Effector memory-type regulatory T cells display phenotypic and functional instability.

Regulatory T cells (Treg cells) hold promise for sustainable therapy of immune disorders. Recent advancements in chimeric antigen receptor development and genome editing aim to enhance the specificity and function of Treg cells. However, impurities and functional instability pose challenges for the development of safe gene-edited Treg cell products. Here, we examined different Treg cell subsets regarding their fate, epigenomic stability, transcriptomes, T cell receptor repertoires, and function ex vivo and after manufacturing. Each Treg cell subset displayed distinct features, including lineage stability, epigenomics, surface markers, T cell receptor diversity, and transcriptomics. Earlier-differentiated memory Treg cell populations, including a hitherto unidentified naïve-like memory Treg cell subset, outperformed late-differentiated effector memory-like Treg cells in regulatory function, proliferative capacity, and epigenomic stability. High yields of stable, functional Treg cell products could be achieved by depleting the small effector memory-like Treg cell subset before manufacturing. Considering Treg cell subset composition appears critical to maintain lineage stability in the final cell product.

Long-termin vitromaintenance of plasma cells in a hydrogel-enclosed human bone marrow microphysiological 3D model system.

Plasma cells (PCs) in bone marrow (BM) play an important role in both protective and pathogenic humoral immune responses, e.g. in various malignant and non-malignant diseases such as multiple myeloma, primary and secondary immunodeficiencies and autoimmune diseases. Dedicated microenvironmental niches in the BM provide PCs with biomechanical and soluble factors that support their long-term survival. There is a high need for appropriate and robust model systems to better understand PCs biology, to develop new therapeutic strategies for PCs-related diseases and perform targeted preclinical studies with high predictive value. Most preclinical data have been derived fromin vivostudies in mice, asin vitrostudies of human PCs are limited due to restricted survival and functionality in conventional 2D cultures that do not reflect the unique niche architecture of the BM. We have developed a microphysiological, dynamic 3D BM culture system (BM-MPS) based on human primary tissue (femoral biopsies), mechanically supported by a hydrogel scaffold casing. While a bioinert agarose casing did not support PCs survival, a photo-crosslinked collagen-hyaluronic acid (Col-HA) hydrogel preserved the native BM niche architecture and allowed PCs survivalin vitrofor up to 2 weeks. Further, the Col-HA hydrogel was permissive to lymphocyte migration into the microphysiological system´s circulation. Long-term PCs survival was related to the stable presence in the culture of soluble factors, as APRIL, BAFF, and IL-6. Increasing immunoglobulins concentrations in the medium confirm their functionality over culture time. To the best of our knowledge, this study is the first report of successful long-term maintenance of primary-derived non-malignant PCsin vitro. Our innovative model system is suitable for in-depthin vitrostudies of human PCs regulation and exploration of targeted therapeutic approaches such as CAR-T cell therapy or biologics.

The m7G Methyltransferase Mettl1 Drives Cardiac Hypertrophy by Regulating SRSF9-Mediated Splicing of NFATc4.

Cardiac hypertrophy is a key factor driving heart failure (HF), yet its pathogenesis remains incompletely elucidated. Mettl1-catalyzed RNA N7-methylguanosine (m7G) modification has been implicated in ischemic cardiac injury and fibrosis. This study aims to elucidate the role of Mettl1 and the mechanism underlying non-ischemic cardiac hypertrophy and HF. It is found that Mettl1 is upregulated in human failing hearts and hypertrophic murine hearts following transverse aortic constriction (TAC) and Angiotensin II (Ang II) infusion. YY1 acts as a transcriptional factor for Mettl1 during cardiac hypertrophy. Mettl1 knockout alleviates cardiac hypertrophy and dysfunction upon pressure overload from TAC or Ang II stimulation. Conversely, cardiac-specific overexpression of Mettl1 results in cardiac remodeling. Mechanically, Mettl1 increases SRSF9 expression by inducing m7G modification of SRSF9 mRNA, facilitating alternative splicing and stabilization of NFATc4, thereby promoting cardiac hypertrophy. Moreover, the knockdown of SRSF9 protects against TAC- or Mettl1-induced cardiac hypertrophic phenotypes in vivo and in vitro. The study identifies Mettl1 as a crucial regulator of cardiac hypertrophy, providing a novel therapeutic target for HF.

The positive feedback loop of the NAT10/Mybbp1a/p53 axis promotes cardiomyocyte ferroptosis to exacerbate cardiac I/R injury.

Ferroptosis is a nonapoptotic form of regulated cell death that has been reported to play a central role in cardiac ischemia‒reperfusion (I/R) injury. N-acetyltransferase 10 (NAT10) contributes to cardiomyocyte apoptosis by functioning as an RNA ac4c acetyltransferase, but its role in cardiomyocyte ferroptosis during I/R injury has not been determined. This study aimed to elucidate the role of NAT10 in cardiac ferroptosis as well as the underlying mechanism. The mRNA and protein levels of NAT10 were increased in mouse hearts after I/R and in cardiomyocytes that were exposed to hypoxia/reoxygenation. P53 acted as an endogenous activator of NAT10 during I/R in a transcription-dependent manner. Cardiac overexpression of NAT10 caused cardiomyocyte ferroptosis to exacerbate I/R injury, while cardiomyocyte-specific knockout of NAT10 or pharmacological inhibition of NAT10 with Remodelin had the opposite effects. The inhibition of cardiomyocyte ferroptosis by Fer-1 exerted superior cardioprotective effects against the NAT10-induced exacerbation of post-I/R cardiac damage than the inhibition of apoptosis by emricasan. Mechanistically, NAT10 induced the ac4C modification of Mybbp1a, increasing its stability, which in turn activated p53 and subsequently repressed the transcription of the anti-ferroptotic gene SLC7A11. Moreover, knockdown of Mybbp1a partially abolished the detrimental effects of NAT10 overexpression on cardiomyocyte ferroptosis and cardiac I/R injury. Collectively, our study revealed that p53 and NAT10 interdependently cooperate to form a positive feedback loop that promotes cardiomyocyte ferroptosis to exacerbate cardiac I/R injury, suggesting that targeting the NAT10/Mybbp1a/p53 axis may be a novel approach for treating cardiac I/R.

Antibacterial and Anti-Inflammatory Polysaccharide from Fructus Ligustri Lucidi Incorporated in PVA/Pectin Hydrogels Accelerate Wound Healing.

In cutaneous wound healing, an overproduction of inflammatory chemokines and bacterial infections impedes the process. Hydrogels can maintain a physiologically moist microenvironment, absorb chemokines, prevent bacterial infection, inhibit bacterial reproduction, and facilitate wound healing at a wound site. The development of hydrogels provides a novel treatment strategy for the entire wound repair process. Here, a series of Fructus Ligustri Lucidi polysaccharide extracts loaded with polyvinyl alcohol (PVA) and pectin hydrogels were successfully fabricated through the freeze-thaw method. A hydrogel containing a 1% mixing weight ratio of FLL-E (named PVA-P-FLL-E1) demonstrated excellent physicochemical properties such as swellability, water retention, degradability, porosity, 00drug release, transparency, and adhesive strength. Notably, this hydrogel exhibited minimal cytotoxicity. Moreover, the crosslinked hydrogel, PVA-P-FLL-E1, displayed multifunctional attributes, including significant antibacterial properties, earlier re-epithelialization, production of few inflammatory cells, the formation of collagen fibers, deposition of collagen I, and faster remodeling of the ECM. Consequently, the PVA-P-FLL-E1 hydrogel stands out as a promising wound dressing due to its superior formulation and enhanced healing effects in wound care.

Integration of ζ-deficient CARs into the CD3ζ gene conveys potent cytotoxicity in T and NK cells.

ABSTRACT: Chimeric antigen receptor (CAR)-redirected immune cells hold significant therapeutic potential for oncology, autoimmune diseases, transplant medicine, and infections. All approved CAR-T therapies rely on personalized manufacturing using undirected viral gene transfer, which results in nonphysiological regulation of CAR-signaling and limits their accessibility due to logistical challenges, high costs and biosafety requirements. Random gene transfer modalities pose a risk of malignant transformation by insertional mutagenesis. Here, we propose a novel approach utilizing CRISPR-Cas gene editing to redirect T cells and natural killer (NK) cells with CARs. By transferring shorter, truncated CAR-transgenes lacking a main activation domain into the human CD3ζ (CD247) gene, functional CAR fusion-genes are generated that exploit the endogenous CD3ζ gene as the CAR's activation domain. Repurposing this T/NK-cell lineage gene facilitated physiological regulation of CAR expression and redirection of various immune cell types, including conventional T cells, TCRγ/δ T cells, regulatory T cells, and NK cells. In T cells, CD3ζ in-frame fusion eliminated TCR surface expression, reducing the risk of graft-versus-host disease in allogeneic off-the-shelf settings. CD3ζ-CD19-CAR-T cells exhibited comparable leukemia control to TCRα chain constant (TRAC)-replaced and lentivirus-transduced CAR-T cells in vivo. Tuning of CD3ζ-CAR-expression levels significantly improved the in vivo efficacy. Notably, CD3ζ gene editing enabled redirection of NK cells without impairing their canonical functions. Thus, CD3ζ gene editing is a promising platform for the development of allogeneic off-the-shelf cell therapies using redirected killer lymphocytes.

The role of lncRNA-mediated ceRNA regulatory networks in liver fibrosis.

In the dynamic realm of molecular biology and biomedical research, the significance of long non-coding RNAs (lncRNAs) acting as competing endogenous RNAs (ceRNAs) continues to grow, encompassing a broad spectrum of both physiological and pathological conditions. Particularly noteworthy is their pivotal role in the intricate series of events leading to the development of hepatic fibrosis, where hepatic stellate cells (HSCs) play a central role. Recent strides in scientific exploration have unveiled the intricate involvement of lncRNAs as ceRNAs in orchestrating the activation of HSCs. This not only deepens our comprehension of the functioning of proteins, DNA, and the extensive array of coding and noncoding RNAs but also sheds light on the intricate molecular interactions among these molecules. Furthermore, the well-established ceRNA networks, involving classical interactions between lncRNAs, microRNAs (miRNAs), and messenger RNAs (mRNAs), are not mere bystanders; they actively participate in instigating and advancing liver fibrosis. This underscores the pressing need for additional thorough research to fully grasp the potential of ceRNA. The unyielding pursuit of knowledge in this field remains a potent driving force with the capacity to enhance the quality of life for numerous individuals grappling with such diseases. It holds the promise of ushering in a new era of precision medicine, signifying a relentless dedication to unraveling the intricacies of molecular interactions that could pave the way for transformative advancements in the diagnosis and treatment of hepatic fibrosis.

Ramelteon alleviates myocardial ischemia/reperfusion injury (MIRI) through Sirt3--dependent regulation of cardiomyocyte apoptosis.

Reperfusion stands as a pivotal intervention for ischemic heart disease. However, the restoration of blood flow to ischemic tissue always lead to further damage, which is known as myocardial ischemia/reperfusion injury (MIRI). Ramelteon is an orally administered drug used to improve sleep quality, which is famous for its high bioadaptability and absence of notable addictive characteristics. However, the specific mechanism by which it improves MIRI is still unclear. Sirtuin-3 (Sirt3), primarily located in mitochondria, is crucial in mitigating many cardiac diseases, including MIRI. Based on the structure of Sirt3, we simulated molecular docking and identified several potential amino acid binding sites between it and ramelteon. Therefore, we propose a hypothesis that ramelteon may exert cardioprotective effects by activating the Sirt3 signaling pathway. Our results showed that the activation levels and expression level of Sirt3 were significantly decreased in MIRI tissue and H2O2 stimulated H9C2 cells, while ramelteon treatment upregulated Sirt3 activity and expression. After treat with 3-TYP, a classic Sirt3 activity inhibitor, we constructed myocardial ischemia/reperfusion surgery in vivo and induced H9C2 cells with H2O2 in vitro. The results showed that the myocardial protection and anti-apoptotic effects of ramelteon were antagonized by 3-TYP, indicating that the activation of Sirt3 is a key mechanism for ramelteon to exert myocardial protection. In summary, our results confirm a novel mechanism by which ramelteon improves MIRI by activating Sirt3 signaling pathway, providing strong evidence for the treatment of MIRI with ramelteon.

M7G modification of FTH1 and pri-miR-26a regulates ferroptosis and chemotherapy resistance in osteosarcoma.

Doxorubicin and platinum are widely used in the frontline treatment of osteosarcoma, but resistance to chemotherapy limits its curative effect. Here, we have identified that METTL1 mediated N7-Methyladenosine (m7G) low expressed in osteosarcoma tissues, plays a critical oncogenic role, and enhances osteosarcoma chemosensitivity in osteosarcoma. Mechanistically, AlkAniline-Seq data revealed that Ferritin heavy chain (FTH1), the main component of ferritin, which is crucial for iron homeostasis and the inhibition of lipid peroxidation, is one of the top 10 genes with the most significant change in m7G methylation sites mediated by METTL1 in human osteosarcoma cells. Interestingly, METTL1 significantly increased the expression of FTH1 at the mRNA level but was remarkably suppressed at the protein level. We then identified primary (pri)-miR-26a and pri-miR-98 in the Top 20 m7G-methylated pri-miRNAs with highly conserved species. Further results confirmed that METTL1 enhances cell ferroptosis by targeting FTH1 and primary (pri)-miR-26a, promoting their maturity by enhancing RNA stability dependent on m7G methylation. The increase of mature miR-26a-5p that resulted from METTL1 overexpression could further target FTH1 mRNA and eliminate FTH1 translation efficiency. Moreover, the reduction of FTH1 translation dramatically increases cell ferroptosis and promotes the sensitivity of osteosarcoma cells to chemotherapy drugs. Collectively, our study demonstrates the METTL1/pri-miR-26a/FTH1 axis signaling in osteosarcoma and highlights the functional importance of METTL1 and m7G methylation in the progression and chemotherapy resistance of osteosarcoma, suggesting that reprogramming RNA m7G methylation as a potential and promising strategy for osteosarcoma treatment.

Unveiling facial kinship: The BioKinVis dataset for facial kinship verification and genetic association studies.

Facial image-based kinship verification represents a burgeoning frontier within the realms of computer vision and biomedicine. Recent genome-wide association studies have underscored the heritability of human facial morphology, revealing its predictability based on genetic information. These revelations form a robust foundation for advancing facial image-based kinship verification. Despite strides in computer vision, there remains a discernible gap between the biomedical and computer vision domains. Notably, the absence of family photo datasets established through biological paternity testing methods poses a significant challenge. This study addresses this gap by introducing the biological kinship visualization dataset, encompassing 5773 individuals from 2412 families with biologically confirmed kinship. Our analysis delves into the distribution and influencing factors of facial similarity among parent-child pairs, probing the potential association between forensic short tandem repeat polymorphisms and facial similarity. Additionally, we have developed a machine learning model for facial image-based kinship verification, achieving an accuracy of 0.80 in the dataset. To facilitate further exploration, we have established an online tool and database, accessible at http://120.55.161.230:88/.

Integration of ζ-deficient CARs into the CD3-zeta gene conveys potent cytotoxicity in T and NK cells.

Chimeric antigen receptor (CAR)-reprogrammed immune cells hold significant therapeutic potential for oncology, autoimmune diseases, transplant medicine, and infections. All approved CAR-T therapies rely on personalized manufacturing using undirected viral gene transfer, which results in non-physiological regulation of CAR-signaling and limits their accessibility due to logistical challenges, high costs and biosafety requirements. Here, we propose a novel approach utilizing CRISPR-Cas gene editing to redirect T cells and natural killer (NK) cells with CARs. By transferring shorter, truncated CAR-transgenes lacking a main activation domain into the human CD3 ζ (CD247) gene, functional CAR fusion-genes are generated that exploit the endogenous CD3 ζ gene as the CAR's activation domain. Repurposing this T/NK-cell lineage gene facilitated physiological regulation of CAR-expression and reprogramming of various immune cell types, including conventional T cells, TCRγ/δ T cells, regulatory T cells, and NK cells. In T cells, CD3 ζ in-frame fusion eliminated TCR surface expression, reducing the risk of graft-versus-host disease in allogeneic off-the-shelf settings. CD3 ζ-CD19-CAR-T cells exhibited comparable leukemia control to T cell receptor alpha constant ( TRAC )-replaced and lentivirus-transduced CAR-T cells in vivo . Tuning of CD3 ζ-CAR-expression levels significantly improved the in vivo efficacy. Compared to TRAC -edited CAR-T cells, integration of a Her2-CAR into CD3 ζ conveyed similar in vitro tumor lysis but reduced susceptibility to activation-induced cell death and differentiation, presumably due to lower CAR-expression levels. Notably, CD3 ζ gene editing enabled reprogramming of NK cells without impairing their canonical functions. Thus, CD3 ζ gene editing is a promising platform for the development of allogeneic off-the-shelf cell therapies using redirected killer lymphocytes. Key points: Integration of ζ-deficient CARs into CD3 ζ gene allows generation of functional TCR-ablated CAR-T cells for allogeneic off-the-shelf use CD3 ζ-editing platform allows CAR reprogramming of NK cells without affecting their canonical functions.

MiRNAs and Their Role in Venous Thromboembolic Complications.

Venous thromboembolic complications (VTCs), which include deep vein thrombosis (DVT) and pulmonary embolism (PE), have remained a pressing problem in modern clinical medicine for a long time. Despite the already wide arsenal of modern methods for diagnosing and treating this disease, VTCs rank third in the structure of causes of death among all cardiovascular diseases, behind myocardial infarction (MI) and ischemic stroke (IS). Numerous studies have confirmed the importance of understanding the molecular processes of VTCs for effective therapy and diagnosis. Significant progress has been made in VTC research in recent years, where the relative contribution of microRNAs (miRNAs) in the mechanism of thrombus formation and their consideration as therapeutic targets have been well studied. In this case, accurate, timely, and as early as possible diagnosis of VTCs is of particular importance, which will help improve both short-term and long-term prognoses of patients. This case accounts for the already well-studied circulating miRNAs as non-invasive biomarkers. This study presents currently available literature data on the role of miRNAs in VTCs, revealing their potential as therapeutic targets and diagnostic and prognostic tools for this terrible disease.

Methods of miRNA delivery and possibilities of their application in neuro-oncology.

In the current phase of medical progress, practical neuro-oncology faces critical challenges. These include the quest for and development of innovative methodological approaches, as well as the enhancement of conventional therapies to boost their efficacy in treating brain tumors, especially the malignant varieties. Recent strides in molecular and cellular biology, molecular genetics, and immunology have charted the primary research pathways in the development of new anti-cancer medications, with a particular focus on microRNA (miRNA)-based therapy. MiRNAs possess the ability to function as suppressors of tumor growth while also having the potential to act as oncogenes. MiRNAs wield control over numerous processes within the human body, encompassing tumor growth, proliferation, invasion, metastasis, apoptosis, angiogenesis, and immune responses. A significant impediment to enhancing the efficacy of brain tumor treatment lies in the unresolved challenge of traversing the blood-brain barrier (BBB) and blood-tumor barrier (BTB) to deliver therapeutic agents directly to the tumor tissue. Presently, there is a worldwide effort to conduct intricate research and design endeavors aimed at creating miRNA-based dosage forms and delivery systems that can effectively target various structures within the central nervous system (CNS). MiRNA-based therapy stands out as one of the most promising domains in neuro-oncology. Hence, the development of efficient and safe methods for delivering miRNA agents to the specific target cells within brain tumors is of paramount importance. In this study, we will delve into recent findings regarding various methods for delivering miRNA agents to brain tumor cells. We will explore the advantages and disadvantages of different delivery systems and consider some clinical aspects of miRNA-based therapy for brain tumors.

Terahertz asymmetric metallic hole arrays with polarization-independent quasi-bound states in the continuum for membrane sensing.

Resonances with both high-quality factor and polarization-independent characteristics are highly desirable for terahertz (THz) sensing. Here, THz sensors based on asymmetric metallic hole arrays (AMHAs) are experimentally demonstrated. Such sensors consisting of four-hole arrays support polarization-independent quasi-bound states in the continuum (BICs). The induced quasi-BIC presents a quality factor exceeding 2000, which enables enhanced sensing for thin membranes. Results show that the frequency shift is 97.5 GHz for the 25-µm thick polyimide (PI), corresponding to a sensitivity of 147.7 GHz/RIU. The sensing performance strongly relates to the enhanced field originating from sharp quasi-BICs. A maximum field enhancement of 15.88 in contrast to the incident field is achieved. When the PI thickness is large than the decay length of enhanced fields, the interaction strength of field-PI becomes weak, resulting in a saturation effect for the shift of quasi-BICs. The proposed sensor possessing polarization-independent quasi-BICs has great potential for practical sensing applications in real-time chemical and biomolecular.

Mettl13 protects against cardiac contractile dysfunction by negatively regulating C-Cbl-mediated ubiquitination of SERCA2a in ischemic heart failure.

Ischemic heart failure (HF) remains a leading cause of morbidity and mortality. Maintaining homeostasis of cardiac function and preventing cardiac remodeling deterioration are critical to halting HF progression. Methyltransferase-like protein 13 (Mettl13) has been shown to regulate protein translation efficiency by acting as a protein lysine methyltransferase, but its role in cardiac pathology remains unexplored. This study aims to characterize the roles and mechanisms of Mettl13 in cardiac contractile function and HF. We found that Mettl13 was downregulated in the failing hearts of mice post-myocardial infarction (MI) and in a cellular model of oxidative stress. Cardiomyocyte-specific overexpression of Mettl13 mediated by AAV9-Mettl13 attenuated cardiac contractile dysfunction and fibrosis in response to MI, while silencing of Mettl13 impaired cardiac function in normal mice. Moreover, Mettl13 overexpression abrogated the reduction in cell shortening, Ca2+ transient amplitude and SERCA2a protein levels in the cardiomyocytes of adult mice with MI. Conversely, knockdown of Mettl13 impaired the contractility of cardiomyocytes, and decreased Ca2+ transient amplitude and SERCA2a protein expression in vivo and in vitro. Mechanistically, Mettl13 impaired the stability of c-Cbl by inducing lysine methylation of c-Cbl, which in turn inhibited ubiquitination-dependent degradation of SERCA2a. Furthermore, the inhibitory effects of knocking down Mettl13 on SERCA2a protein expression and Ca2+ transients were partially rescued by silencing c-Cbl in H2O2-treated cardiomyocytes. In conclusion, our study uncovers a novel mechanism that involves the Mettl13/c-Cbl/SERCA2a axis in regulating cardiac contractile function and remodeling, and identifies Mettl13 as a novel therapeutic target for ischemic HF.

CAR NK-92 cell-mediated depletion of residual TCR+ cells for ultrapure allogeneic TCR-deleted CAR T-cell products.

Graft-versus-host disease (GVHD) is a major risk of the administration of allogeneic chimeric antigen receptor (CAR)-redirected T cells to patients who are HLA unmatched. Gene editing can be used to disrupt potentially alloreactive T-cell receptors (TCRs) in CAR T cells and reduce the risk of GVHD. Despite the high knockout rates achieved with the optimized methods, a subsequent purification step is necessary to obtain a safe allogeneic product. To date, magnetic cell separation (MACS) has been the gold standard for purifying TCRα/ß- CAR T cells, but product purity can still be insufficient to prevent GVHD. We developed a novel and highly efficient approach to eliminate residual TCR/CD3+ T cells after TCRα constant (TRAC) gene editing by adding a genetically modified CD3-specific CAR NK-92 cell line during ex vivo expansion. Two consecutive cocultures with irradiated, short-lived, CAR NK-92 cells allowed for the production of TCR- CAR T cells with <0.01% TCR+ T cells, marking a 45-fold reduction of TCR+ cells compared with MACS purification. Through an NK-92 cell-mediated feeder effect and circumventing MACS-associated cell loss, our approach increased the total TCR- CAR T-cell yield approximately threefold while retaining cytotoxic activity and a favorable T-cell phenotype. Scaling in a semiclosed G-Rex bioreactor device provides a proof-of-principle for large-batch manufacturing, allowing for an improved cost-per-dose ratio. Overall, this cell-mediated purification method has the potential to advance the production process of safe off-the-shelf CAR T cells for clinical applications.

Combining different CRISPR nucleases for simultaneous knock-in and base editing prevents translocations in multiplex-edited CAR T cells.

BACKGROUND: Multiple genetic modifications may be required to develop potent off-the-shelf chimeric antigen receptor (CAR) T cell therapies. Conventional CRISPR-Cas nucleases install sequence-specific DNA double-strand breaks (DSBs), enabling gene knock-out or targeted transgene knock-in. However, simultaneous DSBs provoke a high rate of genomic rearrangements which may impede the safety of the edited cells. RESULTS: Here, we combine a non-viral CRISPR-Cas9 nuclease-assisted knock-in and Cas9-derived base editing technology for DSB free knock-outs within a single intervention. We demonstrate efficient insertion of a CAR into the T cell receptor alpha constant (TRAC) gene, along with two knock-outs that silence major histocompatibility complexes (MHC) class I and II expression. This approach reduces translocations to 1.4% of edited cells. Small insertions and deletions at the base editing target sites indicate guide RNA exchange between the editors. This is overcome by using CRISPR enzymes of distinct evolutionary origins. Combining Cas12a Ultra for CAR knock-in and a Cas9-derived base editor enables the efficient generation of triple-edited CAR T cells with a translocation frequency comparable to unedited T cells. Resulting TCR- and MHC-negative CAR T cells resist allogeneic T cell targeting in vitro. CONCLUSIONS: We outline a solution for non-viral CAR gene transfer and efficient gene silencing using different CRISPR enzymes for knock-in and base editing to prevent translocations. This single-step procedure may enable safer multiplex-edited cell products and demonstrates a path towards off-the-shelf CAR therapeutics.

Exosomes secreted from cardiomyocytes suppress the sensitivity of tumor ferroptosis in ischemic heart failure.

Heart failure (HF) patients in general have a higher risk of developing cancer. Several animal studies have indicated that cardiac remodeling and HF remarkably accelerate tumor progression, highlighting a cause-and-effect relationship between these two disease entities. Targeting ferroptosis, a prevailing form of non-apoptotic cell death, has been considered a promising therapeutic strategy for human cancers. Exosomes critically contribute to proximal and distant organ-organ communications and play crucial roles in regulating diseases in a paracrine manner. However, whether exosomes control the sensitivity of cancer to ferroptosis via regulating the cardiomyocyte-tumor cell crosstalk in ischemic HF has not yet been explored. Here, we demonstrate that myocardial infarction (MI) decreased the sensitivity of cancer cells to the canonical ferroptosis activator erastin or imidazole ketone erastin in a mouse model of xenograft tumor. Post-MI plasma exosomes potently blunted the sensitivity of tumor cells to ferroptosis inducers both in vitro in mouse Lewis lung carcinoma cell line LLC and osteosarcoma cell line K7M2 and in vivo with xenograft tumorigenesis model. The expression of miR-22-3p in cardiomyocytes and plasma-exosomes was significantly upregulated in the failing hearts of mice with chronic MI and of HF patients as well. Incubation of tumor cells with the exosomes isolated from post-MI mouse plasma or overexpression of miR-22-3p alone abrogated erastin-induced ferroptotic cell death in vitro. Cardiomyocyte-enriched miR-22-3p was packaged in exosomes and transferred into tumor cells. Inhibition of cardiomyocyte-specific miR-22-3p by AAV9 sponge increased the sensitivity of cancer cells to ferroptosis. ACSL4, a pro-ferroptotic gene, was experimentally established as a target of miR-22-3p in tumor cells. Taken together, our findings uncovered for the first time that MI suppresses erastin-induced ferroptosis through releasing miR-22-3p-enriched exosomes derived from cardiomyocytes. Therefore, targeting exosome-mediated cardiomyocyte/tumor pathological communication may offer a novel approach for the ferroptosis-based antitumor therapy.

Triazavirin-A Novel Effective Antiviral Drug.

This review outlines the data of numerous studies relating to the broad-spectrum antiviral drug Triazavirin that was launched on the Russian pharmaceutical market in 2014 as an anti-influenza drug (the international non-patented name is Riamilovir). The range of antiviral activity of Triazavirin has been significantly expanded during recent years; in particular, it has been shown that Triazavirin exhibits activity against tick-borne encephalitis, Rift Valley fever, West Nile fever, and other infections of viral etiology. This drug has been approved for treatment of influenza and acute respiratory infections by the Russian Ministry of Health on the basis of comprehensive clinical trials involving over 450 patients. Triazavirin was found to be a highly effective and well-tolerated drug, allowing its over-the-counter sale. The recently published data on the use of Triazavirin in clinical practice for the treatment of patients with COVID-19 are discussed, with special attention paid to potential biological targets for this drug.