-regulating the expression of Cx43 in MM cells, and at the same time promote cell proliferation and drug recistance by secreting multiple cytokines, which finally contributes to the relapse of MM.

Exosomal microRNAs: an emerging player in systemic lupus erythematosus / 生理学报

Exosomes are nanometer-sized membranous extracellular vesicles that can be secreted by almost all types of cells in the body. Exosomes are involved in cell-to-cell communication through autocrine and paracrine forms. Exosomal microRNAs (miRNAs) are stable in plasma, urine and other body fluids, and have various biological functions. They play an irreplaceable role in the occurrence, development, immune regulation of systemic lupus erythematosus (SLE). Recent studies have proposed that exosomal miRNAs have promising application prospects in the pathogenesis, early diagnosis, and treatment of SLE. Therefore, this review aims to introduce the current research progress on exosomal miRNAs in SLE and analyze their potential application value.

Transforming growth factor-β1-induced N-cadherin drives cell-cell communication through connexin43 in osteoblast lineage / 国际口腔科学杂志·英文版

Gap junction (GJ) has been indicated to have an intimate correlation with adhesion junction. However, the direct interaction between them partially remains elusive. In the current study, we aimed to elucidate the role of N-cadherin, one of the core components in adhesion junction, in mediating connexin 43, one of the functional constituents in gap junction, via transforming growth factor-β1(TGF-β1) induction in osteoblasts. We first elucidated the expressions of N-cadherin induced by TGF-β1 and also confirmed the upregulation of Cx43, and the enhancement of functional gap junctional intercellular communication (GJIC) triggered by TGF-β1 in both primary osteoblasts and MC3T3 cell line. Colocalization analysis and Co-IP experimentation showed that N-cadherin interacts with Cx43 at the site of cell-cell contact. Knockdown of N-cadherin by siRNA interference decreased the Cx43 expression and abolished the promoting effect of TGF-β1 on Cx43. Functional GJICs in living primary osteoblasts and MC3T3 cell line were also reduced. TGF-β1-induced increase in N-cadherin and Cx43 was via Smad3 activation, whereas knockdown of Smad3 signaling by using siRNA decreased the expressions of both N-cadherin and Cx43. Overall, these data indicate the direct interactions between N-cadherin and Cx43, and reveal the intervention of adhesion junction in functional gap junction in living osteoblasts.

Effect of exosome / 中南大学学报(医学版)

Traumatic brain injury (TBI) is a main cause of death and disability worldwide, posing a serious threat to public health. But currently, the diagnosis and treatments for TBI are still very limited. Exosomes are a group of extracellular vesicles and participate in multiple physiological processes including intercellular communication and substance transport. Non-coding RNAs (ncRNA) are of great abundancy as cargo of exosomes. Previous studies have shown that ncRNAs are involved in several pathophysiological processes of TBI. However, the concrete mechanisms involved in the effects induced by exosome-derived ncRNA remain largely unknown. As an important component of exosomes, ncRNA is of great significance for diagnosis, precise treatment, response evaluation, prognosis prediction, and complication management after TBI.

The luciferase reporter system of the MMP12 endogenous promoter for investigating transcriptional regulation of the human MMP12 gene

Background: Matrix metalloproteinase 12 (MMP12), a member of MMPs, can take lots of roles including extracellular matrix component degradation, viral infection, inflammation, tissue remodeling and tumorigenesis. To explore the transcriptional regulation of MMP12 gene, a sensitive luciferase reporter HEK293 cell line for endogenous MMP12 promoter was generated by CRISPR/Cas9 technology. Results: The HEK293-MMP12-T2A-luciferase-KI cell line was successfully established by CRISPR/Cas9 technology. The sequencing results indicated that one allele of the genome was proven to have a site-directed insertion of luciferase gene and another allele of the genome was confirmed to have additional 48 bp insertion in this cell line. The cell line was further demonstrated to be a sensitive reporter of the endogenous MMP12 promoter by applying transcription factors STAT3, AP-1 and SP-1 to the cell line. The reporter cell line was then screened with bioactive small molecule library, and a small molecule Tanshinone I was found to significantly inhibit the transcriptional activity of MMP12 gene in HEK293-MMP12-T2A-luciferase-KI cell line by luciferase activity assay, which was further confirmed to inhibit the expression of MMP12 mRNA in wild-type HEK293 cells. Conclusions: This novel luciferase knock-in reporter system will be helpful for investigating the transcriptional regulation of MMP12 gene and screening the drugs targeting MMP12 gene.