14 research outputs found
Gα11 mutation in mice causes hypocalcemia rectifiable by calcilytic therapy
Heterozygous germline gain-of-function mutations of G-protein subunit α11 (Gα11), a signaling
partner for the calcium-sensing receptor (CaSR), result in autosomal dominant hypocalcemia
type 2 (ADH2). ADH2 may cause symptomatic hypocalcemia with low circulating parathyroid
hormone (PTH) concentrations. Effective therapies for ADH2 are currently not available and a
mouse model for ADH2 would help in assessment of potential therapies. We hypothesised that a
previously reported dark skin mouse mutant (Dsk7), which has a germline hypermorphic Gα11
mutation, Ile62Val, may be a model for ADH2 and allow evaluation of calcilytics, which are
CaSR negative allosteric modulators, as a targeted therapy for this disorder. Mutant Dsk7/+
and Dsk7/Dsk7 mice were shown to have hypocalcemia and reduced plasma PTH
concentrations, similar to ADH2 patients. In vitro studies showed the mutant Val62 Gα11 to upregulate
CaSR-mediated intracellular calcium and MAPK signaling, consistent with a gain-offunction.
Treatment with NPS-2143, a calcilytic compound, normalised these signaling
responses. In vivo, NPS-2143 induced a rapid and marked rise in plasma PTH and calcium
concentrations in Dsk7/Dsk7 and Dsk7/+ mice, which became normocalcemic. Thus, these
studies have established Dsk7 mice, which harbor a germline gain-of-function Gα11 mutation, as
a model for ADH2; and demonstrated calcilytics as a potential targeted therapy
Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype-phenotype correlations, codon bias and dominant-negative effects
The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasma membrane constituents such as the calcium-sensing receptor (CaSR). Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium (Ca(2+) o) homeostasis. To elucidate the role of AP2σ2 in Ca(2+) o regulation, we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising 5 Arg15Cys, 4 Arg15His and 8 Arg15Leu mutations. A genotype-phenotype correlation was observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR, which was ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively, for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype-phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Omics analysis of uveal melanoma: Leukocyte gene signatures reveal novel survival distinctions and indicate a prognostic role for cytolytic activity scoring.
OBJECTIVE: The significant metastatic potential of uveal melanoma (UVM) lends to high mortality. Even with successful local tumor treatment, many patients will develop metastatic disease. The present study aims to elucidate the relationship between tumor-infiltrating immune cell (TIIC) diversity and survival to identify potential therapeutic targets and improve UVM prognosis.
METHODS: Bulk deconvolution was used to determine the relative proportions of 22 hematopoietic TIIC from 80 UVM tumor samples. Cytolytic activity (CYT) was determined, and associated survival probabilities were mined using time-to-event data. Nominal
RESULTS: High relative abundance of tumor-infiltrating naïve B cells, resting memory CD4
CONCLUSION: Infiltrating naïve B cells, resting memory CD
Spatial Mapping of Genes Implicated in SARS-CoV-2 Neuroinvasion to Dorsolateral Prefrontal Cortex Gray Matter
Introduction: SARS-CoV-2 is the newest beta coronavirus family member to demonstrate neuroinvasive capability in severe cases of infection. Despite much research activity in the SARS-CoV-2/COVID-19 space, the gene-level biology of this phenomenon remains poorly understood. In the present analysis, we leveraged spatial transcriptomics methodologies to examine relevant gene heterogeneity in tissue retrieved from the human prefrontal cortex. Methods: Expression profiles of genes with established relations to the SARS-CoV-2 neuroinvasion process were spatially resolved in dorsolateral prefrontal cortex tissue (N = 4). Spotplots were generated with mapping to six (6) previously defined gray matter layers. Results: Docking gene BSG, processing gene CTSB, and viral defense gene LY6E demonstrated similar spatial enrichment. Docking gene ACE2 and transmembrane series proteases involved in spike protein processing were lowly expressed across DLPFC samples. Numerous other findings were obtained. Conclusion: Efforts to spatially represent expression levels of key SARS-CoV-2 brain infiltration genes remain paltry to date. Understanding the sobering history of beta coronavirus neuroinvasion represents a weak point in viral research. Here we provide the first efforts to characterize a motley of such genes in the dorsolateral prefrontal cortex
Spatial Mapping of Genes Implicated in SARS-CoV-2 Neuroinvasion to Dorsolateral Prefrontal Cortex Gray Matter
Introduction: SARS-CoV-2 is the newest beta coronavirus family member to demonstrate neuroinvasive capability in severe cases of infection. Despite much research activity in the SARS-CoV-2/COVID-19 space, the gene-level biology of this phenomenon remains poorly understood. In the present analysis, we leveraged spatial transcriptomics methodologies to examine relevant gene heterogeneity in tissue retrieved from the human prefrontal cortex. Methods: Expression profiles of genes with established relations to the SARS-CoV-2 neuroinvasion process were spatially resolved in dorsolateral prefrontal cortex tissue (N = 4). Spotplots were generated with mapping to six (6) previously defined gray matter layers. Results: Docking gene BSG, processing gene CTSB, and viral defense gene LY6E demonstrated similar spatial enrichment. Docking gene ACE2 and transmembrane series proteases involved in spike protein processing were lowly expressed across DLPFC samples. Numerous other findings were obtained. Conclusion: Efforts to spatially represent expression levels of key SARS-CoV-2 brain infiltration genes remain paltry to date. Understanding the sobering history of beta coronavirus neuroinvasion represents a weak point in viral research. Here we provide the first efforts to characterize a motley of such genes in the dorsolateral prefrontal cortex
Primary and Metastatic Cutaneous Melanomas Discriminately Enrich Several Ligand-Receptor Interactions
Introduction: Cutaneous melanoma remains a leading cancer with sobering post-metastasis mortality rates. To date, the ligand-receptor interactome of melanomas remains weakly studied despite applicability to anti-cancer drug discovery. Here we leverage established crosstalk methodologies to characterize important ligand-receptor pairs in primary and metastatic cutaneous melanoma. Methods: Bulk transcriptomic data, representing 470 cutaneous melanoma samples, was retrieved from the Broad Genome Data Analysis Center Firehose portal. Tumor and stroma compartments were computationally derived as a function of tumor purity estimates. Identification of preferential ligand-receptor interactions was achieved by relative crosstalk scoring of 1380 previously established pairs. Results: Metastatic cutaneous melanoma uniquely enriched PTH2-PTH1R for tumor-to-stroma signaling. The Human R-spondin ligand family was involved in 4 of the 15 top-scoring stroma-to-tumor interactions. Receptor ACVR2B was involved in 3 of the 15 top-scoring tumor-to-tumor interactions. Conclusions: Numerous gene-level differences in ligand-receptor crosstalk between primary and metastatic cutaneous melanomas. Further investigation of notable pairings is warranted
Current Approaches to Craniopharyngioma Management.
Craniopharyngiomas (CP) are rare noncancerous brain tumors located in the skull base. To date, CP remain challenging-to-resect tumors, owing to their difficult location and invasive potential, with profound adverse effects for the patient if left to grow. Indeed, gross total resection may also be accompanied by unwelcome sequalae, underscoring the need for continued investigation. In the present work, we provide a scoping review of current CP management, with emphasis on our knowledge of their genesis, available treatment options, post-intervention clinical outcomes. Leading theories of CP development are (1) the embryonic theory, explaining the development of adamantinomatous CP from epithelial remnants of Rathke\u27s pouch and (2) the metaplastic theory, which describes papillary CP development as a result of adenohypophyseal cell metaplasia. Treatment may include surgery, intracystic therapy, or irradiation depending on tumor size, history and location. However, whether a single ideal approach and timing for CP intervention exists remains debated. We appraise and critique these areas with priority for emerging basic results and innovation