Biology subjects

Miah, M.

Publications and source records attributed to Miah, M..

6 recordsLinked to original sources

bioRxiv2024

Beyond the Sin3/HDAC Complex: FAM60A emerges as a regulator of RNA Splicing

FAM60A, traditionally linked to chromatin remodeling within the Sin3/HDAC complex, has emerged as a critical regulator in RNA splicing. Employing an integrative approach that combines immunological assays, CRISPR/Cas9 technology, comprehensive genomics, proteomics, and advanced cross-linking mass spectrometry, complemented by sophisticated 3D molecular modeling, our study challenges and extends the existing understanding of FAM60As functional dynamics. Contravening previous perceptions, our findings elucidate that FAM60A does not interact directly with SIN3A, rather establishes direct interactions with SAP30 and HDAC1, redefining its relationship with the Sin3/HDAC complex. These interactions, deciphered through detailed 3D structural analysis supported by cross-linking constraints, signify a complex architectural role of FAM60A within chromatin remodeling processes. Moreover, our research unveils FAM60As pivotal role in RNA processing, particularly in splicing regulation. Through extensive molecular interactions with a diverse array of mRNA-binding proteins and principal spliceosome components, FAM60A emerges as a key regulator of RNA splicing. This expanded role delineates its influence on gene expression regulation, spotlighting its capacity to modulate critical cellular processes. In sum, this study unveils FAM60As key role in gene regulation and RNA splicing, and suggests new paths for cellular and therapeutic research.

molecular biology↗

bioRxiv2023

A human prenatal skin cell atlas reveals immune cell regulation of skin morphogenesis

Human prenatal skin is populated by innate immune cells including macrophages, and whether they act solely in immunity or have additional functions in morphogenesis is unclear. We assembled the first comprehensive multi-omic reference atlas of prenatal human skin (7-16 post-conception weeks), combining single cell and spatial transcriptomic data, to characterise the skins microenvironmental cellular organisation. This revealed that crosstalk between non-immune and immune cells underpins formation of hair follicles, has implications for scarless wound healing, and is critical for skin angiogenesis. We benchmarked a skin organoid model, derived from human embryonic stem (ES) and induced pluripotent stem (iPS) cells, against prenatal and adult skin, demonstrating close recapitulation of the epidermal and dermal skin components during hair follicle development. Notably, the skin organoid lacked immune cells and had markedly diminished endothelial cell heterogeneity and quantity. From our in vivo skin cell atlas data, we found that macrophages and macrophage-derived growth factors play a key role in driving endothelial development prenatally. Indeed, vascular network formation was enhanced following transfer of autologous iPS-derived macrophages into both endothelial cell angiogenesis assays and skin organoid cultures. In summary, innate immune cells moonlight as key players in skin morphogenesis beyond their conventional immune roles, a function they achieve via extensive crosstalk with non-immune cells. Finally, we leveraged our human prenatal skin cell atlas to further our understanding of the pathogenesis of genetic hair and skin disorders.

developmental biology↗

bioRxiv2023

Post-mortem AT-8 reactive tau species correlate with non-plaque Aβ levels in the frontal cortex of non-AD and AD brains

The amyloid cascade hypothesis states that A{beta} and its aggregates induce pathological changes in tau, leading to formation of neurofibrillary tangles (NFTs) and cell death. A caveat with this hypothesis is the temporo-spatial divide between plaques and NFTs. This has been addressed by the inclusion of soluble species of A{beta} and tau in the revised amyloid cascade hypothesis, however, the demonstration of a correlative relationship between A{beta} and tau burden in post-mortem human tissue has remained elusive. Employing frozen and fixed frontal cortex grey and associated white matter tissue from non-AD controls (Con; n=39) and Alzheimers diseases (AD) cases (n=21), biochemical and immunohistochemical measures of A{beta} and AT-8 phosphorylated tau were assessed. Native-state dot-blot from crude tissue lysates demonstrated robust correlations between intraregional A{beta} and AT-8 tau, such increases in A{beta} immunoreactivity conferred increases in AT-8 immunoreactivity, both when considered across the entire cohort as well as separately in Con and AD cases. In contrast, no such association between A{beta} plaques and AT-8 were reported when using immunohistochemical measurements. However, when using the non-amyloid precursor protein cross reactive MOAB-2, antibody to measure intracellular A{beta} within a subset of cases, a similar correlative relationship with AT-8 tau as that observed in biochemical analysis was observed. Collectively our data suggests that accumulating intracellular A{beta} may influence AT-8 pathology. Despite the markedly lower levels of phospho-tau in non-AD controls correlative relationships between AT-8 phospho-tau and A{beta} as measured in both biochemical and immunohistochemical assays were more robust in non-AD controls, suggesting a physiological association of A{beta} production and tau phosphorylation, at least within the frontal cortex. Such interactions between regional A{beta} load and phospho-tau load may become modified with disease potentially, as a consequence of interregional tau seed propagation, and thus may diminish the linear relationship observed between A{beta} and phospho-tau in non-AD controls. This study provides evidence supportive of the revised amyloid cascade hypothesis, and demonstrates an associative relationship between AT-8 tau pathology and intracellular A{beta} but not extracellular A{beta} plaques.

neuroscience↗

bioRxiv2023

Dichotomy of neutralizing antibody, B cell and T cell responses to SARS-CoV-2 vaccination and protection in healthy adults

Heterogeneity in SARS-CoV-2 vaccine responses is not understood. Here, we identify four patterns of live-virus neutralizing antibody responses: individuals with hybrid immunity (with confirmed prior infection); rare individuals with low responses (paucity of S1-binding antibodies); and surprisingly, two further groups with distinct serological repertoires. One group - broad responders - neutralize a range of SARS-CoV-2 variants, whereas the other - narrow responders - neutralize fewer, less divergent variants. This heterogeneity does not correlate with Ancestral S1-binding antibody, rather the quality of the serological response. Furthermore, IgDlowCD27-CD137+ B cells and CCR6+ CD4+ T cells are enriched in broad responders before dose 3. Notably, broad responders have significantly longer infection-free time after their third dose. Understanding the control and persistence of these serological profiles could allow personalized approaches to enhance serological breadth after vaccination.

immunology↗

bioRxiv2022

Multi-organ functions of yolk sac during human early development

The yolk sac (YS) represents an evolutionarily-conserved extraembryonic structure that ensures timely delivery of nutritional support and oxygen to the developing embryo. However, the YS remains ill-defined in humans. We therefore assemble a complete single cell 3D map of human YS from 3-8 post conception weeks by integrating multiomic protein and gene expression data. We reveal the YS as a site of primitive and definitive haematopoiesis including a YS-specific accelerated route to macrophage production, a source of nutritional/metabolic support and a regulator of oxygen-carrying capacity. We reconstruct the emergence of primitive haematopoietic stem and progenitor cells from YS hemogenic endothelium and their decline upon stromal support modulation as intraembryonic organs specialise to assume these functions. The YS therefore functions as three organs in one revealing a multifaceted relay of vital organismal functions as pregnancy proceeds. One Sentence SummaryHuman yolk sac is a key staging post in a relay of vital organismal functions during human pregnancy.

developmental biology↗

bioRxiv2022

Mapping the developing human immune system across organs

Recent advances in single cell genomics technologies have facilitated studies on the developing immune system at unprecedented scale and resolution. However, these studies have focused on one or a few organs and were thus limited in understanding the developing immune system as a distributed network across tissues. Here, we profiled prenatal haematopoietic organs, lymphoid organs and non-lymphoid tissues using a combination of single-cell RNA sequencing, paired antigen-receptor sequencing and spatial transcriptomics to reconstruct the developing human immune system. Our analysis revealed the acquisition of immune effector transcriptome profiles in macrophages, mast cells and NK cells from the second trimester, and the transcriptomic changes accompanying the late-stage maturation of developing monocytes and T cells that extended from their organ of origin to peripheral tissues. We uncovered system-wide blood and immune cell development beyond the conventional primary haematopoietic organs. We further identified, extensively characterised and functionally validated the human prenatal B1 cells. Finally, we provide evidence for thymocyte-thymocyte selection origin for {beta}TCR- expressing unconventional T cells based on TCR gene usage and an in vitro artificial thymic organoid culture model. Our comprehensive atlas of the developing human immune system provides both valuable data resources and biological insights that will facilitate cell engineering, regenerative medicine and disease understanding. One-Sentence SummaryBy performing a comprehensive single-cell RNA sequencing atlas of human developing immune system together with antigen-receptor sequencing and spatial transcriptomics, we explored the cross-gestation and cross-organ variability in immune cells, discovered system-wide blood and immune cell development, identified, characterised and functionally validated the properties of human prenatal B1 cells and the origin of unconventional T cells.

immunology↗