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Matrix stiffening by lysyl oxidase-like 2 (LOXL2)-mediated collagen cross-linking is proposed as a core feedforward mechanism that promotes fibrogenesis. Failure in clinical trials of simtuzumab (the humanized version of AB0023, a monoclonal antibody against human LOXL2) suggested that targeting LOXL2 may not have disease relevance; however, target engagement was not directly evaluated. We compare the spatial transcriptome of active human lung fibrogenesis sites with different human cell culture models to identify a disease-relevant model. Within the selected model, we then evaluate AB0023, identifying that it does not inhibit collagen cross-linking or reduce tissue stiffness, nor does it inhibit LOXL2 catalytic activity. In contrast, it does potently inhibit angiogenesis consistent with an alternative, non-enzymatic mechanism of action. Thus, AB0023 is anti-angiogenic but does not inhibit LOXL2 catalytic activity, collagen cross-linking, or tissue stiffening. These findings have implications for the interpretation of the lack of efficacy of simtuzumab in clinical trials of fibrotic diseases.
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PURPOSE: To understand how breast cancer is diagnosed in Gaza, and disease stage distribution, treatment, and survival. MATERIALS AND METHODS: A clinical record case series study of women diagnosed in 2017 and 2018 was conducted with follow-up until December 31, 2020. Breast cancer crude incidence rates and age-specific incidence rates were calculated. Clinical characteristics, including investigation, diagnosis, and treatment methods by year of diagnosis, were compared using the chi-square test. The 2-year cumulative risk of death from any cause was estimated using the Kaplan-Meier method, and univariate and multivariate Cox proportional hazard regressions estimated hazard ratios and their 95% CIs. RESULTS: Five hundred twenty-four new diagnoses (mean age, 53 years; range, 23-100) were recorded, giving a crude annual incidence rate of 27 per 100,000 population. Six percent (32/524) were diagnosed at stage I, 35% (185/524) at stage II, 33% (171/524) at stage III, and 19% (99/524) at stage IV. More than one half (52%, 271/524) underwent modified radical mastectomy. Seventy-seven percent (405/524) received chemotherapy, 70% (368/524) hormone therapy, and 39% (204/524) radiotherapy. Data on key prognostic factors were mostly available-stage (93%), estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2; 82%), tumor grade (77%), and tumor size (70%). The overall survival was 95.4% at 1 year and 86.6% at 2 years. CONCLUSION: Women with breast cancer in Gaza have a high short-term survival after diagnosis. However, one half were diagnosed with advanced disease, and their investigations were incomplete. Better reporting on family history, tumor grade, size, and ER, PR, and HER2 receptor status is needed for future studies.
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Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/terapia , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Pessoa de Meia-Idade , Adulto , Idoso , Idoso de 80 Anos ou mais , Oriente Médio/epidemiologia , Adulto Jovem , Incidência , Estadiamento de NeoplasiasRESUMO
Background: People in prison experience poorer mental and physical health compared to their peers in the general population. The causes are multi-dimensional ranging from lifestyle factors to poorer access to healthcare. Little is known about cancer in people in prison or how the cost of their care compares to the general population. Methods: Data on people diagnosed with cancer while in English prisons were identified in National Cancer Registration dataset and linked to Hospital Episode Statistics (HES) for the years 2012-2017. General population matched patients were identified using a 1-5 ratio, based on age, gender, year of diagnosis, cancer type and disease stage. Outpatient and inpatient HES data up to six-months from diagnosis were costed using NHS Reference costs and inflated to 2017/2018 costs. Findings: 879 prison and 4326 general population cancer diagnoses were identified in HES. The adjusted six-month cost of cancer care was significantly lower for people in prison (-£1216.95% confidence interval (CI) -1638 to -795), driven by fewer outpatient attendances. However, people diagnosed in prison had higher emergency care costs (£497.95% CI 375-619). Security escorts further increased the total cost of care. Interpretation: Following a cancer diagnosis, people in English prisons have significantly lower planned care costs, but higher emergency care costs and an overall higher cost due to security escorts. Further work is required to identify ways of improving cancer care for people in prisons to ensure it is equivalent to that received by the general population. Funding: National Institute for Health and Social Care Research 16/52/53.
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Background: Approximately 82,000 people are in prison annually in England and Wales. Limited research has investigated cancer in this population and none has explored experiences of imprisoned people with cancer. This study aimed to address this gap. Methods: We conducted 55 semi-structured, qualitative, audio-recorded interviews with: imprisoned people with cancer (n = 24), custodial staff (n = 6), prison healthcare staff (n = 16) and oncology specialists (n = 9). Data were collected 07/10/2019-20/03/2020. Patients were recruited by prison healthcare staff and interviews were conducted face-to-face. Professionals were recruited via professional networks and interviews were conducted face-to-face or via telephone. Transcribed interviews were analysed using reflexive thematic analysis. We also analysed relevant National Cancer Patient Experience Survey (NCPES) questions for those diagnosed in prison (n = 78) and in the general population (n = 390). Findings: Our findings highlight the complexities of cancer care for imprisoned people. We identified three core themes: control and choice, communication, and care and custody. Whilst people in prison follow a similar diagnostic pathway to those in the community, additional barriers to diagnosis exist including health literacy, the General Practitioner appointment booking system and communication between prison and oncology staff. Tensions between control and choice in prison impacted aspects of cancer care experience such as symptom management and accessing cancer information. NCPES results supported the qualitative findings and showed people in prison reported significantly poorer experiences than in the general population. Interpretation: Our findings demonstrate the complexity of cancer care in custodial settings, identifying barriers and enablers to equitable cancer care provision and offering insights on how to improve care for this population. Funding: National Institute for Health and Social Care Research Delivery Research Programme 16/52/53 and Strategic Priorities Fund 2019/20 Research England via University of Surrey.
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BACKGROUND: The growing and ageing prison population in England makes accurate cancer data of increasing importance for prison health policies. This study aimed to compare cancer incidence, treatment, and survival between patients diagnosed in prison and the general population. METHODS: In this population-based, matched cohort study, we used cancer registration data from the National Cancer Registration and Analysis Service in England to identify primary invasive cancers and cervical cancers in situ diagnosed in adults (aged ≥18 years) in the prison and general populations between Jan 1, 1998, and Dec 31, 2017. Ministry of Justice and Office for National Statistics population data for England were used to calculate age-standardised incidence rates (ASIR) per year and age-standardised incidence rate ratios (ASIRR) for the 20-year period. Patients diagnosed with primary invasive cancers (ie, excluding cervical cancers in situ) in prison between Jan 1, 2012, and Dec 31, 2017 were matched to individuals from the general population and linked to hospital and treatment datasets. Matching was done in a 1:5 ratio according to 5-year age group, gender, diagnosis year, cancer site, and disease stage. Our primary objectives were to compare the incidence of cancer (1998-2017); the receipt of treatment with curative intent (2012-17 matched cohort), using logistic regression adjusted for matching variables (excluding cancer site) and route to diagnosis; and overall survival following cancer diagnosis (2012-17 matched cohort), using a Cox proportional hazards model adjusted for matching variables (excluding cancer site) and route to diagnosis, with stratification for the receipt of any treatment with curative intent. FINDINGS: We identified 2015 incident cancers among 1964 adults (1556 [77·2%] men and 459 [22·8%] women) in English prisons in the 20-year period up to Dec 31, 2017. The ASIR for cancer for men in prison was initially lower than for men in the general population (in 1998, ASIR 119·33 per 100â000 person-years [95% CI 48·59-219·16] vs 746·97 per 100â000 person-years [742·31-751·66]), but increased to a similar level towards the end of the study period (in 2017, 856·85 per 100â000 person-years [675·12-1060·44] vs 788·59 per 100â000 person-years [784·62-792·57]). For women, the invasive cancer incidence rate was low and so ASIR was not reported for this group. Over the 20-year period, the incidence of invasive cancer for men in prison increased (incidence rate ratio per year, 1·05 [95% CI 1·04-1·06], during 1999-2017 compared with 1998). ASIRRs showed that over the 20-year period, overall cancer incidence was lower in men in prison than in men in the general population (ASIRR 0·76 [95% CI 0·73-0·80]). The difference was not statistically significant for women (ASIRR 0·83 [0·68-1·00]). Between Jan 1, 2012, and Dec 31, 2017, patients diagnosed in prison were less likely to undergo curative treatment than matched patients in the general population (274 [32·3%] of 847 patients vs 1728 [41·5%] of 4165; adjusted odds ratio (OR) 0·72 [95% CI 0·60-0·85]). Being diagnosed in prison was associated with a significantly increased risk of death on adjustment for matching variables (347 deaths during 2021·9 person-years in the prison cohort vs 1626 deaths during 10â944·2 person-years in the general population; adjusted HR 1·16 [95% CI 1·03-1·30]); this association was partly explained by stratification by curative treatment and further adjustment for diagnosis route (adjusted HR 1·05 [0·93-1·18]). INTERPRETATION: Cancer incidence increased in people in prisons in England between 1998 and 2017, with patients in prison less likely to receive curative treatments and having lower overall survival than the general population. The association with survival was partly explained by accounting for differences in receipt of curative treatment and adjustment for diagnosis route. Improved routine cancer surveillance is needed to inform prison cancer policies and decrease inequalities for this under-researched population. FUNDING: UK National Institute for Health and Care Research, King's College London, and Strategic Priorities Fund 2019/20 of Research England via the University of Surrey.
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Neoplasias , Prisioneiros , Humanos , Feminino , Masculino , Inglaterra/epidemiologia , Incidência , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Neoplasias/mortalidade , Neoplasias/terapia , Adulto , Prisioneiros/estatística & dados numéricos , Idoso , Adulto Jovem , Adolescente , Prisões/estatística & dados numéricos , Estudos de Coortes , Sistema de Registros/estatística & dados numéricosRESUMO
The factors that determine fibrosis progression or normal tissue repair are largely unknown. We previously demonstrated that autophagy inhibition-mediated epithelial-mesenchymal transition (EMT) in human alveolar epithelial type II (ATII) cells augments local myofibroblast differentiation in pulmonary fibrosis by paracrine signalling. Here, we report that liver kinase B1 (LKB1) inactivation in ATII cells inhibits autophagy and induces EMT as a consequence. In IPF lungs, this is caused by downregulation of CAB39L, a key subunit within the LKB1 complex. 3D co-cultures of ATII cells and MRC5 lung fibroblasts coupled with RNA sequencing (RNA-seq) confirmed that paracrine signalling between LKB1-depleted ATII cells and fibroblasts augmented myofibroblast differentiation. Together these data suggest that reduced autophagy caused by LKB1 inhibition can induce EMT in ATII cells and contribute to fibrosis via aberrant epithelial-fibroblast crosstalk.
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ABSTRACT: During the COVID-19 pandemic, ibrutinib with or without rituximab was approved in England for initial treatment of mantle cell lymphoma (MCL) instead of immunochemotherapy. Because limited data are available in this setting, we conducted an observational cohort study evaluating safety and efficacy. Adults receiving ibrutinib with or without rituximab for untreated MCL were evaluated for treatment toxicity, response, and survival, including outcomes in high-risk MCL (TP53 mutation/deletion/p53 overexpression, blastoid/pleomorphic, or Ki67 ≥ 30%). A total of 149 patients from 43 participating centers were enrolled: 74.1% male, median age 75 years, 75.2% Eastern Cooperative Oncology Group status of 0 to 1, 36.2% high-risk, and 8.9% autologous transplant candidates. All patients received ≥1 cycle ibrutinib (median, 8 cycles), 39.0% with rituximab. Grade ≥3 toxicity occurred in 20.3%, and 33.8% required dose reductions/delays. At 15.6-month median follow-up, 41.6% discontinued ibrutinib, 8.1% due to toxicity. Of 104 response-assessed patients, overall (ORR) and complete response (CR) rates were 71.2% and 20.2%, respectively. ORR was 77.3% (low risk) vs 59.0% (high risk) (P = .05) and 78.7% (ibrutinib-rituximab) vs 64.9% (ibrutinib; P = .13). Median progression-free survival (PFS) was 26.0 months (all patients); 13.7 months (high risk) vs not reached (NR) (low risk; hazard ratio [HR], 2.19; P = .004). Median overall survival was NR (all); 14.8 months (high risk) vs NR (low risk; HR, 2.36; P = .005). Median post-ibrutinib survival was 1.4 months, longer in 41.9% patients receiving subsequent treatment (median, 8.6 vs 0.6 months; HR, 0.36; P = .002). Ibrutinib with or without rituximab was effective and well tolerated as first-line treatment of MCL, including older and transplant-ineligible patients. PFS and OS were significantly inferior in one-third of patients with high-risk disease and those unsuitable for post-ibrutinib treatment, highlighting the need for novel approaches in these groups.
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Adenina , Linfoma de Célula do Manto , Piperidinas , Adulto , Idoso , Feminino , Humanos , Masculino , Adenina/análogos & derivados , Estudos de Coortes , Inglaterra , Linfoma de Célula do Manto/tratamento farmacológico , Rituximab/uso terapêuticoRESUMO
Hyperhaemolysis syndrome (HHS) is a serious complication of transfusion mostly reported in patients with sickle cell disease. HHS is characterised by the destruction of both donor and autologous red blood cells. Tocilizumab is a recombinant humanised monoclonal antibody that inhibits the binding of interleukin-6 and has been used in the treatment of severe/critical coronavirus disease 2019 infection but also some cases of HHS. We describe two further cases of HHS successfully treated with tocilizumab and propose a decision aid for when to consider this treatment.
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Falls in nursing homes (NH) are common and cause significant morbidity and mortality. We proposed that by improving staff education, the volume of emergency calls, hospital conveyance and adverse patient outcomes could be reduced. An analysis of the volume of emergency calls coded as Falls from January 2020 to February 2022, with 4907 calls in total, 866 were falls (17.65%), further 1032 potential falls (21.07%). A survey was sent to NH to evaluate how staff treated residents who fell and showed that 47% of NH do not have any guidelines for falls and emergency services, are contacted 88.24% of the time. Education was delivered focusing on the negative consequences of falls. The package used the acronym "CWTCH" translated from the Welsh language as a hug. Education was offered to all NH (177 staff) and Feedback showed 100% felt more confident and found the session helpful with 90.96% less likely to contact emergency services. Falls remain a significant burden on emergency services, with clear opportunity to improve patient outcomes and experience. A referral pathway was developed diverting calls, showing a significant change in conveyance to hospital (p < 0.05).
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INTRODUCTION: Type 2 diabetes mellitus (T2D) is associated with poor health outcomes whilst tight glycaemic targets are questionable in those aged over 70 years with increased frailty. Our aim was to examine whether people with T2D admitted to hospital with a fall, were more likely to have greater frailty, increased mortality and co-morbidity burden, or risk factors for falls than people without T2D, and whether these differences were associated with medications used for the treatment of T2D. METHODS: The Older Persons Assessment Service (OPAS) is a local emergency department (ED) service, which accepts patients on frailty criteria. The OPAS accepts patients primarily aged over 70 years who present with frailty and geriatric syndromes such as falls, with retrieval from the ED department directly to the service from triage. The OPAS databank was analysed for people with T2D admitted with a fall between June 2020-September 2022. We examined clinical outcomes relating to medication, age, Charlson co-morbidity index (CCI) and clinical frailty score (CFS). RESULTS: 1081 patients were included: 294 (27.2%) with T2D and a mean HbA1c of 53.9 (± 15.8) mmol/mol [7.1%]. People with T2D had a similar mean CFS and age compared to those without T2D, but higher mean CCI (7.0 ± 2.2 vs 5.9 ± 2.1, p < 0.001). Of those people with T2D, 175 (59.5%) and 240 (81.6%) had a HbA1c ≤ 53 mmol/mol [7.0%] and ≤ 64 mmol/mol [8.0%], respectively. In total, 48 (16.3%) people with T2D were identified to have a capillary blood glucose below 4.0 mmol/L on admission to the ED. At 12 months' follow-up, 831 (76.9%) patients were alive and 250 (23.1%) had died. People with T2D treated with insulin and/or gliclazide had a greater 1-year mortality (36.6% vs 23.6%, p < 0.05), greater frequency of hypoglycaemia (35.4% vs 11.8%, p < 0.001), and greater HbA1c (65.5 ± 17.2 mmol/mol [8.2] vs 48.9 ± 12.1 mmol/mol [6.6%]) compared to those who used other agents. Logistic regression confirmed a diagnosis of T2D was associated with 1-year mortality, but mortality was not significantly associated with hypoglycaemic-inducing agents. People with T2D were not more likely to live in deprived areas. CONCLUSIONS: A diagnosis of T2D is associated with greater 1-year mortality, and may be influenced by use of hypoglycaemia-inducing diabetes medications. Clinician awareness can support de-prescribing for patients with frailty and HbA1c < 64 mmol/mol.
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Phosphoinositides (PIs) are phospholipids derived from phosphatidylinositol. PIs are regulated via reversible phosphorylation, which is directed by the opposing actions of PI kinases and phosphatases. PIs constitute a minor fraction of the total cellular lipid pool but play pleiotropic roles in multiple aspects of cell biology. Genetic mutations of PI regulatory enzymes have been identified in rare congenital developmental syndromes, including ciliopathies, and in numerous human diseases, such as cancer and metabolic and neurological disorders. Accordingly, PI regulatory enzymes have been targeted in the design of potential therapeutic interventions for human diseases. Recent advances place PIs as central regulators of membrane dynamics within functionally distinct subcellular compartments. This brief review focuses on the emerging role PIs play in regulating cell signaling within the primary cilium and in directing transfer of molecules at interorganelle membrane contact sites and identifies new roles for PIs in subcellular spaces.
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Fosfatidilinositóis , Transdução de Sinais , Humanos , Fosfatidilinositóis/fisiologia , Transdução de Sinais/fisiologia , Monoéster Fosfórico Hidrolases/metabolismoRESUMO
The ongoing emergence of SARS-CoV-2 virus variants remains a source of concern because it is accompanied by the potential for increased virulence as well as evasion of immunity. Here we show that, although having an almost identical spike gene sequence as another Omicron variant (BA.5.2.1), a BA.4 isolate lacked all the typical disease characteristics of other isolates seen in the Golden Syrian hamster model despite replicating almost as effectively. Animals infected with BA.4 had similar viral shedding profiles to those seen with BA.5.2.1 (up to day 6 post-infection), but they all failed to lose weight or present with any other significant clinical signs. We hypothesize that this lack of detectable signs of disease during infection with BA.4 was due to a small (nine nucleotide) deletion (∆686-694) in the viral genome (ORF1ab) responsible for the production of non-structural protein 1, which resulted in the loss of three amino acids (aa 141-143).
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COVID-19 , Animais , Cricetinae , SARS-CoV-2/genética , Mesocricetus , Aminoácidos , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
The mutation profile of the SARS-CoV-2 Omicron (lineage BA.1) variant posed a concern for naturally acquired and vaccine-induced immunity. We investigated the ability of prior infection with an early SARS-CoV-2 ancestral isolate (Australia/VIC01/2020, VIC01) to protect against disease caused by BA.1. We established that BA.1 infection in naïve Syrian hamsters resulted in a less severe disease than a comparable dose of the ancestral virus, with fewer clinical signs including less weight loss. We present data to show that these clinical observations were almost absent in convalescent hamsters challenged with the same dose of BA.1 50 days after an initial infection with ancestral virus. These data provide evidence that convalescent immunity against ancestral SARS-CoV-2 is protective against BA.1 in the Syrian hamster model of infection. Comparison with published pre-clinical and clinical data supports consistency of the model and its predictive value for the outcome in humans. Further, the ability to detect protection against the less severe disease caused by BA.1 demonstrates continued value of the Syrian hamster model for evaluation of BA.1-specific countermeasures.
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COVID-19 , Animais , Cricetinae , Humanos , Convalescença , Mesocricetus , SARS-CoV-2RESUMO
BACKGROUND: In recent years, the completeness of ethnicity data in the English cancer registration data has greatly improved. Using these data, this study aims to estimate the influence of ethnicity on survival from primary malignant brain tumours. METHODS: Demographic and clinical data on adult patients diagnosed with malignant primary brain tumour from 2012 to 2017 were obtained (n = 24,319). Univariate and multivariate Cox proportional hazards regression analyses were used to estimate hazard ratios (HR) for the survival of the ethnic groups up to one year following diagnosis. Logistic regressions were then used to estimate odds ratios (OR) for different ethnic groups of (1) being diagnosed with pathologically confirmed glioblastoma, (2) being diagnosed through a hospital stay that included an emergency admission, and (3) receiving optimal treatment. RESULTS: After an adjustment for known prognostic factors and factors potentially affecting access to healthcare, patients with an Indian background (HR 0.84, 95% CI 0.72-0.98), Any Other White (HR 0.83, 95% CI 0.76-0.91), Other Ethnic Group (HR 0.70, 95% CI 0.62-0.79), and Unknown/Not Stated Ethnicity (HR 0.81, 95% CI 0.75-0.88) had better one-year survivals than the White British Group. Individuals with Unknown ethnicity are less likely be diagnosed with glioblastoma (OR 0.70, 95% CI 0.58-0.84) and less likely to be diagnosed through a hospital stay that included an emergency admission (OR 0.61, 95% CI 0.53-0.69). CONCLUSION: The demonstrated ethnic variations associated with better brain tumour survival suggests the need to identify risk or protective factors that may underlie these differences in patient outcomes.
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We present a case of a unilateral extraocular muscle haematoma in an adult female patient who was compliant with life-long oral anticoagulation for recurrent deep vein thrombosis. The patient presented with symptoms of sudden-onset left-sided headache radiating to the temporal region, which started 2 days prior. No obvious triggering factors were identified. Cranial and ocular examinations were within normal limits. Imaging revealed a haemorrhage related to the lateral rectus muscle of the left eye. Conservative management was employed with abstinence from anticoagulation for 2 weeks and a weaning regime of oral steroids. Under the clinical review of ophthalmology and interval radiological monitoring, symptoms were reduced with reduction of haemorrhage size. Anticoagulation was reinstated after 2 weeks. To our knowledge, this is the first case of a non-traumatic extraocular muscle haematoma to be reported in a patient on anticoagulation.
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Tratamento Conservador , Músculos Oculomotores , Adulto , Feminino , Humanos , Músculos Oculomotores/diagnóstico por imagem , Olho , Hematoma/induzido quimicamente , Hematoma/diagnóstico por imagem , Anticoagulantes/efeitos adversosRESUMO
Epidemiological studies have indicated adverse effects of geomagnetic disturbance on human health, including increased mortality. There is evidence from plant and animal studies that help to elucidate this interaction. This study tests the hypothesis that geomagnetic disturbance affects living systems, by modifying the metabolic process of photosynthesis, in the natural environment.Continuous 24-h measurements of dissolved oxygen in flasks containing Holtfreiter's solution and strands of healthy Elodea were recorded from May 1996, until September 1998, in an electromagnetically quiet, purpose built, garden shed environment, without mains electricity. Sensormeter recordings of oxygen, light, temperature and air pressure were uploaded weekly to a PC. The hourly total geomagnetic field measurements were obtained from the nearest observatory.Significant decrease in oxygen (diurnal volume of oxygen divided by plant mass and diurnal light), (O/WL), was found on days of high geomagnetic field variability throughout 11 recorded months of the year 1997. This result was independent of temperature and atmospheric pressure. No significant decrease in O/WL during high geomagnetic variability was found for the 7 months recorded in 1996. The 1996 and 1997 data both showed a significant decrease in the diurnal time lag between peak light and peak oxygen for diurnal high geomagnetic variability compared with low geomagnetic variability. Cross correlation analysis for 1997 and 1998 data showed a decrease in positive correlation of oxygen with light in high geomagnetic variability, compared with low geomagnetic variability, and increased positive correlation with the geomagnetic field instead. These experiments support a hypothesis of high geomagnetic field variability as a weak zeitgeber, and a metabolic depressant for photosynthetic oxygen production in plants.
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Hydrocharitaceae , Animais , Humanos , Temperatura , Pressão Atmosférica , Meio AmbienteRESUMO
The golden Syrian hamster (Mesocricetus auratus) is now commonly used in preclinical research for the study of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the assessment of vaccines, drugs and therapeutics. Here, we show that hamsters inoculated via the intranasal route with the same infectious virus dose of prototypical SARS-CoV-2 administered in a different volume present with different clinical signs, weight loss and viral shedding, with a reduced volume resulting in reduced severity of disease similar to that obtained by a 500-fold reduction in the challenge dose. The tissue burden of the virus and the severity of pulmonary pathology were also significantly affected by different challenge inoculum volumes. These findings suggest that a direct comparison between the severity of SARS-CoV-2 variants or studies assessing the efficacy of treatments determined by hamster studies cannot be made unless both the challenge dose and inoculation volume are matched when using the intranasal route. Additionally, analysis of sub-genomic and total genomic RNA PCR data demonstrated no link between sub-genomic and live viral titres and that sub-genomic analyses do not provide any information beyond that provided by more sensitive total genomic PCR.
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COVID-19 , Cricetinae , Animais , Humanos , Mesocricetus , COVID-19/patologia , SARS-CoV-2 , Pulmão , Gravidade do Paciente , Modelos Animais de DoençasRESUMO
Dynamic positioning of endothelial tip and stalk cells, via the interplay between VEGFR2 and NOTCH signaling, is essential for angiogenesis. VEGFR2 activates PI3K, which phosphorylates PI(4,5)P2 to PI(3,4,5)P3, activating AKT; however, PI3K/AKT does not direct tip cell specification. We report that PI(4,5)P2 hydrolysis by the phosphoinositide-5-phosphatase, INPP5K, contributes to angiogenesis. INPP5K ablation disrupted tip cell specification and impaired embryonic angiogenesis associated with enhanced DLL4/NOTCH signaling. INPP5K degraded a pool of PI(4,5)P2 generated by PIP5K1C phosphorylation of PI(4)P in endothelial cells. INPP5K ablation increased PI(4,5)P2, thereby releasing ß-catenin from the plasma membrane, and concurrently increased PI(3,4,5)P3-dependent AKT activation, conditions that licensed DLL4/NOTCH transcription. Suppression of PI(4,5)P2 in INPP5K-siRNA cells by PIP5K1C-siRNA, restored ß-catenin membrane localization and normalized AKT signaling. Pharmacological NOTCH or AKT inhibition in vivo or genetic ß-catenin attenuation rescued angiogenesis defects in INPP5K-null mice. Therefore, PI(4,5)P2 is critical for ß-catenin/DLL4/NOTCH signaling, which governs tip cell specification during angiogenesis.