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Good, M.

Publications and source records attributed to Good, M..

11 recordsLinked to original sources

Transmural Single-Nucleus Transcriptomics Nominates Candidate Disease Programs in Human Necrotizing Enterocolitis

Background & Aims: Necrotizing enterocolitis (NEC) is a life-threatening disease of premature infants marked by inflammation, ischemia, mucosal injury, and, in advanced cases, necrosis extending into deeper layers of the intestinal wall. Because NEC affects specialized, interacting cells in a developing intestine, we used single-nucleus transcriptomics to build a transmural, cell-type-resolved map and nominate hypothesis-generating disease programs distinct from maturation. Methods: Full-thickness intestinal specimens from fetal/prenatal controls, acute NEC cases, and infant controls were analyzed by single-nucleus RNA sequencing (snRNA-seq). Fetal and infant samples served as developmental references. Analyses included cell annotation, NEC-versus-infant differential expression, gene ontology (GO), cross-lineage recurrence, cell death signatures, and developmental maturity. Results: We profiled 53,735 nuclei by snRNA-seq and resolved 34 epithelial, stromal, vascular, immune, neuronal, glial, and smooth muscle populations. We used a morphology-based nuclei scoring system for sample selection that predicted high-quality transcript recovery. NEC nuclei were represented across this cellular landscape, with recurrent gene-expression changes suggesting shared inflammatory recruitment, antimicrobial/redox defense, stress adaptation, complement/vascular activation, reduced homeostatic signaling, and cell death-associated regulation. Developmental maturity analysis identified fetal-like expression levels in subsets of NEC-regulated genes. Proliferative crypt populations retained DNA repair/cell-cycle programs with inflammatory, hypoxic, and ER-stress features, while absorptive enterocytes showed reduced digestive, transport, detoxification, and terminal villus-function programs. Secretory-lineage changes implicated goblet mucus-barrier responses with reduced glycosylation, trafficking, and hydration; enteroendocrine changes in epithelial defense, metabolic stress, and neural signaling; and Paneth cell retention of antimicrobial effector transcripts despite altered ER quality control, autophagy, and granule delivery in NEC. Non-epithelial programs implicated stromal Wnt/BMP niche loss, impaired lymphatic drainage/scavenging, macrophage cytokine activation with reduced clearance machinery, neuroglial circuit defects, and altered smooth muscle contraction-relaxation balance. Conclusions: This single nuclear intestinal cell atlas nominates multicellular programs that may govern NEC initiation, progression toward tissue destruction, and resolution toward functional recovery.

pathology↗

Convergent antigenic drift of the influenza hemagglutinin lateral patch across time and species

The lateral patch epitope of the H1 hemagglutinin (HA) was a dominant target of antibodies following exposure to the 2009 pandemic H1N1 virus. However, the conservation and potential for antigenic drift in the lateral patch remain unresolved. Here, we used lateral patch-specific monoclonal antibodies (mAbs) to understand the antigenicity of the lateral patch of human, avian, and swine H1Nx viruses spanning from 1918 to 2022. We identified discrete mutations that evaded lateral patch-targeting mAbs in pre- and post-2009 H1N1 viruses, leading to genetic differences in lateral patch-targeting antibodies in individuals across birth years. We observed that the lateral patch remains well conserved across zoonotic sources, suggesting existing lateral patch antibodies could protect against a future H1Nx pandemic. Together, these data support that lateral patch antigenic drift has shaped the human B cell repertoire against influenza viruses and that the lateral patch remains an attractive target for pandemic preparedness.

microbiology↗

Distinct genomic and immunologic tumor evolution in germline TP53-driven breast cancers

Pathogenic germline TP53 alterations cause Li-Fraumeni Syndrome (LFS), and breast cancer is the most common cancer in LFS females. We performed first of its kind multimodal analysis of LFS breast cancer (LFS-BC) compared to sporadic premenopausal BC. Nearly all LFS-BC underwent biallelic loss of TP53 with no recurrent oncogenic variants except ERBB2 (HER2) amplification. Compared to sporadic BC, in situ and invasive LFS-BC exhibited a high burden of short amplified aneuploid segments (SAAS). Pro-apoptotic p53 target genes BAX and TP53I3 failed to be up-regulated in LFS-BC as was seen in sporadic BC compared to normal breast tissue. LFS-BC had lower CD8+ T-cell infiltration compared to sporadic BC yet higher levels of proliferating cytotoxic T-cells. Within LFS-BC, progression from in situ to invasive BC was marked by an increase in chromosomal instability with a decrease in proliferating cytotoxic T-cells. Our study uncovers critical events in mutant p53-driven tumorigenesis in breast tissue.

genetics↗

Disruption of IL-17 signaling in the respiratory mucosa results in invasive streptococcal infection

Streptococcus pyogenes infection of the upper respiratory tract and skin can lead to severe invasive streptococcal disease (ISD). Previous studies have demonstrated that the deficiency of IL-17 in mice (IL-17-/-) reduces mucosal immunity against S. pyogenes. However, the impact of IL-17 deficiency on the development of ISD is unknown. Here, we model single or repeated non-lethal, intranasal (IN) S. pyogenes M1 strain infections in immunocompetent and IL-17-/-mice to assess bacterial dissemination following a final IN or skin challenge. Immunocompetent mice that received a single S. pyogenes IN infection displayed long-lasting mucosal immunity and no systemic infection. However, in the absence of IL-17, a single IN infection resulted in the dissemination of S. pyogenes to the spleens, which was further exacerbated by repeated IN infections. Interestingly, immunity following skin challenge did not show a correlation with IL-17 and was instead associated with the activation of germinal center responses and the accumulation of neutrophils in the spleen. Our results highlight the critical role of IL-17 in preventing ISD following S. pyogenes infection of the respiratory mucosa.

immunology↗

The 5:2 diet does not increase adult hippocampal neurogenesis or enhance spatial memory in mice

New neurones are generated throughout life in the mammalian brain in a process known as adult hippocampal neurogenesis (AHN). Since this phenomenon grants a high degree of neuroplasticity influencing learning and memory and mood related behaviour, identifying factors that regulate AHN may be important for ameliorating age-related cognitive decline and neurodegeneration. Calorie restriction (CR), in the absence of malnutrition, has been shown to enhance AHN and improve hippocampal-dependent memory, mediated by the stomach hormone, ghrelin. Intermittent fasting (IF), a dietary strategy offering more flexibility than conventional CR, also promotes aspects of AHN. The 5:2 diet is a popular form of IF linked to a range of health benefits, however its effects on AHN and spatial memory are not well characterised. We hypothesised that the 5:2 diet would enhance AHN in a ghrelin-dependent manner. To assess this, we used immunohistochemistry to quantify new adult-born neurones and new neural stem cells (NSCs) in the hippocampal DG of adolescent and adult wild-type and mice lacking the ghrelin receptor following six weeks on a 5:2 diet. We report an age-related decline in neurogenic processes and identify a novel role for ghrelin-receptor in regulating the formation of new adult born NSCs in an age-dependent manner. However, the 5:2 diet did not affect new neurone or NSC formation in the DG. Consistent with this finding the 5:2 diet did not alter performance on a spatial learning and memory task. These data suggest that the 5:2 diet used in this study does not increase AHN or improve associated spatial memory function. HighlightsO_LI5:2 diet does not increase adult hippocampal neurogenesis C_LIO_LI5:2 diet does not enhance spatial memory performance C_LIO_LIThere is an age-related decline in adult hippocampal neurogenesis C_LIO_LIGhrelin-receptor regulates new neural stem cell and new neurone number in an age-related manner C_LIO_LIGhrelin-receptor is required for intact spatial memory C_LI

neuroscience↗

Comprehensive phenotypic analysis of the Dp1Tyb mouse strain reveals a broad range of Down Syndrome-related phenotypes

Down syndrome (DS), trisomy 21, results in many complex phenotypes including cognitive deficits, heart defects and craniofacial alterations. Phenotypes arise from an extra copy of human chromosome 21 (Hsa21) genes. However, causative genes remain mostly unknown. Animal models enable identification of these genes and pathological mechanisms. The Dp1Tyb mouse model of DS has an extra copy of 63% of Hsa21-orthologous mouse genes. Here, we comprehensively phenotype Dp1Tyb mice and find wide-ranging DS-like phenotypes including aberrant megakaryopoiesis, reduced bone density, and deficits in memory, locomotion, hearing and sleep. Thus, Dp1Tyb mice are an excellent model for studies of many complex DS phenotypes.

genetics↗

Microfluidic Device Facilitates Novel In Vitro Modeling of Human Neonatal Necrotizing Enterocolitis-on-a-Chip

Necrotizing enterocolitis (NEC) is a deadly gastrointestinal disease of premature infants characterized by an exaggerated inflammatory response, dysbiosis of the gut microbiome, decreased epithelial cell proliferation, and gut barrier disruption. Here, we describe a novel in vitro model of human neonatal small intestinal epithelium (Neonatal-Intestine-on-a-Chip) that mimics key features of intestinal physiology by utilizing a combination of premature infant intestinal enteroids co-cultured with human intestinal microvascular endothelial cells within a microfluidic device. We used our Neonatal-Intestine-on-a-Chip to recapitulate NEC pathophysiology in an in vitro model system of the premature gut inoculated with infant-derived microbiota. This model, also known as NEC-on-a-Chip, emulates the prominent features of NEC, demonstrating significant upregulation of pro-inflammatory cytokines, decreased intestinal epithelial cell markers, reduced epithelial proliferation and disrupted epithelial barrier integrity. NEC-on-a-Chip provides a novel preclinical model of NEC, which may be used as a personalized medicine approach to test new therapeutics for this devastating disease.

cell biology↗

Badger territoriality maintained despite disturbance of major road construction

Road ecology has traditionally focused on the impact of in-situ and functional roads on wildlife. However, road construction also poses a major, yet understudied, threat and any implications for key aspects of animal behaviour are unknown. There are also concerns that environmental disturbances, including major roadworks, can disrupt badger territoriality, promoting the spread of tuberculosis to cattle. To address these knowledge gaps, the ranging behaviour of a medium-density Irish badger population was monitored, using GPS-tracking collars, before, during and after a major road realignment project that bisected the study area. We estimated badgers home range sizes, nightly distances travelled and the distance and frequency of extra-territorial excursions during each phase of the study and quantified any changes to these parameters. We show that roadworks had a very limited effect on ranging behaviour. A small increase in nightly distance during the roadworks did not translate into an increase in home range size, nor an increase in the distance or frequency of extra-territorial excursions during the roadworks. In addition, suitable mitigation measures to prevent badger deaths appeared to ensure that normal patterns of ranging behaviour continued once the new road was in place. Our analysis supports the view that road construction did not cause badgers to change their ranging behaviour in ways likely to increase the spread of tuberculosis.

ecology↗

Increased mTOR activity and metabolic efficiency in mouse and human cells containing the African-centric tumor-predisposing p53 variant Pro47Ser

The Pro47Ser variant of p53 exists in African-descent populations, and is associated with increased cancer risk in humans and mice. This variant, hereafter S47, shows altered regulation of the cystine importer Slc7a11, and S47 cells possess increased cysteine and glutathione (GSH) accumulation compared to cells with wild type p53. In this study we show that mice containing the S47 variant have increased mTOR activity, increased oxidative metabolism, larger size, and improved metabolic efficiency. Mechanistically, we show that there is increased association between mTOR and its positive regulator Rheb in S47 cells, due to altered redox state of GAPDH, which normally binds and sequesters Rheb. Compounds that decrease glutathione in S47 cells normalize GAPDH-Rheb complex formation and mTOR activity. The enhanced metabolic efficiency may have been selected for in early Africa, making the S47 variant one of a growing number of cancer-predisposing genetic variants that possesses other positive, potentially selectable attributes.

cancer biology↗

Lower dormancy with rapid germination is an important strategy for seeds in an arid zone with unpredictable rainfall

Seed germination traits are key drivers of population dynamics, yet they are under-represented in community ecology studies, which have predominately focussed on adult plant and seed morphological traits. We studied the seed traits and germination strategy of eight woody plant species to investigate regeneration strategies in the arid zone of eastern Australia. To cope with stochastic and minimal rainfall, we predict that arid seeds will either have rapid germination across a wide range of temperatures, improved germination under cooler temperatures, or dormancy and/or longevity traits to delay or stagger germination across time. To understand how temperature affects germination responses, seeds of eight keystone arid species were germinated under laboratory conditions, and under three diurnal temperatures (30/20{degrees}C, 25/15{degrees}C and 17/7{degrees}C) for 30 days. Seeds of species in this study are currently stored for minesite restoration projects, hence we tested for decline in seed viability across 24 months in dry storage at similar storage conditions ({approx}20{degrees}C). Six of the eight arid species studied had non-dormant, rapidly germinating seeds, and only two species had physiological dormancy traits. Seed longevity differed widely between species, from one recalcitrant species surviving only months in storage (P50 = <3 months) and one serotinous species surviving for many years (P50 = 84 months). Our results highlight the importance of understanding the reproductive strategies of plant species in arid environments. Rapid germination, the dominant seed trait of species included in this study, allows arid species to capitalise on sporadic rainfall. However, some species also exhibit dormancy and delayed germination; this an alternative strategy which spreads the risk of germination failure over time. We highlight important seed traits and germination strategies of plants from an arid zone with stochastic rainfall and discuss the implications for their restoration.

plant biology↗

Altered Hippocampal-Prefrontal Neural Dynamics in Mouse Models of Down Syndrome

Altered neural dynamics in medial prefrontal cortex (mPFC) and hippocampus may contribute to cognitive impairments in the complex chromosomal disorder, Down Syndrome (DS). Here, we demonstrate non-overlapping behavioural differences associated with distinct abnormalities in hippocampal and mPFC electrophysiology during a canonical spatial memory task in three partially trisomic mouse models of DS (Dp1Tyb, Dp10Yey, Dp17Yey) that together cover all regions of homology with human chromosome 21 (Hsa21). Dp1Tyb mice showed slower decision-making (unrelated to the gene dose of DYRK1A, which has been implicated in DS cognitive dysfunction) and altered theta dynamics (reduced frequency, increased hippocampal-mPFC coherence, increased modulation of hippocampal high gamma); Dp10Yey mice showed impaired alternation performance and reduced theta modulation of hippocampal low gamma; while Dp17Yey mice were no different from wildtype mice. These results link specific hippocampal and mPFC circuit dysfunctions to cognitive deficits in DS models and, importantly, map them to discrete regions of Hsa21.

neuroscience↗