EPAS1-mutated paragangliomas associated with haemoglobin disorders

We report a large series of 40 patients presenting EPAS1-mutated paraganglioma (PGL) in whom we investigated a cause underlying chronic hypoxia. Four patients suffered from hypoxaemic heart disease. In patients with available haemoglobin electrophoresis results, 59% presented with a haemoglobin disorder, including six with sickle cell disease, five with sickle cell trait and two with heterozygous haemoglobin C disease. Histological and transcriptomic characterization of EPAS1 tumours revealed increased angiogenesis and high similarities with pseudohypoxic PGLs caused by VHL gene mutations. Sickle haemoglobinopathy carriers could thus be at increased risk for developing EPAS1-PGLs, which should be taken into account in their management and surveillance.

Incidentally detected retroperitoneal paraganglioma in a 10-year-old French bulldog

This article reports a case of a 10-year-old French bulldog initially seen for reluctance to move and episodes of pain. A magnetic resonance imaging study was undertaken in order to rule out a herniated disc. A large, retroperitoneal mass was visualized and cytological analysis suggested a neoplastic proliferation. The mass appeared to compress the caudal vena cava when viewed by abdominal CT scan. The mass was surgically removed. A nephrectomy was also carried out and aortic bleeding identified after dissection of adhesions. Despite these complications, the dog did well after the procedures. Postoperative checkups were normal. Histological and immunohistochemical analyses of the mass were compatible with a retroperitoneal paraganglioma. Key clinical message: This type of tumor is poorly described in the veterinary literature. As the behavior of this tumor type is not yet fully understood, each new description adds to our knowledge and should help in diagnosing and treating it more effectively in the future.

[Biological, preclinical and clinical aspects of the association between radiation therapy and CDK4/6 inhibitors]

Several clinical studies have shown that CDK4/6 inhibitors (CDK4/6i) improve survival in patients with metastatic or locally advanced HR-positive, HER-2-negative breast cancer (BC). The aim of this review was to synthesize the biological, preclinical and clinical aspects of the treatment of BC with CDK4/6i, with a focus on the combination of CDK4/6i and radiotherapy. The DNA damage induced after exposure of cells to ionizing radiation activates control pathways that inhibit cell progression in the G1 and G2 phases and induce a transient delay in progression in the S phase. These checkpoints are in particular mediated by cyclin-dependent kinases (CDK) 4/6 activated by cyclin D1. Several preclinical studies have shown that CDK4/6i could be used as radiosensitizers in non-small cell lung cancer, medulloblastoma, brainstem glioma and breast cancer. CDK4/6 inhibition also protected against radiation-induced intestinal toxicities by inducing redistribution of quiescent intestinal progenitor cells, making them less radiosensitive. Clinical data on the combination of CDK inhibitors and radiotherapy for both locoregional and metastatic irradiation are based on retrospective data. Nevertheless, the most optimal therapeutic sequence would be radiotherapy followed by palbociclib. Pending prospective clinical trials, the concomitant combination of the two treatments should be done under close supervision.

The molecular pathophysiology of mood disorders: From the analysis of single molecular layers to multi-omic integration

Next-generation sequencing now enables the rapid and affordable production of reliable biological data at multiple molecular levels, collectively referred to as "omics". To maximize the potential for discovery, computational biologists have created and adapted integrative multi-omic analytical methods. When applied to diseases with traceable pathophysiology such as cancer, these new algorithms and statistical approaches have enabled the discovery of clinically relevant molecular mechanisms and biomarkers. In contrast, these methods have been much less applied to the field of molecular psychiatry, although diagnostic and prognostic biomarkers are similarly needed. In the present review, we first briefly summarize main findings from two decades of studies that investigated single molecular processes in relation to mood disorders. Then, we conduct a systematic review of multi-omic strategies that have been proposed and used more recently. We also list databases and types of data available to researchers for future work. Finally, we present the newest methodologies that have been employed for multi-omics integration in other medical fields, and discuss their potential for molecular psychiatry studies.

Chronic traumatic encephalopathy

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease linked to repeated traumatic brain injury (TBI). This disorder is mainly observed in subjects at risk for brain traumatisms including boxers, American football and European football (soccer) players, as well as war veterans. Neuropathological findings are marked by abnormally phosphorylated tau accumulations at the depth of cerebral sulci, as well as TDP43, Aβ and α-synuclein positive staining. It has been described 3 clinical variants: the behavioural/mood variant, the cognitive variant and the mixed behavioural/cognitive variant. Cerebral MRI revealed signs of diffuse atrophy with abnormal axonal findings using the diffusion tensor imaging methods. Cerebral PET tau revealed increased standardised uptake value ratio (SUVR) levels in various brain regions of CTE patients compared to controls. The place of CTE among other neurodegenerative diseases is still debated. The focus of CTE management must be on prevention. The best way to prevent CTE in athletes is to put in place strict and appropriate measures by physicians. An individual with concussion should not be allowed to play again immediately (and sometimes never) in cases of abnormal neurological symptoms or imaging abnormalities.

Abstract PS10-40: Real life efficacy of palbociclib and endocrine therapy in HR positive, HER2 negative advanced breast cancer

BackgroundPalbociclib, a highly selective inhibitor of CDK4/6, is indicated for the treatment of hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC), in combination with an aromatase inhibitor or with fulvestrant for patients who have progressed with an aromatase inhibitor, and in premenopausal women with a luteinising-hormone-releasing-hormone (LH-RH) agonist. Emerging real world data suggest that the efficacy of a palbociclib-based therapy is highly conserved. We report here the Institut Curie (IC) experience.

Patients and methodsWe retrospectively reviewed all patients with HR+ HER2- ABC treated with a palbociclib-based therapy as 1st or 2nd line of therapy for ABC, from November 2016 to December 2018. Clinical, biological and imaging data were retrieved from IC electronic health record system. Data lock was December 31st 2020. Descriptive analyses, univariate and multivariate Cox regression analyses were performed.

ResultsWe included 310 consecutive premenopausal (24.5%) and menopausal (75.5%) women. Median age was 61.8 years-old [23.5-92.1]. Among them, Eastern Cooperative Oncology Group (ECOG) performance status was 0 in 59.7%, 1 in 32.1%, and 2 in 8.2% of patients (pts). The ABC diagnosis was de novo for 26.8%. There was at least one visceral lesion in 51.0% of pts, only bone lesions in 30.3%, 28.1% had three metastatic sites or more, and none of them have brain lesions. Previous treatments were chemotherapy (49.4%) and endocrine therapy (60.7%). Among pts pretreated by at least one endocrine therapy, 51.1% had shown prior sensibility, as defined by an absence of recurrence during adjuvant endocrine therapy or during 24 months after its completion, or an absence of progression during 6 months after the beginning of an endocrine therapy for a metastatic disease. Palbociclib was prescribed in the 1st line setting for 72.6% of pts and in the 2nd line setting for 27.4% of pts. The initial dose was 125 mg daily (95.2%). It was associated with an aromatase inhibitor (66.8%) or with fulvestrant (33.2%). LH-RH agonist was prescribed in 19.7% of pts. Denosumab was prescribed in 68.5% of pts with bone lesions. Median follow-up was 20.7 months (m). At 12 m from the initiation of palbociclib, 94.5% of the pts were alive. Median progression free survival was 23.4 m (95%CI: 21.6-NR) for pts without previous endocrine therapy, 22.7 m (95%CI: 14.7-NR) for pts who have shown endocrine sensibility, HR=1.2 (95%CI: 0.81-1.77), p=0.0027 and 13.4 m (95%CI: 10.7-20.8) for pts who have not shown endocrine sensibility, HR=1.88 (95%CI: 1.29-2.73), p=0.003. Although sensibility to previous endocrine therapy was a prognostic factor for progression free survival with the univariate analyse, it was not with the multivariate analysis. Three independent poor prognostic factors for progression free survival were identified: previous chemotherapy, HR=1.6 (95%CI: 1.12-2.29), p<0.001; initial ECOG performance status 2, HR=2.72 (95%CI: 1.55-4.79), p<0.001; and three or more metastatic sites, HR=1.61 (95%CI: 1.152.26), p<0.001. Hematologic grade 3-4 adverse events were neutropenia (72.3%), leukopenia (43.9%), anemia (3.2%) and thrombocytopenia (2.9%). Other adverse events observed (all grades) were infections (16.5%), stomatitis (13.9%) or alopecia (13.9%). At least one dose reduction occurred in 29.4% of pts and permanent discontinuation because of treatment toxicity was observed in 5.7% of pts.

ConclusionIn a non-selected population of patients with HR+ HER2- ABC, the efficacy and safety data are strikingly similar to those previously reported. Palbociclib, in combination with hormone therapy, is a cornerstone treatment of HR+ HER2- metastatic breast cancer.

Citation Format: Baptiste Porte, Matthieu Carton, Delphine Loirat, François-Clement Bidard, Linda Haroun, Audrey Bellesoeur, Youlia Kirova, Paul Cottu. Real life efficacy of palbociclib and endocrine therapy in HR positive, HER2 negative advanced breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS10-40.

Real life efficacy of palbociclib and endocrine therapy in HR positive, HER2 negative advanced breast cancer

BACKGROUND

Palbociclib is indicated for the treatment of hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC), in combination with endocrine therapy. Emerging real-life data suggest that the efficacy of a palbociclib-based therapy is highly conserved. We report the Institut Curie hospital experience.

PATIENTS AND METHODS

We retrospectively reviewed all patients with HR + HER2- ABC treated with a palbociclib-based therapy as first or second line for ABC, with an initial prescription from November 2016 to December 2018. Clinical, laboratory and imaging data were retrieved from electronic records. Data lock was December 31st, 2019. Descriptive analyses, univariate and multivariate Cox regression analyses were performed.

RESULTS

We included 310 consecutive patients. Median age was 61.8 years old. Palbociclib was prescribed in first line in 225 patients (72.6%). Before palbociclib-based therapy initiation, 122 patients (39.3%) were endocrine naive, 96 (31.0%) endocrine sensitive and 92 (29.7%) endocrine resistant. Median follow-up was 20.7 months. Median progression free survival (PFS) was 23.4 months (95%CI: 21.6-NR) in endocrine naive patients, 22.7 months (95%CI: 14.7-NR) in endocrine sensitive, and 13.4 months (95%CI: 10.7-20.8) in endocrine resistant. At 12 months from the initiation of palbociclib, 94.5% of patients were alive. By multivariate analysis, poor prognosis factors for PFS were identified in the endocrine naive/sensitive population: initial ECOG status 2, previous endocrine therapy for ABC, 3 metastatic sites or more. Toxicity profile was similar to previously published data.

CONCLUSION

In a non-selected population of patients with HR + HER2- ABC, the efficacy and safety data are strikingly similar to those previously reported.

STAT3 inhibition protects against neuroinflammation and BACE1 upregulation induced by systemic inflammation

Abnormal activation of the transcriptional factor STAT3 (signal transducer and activator of transcription 3) was recently associated with Alzheimer Disease (AD). STAT3 phosphorylation is critical for cytokine secretion linked to neuroinflammation. Moreover, STAT3 may act as a transcriptional regulator of BACE1 (β-APP cleaving enzyme-1), the key enzyme in amyloid β (Aβ) production. We have previously shown that neuroinflammation and increased brain BACE1 levels triggered by LPS-induced systemic inflammation in wild-type mice are associated with an enhanced STAT3 activation. Using this LPS model, the goal of this study was to investigate if a STAT3 inhibitor administration could be protective against neuroinflammation and abnormal BACE1 regulation. Our results show that intraperitoneal injection of Stattic, a molecule that selectively inhibits the activation of STAT3, decreases LPS-induced microglial activation in the hippocampus. In addition, STAT3 inhibition reduced brain levels of cytokines IL-6, IL-1β and TNF-α triggered by LPS systemic administration. A significant reduction of BACE1 levels was observed in the hippocampus of mice treated with LPS and Stattic compared to those exposed to LPS alone. Taking together, our results show that Stattic can protect hippocampus against two pathological hallmarks of AD, and pave the way for further explorations of the therapeutic potential of STAT3 inhibition in AD.

Institut Curie guidelines on breast target volume delineation for patients treated in lateral position

PURPOSE

To develop guidelines for and describe the delineation of breast for patients treated in lateral position and to transform this three-dimensional technique based on the virtual simulation to volume-based modern intensity-modulated irradiation technique.

MATERIAL AND METHODS

In our department, during the daily delineation, radiation oncologists specialized in breast cancer treatment sought consensus on the delineation of clinical treatment volume of the breast through dialogue based on cases. A radiation oncologist delineated clinical treatment volumes on CT scans of five to 20 patients, followed by a discussion and adaptation of the delineation between all radiation oncologists of the team. The consensus established between clinicians was discussed, corrected and improved. All patients were delineated in treatment position; skin markers were used to visualize the breast tissue after careful palpation.

RESULTS

Breast clinical treatment volume was situated and delineated between pectoral muscle and 5mm below the skin (dosimetric considerations), within the space outlined by skin markers, that showed the limits of the palpable breast tissue. In lateral position some vessels were very useful to define the limits as rami mammarii (from thoracica interna) for the internal one and thoracica lateralis for the external. This is the first atlas proposed for the delineation of the breast clinical treatment volumes for breast cancer using alternative technique of breast irradiation (lateral).

CONCLUSION

This atlas will be helpful for the volume definition in our daily practice of breast irradiation in lateral position and can open perspectives to develop also atlases for other alternative techniques as treatment in prone position.

Concurrent use of palbociclib and radiation therapy: single-centre experience and review of the literature

Palbociclib in combination with endocrine therapy increases progression-free survival in patients with ER-positive, HER2-negative advanced breast cancer (BC). In this study, we retrospectively evaluated safety in the first patient treated with concurrent use of palbociclib and radiation therapy (RT) in the Curie Institute. Between April 2017 and August 2019, 30 women with metastatic BC received locoregional and/or symptomatic irradiation at a metastatic site concurrently with palbociclib. The most common acute toxicities were radiodermatitis and neutropenia. Palbociclib had to be discontinued during RT in three locally treated patients who developed grade 3 radiodermatitis and febrile neutropenia, grade 2 dysphagia and metastatic disease progression, respectively. After a follow-up of at least 6 months, none of the patients had late toxicity. Concomitant administration of palbociclib with RT was reasonably well tolerated in our series of 30 patients. More prospective data with longer follow-up are needed to confirm these results.

Tolerance of concurrent CDK inhibitor and radiation therapy in metastatic breast cancer patients

e12598

Background: Palbociclib, a small-molecule inhibitor of cyclin-dependent kinases (CDK4 and CDK6), combined with letrozole increases progression-free survival among patients with previously untreated ER-positive, HER2 negative advanced breast cancer. The purpose of our study was to retrospectively evaluate the tolerance of the concomitant association of Palbociclib and radiation therapy (RT) at Curie Institute. Methods: Between April 2017 and August 2019, 30 women with ER-positive, HER2 negative metastatic breast cancer received locoregional (LR) and/or symptomatic irradiation at a metastatic site concurrently with Palbociclib at a daily dose of 125 mg, from d1 to d21 every 28 days. Palbociclib was always associated with endocrine therapy: letrozole (with or without an LHRH analogue) or fulvestrant. Thirty-five sites were irradiated: nine patients received post-operative locoregional RT, including the chest wall or breast and lymph node areas, and 26 sites of metastases were irradiated: 17 at the spine, 7 peripheral skeletal lesions, 1 brain lesion and 1 choroidal lesion. The dose prescribed for locoregional mammary radiotherapy was 50 Gy in 25 fractions and varied for the treatment of metastatic sites: 20 Gy in 5 fractions (n = 13), 30 Gy in 10 fractions (n = 10) and 8 Gy in 1 fraction (n = 2). The brain metastasis was stereotactically treated (1 fraction of 18 Gy). The primary endpoint was toxicity scored according to the common terminology criteria for NCI adverse events, version v5.0. Results: Mean number of days of Palbociclib during RT was 8.8 days (range, 1 to 24 days). The most common acute toxicities were dermatitis (12/35, including 2 grade 2) and neutropenia (12/35, including 9 grade 2). Palbociclib had to be stopped during the RT of two patients (2/30): one patient treated locoregionally (bilateral breast and lymph nodes irradiation) developed a grade 3 dermatitis and febrile neutropenia, another treated locoregionally developed grade 2 dysphagia. After a median follow-up since the end of RT of 17 months (6 – 31 months, SD 8), none of the patients have so far exhibited late toxicity. Conclusions: Concomitant administration of palbociclib with RT was reasonably well tolerated in our series of 30 patients. Given this experience, palbociclib should not be discontinued during radiation therapy. Nevertheless, our findings should be confirmed in prospective registration studies collecting larger number of patients.

Are ketogenic diets promising for Alzheimer's disease? A translational review

Background

Brain amyloid deposition and neurofibrillary tangles in Alzheimer’s disease (AD) are associated with complex neuroinflammatory reactions such as microglial activation and cytokine production. Glucose metabolism is closely related to neuroinflammation. Ketogenic diets (KDs) include a high amount of fat, low carbohydrate and medium-chain triglyceride (MCT) intake. KDs lead to the production of ketone bodies to fuel the brain, in the absence of glucose. These nutritional interventions are validated treatments of pharmacoresistant epilepsy, consequently leading to a better intellectual development in epileptic children. In neurodegenerative diseases and cognitive decline, potential benefits of KD were previously pointed out, but the published evidence remains scarce. The main objective of this review was to critically examine the evidence regarding KD or MCT intake effects both in AD and ageing animal models and in humans.

Main body

We conducted a review based on a systematic search of interventional trials published from January 2000 to March 2019 found on MEDLINE and Cochrane databases. Overall, 11 animal and 11 human studies were included in the present review. In preclinical studies, this review revealed an improvement of cognition and motor function in AD mouse model and ageing animals. However, the KD and ketone supplementation were also associated with significant weight loss. In human studies, most of the published articles showed a significant improvement of cognitive outcomes (global cognition, memory and executive functions) with ketone supplementation or KD, regardless of the severity of cognitive impairments previously detected. Both interventions seemed acceptable and efficient to achieve ketosis.

Conclusion

The KD or MCT intake might be promising ways to alter cognitive symptoms in AD, especially at the prodromal stage of the disease. The need for efficient disease-modifying strategies suggests to pursue further KD interventional studies to assess the efficacy, the adherence to this diet and the potential adverse effects of these nutritional approaches.

Abstract P4-12-05: A retrospective study of 27 patients with ER-positive, HER2 negative metastatic breast cancer treated with concomitant palbociclib and radiation therapy

Background: Palbociclib, a small-molecule inhibitor of cyclin-dependent kinases (CDK4 and CDK6), combined with letrozole increases progression-free survival among patients with previously untreated ER-positive, HER2 negative advanced breast cancer. However, the data on the safety of the concomitant association between Palbociclib and radiation therapy are scarce. The purpose of our study was to retrospectively evaluate the tolerance of the first patients treated with this concomitant combination at Institut Curie.

Materials and methods: Between April 2017 and July 2019, 27 women with ER-positive, HER2 negative metastatic breast cancer received locoregional and/or symptomatic irradiation at a metastatic site concomitantly with Palbociclib at a daily dose of 125 mg, from d1 to d21 every 28 days. Palbociclib was always associated with an endocrine treatment: Letrozole (17 patients /27, with or without an LHRH analogue) or Fulvestrant (10 patients /27). Median age at the time of diagnosis of metastases was 60 years (range, 35-85 years). Thirty-two sites were irradiated: 9 patients received post-operative locoregional radiation therapy, including the chest wall or breast and lymph node areas, and 23 sites of metastases were irradiated: 15 at the spine (3 cervical, 6 thoracic, 4 lumbar, 2 sacral), 2 pelvic lesions, 4 peripheral skeletal lesions, 1 brain lesion and 1 choroidal lesion (two patients received locoregional treatment and irradiation in one metastatic site and two patients were treated in two different metastatic sites). The dose prescribed for locoregional mammary radiotherapy was 50 Gy in 25 fractions and varied for the treatment of metastatic sites: 20 Gy in 5 fractions (n=14), 30 Gy in 10 fractions (n=7) and 8 Gy in 1 fraction (n=1). The brain metastasis was stereotactically treated (1 fraction of 18 Gy). The primary endpoint was toxicity scored according to the common terminology criteria for NCI adverse events, version v4.0.

Results: Median follow-up was 22 months (range, 4 to 54). Mean number of days of Palbociclib during radiation therapy was 8.7 days (range, 1 to 23 days). Most common acute toxicities were radiodermatitis (12/27, including 1 grade 3, 2 grade 2 and 9 grade 1) and neutropenia (13/27, including 1 grade 4, 7 grade 3, 5 grade 2). Palbociclib had to be stopped during the radiation therapy of three patients (3/27): one patient treated locoregionally (bilateral breast and lymph nodes irradiation) developed a grade 3 radiodermatitis and febrile neutropenia, another treated locoregionally developed grade 2 dysphagia (loss of 4 kg in 1 month) and one patient treated for sacral metastases (20 Gy in 4 fractions) developed grade 3 proctitis. Of the 19/27 patients with a follow-up of more than 6 months none developed late toxicities.

Conclusion: Concomitant administration of Palbociclib with radiation therapy was reasonably well tolerated in our series of 27 patients. Caution should be exercised when a large volume is irradiated, and when the dose per fraction is high. It remains unsure whether the interruption-causing side effects of Palbociclib was based on synergistic toxicity with radiation therapy. We suggest that our findings are to be confirmed in prospective registration studies collecting larger number of patients.

Citation Format: Arnaud Beddok, Alexandre Arsene-Henry, Baptiste Porte, Kim Cao, Louis Bazire, Nathaniel Scher, Alain Labib, Ilan Darmon, Joëlle Otz, Mathieu Minsat, Hamid Mammar, François Clément Bidar, Alain Fourquet, Paul Cottu, Phlip Poortmans, Youlia Kirova. A retrospective study of 27 patients with ER-positive, HER2 negative metastatic breast cancer treated with concomitant palbociclib and radiation therapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-12-05.

Dose-dependent neuroprotective effect of the JNK inhibitor Brimapitide in 5xFAD transgenic mice

Alzheimer's disease (AD) is a neurodegenerative disease mainly affecting old people. According to the "amyloid cascade hypothesis", the accumulation of Aβ oligomers could lead to kinase activation and Tau phosphorylation. Activated kinases include c-Jun N-terminal kinase (JNK) and previous studies highlighted the beneficial effects of the JNK-specific inhibitor Brimapitide (10 mg/kg) in 5xFAD transgenic mice. Our aim was to evaluate the effects of decreasing doses of Brimapitide on cognition and neurodegeneration in early treated 5xFAD mice. Three month-old 5xFAD were intravenously treated for 6 months with either Brimapitide (3 mg/kg or 0.3 mg/kg) or Nacl. Cognition and amyloid burden, neuronal and synaptic impairments were evaluated. Low doses of Brimapitide (0.3 mg/kg) reduced neuronal degeneration and improved cognition in treated mice compared to non-treated mice. Amyloid burden and synaptic degeneration only decreased with the 3 mg/kg dose. This JNK inhibitor can afford neuroprotection but with a differential effect on amyloid deposition in 5xFAD mice. Brimapitide might partially prevent ongoing neurodegeneration in 5xFAD mice.

Major remodeling of brain microvessels during neonatal period in the mouse: A proteomic and transcriptomic study

Preterm infants born before 29 gestation weeks incur major risk of subependymal/intracerebral/intraventricular hemorrhage. In mice, neonate brain endothelial cells are more prone than adult cells to secrete proteases under glutamate challenge, and invalidation of the Serpine 1 gene is accompanied by high brain hemorrhage risk up to five days after birth. We hypothesized that the structural and functional states of microvessels might account for age-dependent vulnerability in mice up to five days after birth and might represent a pertinent paradigm to approach the hemorrhage risk window observed in extreme preterms. Mass spectrometry proteome analyses of forebrain microvessels at days 5, 10 and in adult mice revealed 899 proteins and 36 enriched pathways. Microarray transcriptomic study identified 5873 genes undergoing at least two-fold change between ages and 93 enriched pathways. Both approaches pointed towards extracellular matrix, cell adhesion and junction pathways, indicating delayed microvascular strengthening after P5. Furthermore, glutamate receptors, proteases and their inhibitors exhibited convergent evolutions towards excitatory aminoacid sensitivity and low proteolytic control likely accounting for vascular vulnerability in P5 mice. Thus, age vascular specificities must be considered in future therapeutic interventions in preterms. Data are available on ProteomeXchange (identifier PXD001718) and NCBI Gene-Expression-Omnibus repository (identification GSE67870).

Proteomic and transcriptomic study of brain microvessels in neonatal and adult mice

Infants born before 29 weeks gestation incur a major risk of preterm encephalopathy and subependymal/intracerebral/intraventricular haemorrhage. In mice, an ontogenic window of haemorrhage risk was recorded up to 5 days after birth in serpine1 knock-out animals. Using proteome and transcriptome approaches in mouse forebrain microvessels, we previously described the remodelling of extracellular matrix and integrins likely strengthening the vascular wall between postnatal day 5 (P5) and P10. Haemorrhage is the ultimate outcome of vessel damage (i.e., during ischaemia), although discreet vessel insults may be involved in the aetiology of preterm encephalopathy. In this study, we examined proteins identified by mass spectrometry and segregating in gene ontology pathways in forebrain microvessels in P5, P10, and adult wild type mice. In parallel, comparative transcript levels were obtained using RNA hybridization microarrays and enriched biological pathways were extracted from genes exhibiting at least a two-fold change in expression. Five major biological functions were observed in those genes detected both as proteins and mRNA expression undergoing at least a two-fold change in expression in one or more age comparisons: energy metabolism, protein metabolism, antioxidant function, ion exchanges, and transport. Adult microvessels exhibited the highest protein and mRNA expression levels for a majority of genes. Energy metabolism-enriched gene ontology pathways pointed to the preferential occurrence of glycolysis in P5 microvessels cells versus P10 and adult preparations enriched in aerobic oxidative enzymes. Age-dependent levels of RNA coding transport proteins at the plasma membrane and mitochondria strengthened our findings based on protein data. The data suggest that immature microvessels have fewer energy supply alternatives to glycolysis than mature structures. In the context of high energy demand, this constraint might account for vascular damage and maintenance of the high bleeding occurrence in specific areas in immature brain.

Hypoxia-ischemia or excitotoxin-induced tissue plasminogen activator- dependent gelatinase activation in mice neonate brain microvessels

Hypoxia-ischemia (HI) and excitotoxicity are validated causes of neonatal brain injuries and tissue plasminogen activator (t-PA) participates in the processes through proteolytic and receptor-mediated pathways. Brain microvascular endothelial cells from neonates in culture, contain and release more t-PA and gelatinases upon glutamate challenge than adult cells. We have studied t-PA to gelatinase (MMP-2 and MMP-9) activity links in HI and excitotoxicity lesion models in 5 day–old pups in wild type and in t-PA or its inhibitor (PAI-1) genes inactivated mice. Gelatinolytic activities were detected in SDS-PAGE zymograms and by in situ fluorescent DQ-gelatin microscopic zymographies. HI was achieved by unilateral carotid ligature followed by a 40 min hypoxia (8%O₂). Excitotoxic lesions were produced by intra parenchymal cortical (i.c.) injections of 10 µg ibotenate (Ibo). Gel zymograms in WT cortex revealed progressive extinction of MMP-2 and MMP-9 activities near day 15 or day 8 respectively. MMP-2 expression was the same in all strains while MMP-9 activity was barely detectable in t-PA^−/− and enhanced in PAI-1^−/− mice. HI or Ibo produced activation of MMP-2 activities 6 hours post-insult, in cortices of WT mice but not in t-PA^−/− mice. In PAI-1^−/− mice, HI or vehicle i.c. injection increased MMP-2 and MMP-9 activities. In situ zymograms using DQ-gelatin revealed vessel associated gelatinolytic activity in lesioned areas in PAI-1^−/− and in WT mice. In WT brain slices incubated ex vivo, glutamate (200 µM) induced DQ-gelatin activation in vessels. The effect was not detected in t-PA^−/−mice, but was restored by concomitant exposure to recombinant t-PA (20 µg/mL). In summary, neonatal brain lesion paradigms and ex vivo excitotoxic glutamate evoked t-PA-dependent gelatinases activation in vessels. Both MMP-2 and MMP-9 activities appeared t-PA-dependent. The data suggest that vascular directed protease inhibition may have neuroprotection potential against neonatal brain injuries.

Mélanome de l’avant-bras. À propos d’un cas historique

We present the case of a melanoma of the forearm notable for its depth (Breslow index 35 mm), due to a longstanding lack of interest and care by the patient as well as her physician. Because of systemic metastases, only palliative treatment, consisting of an excision of the lesion for local hygiene, could be offered. The patient survived for only three months. This case illustrates the absolute necessity to remove without delay, any cutaneous tumor that resembles a melanoma, in order to avoid diagnosis being made at a late stage when curative treatment cannot be performed.