Recipient Cells Research Articles

Integration of horizontally acquired light-harvesting genes into an ancestral regulatory network in the cyanobacterium Acaryochloris marina MBIC11017

ABSTRACT The acquisition of new capabilities by horizontal gene transfer (HGT) shapes the distribution of traits during microbial diversification. In the Chlorophyll (Chl) d -producing cyanobacterium Acaryochloris marina , the genes involved in the production and disassembly of the light-harvesting phycobiliprotein phycocyanin (PC) were lost in the A. marina common ancestor but then subsequently regained via HGT in A. marina strain MBIC11017. However, it remains unknown how the HGT-acquired PC genes in MBIC11017 have been reintegrated into its existing regulatory network after tens of millions of years since their loss. Here, we investigated potential mechanisms of regulatory assimilation of PC genes by comparing the transcriptomes of A. marina strain MBIC11017 and a PC-lacking close relative under both low irradiance far-red light and high irradiance white light. We found that PC assembly and degradation processes have been re-assimilated into a conserved ancestral response to high light. Further, we identified putative regulatory elements that were likely co-transferred with PC genes and could be recognized by A. marina ’s pre-existing light response machinery. This study offers insights into how HGT-acquired genes can be reintegrated into an existing transcriptional regulatory network that has evolved in their absence. IMPORTANCE Horizontal gene transfer, the asymmetric movement of genetic information between donor and recipient organisms, is an important mechanism for acquiring new traits. In order for newly acquired gene content to be retained, it must be integrated into the genetic repertoire and regulatory networks of the recipient cell. In a strain of the Chlorophyll d -producing cyanobacterium Acaryochloris marina , the recent reacquisition of the genes required to produce the light-harvesting pigment phycocyanin offers a rare opportunity to understand the mechanisms underlying the regulatory assimilation of an acquired complex trait in bacteria. The significance in our research is in characterizing how an ancestrally lost, complex trait can be reintegrated into a conserved regulatory network, even after millions of years.

Abstract A033: Integrating spatial transcriptomics and second harmonic generation imaging to identify targets of supermere-associated Discoidin Domain Receptor 1 involved in collagen alignment

Abstract Immune checkpoint blockade has been shown to be an effective treatment for colorectal cancers (CRCs) highly infiltrated by CD8+ T cells. However, there is a paucity of CD8+ T-cell infiltration in the majority of CRCs. We previously identified the collagen-activated receptor Discoidin Domain Receptor 1 (DDR1) as a member of a four-gene signature associated with T-cell exclusion in CRC. The cleaved ectodomain (cECD) of DDR1 induces collagen alignment, leading to T-cell exclusion in a breast cancer model. We found that almost all DDR1 cECD is found in supermeres, a novel secreted nanoparticle identified by our lab, and that DDR1 cECD is required for supermere signaling in recipient cells. We hypothesized that supermere-associated DDR1 cECD signals to CRC stromal cells, leading to collagen alignment. To test this hypothesis, we developed a method to determine which genes are associated with collagen alignment and DDR1 expression. To do this, 30 μm thick CRC sections are imaged using a Nikon AX multiphoton microscope by second harmonic generation imaging, which permits label-free imaging of collagen fibers. Spatial heatmaps of the collagen alignment are generated from the resulting images. Spatial transcriptomics is performed on a serial tumor section using the Visium v2 platform and the gene expression matrix is integrated with the collagen alignment heatmap data. As proof-of-principle, two CRC tumors have been analyzed using this method. Highly aligned regions were found to be associated with expression of genes involved in extracellular matrix organization, keloidal collagen and specific fibroblast subtypes. Genes which may be regulated by DDR1 cECD and be involved in collagen alignment will be confirmed at the protein level by multiplexed immunofluorescence on serial sections and in vitro experiments. This method will provide a rich dataset to elucidate the roles of supermeres and DDR1 cECD in T-cell exclusion and collagen fiber alignment and may support the discovery of new strategies to overcome immune exclusion in CRC. Citation Format: Maxwell S. Hamilton, Oleg Tutanov, Harsimran Kaur, Alan J. Simmons, Clark Massick, Kasey Vickers, Ken S. Lau, Ambra Pozzi, Robert J. Coffey. Integrating spatial transcriptomics and second harmonic generation imaging to identify targets of supermere-associated Discoidin Domain Receptor 1 involved in collagen alignment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A033.

Abstract B011: Sensory neurons regulate intracellular and intercellular mitochondrial dynamics in breast cancer cells

Abstract Crosstalk between cancer and the nervous system regulates tumor progression. These interactions occur at both the local (i.e., within the tumor parenchyma) and systemic (e.g., endocrine signaling) levels. More recent work has determined that cancer cells not only interact with their local environment via secreted molecules, but in some cases, via acquiring proteins or organelles from other cells within the tumor microenvironment (TME). Here, we demonstrate that breast cancer cells acquire mitochondria from neurons. Breast cancer cells with higher metastatic potential acquire more mitochondria in NGF dependent manner compared to the cell line with lower metastatic potential. These results suggest that in addition to their known roles in electrochemical and paracrine signaling, tumor-innervating nerves can also enhance cancer cell fitness via transfer of mitochondria. We are now characterizing the mechanisms underlying this transfer, determining the fate of transferred mitochondria in recipient cells, and defining how transferred mitochondria drive cancer development, progression, and metastasis. Further, sensory neurons at the tumor microenvironment dictate the intracellular mitochondria dynamics affecting morphology and function. The change in mitochondria dynamics enhances cancer cell survival and metastasis, we are uncovering how sensory neuron induced mitochondria dynamics drives tumor progression. Citation Format: Ankit Tiwari, Yue Wu, Jeremy C. Borniger. Sensory neurons regulate intracellular and intercellular mitochondrial dynamics in breast cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B011.

Abstract B022: Characterizing invasiveness in CCCR cells: Role of miR-100, miR-125b and EVs

Abstract Introduction: Extracellular vesicles have been found to be important regulators of intercellular communication between cancer cells. EV cargo varies greatly between different cell types, the composition of which provides important insights into the role of donor and recipient cells. Cetuximab Resistant Colorectal Cancer (CCCR) cells upregulate miR-100 and miR-125b and select them as cargo for their respective secreted EVs. These miRNAs are responsible for altered gene expression in the CCCR cells and can also be functionally transferred as part of EVs between donor and recipient cells. Bioinformatic analysis identified Cingulin (CGN) mRNA as one of the possible targets of miR-100 and miR-125b. The action of miRNAs leads to degradation of CGN mRNA ultimately decreasing cellular concentration of the functional protein. Absence of CGN has been associated with increased invasiveness and metastatic potential in the cancer cells. We carried out immunofluorescent imaging of CCCR cells which revealed downregulation of CGN in CCCR cells compared to the parental Cetuximab sensitive Colorectal Cancer (CC) cells. Similar effects were observed in recipient cells that obtained the miRNAs as part of EVs originating from CCCR donor cells. This project helps elucidate the roles of miR-100 and miR-125b in CCCR cells and how EVs facilitate their functional transfer between nearby cancer cells. Methods: CCCR cell lines were derived from parental CC cells in the lab of Dr. Robert Coffey by iterative selection of cetuximab resistance after growth in 3D. CRISPR/Cas9 technology was used to knockout miR-100 and miR-125b in CCCR cells. Transwell co-culture experiments were carried out to analyze EV transfer of miRNAs. Transfer was monitored by immunofluorescence using antibodies against CGN. Cells were stained and imaged as Z stacks under the 63x Immersion setting. ImageJ was used to analyze the stacks and CGN concentrations between the cells. For quantification of immunofluorescence, additional Z stack images were obtained from an inverted microscope and fluorescence digital camera. Images were analyzed using Fiji software to obtain specific CGN concentrations between the cells. Results and Discussion: Immunofluorescent imaging revealed statistically significant downregulation of CGN in CCCR cells. The protein was also downregulated in the recipient knockout cells as part of the Transwell co-culture experiment with CCCR donor cells. CGN is a tight junction protein and its absence confers increased invasiveness in 3D growth with enhanced metastasis. Decreased CGN concentration in the miR-100 and miR-125b enriched EV recipient knockout cells is indicative of functional transfer of the two miRNAs between cancer cells. These distinctive cellular dynamics could be harnessed to develop potential cancer therapies that provide a better prognosis and limit the metastatic potential of targeted cancer cells. Citation Format: Muhammad Shameer, Hannah M Nelson, Shimian Qu, Liyu Huang, Kevin C Corn, Sydney N Chapman, Nicole L Luthcke, Sara A Schuster, Tellie D Stamaris, Lauren A Turnbull, Lucas L Guy, Xiao Liu, Danielle L Michell, Elizabeth M Semler, Kasey C Vickers, Qi Liu, Jeffrey L Franklin, Alissa M Weaver, Marjan Rafat, Robert J Coffey, James G Patton. Characterizing invasiveness in CCCR cells: Role of miR-100, miR-125b and EVs [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr B022.

A conserved interaction between the effector Sca4 and host clathrin suggests additional contributions for Sca4 during rickettsial infection.

Intracellular bacterial pathogens deploy secreted effector proteins that manipulate diverse host machinery and pathways to promote infection. Although many effectors carry out a single function or interaction, there are a growing number of secreted effectors capable of interacting with multiple host factors. However, few effectors secreted by arthropod-borne obligate intracellular Rickettsia species have been linked to multiple host targets. Here, we investigated the conserved rickettsial secreted effector Sca4, which was previously shown to interact with host vinculin in donor cells to promote cell-to-cell spread in the model Rickettsia species R. parkeri. We discovered that Sca4 also binds the host cell protein clathrin heavy chain (CHC, CLTC) via a conserved segment in the Sca4 N-terminus. In mammalian host cells, ablation of CLTC expression or chemical inhibition of endocytosis reduced R. parkeri cell-to-cell spread, indicating that clathrin promotes efficient spread. Unexpectedly, the contribution of CHC to spread was independent of Sca4 and appeared restricted to the recipient host cell, suggesting that the Sca4-clathrin interaction regulates another aspect of the infectious lifecycle. Indeed, R. parkeri lacking Sca4 or expressing a Sca4 truncation unable to bind clathrin had markedly reduced burdens in tick cells, hinting at a cell type-specific function for the Sca4-clathrin interaction. Sca4 homologs from diverse Rickettsia species also bound clathrin, suggesting that the function of this novel effector-host interaction may be broadly important for rickettsial infection. We conclude that Sca4 has multiple targets during infection and that rickettsiae may manipulate host endocytic machinery to facilitate several stages of their life cycles.

Discovering the role of microRNAs and exosomal microRNAs in chest and pulmonary diseases: a spotlight on chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition and ranks as the fourth leading cause of mortality worldwide. Despite extensive research efforts, a reliable diagnostic or prognostic tool for COPD remains elusive. The identification of novel biomarkers may facilitate improved therapeutic strategies for patients suffering from this debilitating disease. MicroRNAs (miRNAs), which are small non-coding RNA molecules, have emerged as promising candidates for the prediction and diagnosis of COPD. Studies have demonstrated that dysregulation of miRNAs influences critical cellular and molecular pathways, including Notch, Wnt, hypoxia-inducible factor-1α, transforming growth factor, Kras, and Smad, which may contribute to the pathogenesis of COPD. Extracellular vesicles, particularly exosomes, merit further investigation due to their capacity to transport various biomolecules such as mRNAs, miRNAs, and proteins between cells. This intercellular communication can significantly impact the progression and severity of COPD by modulating signaling pathways in recipient cells. A deeper exploration of circulating miRNAs and the content of extracellular vesicles may lead to the discovery of novel diagnostic and prognostic biomarkers, ultimately enhancing the management of COPD. The current review focus on the pathogenic role of miRNAs and their exosomal counterparts in chest and respiratory diseases, centering COPD.

Allorecognition Unveiled: Integrating Recent Breakthroughs Into the Current Paradigm

In transplantation, genetic differences between donor and recipient trigger immune responses that cause graft rejection. Allorecognition, the process by which the immune system discriminates allogeneic grafts, targets major histocompatibility complex (MHC) and minor histocompatibility antigens. Historically, it was believed that allorecognition was solely mediated by the recipient’s adaptive immune system recognizing donor-specific alloantigens. However, recent research has shown significant roles for innate immune components, such as lymphoid and myeloid cells, which are sometimes triggered by the mere absence of a self-protein in the graft. This review integrates recent breakthroughs into the current allorecognition paradigm based on the well-established direct and indirect pathways, emphasizing the semi-direct pathway where recipient antigen-presenting cells (APCs) acquire donor MHC molecules, and the inverted direct pathway where donor CD4+ T cells within the graft activate recipient B cells to produce donor-specific antibodies (DSAs). The review also explores the role of natural killer (NK) cells in both promoting and inhibiting graft rejection, highlighting their dual role in innate allorecognition. Additionally, it discusses the emerging understanding of myeloid cell-mediated allorecognition and its implications for initiating adaptive immune responses. These insights aim to provide a more comprehensive understanding of allorecognition, potentially leading to improved transplant outcomes.

The Role of Exosomal miRNAs in Regulating Lipid Metabolism in Obesity-Associated Hyperlipidemia

Obesity-associated hyperlipidemia is a major risk factor for cardiovascular diseases, metabolic syndrome, and other complications. The dysregulation of lipid metabolism in obesity is driven by a complex network of molecular and cellular mechanisms. Among these, exosomal microRNAs (miRNAs) have emerged as key regulators in the communication between adipose tissue, the liver, and other metabolic organs. Exosomes, small vesicles secreted by various cell types, contain miRNAs that can modulate gene expression in recipient cells, thereby influencing lipid metabolism. This review explores the role of exosomal miRNAs in obesity-associated hyperlipidemia, focusing on their mechanisms of action, regulatory functions, and potential therapeutic implications. We highlight specific exosomal miRNAs involved in lipid metabolism pathways, their role in adipogenesis, lipogenesis, and lipid storage, as well as their impact on systemic lipid homeostasis. Additionally, we discuss the potential of targeting exosomal miRNAs as a novel therapeutic approach for managing hyperlipidemia and obesity-related metabolic disorders. Keywords: exosomal miRNAs, lipid metabolism, obesity, hyperlipidemia, adipogenesis, lipogenesis, therapeutic targeting

Mutations in human cytymegalovirus (Orthoherpesviridae: Herpesvirales: Cytomegalovirus: Cytomegalovirus humanbeta 5) UL97 gene lead to increase in viremia duration and poor antiviral response in recipients of allogeneic hematopoietic stem cells.

Human cytomegalovirus (Orthoherpesviridae: Herpesvirales: Cytomegalovirus: Cytomegalovirus humanbeta 5) (HCMV) is one of the most commonly detected viruses in recipients of allogeneic hematopoietic stem cell (allo-HSCT) transplants. However, the emergence of resistance to antiviral drugs such as ganciclovir (GCV) poses a challenge in managing these patients. This study aims to investigate the prevalence and impact of mutations in the HCMV UL97 gene associated with resistance to GCV on the course of infection among allo-HSCT patients. The study examined the association between UL97 mutations and the clinical course of HCMV infection in allo-HSCT patients. Genetic sequencing was performed to identify mutations, and their impact on viral replication and resistance to GCV was assessed. Six mutations were identified (D490A, T502A, C592G, C592F, E596G, C603W). C592G, C592F, E596G, and C603W are associated with resistance to antiviral drugs, while D490A and T502A described for the first time. When comparing patients with wild-type and those carrying the mutant variant, several parameters of peripheral blood were significantly lower in the former group. The median time to peak viral load following allo-HSCT, duration of viremia, and rate of virological response to high-dose therapy also differed significantly between the two groups. It was shown that approximately one third (4 out of 14) of allogeneic stem cell transplant recipients had mutations associated with resistance to GCV. Patients carrying the mutant variant of HCMV had longer viremia and took longer to achieve a negative virological test result after starting high-dose therapy. Performing genotyping may help make more evidence-based therapeutic decisions.

Combining Cre-LoxP and single-cell sequencing technologies: insights into the extracellular vesicle cargo transfer

The recent study from the Pogge von Strandmann group published in Cellular and Molecular Immunology , by Alashkar Alhamwe et al ., combined for the first time the Cre-LoxP recombination system with single-cell sequencing. The group monitored the tumor-derived extracellular vesicle (EV) uptake and the EV functions in the recipient non-malignant cells in a pancreatic ductal adenocarcinoma mouse model. Recombination events and EV uptake, together with resulting gene expression changes in macrophages, neutrophils, and mast cells, were detected by single-cell sequencing technology of the tumor tissue. This new approach is highly specific, as it can identify single EV recipient cells without interfering with the EV biogenesis or the phenotype.

Differential Effects of Extracellular Vesicles from Two Different Glioblastomas on Normal Human Brain Cells

Background/Objectives: Glioblastomas (GBMs) are dreadful brain tumors with abysmal survival outcomes. GBM extracellular vesicles (EVs) dramatically affect normal brain cells (largely astrocytes) constituting the tumor microenvironment (TME). We asked if EVs from different GBM patient-derived spheroid lines would differentially alter recipient brain cell phenotypes. This turned out to be the case, with the net outcome of treatment with GBM EVs nonetheless converging on increased tumorigenicity. Methods: GBM spheroids and brain slices were derived from neurosurgical patient tissues following informed consent. Astrocytes were commercially obtained. EVs were isolated from conditioned culture media by ultrafiltration, concentration, and ultracentrifugation. EVs were characterized by nanoparticle tracking analysis, electron microscopy, biochemical markers, and proteomics. Astrocytes/brain tissues were treated with GBM EVs before downstream analyses. Results: EVs from different GBMs induced brain cells to alter secretomes with pro-inflammatory or TME-modifying (proteolytic) effects. Astrocyte responses ranged from anti-viral gene/protein expression and cytokine release to altered extracellular signal-regulated protein kinase (ERK1/2) signaling pathways, and conditioned media from EV-treated cells increased GBM cell proliferation. Conclusions: Astrocytes/brain slices treated with different GBM EVs underwent non-identical changes in various omics readouts and other assays, indicating “personalized” tumor-specific GBM EV effects on the TME. This raises concern regarding reliance on “model” systems as a sole basis for translational direction. Nonetheless, net downstream impacts from differential cellular and TME effects still led to increased tumorigenic capacities for the different GBMs.

Extracellular Vesicle lncRNAs as Key Biomolecules for Cell-to-Cell Communication and Circulating Cancer Biomarkers

Extracellular vesicles (EVs) are secreted by almost every cell type and are considered carriers of active biomolecules, such as nucleic acids, proteins, and lipids. Their content can be uptaken and released into the cytoplasm of recipient cells, thereby inducing gene reprogramming and phenotypic changes in the acceptor cells. Whether the effects of EVs on the physiology of recipient cells are mediated by individual biomolecules or the collective outcome of the total transferred EV content is still under debate. The EV RNA content consists of several types of RNA, such as messenger RNA (mRNA), microRNA (miRNA), and long non-coding RNA (lncRNA), the latter defined as transcripts longer than 200 nucleotides that do not code for proteins but have important established biological functions. This review aims to update our insights on the functional roles of EV and their cargo non-coding RNA during cancer progression, to highlight the utility of EV RNA as novel diagnostic or prognostic biomarkers in cancer, and to tackle the technological advances and limitations for EV RNA identification, integrity assessment, and preservation of its functionality.

Mitochondrial donation as a mechanism of participation by mesenchymal stromal cells in regenerative processes

Mesenchymal stromal cells (MSCs) are universal regulators of regenerative processes due to their ability to secrete regulatory molecules or replace dead cells through differentiation in the appropriate direction. Recently, another mechanism for the beneficial effects of MSCs on damaged tissue has been discovered, such as the transfer of mitochondria into its cells in response to stress signals. MSCs can transfer mitochondria through tunneling nanotubes that form a communication bridge between cells, through gap junctions, by release as part of extracellular vesicles or in free form, and as a result of complete or partial fusion with recipient cells. In damaged cells that received mitochondria from MSCs, impaired energy metabolism is restored and oxidative stress is reduced, which is accompanied by increased survival, and in some cases also increased proliferation or a change in differentiation status. The restoration of energy after the transfer of mitochondria from MSCs has a beneficial effect on the functional activity of recipient cells and suppresses inflammatory reactions. A significant contribution of the MSC mitochondrial donation to the therapeutic efficacy of MSCs has been repeatedly demonstrated in models of damage to various organs in experimental animals. This stimulates the search for methods to enhance the process of mitochondrial donation. However, it should be taken into account that MSCs are able to transfer mitochondria to malignant cells as well, thereby stimulating tumor growth and increasing its resistance to chemotherapy. These data make it necessary to evaluate the prospects for the use of MSCs in cell therapy with caution. On the other hand, they can serve as a basis for the search for new therapeutic targets in the treatment of oncological diseases.

Microcell-mediated chromosome transfer between non-identical human iPSCs

Microcell-mediated chromosome transfer (MMCT) is anticipated as a unique strategy to manipulate numbers of chromosomes, including the generation of hyperaneuploidy syndrome models with human induced pluripotent stem cells (hiPSCs). Mouse A9/Chinese hamster ovary (CHO) cell libraries of human monochromosomal hybrids as chromosome donor cells frequently show chromosomal rearrangement in the components. The generation of a new A9/CHO library is time-consuming and laborious. Here, we developed an MMCT method using hiPSCs as chromosome donor and recipient cells, through micronucleation using paclitaxel and reversine. Membrane fusion during the MMCT was mediated through interactions between the ecotropic viral envelope transiently expressed in chromosome donor cells and mCAT-1 in chromosome recipient cells. This approach involved tagging Chr21 and ChrY by CRISPR/Cas9 and transferring human/mouse artificial chromosomes, Chr21, ChrX, and ChrY, wherein there are no previous reports demonstrating a full-length introduction. Thus, a strategy that combined CRISPR/Cas9-mediated chromosome tagging and MMCT from hiPSCs as chromosome donor cells to hiPSCs as recipient cells systematically produced isogenic disease model hiPSCs with hyperaneuploidy. This approach allows the study of rare diseases and promises to provide new insights into early developmental mechanisms by introducing a comprehensive set of influential chromosomes/regions into hiPSCs.

Deciphering the roles of cellular and extracellular non-coding RNAs in chemotherapy-induced cardiotoxicity.

Chemotherapy-induced cardiotoxicity is a major adverse effect, driven by multiple factors in its pathogenesis. Notably, RNAs have emerged as significant contributors in both cancer and heart failure (HF). RNAs carry genetic and metabolic information that mirrors the current state of cells, making them valuable as potential biomarkers and therapeutic tools for diagnosing, predicting, and treating a range of diseases, including cardiotoxicity. Over 97% of the genome is transcribed into non-coding RNAs (ncRNAs), including ribosomal RNA (rRNAs), transfer RNAs (tRNAs), and newly identified microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs). NcRNAs function not only within their originating cells but also in recipient cells by being transported through extracellular compartments, referred to as extracellular RNAs (exRNAs). Since ncRNAs were identified as key regulators of gene expression, numerous studies have highlighted their significance in both cancer and cardiovascular diseases. Nevertheless, the role of ncRNAs in cardiotoxicity remains not fully elucidated. The study aims to review the existing knowledge on ncRNAs in Cardio-Oncology and explore the potential of ncRNA-based biomarkers and therapies. These investigations could advance the clinical application of ncRNA research, improving early detection and mitigating of chemotherapy-induced cardiotoxicity.

Glutathione transferase omega 1-1 (GSTO1-1) can effect the inter-cell transfer of cisplatin resistance through the exosomal route.

Glutathione transferase omega-1-1 (GSTO1-1) is a member of the glutathione transferase superfamily (GSTs) involved in the modulation of cell survival, proliferation and metabolism. Increased levels of GSTO1-1 have been associated with cancer progression and chemoresistance in different types of cancer cells, possibly supported by the post-traslational regulation of some major prosurvival pathways regulated by the enzyme. Our data demonstrate for the first time that GSTO1-1 can be released by cancer cells through the exosomal route and transferred to GSTO1-1 knock-out cells, this resulting in an increased resistance against cisplatin toxicity in recipient cells. The use of the exosomal route to transfer the regulatory competences of GSTO1-1 could be a further element supporting its role in neoplastic progression.

Novel intercellular spread mode of respiratory syncytial virus contributes to neutralization escape

Developing widely used respiratory syncytial virus (RSV) vaccines remains a significant challenge, despite the recent authorization of two pre-F vaccines for elderly adults. Previous reports have suggested that even when vaccine-induced immunity generates high titers of potent neutralizing antibodies targeting the pre-F protein, it may not fully inhibit breakthrough of RSV infections. This incomplete inhibition of RSV breakthrough infections can lead to an increased risk of enhanced respiratory disease (ERD) in vaccinated individuals. The reasons why potent neutralizing antibodies cannot fully prevent RSV breakthrough infections are not yet clear. In an attempt to explain this phenomenon, we investigated the effect of potent neutralizing antibodies on the intercellular spread of RSV. Our findings indicated that a specific titer of potent neutralizing antibodies, such as 5C4, could block certain modes of intercellular spread, such as the diffusion of cell-free virions and the delivery of virions through filopodia. However, these antibodies did not fully inhibit the entire process of intercellular spread. Through the use of super-resolution imaging techniques, we observed a novel and efficient spread mode called the transition of viral materials through intercellular nanotubes (TVMIN), independent of virions and insensitive to the presence of antibodies. TVMIN allowed RSV-infected cells to directly transfer viral materials to neighboring cells via intercellular nanotubes that are rich in microfilaments. TVMIN began as early as 5 h post-infection (h.p.i.) and rapidly initiated infection in recipient cells. Our data provided new insights into the intercellular spread of RSV and might help explain the occurrence of breakthrough infections.

Multiplex analysis of cancer cells treated with induced mesenchymal stem cell membrane vesicles

BACKGROUND: Extracellular vesicles (EVs) are membrane-derived vesicles released by cells into the extracellular space, playing a crucial role in intercellular communication and regulating a range of biological processes. These vesicles are found in tumor tissue, where they serve as mediators in signal transduction between tumor cells and the cells of the microenvironment. Similar to their parent mesenchymal stem cells (MSCs), extracellular vesicles demonstrate contradictory effects on tumor development. Studies have shown that MSC-derived EVs promote tumor growth; however, some research has also demonstrated their inhibitory role. AIM: The aim is to assess the effect of mesenchymal stem cell-derived membrane vesicles on the molecular composition of cancer cells. METHODS: Induced membrane vesicles were obtained from mesenchymal stem cells through treatment with cytochalasin B. Mesenchymal stem cells were initially sourced from adipose tissue. To simulate intercellular communication between tumor cells and MSCs, induced membrane vesicles were applied at varying protein concentrations to recipient cells (SH-SY5Y, PC3, MCF7). The bicinchoninic acid method was used to measure the total protein concentration isolated from human cells/induced membrane vesicles. Subsequently, the molecular composition of the recipient cells after the application of induced membrane vesicles was analyzed using multiplex assays. RESULTS: We determined that after the application of MSC-derived membrane vesicles to cancer cells, significant alterations occur in the expression of numerous biologically active molecules, including cytokines, chemokines, and growth factors. Specifically, increased concentrations of growth factor FGF-2, cytokines G-CSF, Fractalkine, IL-12p40, IL-9, IL-4, IL-6, IL-8, and chemokines IP-10, MCP-1, among others, were observed. The analysis also revealed that most of these molecules are associated with cell proliferation, migration, and immune response. CONCLUSION: Mesenchymal stem cell-derived membrane vesicles are capable of altering the molecular profile of cancer cells, increasing the concentration of molecules linked to cell survival and migration.

Human adipose and umbilical cord mesenchymal stem cell-derived extracellular vesicles mitigate photoaging via TIMP1/Notch1

UVB radiation induces oxidative stress, DNA damage, and inflammation, leading to skin wrinkling, compromised barrier function, and an increased risk of carcinogenesis. Addressing or preventing photoaging may offer a promising therapeutic avenue for these conditions. Recent research indicated that mesenchymal stem cells (MSCs) exhibit significant therapeutic potential for various skin diseases. Given that extracellular vesicles (EV) can deliver diverse cargo to recipient cells and elicit similar therapeutic effects, we investigated the roles and underlying mechanisms of both adipose-derived MSC-derived EV (AMSC-EV) and umbilical cord-derived MSC-derived EV (HUMSC-EV) in photoaging. Our findings indicated that in vivo, treatment with AMSC-EV and HUMSC-EV resulted in improvements in wrinkles and skin hydration while also mitigating skin inflammation and thickness alterations in both the epidermis and dermis. Additionally, in vitro studies using human keratinocytes (HaCaTs), human dermal fibroblast cells (HDFs), and T-Skin models revealed that AMSC-EV and HUMSC-EV attenuated senescence, reduced levels of reactive oxygen species (ROS) and DNA damage, and alleviated inflammation induced by UVB. Furthermore, EV treatment enhanced cell viability and migration capacity in the epidermis and promoted extracellular matrix (ECM) remodeling in the dermis in photoaged cell models. Mechanistically, proteomics results showed that TIMP1 was highly expressed in both AMSC-EV and HUMSC-EV and could exert similar effects as MSC-EV. In addition, we found that EV and TIMP1 could inhibit Notch1 and downstream targets Hes1, P16, P21, and P53. Collectively, our data suggests that both AMSC-EV and HUMSC-EV attenuate skin photoaging through TIMP1/Notch1.

Characterization of bla NDM in two Escherichia coli ST1193 clinical isolates in the Gulf region.

Escherichia coli ST1193 is an emerging high-risk clone associated with the production of plasmid-mediated CTX-type extended-spectrum β-lactamases. However, this clone has seldom been found to contain plasmids carrying carbapenemase genes. We report two epidemiologically unlinked multidrug-resistant (MDR) clinical isolates of E. coli ST1193 with plasmids harbouring NDM-type carbapenemase genes from the Gulf region. The isolates were identified by MALDI-TOF MS and antibiotic susceptibility testing was performed using the VITEK 2/Phoenix system. A conjugation experiment was performed to assess the transferability of the resistance plasmids. Genomic DNA of both isolates was subject to Illumina sequencing; one isolate was also sequenced using Oxford Nanopore technology. Bioinformatics analyses were performed to detect antimicrobial resistance genes, and to annotate the genetic context of the NDM genes. Both isolates were resistant to carbapenems using phenotypic tests. Conjugation experiment confirmed that NDM-5-encoding plasmids of both strains could be transferred to the recipient cells. The completed NDM-5-encoding plasmid of E. coli isolate FQ71 was highly similar to several plasmids from ST410 isolates in the NCBI database. Genomic analysis revealed the presence of transposase genes and transposons in the flanking regions of the NDM genes in the plasmids. Since carbapenems constitute first-line agents for the treatment of serious infections caused by ESBL producers, E. coli ST1193 isolates co-producing ESBL and NDM-type carbapenemases represent a serious challenge for antimicrobial stewardship and infection control programmes.