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Cell Death and Differentiation Nov 2023Receptor clustering is the most critical step to activate extrinsic apoptosis by death receptors belonging to the TNF superfamily. Although clinically unsuccessful,...
Receptor clustering is the most critical step to activate extrinsic apoptosis by death receptors belonging to the TNF superfamily. Although clinically unsuccessful, using agonist antibodies, the death receptors-5 remains extensively studied from a cancer therapeutics perspective. However, despite its regulatory role and elevated function in ovarian and other solid tumors, another tumor-enriched death receptor called Fas (CD95) remained undervalued in cancer immunotherapy until recently, when its role in off-target tumor killing by CAR-T therapies was imperative. By comprehensively analyzing structure studies in the context of the binding epitope of FasL and various preclinical Fas agonist antibodies, we characterize a highly significant patch of positively charged residue epitope (PPCR) in its cysteine-rich domain 2 of Fas. PPCR engagement is indispensable for superior Fas agonist signaling and CAR-T bystander function in ovarian tumor models. A single-point mutation in FasL or Fas that interferes with the PPCR engagement inhibited apoptotic signaling in tumor cells and T cells. Furthermore, considering that clinical and immunological features of the autoimmune lymphoproliferative syndrome (ALPS) are directly attributed to homozygous mutations in FasL, we reveal differential mechanistic details of FasL/Fas clustering at the PPCR interface compared to described ALPS mutations. As Fas-mediated bystander killing remains vital to the success of CAR-T therapies in tumors, our findings highlight the therapeutic analytical design for potentially effective Fas-targeting strategies using death agonism to improve cancer immunotherapy in ovarian and other solid tumors.
Topics: Humans; Female; Receptors, Chimeric Antigen; Epitopes; fas Receptor; Fas Ligand Protein; T-Lymphocytes; Ovarian Neoplasms; Apoptosis; Antibodies
PubMed: 37838774
DOI: 10.1038/s41418-023-01229-7 -
MIRO-1 interacts with VDAC-1 to regulate mitochondrial membrane potential in Caenorhabditis elegans.EMBO Reports Aug 2023Precise regulation of mitochondrial fusion and fission is essential for cellular activity and animal development. Imbalances between these processes can lead to...
Precise regulation of mitochondrial fusion and fission is essential for cellular activity and animal development. Imbalances between these processes can lead to fragmentation and loss of normal membrane potential in individual mitochondria. In this study, we show that MIRO-1 is stochastically elevated in individual fragmented mitochondria and is required for maintaining mitochondrial membrane potential. We further observe a higher level of membrane potential in fragmented mitochondria in fzo-1 mutants and wounded animals. Moreover, MIRO-1 interacts with VDAC-1, a crucial mitochondrial ion channel located in the outer mitochondrial membrane, and this interaction depends on the residues E473 of MIRO-1 and K163 of VDAC-1. The E473G point mutation disrupts their interaction, resulting in a reduction of the mitochondrial membrane potential. Our findings suggest that MIRO-1 regulates membrane potential and maintains mitochondrial activity and animal health by interacting with VDAC-1. This study provides insight into the mechanisms underlying the stochastic maintenance of membrane potential in fragmented mitochondria.
Topics: Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Membranes; Voltage-Dependent Anion Channel 1
PubMed: 37306041
DOI: 10.15252/embr.202256297 -
Biochemical Society Transactions Oct 2023Genes encoding histone proteins are recurrently mutated in tumor samples, and these mutations may impact nucleosome stability, histone post-translational modification,...
Genes encoding histone proteins are recurrently mutated in tumor samples, and these mutations may impact nucleosome stability, histone post-translational modification, or chromatin dynamics. The prevalence of histone mutations across diverse cancer types suggest that normal chromatin structure is a barrier to tumorigenesis. Oncohistone mutations disrupt chromatin structure and gene regulatory mechanisms, resulting in aberrant gene expression and the development of cancer phenotypes. Examples of oncohistones include the histone H3 K27M mutation found in pediatric brain cancers that blocks post-translational modification of the H3 N-terminal tail and the histone H2B E76K mutation found in some solid tumors that disrupts nucleosome stability. Oncohistones may comprise a limited fraction of the total histone pool yet cause global effects on chromatin structure and drive cancer phenotypes. Here, we survey histone mutations in cancer and review their function and role in tumorigenesis.
Topics: Humans; Child; Histones; Nucleosomes; Mutation; Neoplasms; Chromatin; Carcinogenesis; Cell Transformation, Neoplastic
PubMed: 37721138
DOI: 10.1042/BST20210567 -
BioRxiv : the Preprint Server For... Sep 2023The two strands of the DNA double helix locally and spontaneously separate and recombine in living cells due to the inherent thermal DNA motion.This dynamics results in...
MOTIVATION
The two strands of the DNA double helix locally and spontaneously separate and recombine in living cells due to the inherent thermal DNA motion.This dynamics results in transient openings in the double helix and is referred to as "DNA breathing" or "DNA bubbles." The propensity to form local transient openings is important in a wide range of biological processes, such as transcription, replication, and transcription factors binding. However, the modeling and computer simulation of these phenomena, have remained a challenge due to the complex interplay of numerous factors, such as, temperature, salt content, DNA sequence, hydrogen bonding, base stacking, and others.
RESULTS
We present pyDNA-EPBD, a parallel software implementation of the Extended Peyrard-Bishop- Dauxois (EPBD) nonlinear DNA model that allows us to describe some features of DNA dynamics in detail. The pyDNA-EPBD generates genomic scale profiles of average base-pair openings, base flipping probability, DNA bubble probability, and calculations of the characteristically dynamic length indicating the number of base pairs statistically significantly affected by a single point mutation using the Markov Chain Monte Carlo (MCMC) algorithm.
PubMed: 37745370
DOI: 10.1101/2023.09.09.557010 -
Nature Communications Sep 2023The interplay between 3D chromatin architecture and gene silencing is incompletely understood. Here, we report a novel point mutation in the non-canonical SMC protein...
The interplay between 3D chromatin architecture and gene silencing is incompletely understood. Here, we report a novel point mutation in the non-canonical SMC protein SMCHD1 that enhances its silencing capacity at endogenous developmental targets. Moreover, it also results in enhanced silencing at the facioscapulohumeral muscular dystrophy associated macrosatellite-array, D4Z4, resulting in enhanced repression of DUX4 encoded by this repeat. Heightened SMCHD1 silencing perturbs developmental Hox gene activation, causing a homeotic transformation in mice. Paradoxically, the mutant SMCHD1 appears to enhance insulation against other epigenetic regulators, including PRC2 and CTCF, while depleting long range chromatin interactions akin to what is observed in the absence of SMCHD1. These data suggest that SMCHD1's role in long range chromatin interactions is not directly linked to gene silencing or insulating the chromatin, refining the model for how the different levels of SMCHD1-mediated chromatin regulation interact to bring about gene silencing in normal development and disease.
Topics: Animals; Mice; Chromatin; Epigenomics; Gene Silencing; Genes, Homeobox; Muscular Dystrophy, Facioscapulohumeral; Chromosomal Proteins, Non-Histone
PubMed: 37749075
DOI: 10.1038/s41467-023-40992-6 -
Nature Communications Jul 2023Andes virus (ANDV) and Sin Nombre virus (SNV) are the etiologic agents of severe hantavirus cardiopulmonary syndrome (HCPS) in the Americas for which no FDA-approved...
Andes virus (ANDV) and Sin Nombre virus (SNV) are the etiologic agents of severe hantavirus cardiopulmonary syndrome (HCPS) in the Americas for which no FDA-approved countermeasures are available. Protocadherin-1 (PCDH1), a cadherin-superfamily protein recently identified as a critical host factor for ANDV and SNV, represents a new antiviral target; however, its precise role remains to be elucidated. Here, we use computational and experimental approaches to delineate the binding surface of the hantavirus glycoprotein complex on PCDH1's first extracellular cadherin repeat domain. Strikingly, a single amino acid residue in this PCDH1 surface influences the host species-specificity of SNV glycoprotein-PCDH1 interaction and cell entry. Mutation of this and a neighboring residue substantially protects Syrian hamsters from pulmonary disease and death caused by ANDV. We conclude that PCDH1 is a bona fide entry receptor for ANDV and SNV whose direct interaction with hantavirus glycoproteins could be targeted to develop new interventions against HCPS.
Topics: Animals; Cricetinae; Orthohantavirus; Point Mutation; Protocadherins; Communicable Diseases; Cadherins; Mesocricetus; RNA Viruses; Syndrome
PubMed: 37488123
DOI: 10.1038/s41467-023-40126-y -
Advanced Science (Weinheim,... Oct 2023Hereditary primary hypogonadism (HPH), caused by gene mutation related to testosterone synthesis in Leydig cells, usually impairs male sexual development and...
Hereditary primary hypogonadism (HPH), caused by gene mutation related to testosterone synthesis in Leydig cells, usually impairs male sexual development and spermatogenesis. Genetically corrected stem Leydig cells (SLCs) transplantation may provide a new approach for treating HPH. Here, a novel nonsense-point-mutation mouse model (Lhcgr ) is first generated based on a gene mutation relative to HPH patients. To verify the efficacy and feasibility of SLCs transplantation in treating HPH, wild-type SLCs are transplanted into Lhcgr mice, in which SLCs obviously rescue HPH phenotypes. Through comparing several editing strategies, optimized PE2 protein (PEmax) system is identified as an efficient and precise approach to correct the pathogenic point mutation in Lhcgr. Furthermore, delivering intein-split PEmax system via lentivirus successfully corrects the mutation in SLCs from Lhcgr mice ex vivo. Gene-corrected SLCs from Lhcgr mice exert ability to differentiate into functional Leydig cells in vitro. Notably, the transplantation of gene-corrected SLCs effectively regenerates Leydig cells, recovers testosterone production, restarts sexual development, rescues spermatogenesis, and produces fertile offspring in Lhcgr mice. Altogether, these results suggest that PE-based gene editing in SLCs ex vivo is a promising strategy for HPH therapy and is potentially leveraged to address more hereditary diseases in reproductive system.
Topics: Animals; Humans; Male; Mice; Cell Differentiation; Hypogonadism; Leydig Cells; Mutation; Receptors, G-Protein-Coupled; Testosterone; Receptors, LH
PubMed: 37697644
DOI: 10.1002/advs.202300993 -
Scientific Reports Nov 2023Hair loss disorders such as androgenetic alopecia have caused serious disturbances to normal human life. Animal models play an important role in exploring pathogenesis...
Hair loss disorders such as androgenetic alopecia have caused serious disturbances to normal human life. Animal models play an important role in exploring pathogenesis of disease and evaluating new therapies. NIH hairless mice are a spontaneous hairless mouse discovered and bred in our laboratory. In this study, we resequenced the genomes of NIH normal mice and NIH hairless mice and obtained 3,575,560 high-quality, plausible SNP loci and 995,475 InDels. The Euclidean distance algorithm was used to assess the association of SNP loci with the hairless phenotype, at a threshold of 0.62. Two regions of chromosome 18 having the highest association with the phenotype contained 345 genes with a total length of 13.98 Mb. The same algorithm was used to assess the association of InDels with the hairless phenotype at a threshold of 0.54 and revealed a region of 25.45 Mb in length, containing 518 genes. The mutation candidate gene Lama3 (NM_010680.2: c.652C>T; NP_034810.1: p. Arg217Cys) was selected based on the results of functional gene analysis and mutation prediction screening. Lama3 (R217C) mutant mice were further constructed using CRISPR/Cas9 technology, and the relationship between Lama3 point mutations and the hairless phenotype were clarified by phenotypic observation. The results showed that male Lama3 point mutation mice started to lose hair on the 80th day after birth, and the hair loss area gradually expanded over time. H&E staining of skin sections showed that the point mutation mice had increased sebaceous glands in the dermis and missing hair follicle structure (i.e., typical symptoms of androgenetic alopecia). This study is a good extension of the current body of knowledge about the function of Lama3, and the constructed Lama3 (R217C) mutant mice may be a good animal model for studying androgenetic alopecia.
Topics: Animals; Male; Mice; Alopecia; Androgens; Extracellular Matrix Proteins; Hair; Mice, Hairless; Mutation; Mutation, Missense; Laminin
PubMed: 38012251
DOI: 10.1038/s41598-023-48337-5 -
Science Bulletin Dec 2023Gene editing ushers in a new era of disease treatment since many genetic diseases are caused by base-pair mutations in genomic DNA. With the rapid development of genome... (Review)
Review
Gene editing ushers in a new era of disease treatment since many genetic diseases are caused by base-pair mutations in genomic DNA. With the rapid development of genome editing technology, novel editing tools such as base editing and prime editing (PE) have attracted public attention, heralding a great leap forward in this field. PE, in particular, is characterized by no need for double-strand breaks (DSBs) or homology sequence templates with variable application scenarios, including point mutations as well as insertions or deletions. With higher editing efficiency and fewer byproducts than traditional editing tools, PE holds great promise as a therapeutic strategy for human diseases. Subsequently, a growing demand for the standard construction of PE system has spawned numerous easy-to-access internet resources and tools for personalized prime editing guide RNA (pegRNA) design and off-target site prediction. In this review, we mainly introduce the innovation and evolutionary strategy of PE systems and the auxiliary tools for PE design and analysis. Additionally, its application and future potential in the clinical field have been summarized and envisaged.
Topics: Humans; CRISPR-Cas Systems; RNA, Guide, CRISPR-Cas Systems; Gene Editing; Mutation; Point Mutation
PubMed: 37973465
DOI: 10.1016/j.scib.2023.11.015