Biology subjects

Hogg, C.

Publications and source records attributed to Hogg, C..

10 recordsLinked to original sources

bioRxiv2024

Single-cell analysis identifies distinct macrophage phenotypes associated with pro-disease and pro-resolving functions in the endometriotic niche

Endometriosis negatively impacts the health-related quality of life of 190 million women worldwide. Novel advances in non-hormonal treatments for this debilitating condition are desperately needed. Macrophages play a vital role in the pathophysiology of endometriosis and represent a promising therapeutic target. In the current study, we revealed the full transcriptomic complexity of endometriosis-associated macrophage subpopulations using single-cell analyses in a preclinical mouse model of experimental endometriosis. We have identified two key lesion-resident populations that resemble i) tumour-associated macrophages (characterized by expression of Folr2, Mrc1, Gas6 and Ccl8+) that promoted expression of Col1a1 and Tgfb1 in human endometrial stromal cells and increased angiogenic meshes in human umbilical vein endothelial cells, and ii) scar-associated macrophages (Mmp12, Cd9, Spp1, Trem2+) that exhibited a phenotype associated with fibrosis and matrix remodelling. We also described a population of pro-resolving large peritoneal macrophages (LpM) that align with a lipid-associated macrophage phenotype (Apoe, Saa3, Pid1) concomitant with altered lipid metabolism and cholesterol efflux. Gain of function experiments using an Apoe mimetic resulted in decreased lesion size and fibrosis, and modification of peritoneal macrophage populations in the preclinical model. Using cross-species analysis of mouse and human single-cell datasets, we determined the concordance of peritoneal and lesion-resident macrophage subpopulations, identifying key similarities and differences in transcriptomic phenotypes. Ultimately, we envisage that these findings will inform the design and use of specific macrophage-targeted therapies and open new avenues for the treatment of endometriosis.

immunology↗

bioRxiv2023

IDHwt glioblastomas can be stratified by their transcriptional response to standard treatment, with implications for targeted therapy

Glioblastoma (GBM) brain tumours lacking IDH1 mutations (IDHwt) have the worst prognosis of all brain neoplasms. Patients receive surgery and chemoradiotherapy but tumours almost always fatally recur. Using RNAseq data from 107 pairs of pre- and post-standard treatment locally recurrent IDHwt GBM tumours, we identified two responder subtypes based on therapy-driven changes in gene expression. In two thirds of patients a specific subset of genes is up-regulated from primary to recurrence (Up responders) and in one third the same genes are down-regulated (Down responders). Characterisation of the responder subtypes indicates subtype-specific adaptive treatment resistance mechanisms. In Up responders treatment enriches for quiescent proneural GBM stem cells and differentiated neoplastic cells with increased neurotransmitter signalling, whereas Down responders commonly undergo therapy-driven mesenchymal transition. Stratifying GBM tumours by response subtype may lead to more effective treatment. In support of this, modulators of gamma aminobutyric acid (GABA) neurotransmitter signalling differentially sensitise Up and Down responder GBM models to standard treatment in vitro.

cancer biology↗

bioRxiv2021

Long wavelength light that improves aged mitochondrial function selectively increases cytokine expression in serum and the retina

Aged mitochondrial function can be improved with long wavelength light exposure. This reduces cellular markers of inflammation and can improve system function from fly though to human. Here, we ask what impact 670nm light has on cytokine expression using a 40 cytokine array in blood serum and retina in C57Bl6 mice. There was a relatively uniform increase in cytokine expression between 3 and 12 months of age in serum and retina. 670nm exposure was delivered daily for a week in 12 month old mice. This shifted patterns of cytokine expression in both serum and retina inducing a selective increase with some in serum increasing >5 fold. Changes in retina were smaller. In serum there were major increases in IL-7, 6, 13, 16 and 23, also in TNF- and CXCL 9 and 10. In retina the increases were found mainly in some IL (interleukins) and CXCLs (chemokines). A few cytokines were reduced by light exposure. Changes in serum cytokines implies that long wavelengths impacts systemically even to unexposed tissues deep in the body. In the context of wider literature, increased cytokine expression may be protective. However, their upregulation by light merits further analysis as cytokines upregulation can also be negative.

molecular biology↗

bioRxiv2021

The morning burst: Shifting daily patterns of ATP production in Drosophila and temporal windows for their improvement in ageing

Mitochondria produce energy for cell function via adenosine triphosphate (ATP) and are regulated by a molecular 24h clock. Here we use Drosophila melanogaster to reveal shifts in whole animal ATP production over 24h, showing a marked peak in the morning that declines around midday and remains low from then through to the following morning. Mitochondrial membrane potential and ATP production has been shown previously to improve after long wavelength exposure, but apparently not at all times. Hence, to explore this further we exposed flies to 670nm at different times. Exposures between 08.00 and 11.00 resulted in a significant increase in ATP, while exposures at other times had no effect. Within the morning window, not all times were equally effective, however, 670nm exposure mid-morning when ATP production was maximal did not increase ATP, possibly because mitochondria lacked spare capacity at this time. Hence, in the morning there is a complex dynamic relationship between long wavelength light and mitochondria. Mitochondrial function and the influence of long wavelengths are conserved across species from fly to human, and determining the time points for light administration to improve function in ageing and disease is of key importance. Our data progress this search and reveal the outline of these times.

physiology↗

bioRxiv2021

Ultrastructural insight into SARS-CoV-2 attachment, entry and budding in human airway epithelium

Ultrastructural studies of SARS-CoV-2 infected cells are crucial to better understand the mechanisms of viral entry and budding within host cells. Many studies are limited by the lack of access to appropriate cellular models. As the airway epithelium is the primary site of infection it is essential to study SARS-CoV-2 infection of these cells. Here, we examined human airway epithelium, grown as highly differentiated air-liquid interface cultures and infected with three different isolates of SARS-CoV-2 including the B.1.1.7 variant (Variant of Concern 202012/01) by transmission electron microscopy and tomography. For all isolates, the virus infected ciliated but not goblet epithelial cells. Two key SARS-CoV-2 entry molecules, ACE2 and TMPRSS2, were found to be localised to the plasma membrane including microvilli but excluded from cilia. Consistent with these observations, extracellular virions were frequently seen associated with microvilli and the apical plasma membrane but rarely with ciliary membranes. Profiles indicative of viral fusion at the apical plasma membrane demonstrate that the plasma membrane is one site of entry where direct fusion releasing the nucleoprotein-encapsidated genome occurs. Intact intracellular virions were found within ciliated cells in compartments with a single membrane bearing S glycoprotein. Profiles strongly suggesting viral budding from the membrane was observed in these compartments and this may explain how virions gain their S glycoprotein containing envelope.

microbiology↗

bioRxiv2020

Post release immune responses of Tasmanian devils vaccinated with an experimental devil facial tumour disease vaccine

Disease is increasingly becoming a driver of wildlife population declines and extinction risk. Vaccines have been one of the most successful health interventions in human history, but few have been tested for mitigating wildlife disease. The transmissible cancer, devil facial tumour disease (DFTD), triggered the Tasmanian devils (Sarcophilus harrisii) inclusion on the international endangered species list. Development of a protective DFTD vaccine would provide a valuable management approach for conservation of the species. In 2016, 33 devils from a DFTD-free insurance population were given an experimental DFTD vaccination prior to their release on the north coast of Tasmania. The release site was already home to an incumbent population of devils, including some individuals with DFTD. To determine the efficacy of the vaccination protocol and the longevity of the response it induced, six trapping trips took place at the site over the 2.5 years following release. Eight of the 33 vaccinated devils were re-trapped, and six of those developed DFTD within the monitoring period. Despite the apparent lack of protection provided by the vaccine for the re-trapped devils, we observed several signs of immune activation not usually found in unvaccinated devils. Firstly, sera collected from the eight devils showed that anti-DFTD antibodies persisted for up to two years post vaccination. Secondly, tumour infiltrating lymphocytes were found in three out of four biopsies collected from vaccinated devils which contrasts with the "immune deserts" typical of DFTs; only one out of twenty incumbent devils with DFTD trapped during the same period had a tumour biopsy exhibiting immune cell infiltrate. Thirdly, immunohistochemical analysis of tumour biopsies from the vaccinated devils identified the functional immune molecules associated with antigen presenting cells (MHC-II) and T cells (CD3), and the immune checkpoint molecule PD-1, all associated with anti-tumour immunity in other species. These results correlate with our previous study on captive devils in which a prophylactic vaccine primed the devil immune system and, following DFTD challenge and tumour growth, immunotherapy induced complete tumour regressions. The field trial results presented here provide further evidence that the devil immune system can be primed to recognise DFTD cells, but additional immune manipulation could be needed for complete protection or induction of tumour regressions.

immunology↗

bioRxiv2020

Macrophages can either inhibit or enhance endometriosis depending on their origin

Macrophages are intimately involved in the pathophysiology of endometriosis, a chronic inflammatory disorder characterized by the growth of endometrial-like tissue (lesions) outside the uterus. By combining genetic and pharmacological monocyte and macrophage depletion strategies we determined the ontogeny and function of macrophages in a mouse model of induced endometriosis. We demonstrate that lesion-resident macrophages are derived from eutopic endometrial tissue, infiltrating large peritoneal macrophages (LpM) and monocytes. Furthermore, we found endometriosis to trigger continuous recruitment of monocytes and expansion of CCR2+ LpM. Depletion of eutopic endometrial macrophages results in smaller endometriosis lesions, whereas constitutive inhibition of monocyte recruitment significantly reduces peritoneal macrophage populations and increased the number of lesions. We propose a putative model whereby endometrial macrophages are pro-endometriosis whilst newly-recruited monocyte-derived macrophages, possibly in LpM form, are anti-endometriosis. These observations highlight the importance of monocyte-derived macrophages in limiting disease progression.

immunology↗

bioRxiv2020

Red light corrects neonicotinoid induced immunodeficiency and impaired respiration in poisoned bumblebees

Neonicotinoid pesticides undermine mitochondrial function in insects including bumblebees, reducing ATP, mobility and leading to death. They also reduce bumblebee immunocompetency leaving them vulnerable to pathogen attack. This undermines key pollinators critical in the agricultural economy. However, 670nm light exposure improves mitochondrial function undermined by age or disease, increasing respiratory chain efficiency, improving ATP production, mobility and survival in bumblebees and fruit flies. Here we show that 670nm restores immunocompetence, improving hemocyte counts and hemolymph anti-microbial action. Additionally, we measure whole body respiration in vivo in individual bumblebees revealing that it is a functional metric of both neonicotinoid impact and light induced mitochondrial protection. Critically we show that only 1 min 670nm exposure is sufficient to correct respiratory deficits induced by pesticide and restore normal immune ability. Longer exposures are not more effective. Further, single 1 min exposure protects respiration and immunity for approximately 3-6 days. Hence, 670nm impact is not dose dependent but switch like. These data provide a compelling rational for 670nm application to protect pollinators on which a major part of the agro economy is based and who are being challenged by aggressive pesticide application.

immunology↗

bioRxiv2018

Characterisation of the faecal virome of captive and wild Tasmanian devils using virus-like particles metagenomics and meta-transcriptomics

BackgroundThe Tasmanian devil is an endangered carnivorous marsupial threatened by devil facial tumour disease (DFTD). While research on DFTD has been extensive, little is known about the viruses present in devils, and whether any of these are of potential conservation relevance for this endangered species.\n\nMethodsUsing both metagenomics based on virus-like particle (VLP) enrichment and sequence-independent amplification (VLP metagenomics), and meta-transcriptomics based on bulk RNA sequencing, we characterised and compared the faecal viromes of captive and wild Tasmanian devils.\n\nResultsA total of 54 devil faecal samples collected from captive (n = 2) and wild (n = 4) populations were processed for virome characterisation using both approaches. We detected many novel, highly divergent viruses, including vertebrate viruses, bacteriophage and other dietary associated plant and insect viruses. In total, 18 new vertebrate viruses, including novel sapelovirus, astroviruses, bocaviruses, papillomaviruses and gammaherpesvirus were identified, as well as known mammalian pathogens including rabbit haemorrhagic disease virus 2 (RHDV2). Captive devils showed significantly lower levels of viral diversity than wild devils. Comparison of the two methodological approaches revealed substantial differences in the number and types of viruses detected, with meta-transcriptomics mainly identifying RNA viruses, and VLP metagenomics largely identifying DNA viruses.\n\nConclusionThis study has greatly expanded our knowledge of eukaryotic viruses in the Tasmanian devil and provides important baseline information that will contribute to the conservation and captive management of this endangered species. In addition, our results showed that a combination of VLP metagenomics and meta-transcriptomics may be a more comprehensive approach to virome characterisation than either method alone.

molecular biology↗

bioRxiv2017

C11orf70 mutations causing primary ciliary dyskinesia disrupt a conserved step in the intraflagellar transport-dependent assembly of multiple axonemal dyneins

Primary ciliary dyskinesia (PCD) is a genetically and phenotypically heterogeneous disorder characterized by destructive respiratory disease and laterality abnormalities due to randomised left-right body asymmetry. PCD is mostly caused by mutations affecting components of the core axoneme structure of motile cilia that are essential for cilia movement. In addition, there is a growing group of PCD genes that encode proteins essential for the assembly of the ciliary dynein motors and the active transport process that delivers them from their cytoplasmic assembly site into the axoneme. We screened a cohort of affected individuals for disease-causing mutations using a targeted next generation sequencing panel and identified 2 unrelated families (3 affected children) with mutations in the uncharacterized C11orf70 gene. The affected children share a consistent PCD phenotype from early life with laterality defects and immotile respiratory cilia displaying combined loss of inner and outer dynein arms (IDA+ODA). Phylogenetic analysis shows C11orf70 is highly conserved, distributed across species similarly to proteins involved in the intraflagellar transport (IFT)-dependant assembly of axonemal dyneins. Paramecium C11orf70 RNAi knockdown led to combined loss of ciliary IDA+ODA with reduced cilia beating and swim velocity. Fluorescently tagged C11orf70 in Paramecium and Chlamydomonas localises mainly in the cytoplasm with a small amount in the ciliary component, its abundance in the axoneme being IFT-dependant. During ciliogenesis, C11orf70 accumulates at the ciliary tips in a similar distribution to the IFT-B protein IFT46. In summary, C11orf70 is essential for IFT-dependant assembly of dynein arms and C11orf70 mutations cause defective cilia motility and PCD.

genetics↗