Biology subjects

Maienschein-Cline, M.

Publications and source records attributed to Maienschein-Cline, M..

13 recordsLinked to original sources

bioRxiv2026

Multi-omics analysis of type II diabetic wound healing reveals CD44-mediated immune cell crosstalk dysfunction in mice and humans

Type II diabetes mellitus (T2DM) is one of the most prevalent diseases in the United States and is associated with diabetic foot ulcers (DFU) and their impaired, often chronic, wound healing. The T2DM mouse model with dysfunctional leptin receptor (db/db) has been used in basic and translational studies of wound healing due to its systemic phenotypes (hyperphagia, hypometabolism, obesity, T2DM) and its notable delayed skin wound healing. However, a characterization of the temporal cellular dynamics of the db/db wound healing model has not been performed, nor has the model been systematically compared to human DFUs. We performed the first comprehensive single-cell, multi-omic analysis of dermal cells in diabetic (db/db) compared to non-diabetic (ND) mice across three time points ranging from the inflammatory to the delayed proliferative and resolution phases of healing. Single-cell transcriptomics were uniquely linked to their corresponding cells surface protein expressions of cell-specific receptors, including immune cells (CD45) such as neutrophils (CD11b, Ly6G), monocytes/macrophages (CD11b, F4/80, CD11c, Ly6C) and T lymphocytes (CD3, CD4), and dermal cells such as endothelial cells (CD31) and fibroblasts (CD26, CD140a), and showed high concordance between protein cell markers and their gene expressions in major cell types. Differential multi-omic analyses characterized two neutrophil (Tnfaip3+Sod2+Ly6G+, Csf3r+Fos+Ly6G+), three monocyte/macrophage (F4/80highCD11bhigh, Ly6chighCD11bhigh, CD11chighCD11blow) and three fibroblast (Pi16+Dpp4+CD26high, Lrrc15+Tnc+CD140ahigh, Cilp+Mgp+CD26low) subtypes showing dysregulated dynamics across the time course of healing in db/db vs ND mice. Notably, NETotic Tnfaip3+Sod2+Ly6G+ neutrophils and phagocytic F4/80highCD11bhigh macrophage subtypes were drastically up-regulated in diabetic wounds. Differential cell-cell communication analyses revealed striking differences in crosstalk dynamics between fibroblast, macrophage and neutrophil subtypes in the early phase of healing, and ligand-receptor interactome analyses identified CD44 as the hub of dysregulated immune cell interactions in diabetic wounds, implicating cell adhesion, migration and inflammatory pathways, especially those mediated by ICAM1. Inhibition of CD44 using blocking antibodies in primary macrophages from db/db mice and via intradermal injections in db/db mice significantly normalized the early wound immune dysfunction, in part by inhibiting ICAM1 and reversing the excessive neutrophil influx into diabetic wounds. A new integrated dataset of single-cell human chronic wound studies revealed similar CD44-mediated immune cell dysfunctions in diabetic vs non-diabetic foot ulcers, pointing to CD44 as a promising therapeutic target for T2DM-associated chronic wounds.

molecular biology↗

bioRxiv2026

A Novel Monocyte-derived Antigen Presenting Cell-T regulatory Cell Axis Contributes to Skin Wound healing and is Impaired in Diabetic Mice

Despite a vast literature on the role of macrophages in wound healing, the role of dermal monocyte (Mo)-derived antigen presenting cells (APC) has received scant attention. Using scRNAseq and flow cytometry, we identify a population of APC that is prominent in wounds of non-diabetic mice but is reduced in wounds of diabetic mice. Using adoptive transfer experiments and Ccr2 knockout mice, we demonstrate that wound APC are derived primarily from Mo and that the diabetic wound environment inhibits differentiation of Mo into APC. We also show that Mo-specific Irf4 knockout mice exhibit reduced differentiation of Mo into APC, decreased levels of IL27 and numbers of activated Treg cells in wounds. and impaired wound healing. Importantly, adoptive transfer of bone marrow Mo that express Irf4 into wounds of Mo-specific Irf4 knockout mice rescued levels of wound APC and activated Treg, as well as wound healing. Local administration of recombinant IL27 into wounds of these mice also rescued levels of activated Treg in wounds, along with wound healing, Together, these findings identify a novel pathway in which IRF4 induces Mo differentiation into APC in wounds, which in turn produce IL27 that activates Treg to promote healing. This pathway is impaired in wounds of diabetic mice, which provides a novel target to improve diabetic wound healing.

immunology↗

bioRxiv2025

Unraveling Streptococcus pyogenes Carriage: Genomic and Transcriptomic Insights from Acute and Post-Treatment Phases

The carrier state of Streptococcus pyogenes (Group A Streptococcus, GAS), is defined by the presence of the organism without symptoms or an immune response. Carriage poses challenges for clinical management and contributes to transmission in the community. Prior studies suggest genetic and phenotypic differences between isolates from symptomatic (acute) infections and those from carriers, yet comprehensive genomic and transcriptomic analyses of naturally acquired human GAS carriage have been lacking. In this study, we collected longitudinal samples from individuals before and after antibiotic treatment for acute pharyngitis, performing whole genome sequencing and RNA-seq on selected isolates. This is the first report of transcriptional profiling of GAS directly from human derived oropharyngeal swabs. Genomic analysis revealed no consistent carrier-specific genotypes, and in vitro assays showed no major differences in biofilm formation or antibiotic susceptibility between carrier and acute isolates. Transcriptional profiling from oropharyngeal swabs identified distinct gene expression patterns when comparing the acute infection and post-treatment carriage phases, although early acute expression profiles did not predict treatment failure. These findings suggest that GAS carriage is likely influenced by conserved bacterial traits as well as host factors, advancing our understanding of GAS persistence and transmission. SummaryLongitudinal samples were collected from individuals before and after treatment for acute Group A Streptococcal pharyngitis. Whole genome sequencing and RNA-seq was performed on selected isolates. This is the first report of transcriptional profiling of GAS directly from human oropharyngeal swabs. Distinct gene expression patterns were observed when comparing the acute infection and post-treatment carriage.

microbiology↗

bioRxiv2025

MiR-34a deficiency enhances nucleic acid sensing and type I IFN signaling in a mouse model of Alzheimer's disease

MiR-34a is implicated in aging, cell senescence, inflammation, and neurodegenerative diseases. In order to investigate the role of miR-34a in Alzheimers disease (AD), we produced an AD mouse model, Tg-SwDI mice, with whole body/constitutive miR-34a knockout (KO). MiR-34a KO improved long-term memory in Tg-SwDI mice, which was associated with decreases in the ratio of insoluble A{beta}42 to A{beta}40 and with increases in soluble and insoluble A{beta}40 in the cerebral cortex. Anti-Iba1 immunofluorescence revealed increases in activated microglia. Bulk RNA-sequencing of the hippocampus followed by a gene set enrichment analysis (Enrichr) identified "cellular response to type I interferon" and "type I interferon signaling pathway" as the most prominent gene sets in miR-34a KO Tg-SwDI mice compared to miR-34a wild-type Tg-SwDI mice. Many interferon-stimulated genes (ISGs) that characterize interferon responsive microglia (IRM) were upregulated in miR-34a KO Tg-SwDI mice. MiR-34a knockdown strongly enhanced ISGs expression in TLR7 ligand-stimulated BV2 microglia. These results suggest that miR-34a inhibits the transition of microglia to the IRM state that may modulate synaptic and cognitive functions in neurodegenerative diseases and aging.

neuroscience↗

bioRxiv2025

CaMKKβ regulates transcription factor Elf2 gene methylation to maintain endothelial junctional barrier integrity

The expression of endothelial-enriched receptor tyrosine kinase Tie2 and vascular endothelial cadherin VE-cadherin in endothelial cells (EC) is essential for maintaining endothelial barrier integrity and vascular homeostasis. The Ets family of transcription factors plays a critical role in regulating the expression of Tie2 and VE-cadherin in EC. However, the transcriptional regulation of these factors remains poorly understood. In this study, we performed whole genome methylation analysis and found that the gene encoding the Ets family transcription factor Elf2/Nerf2 was hypermethylated in Camkk{beta}-deficient (Camkk{beta}-/-) mice. Notably, these mice exhibited significantly reduced mRNA and protein levels of Elf2, Tie2, and VE-cadherin, along with uncontrolled lung vascular injury following LPS challenge. Additionally, either depletion of CaMKK{beta} in human lung microvascular endothelial cells or EC-specific deletion of Camkk{beta} in mice led to a decrease in the expression of Elf2, Tie2, and VE-cadherin. Furthermore, administration of the DNA methyltransferase inhibitor 5-azacytidine (5-AZA) or EC-specific expression of wild-type CaMKK{beta} but not the kinase-defective mutant restored the expression of Elf2, Tie2, and VE-cadherin in Camkk{beta}-/-mice. We find that under baseline conditions, methyl CpG binding protein MeCP2 repressed Elf2 expression in EC. Importantly, in EC-restricted Elf2 knockout mice (Elf21EC), lung endothelial barrier integrity was compromised due to dramatically reduced levels of Tie2 and VE-cadherin. Together, these findings underscore the crucial role of CaMKK{beta} in regulating endothelial junctional barrier integrity by controlling Elf2 expression.

cell biology↗

bioRxiv2025

Jk DNA GAGA MOTIFS ARE REQUIRED FOR LOCAL NUCLEOSOME REMODELING AND Vk-Jk RECOMBINATION

Immunoreceptor gene recombination requires complementary 12 bp and 23 bp recombination signal sequences (RSSs). In addition, the RSSs that assemble the RAG proteins, recombination centers, must be accessible yet flanked by a 5 nucleosome decorated with H3K4me3. In Drosophila, DNA GAGA motifs play an important role in nucleosome positioning. Herein, we report that 5 to each functional Jk RSS is a DNA GAGA motif conserved across mammalian species. In mice, the GAGA motif 5 to Jk1 regulated local RSS accessibility and 5 nucleosome placement. Furthermore, it was required for Vk-Jk1 recombination. Murine Jk3 is nonfunctional, having mutations in both RSS and GAGA motifs. Restoring both GAGA and RSS motifs rescued Vk-Jk3 recombination. In contrast, restoring the RSS alone did not. Genome-wide, strong cryptic 23 RSSs were preferentially bound to nucleosomes. Furthermore, evolutionary selection against cRSS only occurred in the A Compartment of B lymphocytes, not embryonic stem cells. These data indicate that in developing B cells, nucleosome positioning both enables and restricts recombination to Jk. Furthermore, our data suggest an expanded definition of recombination center-associated RSSs to include a 5 GAGA sequence that dictates the local epigenetic state required for gene recombination. SummaryRecombination center assembly requires a specific epigenetic topology at recombination signal sequences. Herein, we report that conserved GAGA motifs 5 to each Jk segment are required for establishing this epigenetic topology and subsequent local gene recombination.

cell biology↗

bioRxiv2024

BRWD1 establishes epigenetic states for germinal center initiation, maintenance, and function

Germinal center (GC) B cells segregate into three subsets that compartmentalize the antagonistic molecular programs of selection, proliferation, and somatic hypermutation. In bone marrow, the epigenetic reader BRWD1 orchestrates and insulates the sequential stages of cell proliferation and Igk recombination. We hypothesized BRWD1 might play similar insulative roles in the periphery. In Brwd1-/- follicular B cells, GC initiation and class switch recombination following immunization were inhibited. In contrast, in Brwd1-/- GC B cells there was admixing of chromatin accessibility across GC subsets and transcriptional dysregulation including induction of inflammatory pathways. This global molecular GC dysregulation was associated with specific defects in proliferation, affinity maturation, and tolerance. These data suggest that GC subset identity is required for some but not all GC-attributed functions. Furthermore, these data demonstrate a central role for BRWD1 in orchestrating epigenetic transitions at multiple steps along B cell developmental and activation pathways.

immunology↗

bioRxiv2023

Effect of the LSD1 Inhibitor RN-1 on gamma;-globin and Global Gene Expression during Erythroid Differentiation in Baboons (Papio anubis)

Increased levels of Fetal Hemoglobin reduce the severity of symptoms of patients with sickle cell disease and decrease the risk of death. An affordable, small molecule drug that stimulates HbF expression in vivo would be ideally suited to treat the large numbers of SCD patients that exist worldwide. Our previous work showed that administration of the LSD1 (KDM1A) inhibitor RN-1 to normal baboons increased Fetal Hemoglobin (HbF) and was tolerated over a prolonged treatment period. HbF elevations were associated with changes in epigenetic modifications that included increased levels of H3K4 di-and tri-methyl lysine at the {gamma}-globin promoter. While dramatic effects of the loss of LSD1 on hematopoietic differentiation have been observed in murine LSD1 gene deletion and silencing models, the effect of pharmacological inhibition of LSD1 in vivo on hematopoietic differentiation is unknown. The goal of these experiments was to investigate the in vivo mechanism of action of the LSD1 inhibitor RN-1 by determining its effect on {gamma}-globin expression in highly purified subpopulations of bone marrow erythroid cells enriched for varying stages of erythroid differentiation isolated directly from baboons treated with RN-1 and also by investigating the effect of RN1 on the global transcriptome in a highly purified population of proerythroblasts. Our results show that RN-1 administered to baboons targets an early event during erythroid differentiation responsible for {gamma}-globin repression and increases the expression of a limited number of genes including genes involved in erythroid differentiation such as GATA2, GFi-1B, and LYN.

molecular biology↗

bioRxiv2023

Prostate-derived circulating microRNAs add prognostic value to prostate cancer risk calculators

Prostate cancer is the second leading cause of malignancy-related deaths among American men. Active surveillance is a safe option for many men with less aggressive disease, yet definitively determining low-risk cancer is challenging with biopsy alone. Herein, we sought to identify prostate-derived microRNAs in patient sera and serum extracellular vesicles, and determine if those microRNAs improve upon the current clinical risk calculators for prostate cancer prognosis before and after biopsy. Prostate-derived intracellular and extracellular vesicle-contained microRNAs were identified by small RNA sequencing of prostate cancer patient explants and primary cells. Abundant microRNAs were included in a custom microRNA PCR panel that was queried in whole serum and serum extracellular vesicles from a diverse cohort of men diagnosed with prostate cancer. The levels of these circulating microRNAs significantly differed between indolent and aggressive disease and improved the area under the curve for pretreatment nomograms of prostate cancer disease risk. The microRNAs within the extracellular vesicles had improved prognostic value compared to the microRNAs in the whole serum. In summary, quantifying microRNAs circulating in extracellular vesicles is a clinically feasible assay that may provide additional information for assessing prostate cancer risk stratification.

cancer biology↗

bioRxiv2023

BRWD1 orchestrates chromatin topology by converting static to dynamic cohesin complexes

Lymphocyte development consists of sequential and mutually exclusive cell states of proliferative selection and antigen receptor gene recombination1. Transitions between each state require large, coordinated changes in epigenetic landscapes and transcriptional programs2,3. How this occurs remains unclear. Herein, we demonstrate that in small pre-B cells, the lineage and stagespecific epigenetic reader Bromodomain and WD Repeating Containing Protein 1 (BRWD1)2,4 reorders three-dimensional chromatin topology to affect transition between proliferative and gene recombination molecular programs. BRWD1 regulated the switch between poised and active enhancers interacting with promoters and coordinated this with Igk locus contraction. BRWD1 did so by converting chromatin-bound static cohesin to dynamic complexes competent to mediate long-range looping. Remarkably, ATP depletion recapitulated cohesin distributions observed in Brwd1-/- cells. Therefore, in small pre-B cells, cohesin conversion is the main energetic mechanism dictating where dynamic looping occurs in the genome. Our findings provide a new mechanism of cohesin regulation and reveal how cohesin function can be dictated by lineage contextual mechanisms to facilitate specific cell fate transitions.

immunology↗

bioRxiv2022

STAT3 signaling in B cells controls germinal center zone organization and recycling

Germinal centers (GCs), sites of antibody affinity maturation, are organized into dark (DZ) and light (LZ) zones. Here, we uncovered a B cell intrinsic role for STAT3 in GC DZ and LZ organization. Altered zonal organization of STAT3-deficient GCs dampened GC output of long-lived plasma cells (LL-PCs) but increased memory B cells (MBCs). Tfh-GC B cell interaction drive STAT3 tyrosine 705 and serine 727 phosphorylation in LZ B cells, facilitating their recycling into the DZ. An inducible system confirmed STAT3 is not involved in initiating or maintaining the GC but sustains GC zonal organization by regulating GC B cell recycling. RNAseq and ChIPseq analysis identified genes regulated by STAT3 that are critical for LZ cell recycling and transiting through the DZ proliferation and differentiation phases of the DZ. Thus, STAT3 signaling in B cells controls GC zone organization and recycling, and GC egress of LL-PCs, but negatively regulates MBC output. SummaryFike et al. describe a previously unrecognized mechanism by which B cell intrinsic STAT3 signaling controls the germinal center (GC) dark and light zone organization, GC B cell recycling, and GC output of long-lived plasma cells but negatively regulates memory B cells.

immunology↗

bioRxiv2020

Genetic Evidence for Selective Transfer of Microbes Between the International Space Station and an Astronaut

Microbial transfer from the environment can influence a persons health, but relevant studies often have confounding variables and short durations. Here, we used the unique environment of the International Space Station (ISS) to track movement of microbes between an astronauts commensal microbiomes and their environment. We identified several microbial taxa, including Serratia proteamaculans and Rickettsia australis which appear to have been transferred from the ISS to the commensal microbiomes of the astronaut. Strains were matched at the SNP and haplotype-level, and notably some strains persisted even after the astronauts return to Earth. Some transferred taxa correspond to secondary strains in the ISS environment, suggesting that transfer may be mediated by evolutionary selection. Finally, we show evidence that the T-Cell repertoire of the astronaut changes to become more specific to environmental taxa, suggesting that continual microbial and immune monitoring can help guide spaceflight mission planning, health monitoring, and habitat design.

microbiology↗

bioRxiv2020

Selective Nanotherapeutic Targeting of the Neutrophil Subset Mediating Inflammatory Injury

Inflammatory tissue injury such as acute lung injury (ALI) is a disorder that leads to respiratory failure, a major cause of morbidity and mortality worldwide. Excessive neutrophil influx is a critical pathogenic factor in the development of ALI. Here, we identify the subset of neutrophils that is responsible for ALI and lethality in polymicrobial sepsis. The pro-inflammatory neutrophil subpopulation was characterized by its unique ability to endocytose albumin nanoparticles (ANP), upregulation of pro-inflammatory cytokines and chemokines as well as the excessive production of reactive oxygen species (ROS) in models of endotoxemia and septicemia. ANP delivery of the drug piceatannol, a spleen tyrosine kinase (Syk) inhibitor, to the susceptible subset of neutrophils, prevented ALI and mortality in mice subjected to polymicrobial infection. Targeted inhibition of Syk in ANP-susceptible neutrophils had no detrimental effect on neutrophil-dependent host defense because the subset of ANPlow neutrophils effectively controlled polymicrobial infection. The results show that neutrophil heterogeneity can be leveraged therapeutically to prevent ALI without compromising host defense.Competing Interest StatementABM, AS, KB have interests in the biotechnology company Nano Biotherapeutics Inc.View Full Text

immunology↗