Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 97
Filter
1.
bioRxiv ; 2024 May 05.
Article in English | MEDLINE | ID: mdl-38746313

ABSTRACT

Schwann cells are vital to development and maintenance of the peripheral nervous system and their dysfunction has been implicated in a range of neurological and neoplastic disorders, including NF2 -related schwannomatosis. We have developed a novel human induced pluripotent stem cell (hiPSC) model for the study of Schwann cell differentiation in health and disease. We performed transcriptomic, immunofluorescence, and morphological analysis of hiPSC derived Schwann cell precursors (SPCs) and terminally differentiated Schwann-like cells (SLCs) representing distinct stages of development. To further validate our findings, we performed integrated, cross-species analyses across multiple external datasets at bulk and single cell resolution. Our hiPSC model of Schwann cell development shared overlapping gene expression signatures with human amniotic mesenchymal stem cell (hAMSCs) derived SLCs and in vivo mouse models, but also revealed unique features that may reflect species-specific aspects of Schwann cell biology. Moreover, we have identified gene co-expression modules that are dynamically regulated during hiPSC to SLC differentiation associated with ear and neural development, cell fate determination, the NF2 gene, and extracellular matrix (ECM) organization. By cross-referencing results between multiple datasets and analyses, we have identified potential new genes that are related to NF2 for further study including: ANXA1, CDH6, COL1A1, COL8A1, MFAP5, IGFBP5, FGF1, AHNAK, CDKN2B, LOX, CAV1 , and CAV2 . Our hiPSC model further provides a tractable platform for studying Schwann cell development in the context of human disease.

2.
Mol Metab ; 84: 101951, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38729241

ABSTRACT

OBJECTIVE: Hypothalamic signals potently stimulate energy expenditure by engaging peripheral mechanisms to restore energy homeostasis. Previous studies have identified several critical hypothalamic sites (e.g. preoptic area (POA) and ventromedial hypothalamic nucleus (VMN)) that could be part of an interconnected neurocircuit that controls tissue thermogenesis and essential for body weight control. However, the key neurocircuit that can stimulate energy expenditure has not yet been established. METHODS: Here, we investigated the downstream mechanisms by which VMN neurons stimulate adipose tissue thermogenesis. We manipulated subsets of VMN neurons acutely as well as chronically and studied its effect on tissue thermogenesis and body weight control, using Sf1Cre and Adcyap1Cre mice and measured physiological parameters under both high-fat diet and standard chow diet conditions. To determine the node efferent to these VMN neurons, that is involved in modulating energy expenditure, we employed electrophysiology and optogenetics experiments combined with measurements using tissue-implantable temperature microchips. RESULTS: Activation of the VMN neurons that express the steroidogenic factor 1 (Sf1; VMNSf1 neurons) reduced body weight, adiposity and increased energy expenditure in diet-induced obese mice. This function is likely mediated, at least in part, by the release of the pituitary adenylate cyclase-activating polypeptide (PACAP; encoded by the Adcyap1 gene) by the VMN neurons, since we previously demonstrated that PACAP, at the VMN, plays a key role in energy expenditure control. Thus, we then shifted focus to the subpopulation of VMNSf1 neurons that contain the neuropeptide PACAP (VMNPACAP neurons). Since the VMN neurons do not directly project to the peripheral tissues, we traced the location of the VMNPACAP neurons' efferents. We identified that VMNPACAP neurons project to and activate neurons in the caudal regions of the POA whereby these projections stimulate tissue thermogenesis in brown and beige adipose tissue. We demonstrated that selective activation of caudal POA projections from VMNPACAP neurons induces tissue thermogenesis, most potently in negative energy balance and activating these projections lead to some similar, but mostly unique, patterns of gene expression in brown and beige tissue. Finally, we demonstrated that the activation of the VMNPACAP neurons' efferents that lie at the caudal POA are necessary for inducing tissue thermogenesis in brown and beige adipose tissue. CONCLUSIONS: These data indicate that VMNPACAP connections with the caudal POA neurons impact adipose tissue function and are important for induction of tissue thermogenesis. Our data suggests that the VMNPACAP → caudal POA neurocircuit and its components are critical for controlling energy balance by activating energy expenditure and body weight control.


Subject(s)
Energy Metabolism , Neurons , Preoptic Area , Thermogenesis , Ventromedial Hypothalamic Nucleus , Animals , Ventromedial Hypothalamic Nucleus/metabolism , Thermogenesis/physiology , Preoptic Area/metabolism , Mice , Neurons/metabolism , Male , Steroidogenic Factor 1/metabolism , Steroidogenic Factor 1/genetics , Pituitary Adenylate Cyclase-Activating Polypeptide/metabolism , Pituitary Adenylate Cyclase-Activating Polypeptide/genetics , Diet, High-Fat , Mice, Inbred C57BL , Body Weight , Adipose Tissue, Brown/metabolism
3.
Nat Commun ; 15(1): 4144, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38755140

ABSTRACT

Multiple Myeloma is an incurable plasma cell malignancy with a poor survival rate that is usually treated with immunomodulatory drugs (iMiDs) and proteosome inhibitors (PIs). The malignant plasma cells quickly become resistant to these agents causing relapse and uncontrolled growth of resistant clones. From whole genome sequencing (WGS) and RNA sequencing (RNA-seq) studies, different high-risk translocation, copy number, mutational, and transcriptional markers can be identified. One of these markers, PHF19, epigenetically regulates cell cycle and other processes and is already studied using RNA-seq. In this study, we generate a large (325,025 cells and 49 patients) single cell multi-omic dataset and jointly quantify ATAC- and RNA-seq for each cell and matched genomic profiles for each patient. We identify an association between one plasma cell subtype with myeloma progression that we call relapsed/refractory plasma cells (RRPCs). These cells are associated with chromosome 1q alterations, TP53 mutations, and higher expression of PHF19. We also identify downstream regulation of cell cycle inhibitors in these cells, possible regulation by the transcription factor (TF) PBX1 on chromosome 1q, and determine that PHF19 may be acting primarily through this subset of cells.


Subject(s)
Chromosomes, Human, Pair 1 , DNA-Binding Proteins , Multiple Myeloma , Multiple Myeloma/genetics , Multiple Myeloma/pathology , Multiple Myeloma/drug therapy , Humans , Chromosomes, Human, Pair 1/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Gene Expression Regulation, Neoplastic , Plasma Cells/metabolism , Mutation , Neoplasm Recurrence, Local/genetics , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Drug Resistance, Neoplasm/genetics , Gene Amplification
5.
Sci Rep ; 14(1): 6974, 2024 03 23.
Article in English | MEDLINE | ID: mdl-38521863

ABSTRACT

Drosophila melanogaster is unique among animal models because it has a fully defined synthetic diet available to study nutrient-gene interactions. However, use of this diet is limited to adult studies due to impaired larval development and survival. Here, we provide an adjusted formula that reduces the developmental period, restores fat levels, enhances body mass, and fully rescues survivorship without compromise to adult lifespan. To demonstrate an application of this formula, we explored pre-adult diet compositions of therapeutic potential in a model of an inherited metabolic disorder affecting the metabolism of branched-chain amino acids. We reveal rapid, specific, and predictable nutrient effects on the disease state consistent with observations from mouse and patient studies. Together, our diet provides a powerful means with which to examine the interplay between diet and metabolism across all life stages in an animal model.


Subject(s)
Diet , Drosophila melanogaster , Animals , Drosophila melanogaster/metabolism , Longevity , Models, Animal , Nutrients
6.
Cell Rep ; 43(3): 113861, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38416643

ABSTRACT

Inherited metabolic disorders are a group of genetic conditions that can cause severe neurological impairment and child mortality. Uniquely, these disorders respond to dietary treatment; however, this option remains largely unexplored because of low disorder prevalence and the lack of a suitable paradigm for testing diets. Here, we screened 35 Drosophila amino acid disorder models for disease-diet interactions and found 26 with diet-altered development and/or survival. Using a targeted multi-nutrient array, we examine the interaction in a model of isolated sulfite oxidase deficiency, an infant-lethal disorder. We show that dietary cysteine depletion normalizes their metabolic profile and rescues development, neurophysiology, behavior, and lifelong fly survival, thus providing a basis for further study into the pathogenic mechanisms involved in this disorder. Our work highlights the diet-sensitive nature of metabolic disorders and establishes Drosophila as a valuable tool for nutrigenomic studies for informing potential dietary therapies.


Subject(s)
Amino Acid Metabolism, Inborn Errors , Metabolic Diseases , Infant , Child , Animals , Humans , Nutrigenomics , Drosophila , Diet , Metabolic Diseases/genetics
7.
bioRxiv ; 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38328172

ABSTRACT

Diabetes affects >10% of adults worldwide and is caused by impaired production or response to insulin, resulting in chronic hyperglycemia. Pancreatic islet ß-cells are the sole source of endogenous insulin and our understanding of ß-cell dysfunction and death in type 2 diabetes (T2D) is incomplete. Single-cell RNA-seq data supports heterogeneity as an important factor in ß-cell function and survival. However, it is difficult to identify which ß-cell phenotypes are critical for T2D etiology and progression. Our goal was to prioritize specific disease-related ß-cell subpopulations to better understand T2D pathogenesis and identify relevant genes for targeted therapeutics. To address this, we applied a deep transfer learning tool, DEGAS, which maps disease associations onto single-cell RNA-seq data from bulk expression data. Independent runs of DEGAS using T2D or obesity status identified distinct ß-cell subpopulations. A singular cluster of T2D-associated ß-cells was identified; however, ß-cells with high obese-DEGAS scores contained two subpopulations derived largely from either non-diabetic or T2D donors. The obesity-associated non-diabetic cells were enriched for translation and unfolded protein response genes compared to T2D cells. We selected DLK1 for validation by immunostaining in human pancreas sections from healthy and T2D donors. DLK1 was heterogeneously expressed among ß-cells and appeared depleted from T2D islets. In conclusion, DEGAS has the potential to advance our holistic understanding of the ß-cell transcriptomic phenotypes, including features that distinguish ß-cells in obese non-diabetic or lean T2D states. Future work will expand this approach to additional human islet omics datasets to reveal the complex multicellular interactions driving T2D.

8.
Methods Mol Biol ; 2746: 101-108, 2024.
Article in English | MEDLINE | ID: mdl-38070083

ABSTRACT

The fruit fly Drosophila melanogaster is a powerful genetic model that has been used for many decades to study nervous system function, development, and behavior. There are a large number of developmental and behavioral traits that can be measured to provide a broad readout of neurological function. These include patterned motor behaviors, such as larval locomotion, which can be used to assess whether genetic or environmental factors affect nervous system function to provide an entry point for deeper mechanistic studies. Here, we describe a protocol for quantifying larval locomotion using a simple camera setup and a freely available image analysis software. This protocol can be readily applied to human disease models or in toxicology studies, for example, to broadly assess the impact of treatments on neurological function.


Subject(s)
Drosophila Proteins , Drosophila melanogaster , Animals , Humans , Drosophila melanogaster/genetics , Larva/genetics , Drosophila , Drosophila Proteins/genetics , Locomotion/physiology
9.
Methods Mol Biol ; 2746: 201-211, 2024.
Article in English | MEDLINE | ID: mdl-38070091

ABSTRACT

Synapses are specialized junctions between cells that mediate neurotransmission to modify brain activity and body function. Studies on synapse structure and function play an important role in understanding how neurons communicate and the consequences of their dysfunction in neurological disorders. The Drosophila larval neuromuscular junction is an excellent model for dissecting the cellular and molecular mechanisms of the synapse, with its large size, accessibility, and well-characterized genetics. This protocol describes the steps required for morphological and immunohistochemical analysis of the Drosophila larval neuromuscular junction including its dissection and multiplex labeling of synaptic proteins. This technique can be used to assess the impact of genetic manipulations on synaptic development, integrity, and plasticity, thus providing a valuable tool for probing complex neurological processes in a whole animal system.


Subject(s)
Drosophila Proteins , Drosophila , Animals , Drosophila/genetics , Larva/physiology , Neuromuscular Junction/physiology , Synapses/physiology , Synaptic Transmission
10.
bioRxiv ; 2023 Nov 14.
Article in English | MEDLINE | ID: mdl-38014136

ABSTRACT

Many mechanistic theories of ageing argue that a progressive failure of somatic maintenance, the use of energy and resources to prevent and repair damage to the cell, underpins ageing. To sustain somatic maintenance an organism must acquire dozens of essential nutrients from the diet, including essential amino acids (EAAs), which are physiologically limiting for many animals. In Drosophila, adulthood deprivation of each individual EAA yields vastly different lifespan trajectories, and adulthood deprivation of one EAA, phenylalanine (Phe), has no associated lifespan cost; this is despite each EAA being strictly required for growth and reproduction. Moreover, survival under any EAA deprivation depends entirely on the conserved AA sensor GCN2, a component of the integrated stress response (ISR), suggesting that a novel ISR-mediated mechanism sustains lifelong somatic maintenance during EAA deprivation. Here we investigated this mechanism, finding that flies chronically deprived of dietary Phe continue to incorporate Phe into new proteins, and that challenging flies to increase the somatic requirement for Phe shortens lifespan under Phe deprivation. Further, we show that autophagy is required for full lifespan under Phe deprivation, and that activation of the ISR can partially rescue the shortened lifespan of GCN2-nulls under Phe deprivation. We therefore propose a mechanism by which GCN2, via the ISR, activates autophagy during EAA deprivation, breaking down a larvally-acquired store of EAAs to support somatic maintenance. These data refine our understanding of the strategies by which flies sustain lifelong somatic maintenance, which determines length of life in response to changes in the nutritional environment.

11.
Commun Biol ; 6(1): 1056, 2023 10 18.
Article in English | MEDLINE | ID: mdl-37853189

ABSTRACT

Neuroligins are transmembrane cell adhesion proteins well-known for their genetic links to autism spectrum disorders. Neuroligins can function by regulating the actin cytoskeleton, however the factors and mechanisms involved are still largely unknown. Here, using the Drosophila neuromuscular junction as a model, we reveal that F-Actin assembly at the Drosophila NMJ is controlled through Cofilin signaling mediated by an interaction between DNlg2 and RACK1, factors not previously known to work together. The deletion of DNlg2 displays disrupted RACK1-Cofilin signaling pathway with diminished actin cytoskeleton proteo-stasis at the terminal of the NMJ, aberrant NMJ structure, reduced synaptic transmission, and abnormal locomotion at the third-instar larval stage. Overexpression of wildtype and activated Cofilin in muscles are sufficient to rescue the morphological and physiological defects in dnlg2 mutants, while inactivated Cofilin is not. Since the DNlg2 paralog DNlg1 is known to regulate F-actin assembly mainly via a specific interaction with WAVE complex, our present work suggests that the orchestration of F-actin by Neuroligins is a diverse and complex process critical for neural connectivity.


Subject(s)
Drosophila Proteins , Drosophila , Animals , Drosophila/genetics , Drosophila/metabolism , Actin Depolymerizing Factors/genetics , Actin Depolymerizing Factors/metabolism , Actins/metabolism , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Signal Transduction/physiology , Receptors for Activated C Kinase/genetics
12.
Front Immunol ; 14: 1207108, 2023.
Article in English | MEDLINE | ID: mdl-37593744

ABSTRACT

Introduction: In spontaneous type 1 diabetes (T1D) non-obese diabetic (NOD) mice, the insulin B chain peptide 9-23 (B:9-23) can bind to the MHC class II molecule (IAg7) in register 3 (R3), creating a bimolecular IAg7/InsulinB:9-23 register 3 conformational epitope (InsB:R3). Previously, we showed that the InsB:R3-specific chimeric antigen receptor (CAR), constructed using an InsB:R3-monoclonal antibody, could guide CAR-expressing CD8 T cells to migrate to the islets and pancreatic lymph nodes. Regulatory T cells (Tregs) specific for an islet antigen can broadly suppress various pathogenic immune cells in the islets and effectively halt the progression of islet destruction. Therefore, we hypothesized that InsB:R3 specific Tregs would suppress autoimmune reactivity in islets and efficiently protect against T1D. Methods: To test our hypothesis, we produced InsB:R3-Tregs and tested their disease-protective effects in spontaneous T1D NOD.CD28-/- mice. Results: InsB:R3-CAR expressing Tregs secrete IL-10 dominated cytokines upon engagement with InsB:R3 antigens. A single infusion of InsB:R3 Tregs delayed the onset of T1D in 95% of treated mice, with 35% maintaining euglycemia for two healthy lifespans, readily home to the relevant target whereas control Tregs did not. Our data demonstrate that Tregs specific for MHC class II: Insulin peptide epitope (MHCII/Insulin) protect mice against T1D more efficiently than polyclonal Tregs lacking islet antigen specificity, suggesting that the MHC II/insulin-specific Treg approach is a promising immune therapy for safely preventing T1D.


Subject(s)
Diabetes Mellitus, Type 1 , Animals , Mice , Mice, Inbred NOD , T-Lymphocytes, Regulatory , Epitopes , Insulin , Peptides
13.
bioRxiv ; 2023 Jul 28.
Article in English | MEDLINE | ID: mdl-37546928

ABSTRACT

Asymptomatic Alzheimer's disease (AsymAD) describes the status of subjects with preserved cognition but with identifiable Alzheimer's disease (AD) brain pathology (i.e. Aß-amyloid deposits, neuritic plaques, and neurofibrillary tangles) at autopsy. In this study, we investigated the postmortem brains of a cohort of AsymAD cases to gain insight into the underlying mechanisms of resilience to AD pathology and cognitive decline. Our results showed that AsymAD cases exhibit an enrichment of core plaques and decreased filamentous plaque accumulation, as well as an increase in microglia surrounding this last type. In AsymAD cases we found less pathological tau aggregation in dystrophic neurites compared to AD and tau seeding activity comparable to healthy control subjects. We used spatial transcriptomics to further characterize the plaque niche and found autophagy, endocytosis, and phagocytosis within the top upregulated pathways in the AsymAD plaque niche, but not in AD. Furthermore, we found ARP2, an actin-based motility protein crucial to initiate the formation of new actin filaments, increased within microglia in the proximity of amyloid plaques in AsymAD. Our findings support that the amyloid-plaque microenvironment in AsymAD cases is characterized by microglia with highly efficient actin-based cell motility mechanisms and decreased tau seeding compared to AD. These two mechanisms can potentially provide protection against the toxic cascade initiated by Aß that preserves brain health and slows down the progression of AD pathology.

14.
Clin Transl Gastroenterol ; 14(11): e00630, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37594044

ABSTRACT

INTRODUCTION: Mirikizumab, an anti-interleukin-23p19 monoclonal antibody, demonstrated efficacy in phase 2 and 3 randomized clinical trials of patients with moderate-to-severe ulcerative colitis (UC). Previous results have shown that 12 weeks of mirikizumab treatment downregulated transcripts associated with UC disease activity and tumor necrosis factor inhibitor resistance. We assessed week-52 gene expression from week-12 responders receiving mirikizumab or placebo. METHODS: In the phase 2 AMAC study (NCT02589665), mirikizumab-treated patients achieving week-12 clinical response were rerandomized to mirikizumab 200 mg subcutaneous every 4 or 12 weeks through week 52 (N = 31). Week-12 placebo responders continued placebo through week 52 (N = 7). The limma R package clustered transcript changes in colonic mucosa biopsies from baseline to week 12 into differentially expressed genes (DEGs). Among DEGs, similarly expressed genes (DEGSEGs) maintaining week-12 expression through week 52 were identified. RESULTS: Of 89 DEGSEGs, 63 (70.8%) were present only in mirikizumab induction responders, 5 (5.6%) in placebo responders, and 21 (23.6%) in both. Week-12 magnitudes and week-52 consistency of transcript changes were greater in mirikizumab than in placebo responders (log2FC > 1). DEGSEG clusters (from 84 DEGSEGs identified in mirikizumab and mirikizumab/placebo responders) correlated to modified Mayo score (26/84 with Pearson correlation coefficient [PCC] >0.5) and Robarts Histopathology Index (55/84 with PCC >0.5), sustained through week 52. DISCUSSION: Mirikizumab responders had broader, more sustained transcriptional changes of greater magnitudes at week 52 vs placebo. Mirikizumab responder DEGSEGs suggest a distinct molecular healing pathway associated with mirikizumab interleukin-23 inhibition. The cluster's correlation with disease activity illustrates relationships between clinical, endoscopic, and molecular healing in UC.


Subject(s)
Colitis, Ulcerative , Humans , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/genetics , Transcriptome , Remission Induction , Treatment Outcome , Biopsy
15.
Sci Rep ; 13(1): 12919, 2023 08 09.
Article in English | MEDLINE | ID: mdl-37558676

ABSTRACT

High-fat diet (HFD) is associated with Alzheimer's disease (AD) and type 2 diabetes risk, which share features such as insulin resistance and amylin deposition. We examined gene expression associated with astrocytes and microglia since dysfunction of these cell types is implicated in AD pathogenesis. We hypothesize gene expression changes in disease-associated astrocytes (DAA), disease-associated microglia and human Alzheimer's microglia exist in diabetic and obese individuals before AD development. By analyzing bulk RNA-sequencing (RNA-seq) data generated from brains of mice fed HFD and humans with AD, 11 overlapping AD-associated differentially expressed genes were identified, including Kcnj2, C4b and Ddr1, which are upregulated in response to both HFD and AD. Analysis of single cell RNA-seq (scRNA-seq) data indicated C4b is astrocyte specific. Spatial transcriptomics (ST) revealed C4b colocalizes with Gfad, a known astrocyte marker, and the colocalization of C4b expressing cells with Gad2 expressing cells, i.e., GABAergic neurons, in mouse brain. There also exists a positive correlation between C4b and Gad2 expression in ST indicating a potential interaction between DAA and GABAergic neurons. These findings provide novel links between the pathogenesis of obesity, diabetes and AD and identify C4b as a potential early marker for AD in obese or diabetic individuals.


Subject(s)
Alzheimer Disease , Diabetes Mellitus, Type 2 , Mice , Humans , Animals , Astrocytes/metabolism , Diet, High-Fat/adverse effects , Diabetes Mellitus, Type 2/metabolism , Microglia/metabolism , Alzheimer Disease/metabolism
16.
Res Sq ; 2023 Aug 16.
Article in English | MEDLINE | ID: mdl-37645789

ABSTRACT

Multiple Myeloma is an incurable plasma cell malignancy with a poor survival rate that is usually treated with immunomodulatory drugs (iMiDs) and proteosome inhibitors (PIs). The malignant plasma cells quickly become resistant to these agents causing relapse and uncontrolled growth of resistant clones. From whole genome sequencing (WGS) and RNA sequencing (RNA-seq) studies, different high-risk translocation, copy number, mutational, and transcriptional markers have been identified. One of these markers, PHF19, epigenetically regulates cell cycle and other processes and has already been studied using RNA-seq. In this study a massive (325,025 cells and 49 patients) single cell multiomic dataset was generated with jointly quantified ATAC- and RNA-seq for each cell and matched genomic profiles for each patient. We identified an association between one plasma cell subtype with myeloma progression that we have called relapsed/refractory plasma cells (RRPCs). These cells are associated with 1q alterations, TP53 mutations, and higher expression of PHF19. We also identified downstream regulation of cell cycle inhibitors in these cells, possible regulation of the transcription factor (TF) PBX1 on 1q, and determined that PHF19 may be acting primarily through this subset of cells.

17.
Development ; 150(6)2023 03 15.
Article in English | MEDLINE | ID: mdl-36971361

ABSTRACT

The development and function of male gametes is dependent on a dynamic microtubule network, yet how this is regulated remains poorly understood. We have recently shown that microtubule severing, via the action of the meiotic AAA ATPase protein clade, plays a crucial role in this process. Here, we sought to elucidate the roles of spastin, an as-yet-unexplored member of this clade in spermatogenesis. Using a SpastKO/KO mouse model, we reveal that spastin loss resulted in a complete loss of functional germ cells. Spastin plays a crucial role in the assembly and function of the male meiotic spindle. Consistent with meiotic failure, round spermatid nuclei were enlarged, indicating aneuploidy, but were still able to enter spermiogenesis. During spermiogenesis, we observed extreme abnormalities in manchette structure, acrosome biogenesis and, commonly, a catastrophic loss of nuclear integrity. This work defines an essential role for spastin in regulating microtubule dynamics during spermatogenesis, and is of potential relevance to individuals carrying spastin variants and to the medically assisted reproductive technology industry.


Subject(s)
Acrosome , Microtubules , Animals , Mice , Male , Spastin/genetics , Acrosome/metabolism , Microtubules/metabolism , Spermatogenesis/genetics , Meiosis/genetics
18.
Trends Endocrinol Metab ; 34(2): 85-105, 2023 02.
Article in English | MEDLINE | ID: mdl-36567227

ABSTRACT

Amino acid disorders (AADs) are a large group of rare inherited conditions that collectively impact one in 6500 live births, often resulting in rapid neurological decline and death during infancy. For several AADs, including phenylketonuria, dietary modification prevents physiological deterioration and ameliorates symptoms. Despite this remarkable potential for treatment success, dietary therapy for most AADs remains largely unexplored. Although animal models have provided novel insights into AAD mechanisms, few have been used for therapeutic diet discovery. Here, we find that of all the animal models, Drosophila is particularly well suited for nutrigenomic disease modelling, having amino acid pathways conserved with humans, exceptional genetic tractability, and the unique availability of a synthetic customisable diet.


Subject(s)
Diet , Drosophila , Animals , Humans , Drosophila/metabolism , Nutrigenomics/methods , Amino Acids/metabolism
19.
Cancers (Basel) ; 14(19)2022 Oct 04.
Article in English | MEDLINE | ID: mdl-36230778

ABSTRACT

BACKGROUND: Cancer is the leading cause of death worldwide with breast and prostate cancer the most common among women and men, respectively. Gene expression and image features are independently prognostic of patient survival; but until the advent of spatial transcriptomics (ST), it was not possible to determine how gene expression of cells was tied to their spatial relationships (i.e., topology). METHODS: We identify topology-associated genes (TAGs) that correlate with 700 image topological features (ITFs) in breast and prostate cancer ST samples. Genes and image topological features are independently clustered and correlated with each other. Themes among genes correlated with ITFs are investigated by functional enrichment analysis. RESULTS: Overall, topology-associated genes (TAG) corresponding to extracellular matrix (ECM) and Collagen Type I Trimer gene ontology terms are common to both prostate and breast cancer. In breast cancer specifically, we identify the ZAG-PIP Complex as a TAG. In prostate cancer, we identify distinct TAGs that are enriched for GI dysmotility and the IgA immunoglobulin complex. We identified TAGs in every ST slide regardless of cancer type. CONCLUSIONS: These TAGs are enriched for ontology terms, illustrating the biological relevance to our image topology features and their potential utility in diagnostic and prognostic models.

20.
Bioinformatics ; 38(23): 5236-5244, 2022 11 30.
Article in English | MEDLINE | ID: mdl-36250795

ABSTRACT

MOTIVATION: The integrative analysis of single-cell gene expression and chromatin accessibility measurements is essential for revealing gene regulation, but it is one of the key challenges in computational biology. Gene expression and chromatin accessibility are measurements from different modalities, and no common features can be directly used to guide integration. Current state-of-the-art methods lack practical solutions for finding heterogeneous clusters. However, previous methods might not generate reliable results when cluster heterogeneity exists. More importantly, current methods lack an effective way to select hyper-parameters under an unsupervised setting. Therefore, applying computational methods to integrate single-cell gene expression and chromatin accessibility measurements remains difficult. RESULTS: We introduce AIscEA-Alignment-based Integration of single-cell gene Expression and chromatin Accessibility-a computational method that integrates single-cell gene expression and chromatin accessibility measurements using their biological consistency. AIscEA first defines a ranked similarity score to quantify the biological consistency between cell clusters across measurements. AIscEA then uses the ranked similarity score and a novel permutation test to identify cluster alignment across measurements. AIscEA further utilizes graph alignment for the aligned cell clusters to align the cells across measurements. We compared AIscEA with the competing methods on several benchmark datasets and demonstrated that AIscEA is highly robust to the choice of hyper-parameters and can better handle the cluster heterogeneity problem. Furthermore, AIscEA significantly outperforms the state-of-the-art methods when integrating real-world SNARE-seq and scMultiome-seq datasets in terms of integration accuracy. AVAILABILITY AND IMPLEMENTATION: AIscEA is available at https://figshare.com/articles/software/AIscEA_zip/21291135 on FigShare as well as {https://github.com/elhaam/AIscEA} onGitHub. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Subject(s)
Chromatin , Computational Biology , Chromatin/genetics , Computational Biology/methods , Gene Expression , Single-Cell Analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...