N-acetyl cysteine turns EPAC activators into potent killers of acute lymphoblastic leukemia cells.

Today, the majority of patients with pediatric B cell precursor acute lymphoblastic leukemia (BCP-ALL, hereafter ALL) survive their disease, but many of the survivors suffer from life-limiting late effects of the treatment. ALL develops in the bone marrow, where the cells are exposed to cAMP-generating prostaglandin E2. We have previously identified the cAMP signaling pathway as a putative target for improved efficacy of ALL treatment, based on the ability of cAMP signaling to reduce apoptosis induced by DNA damaging agents. In the present study, we have identified the antioxidant N-acetyl cysteine (NAC) as a powerful modifier of critical events downstream of the cell-permeable cAMP analog 8-(4-chlorophenylthio) adenosine-3', 5'- cyclic monophosphate (8-CPT). Accordingly, we found NAC to turn 8-CPT into a potent killer of ALL cells in vitro both in the presence and absence of DNA damaging treatment. Furthermore, we revealed that NAC in combination with 8-CPT is able to delay the progression of ALL in a xenograft model in NOD-scid IL2Rγnull mice. NAC was shown to rely on the ability of 8-CPT to activate the guanine-nucleotide exchange factor EPAC, and we demonstrated that the ALL cells are killed by apoptosis involving sustained elevated levels of calcium imposed by the combination of the two drugs. Taken together, we propose that 8-CPT in the presence of NAC might be utilized as a novel strategy for treating pediatric ALL patients, and that this powerful combination might be exploited to enhance the therapeutic index of current ALL targeting therapies.

SARS-CoV-2 and Stroke Characteristics: A Report From the Multinational COVID-19 Stroke Study Group.

[Figure: see text].

Congenital obstruction of foramen of Monro: report of 10 patients and literature review.

INTRODUCTION: A wide spectrum of etiologies can obstruct foramen of Monro (FOM) and result in hydrocephalus. Congenital occlusion of FOM is a rare entity which may present either in childhood or in adulthood. METHODS: Between 2007 and 2016, we screened all pediatric patients with hydrocephalus of either one or both lateral ventricles. Congenital occlusion of FOM was confirmed in the absence of masses occupying the FOM, prenatal or postnatal central nervous system (CNS) infections, intraventricular hemorrhage, previous cerebral intervention, or associated CNS anomalies affecting the flow of cerebrospinal fluid (CSF). We have performed a comprehensive literature review of the previously reported cases and provided a tentative embryological pathogenesis of FOM occlusion. RESULTS: We introduce 10 new cases of congenital FOM obstruction. The mean age of the patients was 6.65 ± 10.51 months. Two patients underwent ventriculo-peritoneal (VP) shunting as the primary intervention, while endoscopic septostomy was performed in the others. The mean follow-up was 3.05 ± 2.16 years (1-8 years). Although the hydrocephalus was controlled, all patients remained hemiparetic with some degree of developmental and cognitive impairments. Previously, 38 similar cases were reported: 10 of them (26.3%) were adults. Overall, VP shunting was the treatment of choice in 44.7% of patients. While most adults fully recovered, 7.2% of pediatrics remained hemiparetic and 10.7% of them had cognitive and developmental delay. CONCLUSION: Ten cases of congenital obstruction of the foramen of Monro have been managed through a period of 9-year study. Details of these patients in addition to 38 previously reported cases are presented in this study.

Bone marrow stroma-derived PGE2 protects BCP-ALL cells from DNA damage-induced p53 accumulation and cell death.

BACKGROUND: B cell precursor acute lymphoblastic leukaemia (BCP-ALL) is the most common paediatric cancer. BCP-ALL blasts typically retain wild type p53, and are therefore assumed to rely on indirect measures to suppress transformation-induced p53 activity. We have recently demonstrated that the second messenger cyclic adenosine monophosphate (cAMP) through activation of protein kinase A (PKA) has the ability to inhibit DNA damage-induced p53 accumulation and thereby promote survival of the leukaemic blasts. Development of BCP-ALL in the bone marrow (BM) is supported by resident BM-derived mesenchymal stromal cells (MSCs). MSCs are known to produce prostaglandin E(2) (PGE(2)) which upon binding to its receptors is able to elicit a cAMP response in target cells. We hypothesized that PGE(2) produced by stromal cells in the BM microenvironment could stimulate cAMP production and PKA activation in BCP-ALL cells, thereby suppressing p53 accumulation and promoting survival of the malignant cells. METHODS: Primary BCP-ALL cells isolated from BM aspirates at diagnosis were cocultivated with BM-derived MSCs, and effects on DNA damage-induced p53 accumulation and cell death were monitored by SDS-PAGE/immunoblotting and flow cytometry-based methods, respectively. Effects of intervention of signalling along the PGE(2)-cAMP-PKA axis were assessed by inhibition of PGE(2) production or PKA activity. Statistical significance was tested by Wilcoxon signed-rank test or paired samples t test. RESULTS: We demonstrate that BM-derived MSCs produce PGE(2) and protect primary BCP-ALL cells from p53 accumulation and apoptotic cell death. The MSC-mediated protection of DNA damage-mediated cell death is reversible upon inhibition of PGE(2) synthesis or PKA activity. Furthermore our results indicate differences in the sensitivity to variations in p53 levels between common cytogenetic subgroups of BCP-ALL. CONCLUSIONS: Our findings support our hypothesis that BM-derived PGE(2), through activation of cAMP-PKA signalling in BCP-ALL blasts, can inhibit the tumour suppressive activity of wild type p53, thereby promoting leukaemogenesis and protecting against therapy-induced leukaemic cell death. These novel findings identify the PGE(2)-cAMP-PKA signalling pathway as a possible target for pharmacological intervention with potential relevance for treatment of BCP-ALL.

Selective inhibition of cell death in malignant vs normal B-cell precursors: implications for cAMP in development and treatment of BCP-ALL.

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is the most commonly occurring pediatric cancer. Despite its relatively good prognosis, there is a steady search for strategies to improve treatment effects and prevent the undesired side effects on normal cells. In the present paper, we demonstrate a differential effect of cyclic adenosine monophosphate (cAMP) signaling between normal BCPs and BCP-ALL blasts, pointing to a potential therapeutic window allowing for manipulation of cAMP signaling in the treatment of BCP-ALL. By studying primary cells collected from pediatric BCP-ALL patients and healthy controls, we found that cAMP profoundly decreased basal and DNA damage-induced p53 levels and cell death in malignant cells, whereas normal BCP counterparts displayed slightly augmented cell death when exposed to cAMP-increasing agents. We did not find evidence for a selection process involving generation of increased basal cAMP levels in BCP-ALL cells, but we demonstrate that paracrine signaling involving prostaglandin E2-induced cAMP generation has the potential to suppress p53 activation and cell death induction. The selective inhibitory effect of cAMP signaling on DNA damage-induced cell death in BCP-ALL cells appears to be an acquired trait associated with malignant transformation, potentially allowing the use of inhibitors of this pathway for directed killing of the malignant blasts.

Effects of atorvastatin on plasma matrix metalloproteinase-9 concentration after glial tumor resection; a randomized, double blind, placebo controlled trial.

BACKGROUND: Neurosurgical procedures such as craniotomy and brain tumor resection could potentially lead to unavoidable cerebral injuries. Matrix metalloproteinase-9 (MMP-9) is up-regulated in neurological injuries. Statins have been suggested to reduce MMP- 9 level and lead to neuroprotection. Atorvastatin preoperatively administered to evaluate its neuroprotective effects and outcome assessment in neurosurgical-induced brain injuries after glial tumor resection. In this prospective, randomized, double-blind, placebo-controlled trial, 42 patients undergoing glial tumor surgery randomly received 40 mg atorvastatin or placebo twice daily from seven days prior to operation and continued for a 3 weeks period. Plasma MMP-9 concentration measured 4 times, immediately before starting atorvastatin or placebo, immediately before surgery, 24 hours and two weeks after the surgery. Karnofsky performance score was assessed before first dose of atorvastatin as a baseline and 2 months after the surgery. RESULTS: Karnofsky performance scale after surgery raised significantly more in Atorvastatin group (11.43 +/- 10.62 vs. 4.00 +/- 8.21) (p = 0.03). Atorvastatin did not significantly reduce MMP-9 plasma concentration 24 hours after surgery in comparison to placebo. No statistical significance detected regarding length of hospital stay among the groups. Significant reduction in MMP-9 plasma concentration was recorded in atorvastatin group two weeks after surgery (p = 0.048). CONCLUSIONS: Significant statistical differences detected with atorvastatin group regarding MMP-9 plasma concentration, clinical outcome and Karnofsky performance score. Consequently, atorvastatin use may lead to better outcome after neurosurgical procedures.

SARS-CoV-2 infection might be a predictor of mortality in intracerebral hemorrhage.

BACKGROUND: SARS-CoV-2 infection may be associated with uncommon complications such as intracerebral hemorrhage (ICH), with a high mortality rate. We compared a series of hospitalized ICH cases infected with SARS-CoV-2 with a non-SARS-CoV-2 infected control group and evaluated if the SARS-CoV-2 infection is a predictor of mortality in ICH patients. METHODS: In a multinational retrospective study, 63 cases of ICH in SARS-CoV-2 infected patients admitted to 13 tertiary centers from the beginning of the pandemic were collected. We compared the clinical and radiological characteristics and in-hospital mortality of these patients with a control group of non-SARS-CoV-2 infected ICH patients of a previous cohort from the country where the majority of cases were recruited. RESULTS: Among 63 ICH patients with SARS-CoV-2 infection, 23 (36.5%) were women. Compared to the non-SARS-CoV-2 infected control group, in SARS-CoV-2 infected patients, ICH occurred at a younger age (61.4 ± 18.1 years versus 66.8 ± 16.2 years, P = 0.044). These patients had higher median ICH scores ([3 (IQR 2-4)] versus [2 (IQR 1-3)], P = 0.025), a more frequent history of diabetes (34% versus 16%, P = 0.007), and lower platelet counts (177.8 ± 77.8 × 109/L versus 240.5 ± 79.3 × 109/L, P < 0.001). The in-hospital mortality was not significantly different between cases and controls (65% versus 62%, P = 0.658) in univariate analysis; however, SARS-CoV-2 infection was significantly associated with in-hospital mortality (aOR = 4.3, 95% CI: 1.28-14.52) in multivariable analysis adjusting for potential confounders. CONCLUSION: Infection with SARS-CoV-2 may be associated with increased odds of in-hospital mortality in ICH patients.

The protein phosphatase 1 regulator PNUTS is a new component of the DNA damage response.

The function of protein phosphatase 1 nuclear-targeting subunit (PNUTS)--one of the most abundant nuclear-targeting subunits of protein phosphatase 1 (PP1c)--remains largely uncharacterized. We show that PNUTS depletion by small interfering RNA activates a G2 checkpoint in unperturbed cells and prolongs G2 checkpoint and Chk1 activation after ionizing-radiation-induced DNA damage. Overexpression of PNUTS-enhanced green fluorescent protein (EGFP)--which is rapidly and transiently recruited at DNA damage sites--inhibits G2 arrest. Finally, γH2AX, p53-binding protein 1, replication protein A and Rad51 foci are present for a prolonged period and clonogenic survival is decreased in PNUTS-depleted cells after ionizing radiation treatment. We identify the PP1c regulatory subunit PNUTS as a new and integral component of the DNA damage response involved in DNA repair.

Cranial dermal sinus: presentation, complications and management.

OBJECTIVE: Cranial dermal sinus is a very rare anomaly mostly found in the midline occipital area, presenting with diverse clinical features from asymptomatic dermal sinus to symptomatic situations including meningitis, dermoid tumor or abscess. METHODS: Medical records of 18 patients with 19 cranial dermal sinuses operated at the Children's Hospital Medical Center in Tehran from 1999 to 2011 were retrospectively studied. Their presentations, accompanying anomalies, radiological and surgical findings were evaluated. RESULTS: Patients were aged 1 month to 6 years and were followed for 2-12 years. Most sinuses were located in the midline occipital region. Infection was the most common reason for referral (50%) followed by skin dimple (33.3%). Creamy white discharge was found in 50% of patients. Posterior fossa abscess, hydrocephalus and meningitis were observed in 38.9, 38.9 and 22.2% of children, respectively. All sinus tracts with associated dermoid tumors or abscesses were removed en bloc to decrease the risk of recurrence. CONCLUSION: The sinus tracts are a portal of entry for pathogens which result in serious complications of meningitis or abscess. In this series, 67% of children presented with serious symptoms; therefore, we recommend prophylactic surgery in all cranial dermal sinuses. The exact time of surgery is not obvious as the natural course of the disease is unknown. If any symptom is observed surgery should be done as soon as possible. For asymptomatic sinuses identified by the pediatrician during a regular visit prophylactic surgery is recommended as soon as the child can tolerate operation.

Intracranial Aneurysm Rupture after SARS-CoV2 Infection: Case Report and Review of Literature.

BACKGROUND: SARS-CoV virus infection results in a dysbalanced and severe inflammatory response with hypercytokinemia and immunodepression. Viral infection triggers systemic inflammation and the virus itself can potentially cause vascular damage, including blood-brain barrier (BBB) disruption and alterations in the coagulation system, which may result in cardiovascular and neurovascular events. Here, we review the literature and present a case of COVID-19 infection leading to an aneurysmal subarachnoid haemorrhage (aSAH). CASE DESCRIPTION: A 61-year-old woman presented with dyspnea, cough, and fever. She had a history of hypertension and was overweight with a body mass-index of 34. There was no history of subarachnoid hemorrhage in the family. Due to low oxygen saturation (89%) she was admitted into ICU. A chest CT showed a typical picture of COVID-19 pneumonia. The PCR-based test of an oropharyngeal swab was COVID-19-positive. In addition to oxygen support she was prescribed with favipiravir and hydroxychloroquine. She experienced a sudden headache and lost consciousness on the second day. Computer tomography (CT) with CT-angiography revealed a subarachnoid haemorrhage in the basal cisterns from a ruptured anterior communicating artery aneurysm. The aneurysm was clipped microsurgically through a left-sided standard pterional approach and the patient was admitted again to the intensive care unit for further intensive medical treatment. Post-operatively, the patient showed slight motor dysphasia. No other neurological deficits. CONCLUSION: Systemic inflammation and ventilator support-associated blood pressure fluctuations may trigger aneurysmal subarachnoid haemorrhage secondary to COVID-19 infection. COVID-19 infection could be considered as one of the possible risk factors leading to instability and rupture of intracranial aneurysm.

Hyperactivation of NF-κB via the MEK signaling is indispensable for the inhibitory effect of cAMP on DNA damage-induced cell death.

With cAMP signaling having a profound inhibitory effect on DNA damage-induced apoptosis in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) cells, understanding how this signaling pathway affects the survival capacity of the cell has important implications for cancer therapy. We have recently shown that p53 is critical for the inhibitory effect of cAMP on genotoxic agents-mediated apoptosis in BCP-ALLs. Here, we show that elevation of cAMP levels in cells exposed to DNA damage enhances the nuclear translocation and DNA binding of NF-κB by accelerating the phosphorylation of IKKß and thereby phosphorylation and degradation of IκBα. Furthermore, we show that the ability of cAMP to potentiate the ionizing radiation-induced activation of NF-κB requires the activity of MEK. Importantly, pharmacological or genetic ablation of NF-κB reversed the inhibitory effect of cAMP on DNA damage-induced apoptosis, demonstrating that, in addition to p53, cAMP relies on the activity of NF-κB to provide cells with a survival advantage in the face of DNA damage. Collectively, our results uncover a novel and important interaction between the cAMP and NF-κB pathways that may have implications for the targeted treatment of lymphoid malignancies, such as BCP-ALL, in which aberrant NF-κB activity functions as a driving force for treatment resistance.

Activation of cAMP signaling inhibits DNA damage-induced apoptosis in BCP-ALL cells through abrogation of p53 accumulation.

In lymphocytes, the second messenger cyclic adenosine monophosphate (cAMP) plays a well-established antiproliferative role through inhibition of G(1)/S transition and S-phase progression. We have previously demonstrated that, during S-phase arrest, cAMP inhibits the action of S phase-specific cytotoxic compounds, leading to reduction in their apoptotic response. In this report, we provide evidence that cAMP can also inhibit the action of DNA-damaging agents independently of its effect on S phase. Elevation of cAMP in B-cell precursor acute lymphoblastic leukemia cells is shown to profoundly inhibit the apoptotic response to ionizing radiation, anthracyclins, alkylating agents, and platinum compounds. We further demonstrate that this effect depends on the ability of elevated cAMP levels to quench DNA damage-induced p53 accumulation by increasing the p53 turnover, resulting in attenuated Puma and Bax induction, mitochondrial outer membrane depolarization, caspase activation, and poly(ADP-ribose) polymerase cleavage. On the basis of our findings, we suggest that cAMP levels may influence p53 function in malignant cells that retain wild-type p53, potentially affecting p53 both as a tumor suppressor during cancer initiation and maintenance, and as an effector of the apoptotic response to DNA-damaging agents during anticancer treatment.

Cyclic AMP induces apoptosis in multiple myeloma cells and inhibits tumor development in a mouse myeloma model.

BACKGROUND: Multiple myeloma is an incurable disease requiring the development of effective therapies which can be used clinically. We have elucidated the potential for manipulating the cAMP signaling pathway as a target for inhibiting the growth of multiple myeloma cells. METHODS: As a model system, we primarily used the murine multiple myeloma cell line MOPC315 which can be grown both in vivo and in vitro. Human multiple myeloma cell lines U266, INA-6 and the B-cell precursor acute lymphoblastic leukemia cell line Reh were used only for in vitro studies. Cell death was assessed by flow cytometry and western blot analysis after treatment with cAMP elevating agents (forskolin, prostaglandin E2 and rolipram) and cAMP analogs. We followed tumor growth in vivo after forskolin treatment by imaging DsRed-labelled MOPC315 cells transplanted subcutaneously in BALB/c nude mice. RESULTS: In contrast to the effect on Reh cells, 50 µM forskolin more than tripled the death of MOPC315 cells after 24 h in vitro. Forskolin induced cell death to a similar extent in the human myeloma cell lines U266 and INA-6. cAMP-mediated cell death had all the typical hallmarks of apoptosis, including changes in the mitochondrial membrane potential and cleavage of caspase 3, caspase 9 and PARP. Forskolin also inhibited the growth of multiple myeloma cells in a mouse model in vivo. CONCLUSIONS: Elevation of intracellular levels of cAMP kills multiple myeloma cells in vitro and inhibits development of multiple myeloma in vivo. This strongly suggests that compounds activating the cAMP signaling pathway may be useful in the field of multiple myeloma.

Adjunctive treatment of myxopapillary ependymoma.

Myxopapillary ependymoma are rare tumors and optimal therapeutic strategy is remained controversial. The main treatments for myxopapillary ependymoma tumors include surgery and radiotherapy. Hence, the present study aimed to review adjuvant treatment of myxopapillary ependymoma, focusing on spinal myxopapillary ependymoma. The information sources of all articles were the English authoritative databases including PubMed, Web of science, Scopus, Science direct and Google scholar. In this review study, the keywords including adjuvant, treatment, myxopapillary and ependymoma were selected from MeSH medical library. Related articles were published from 2000 to 2020. Given radiation tolerance in the spinal cord is 10-15% lower than that of the brain, it also should be noted that with increased dose and scope of therapeutic field, the corresponding risks are increased, as well. Also, chemotherapy has never been used as the primary treatment approach. Radiotherapy's value is considered while involving with sensitive areas where chemotherapy is also recommended. Gross total resection is the preferred primary treatment. But the role of adjuvant radiotherapy is debated in different tumor and patient scenarios and no standard treatment strategy had been defined yet. The bottom line is that as long as cellular and molecular methods or gene therapy can be used in the treatment of myxopapillary ependymoma, all the studies confirm that the best treatment method is still wide surgical resection as much as possible.

Systemic Inflammatory Index Is a Novel Predictor of Intubation Requirement and Mortality after SARS-CoV-2 Infection.

Coronavirus disease 2019 (COVID-19), with an increasing number of deaths worldwide, has created a tragic global health and economic emergency. The disease, caused by severe acute respiratory syndrome coronavirus 2019 (SARS-CoV-19), is a multi-system inflammatory disease with many of COVID-19-positive patients requiring intensive medical care due to multi-organ failures. Biomarkers to reliably predict the patient's clinical cause of the virus infection, ideally, to be applied in point of care testing or through routine diagnostic approaches, are highly needed. We aimed to probe if routinely assessed clinical lab values can predict the severity of the COVID-19 course. Therefore, we have retrospectively analyzed on admission laboratory findings in 224 consecutive patients from four hospitals and show that systemic immune inflammation index (SII) is a potent marker for predicting the requirement for invasive ventilator support and for worse clinical outcome of the infected patient. Patients' survival and severity of SARS-CoV-2 infection could reliably be predicted at admission by calculating the systemic inflammatory index of individual blood values. We advocate this approach to be a feasible and easy-to-implement assay that may be particularly useful to improve patient management during high influx crisis. We believe with this work to contribute to improving infrastructure availability and case management associated with COVID-19 pandemic hurdles.

SARS-CoV-2 Is a Culprit for Some, but Not All Acute Ischemic Strokes: A Report from the Multinational COVID-19 Stroke Study Group.

BACKGROUND: SARS-CoV-2 infected patients are suggested to have a higher incidence of thrombotic events such as acute ischemic strokes (AIS). This study aimed at exploring vascular comorbidity patterns among SARS-CoV-2 infected patients with subsequent stroke. We also investigated whether the comorbidities and their frequencies under each subclass of TOAST criteria were similar to the AIS population studies prior to the pandemic. METHODS: This is a report from the Multinational COVID-19 Stroke Study Group. We present an original dataset of SASR-CoV-2 infected patients who had a subsequent stroke recorded through our multicenter prospective study. In addition, we built a dataset of previously reported patients by conducting a systematic literature review. We demonstrated distinct subgroups by clinical risk scoring models and unsupervised machine learning algorithms, including hierarchical K-Means (ML-K) and Spectral clustering (ML-S). RESULTS: This study included 323 AIS patients from 71 centers in 17 countries from the original dataset and 145 patients reported in the literature. The unsupervised clustering methods suggest a distinct cohort of patients (ML-K: 36% and ML-S: 42%) with no or few comorbidities. These patients were more than 6 years younger than other subgroups and more likely were men (ML-K: 59% and ML-S: 60%). The majority of patients in this subgroup suffered from an embolic-appearing stroke on imaging (ML-K: 83% and ML-S: 85%) and had about 50% risk of large vessel occlusions (ML-K: 50% and ML-S: 53%). In addition, there were two cohorts of patients with large-artery atherosclerosis (ML-K: 30% and ML-S: 43% of patients) and cardioembolic strokes (ML-K: 34% and ML-S: 15%) with consistent comorbidity and imaging patterns. Binominal logistic regression demonstrated that ischemic heart disease (odds ratio (OR), 4.9; 95% confidence interval (CI), 1.6-14.7), atrial fibrillation (OR, 14.0; 95% CI, 4.8-40.8), and active neoplasm (OR, 7.1; 95% CI, 1.4-36.2) were associated with cardioembolic stroke. CONCLUSIONS: Although a cohort of young and healthy men with cardioembolic and large vessel occlusions can be distinguished using both clinical sub-grouping and unsupervised clustering, stroke in other patients may be explained based on the existing comorbidities.

Cerebral venous sinus thrombosis associated with SARS-CoV-2; a multinational case series.

BACKGROUND: SARS-CoV-2 induced coagulopathy can lead to thrombotic complications such as stroke. Cerebral venous sinus thrombosis (CVST) is a less common type of stroke which might be triggered by COVID-19. We present a series of CVST cases with SARS-CoV-2 infection. METHODS: In a multinational retrospective study, we collected all cases of CVST in SARS-CoV-2 infected patients admitted to nine tertiary stroke centers from the beginning of the pandemic to June 30th, 2020. We compared the demographics, clinical and radiological characteristics, risk factors, and outcome of these patients with a control group of non-SARS-CoV-2 infected CVST patients in the same seasonal period of the years 2012-2016 from the country where the majority of cases were recruited. RESULTS: A total of 13 patients fulfilled the inclusion criteria (62% women, mean age 50.9 ± 11.2 years). Six patients were discharged with good outcomes (mRS ≤ 2) and three patients died in hospital. Compared to the control group, the SARS-CoV-2 infected patients were significantly older (50.9 versus 36.7 years, p < 0.001), had a lower rate of identified CVST risk factors (23.1% versus 84.2%, p < 0.001), had more frequent cortical vein involvement (38.5% versus 10.5%, p: 0.025), and a non-significant higher rate of in-hospital mortality (23.1% versus 5.3%, p: 0.073). CONCLUSION: CVST should be considered as potential comorbidity in SARS-CoV-2 infected patients presenting with neurological symptoms. Our data suggest that compared to non-SARS-CoV-2 infected patients, CVST occurs in older patients, with lower rates of known CVST risk factors and might lead to a poorer outcome in the SARS-CoV-2 infected group.

Risk of stroke in hospitalized SARS-CoV-2 infected patients: A multinational study.

BACKGROUND: There is an increased attention to stroke following SARS-CoV-2. The goal of this study was to better depict the short-term risk of stroke and its associated factors among SARS-CoV-2 hospitalized patients. METHODS: This multicentre, multinational observational study includes hospitalized SARS-CoV-2 patients from North and South America (United States, Canada, and Brazil), Europe (Greece, Italy, Finland, and Turkey), Asia (Lebanon, Iran, and India), and Oceania (New Zealand). The outcome was the risk of subsequent stroke. Centres were included by non-probability sampling. The counts and clinical characteristics including laboratory findings and imaging of the patients with and without a subsequent stroke were recorded according to a predefined protocol. Quality, risk of bias, and heterogeneity assessments were conducted according to ROBINS-E and Cochrane Q-test. The risk of subsequent stroke was estimated through meta-analyses with random effect models. Bivariate logistic regression was used to determine the parameters with predictive outcome value. The study was reported according to the STROBE, MOOSE, and EQUATOR guidelines. FINDINGS: We received data from 26,175 hospitalized SARS-CoV-2 patients from 99 tertiary centres in 65 regions of 11 countries until May 1st, 2020. A total of 17,799 patients were included in meta-analyses. Among them, 156(0.9%) patients had a stroke-123(79%) ischaemic stroke, 27(17%) intracerebral/subarachnoid hemorrhage, and 6(4%) cerebral sinus thrombosis. Subsequent stroke risks calculated with meta-analyses, under low to moderate heterogeneity, were 0.5% among all centres in all countries, and 0.7% among countries with higher health expenditures. The need for mechanical ventilation (OR: 1.9, 95% CI:1.1-3.5, p = 0.03) and the presence of ischaemic heart disease (OR: 2.5, 95% CI:1.4-4.7, p = 0.006) were predictive of stroke. INTERPRETATION: The results of this multi-national study on hospitalized patients with SARS-CoV-2 infection indicated an overall stroke risk of 0.5%(pooled risk: 0.9%). The need for mechanical ventilation and the history of ischaemic heart disease are the independent predictors of stroke among SARS-CoV-2 patients. FUNDING: None.

EBV infection renders B cells resistant to growth inhibition via adenylyl cyclase.

Cyclic AMP (cAMP) is an important physiological growth inhibitor of lymphoid cells, and the cAMP/protein kinase A (PKA) pathway is disrupted in several immunological disorders and cancers. Epstein Barr virus (EBV) infection of B lymphocytes is responsible for the development of lymphoproliferative disease as well as certain B-lymphoid malignancies. Here we hypothesized that EBV infection might render B lymphocytes resistant to cAMP/PKA-mediated growth inhibition. To test this, we assessed the growth-inhibitory response of cAMP-elevating compounds such as forskolin and isoproterenol, as well as the PKA activator 8-CPT-cAMP in normal B lymphocytes, EBV-infected B cells and in the EBV-negative B lymphoid cell line Reh. We could demonstrate that EBV infection indeed abolished cAMP-mediated growth inhibition of B cells. The defect was pinpointed to defective adenylyl cyclase (AC) activation by forskolin and isoproterenol, resulting in reduced formation of cAMP and lack of PKA activation and CREB phosphorylation. In contrast, 8-CPT-cAMP which directly activates PKA was able to inhibit EBV-infected B cell growth. The physiological implications of these results were underlined by the observation that the ability of forskolin to inhibit camptothecin-induced apoptosis was abolished in EBV-infected B cells. We conclude that EBV infection of B cells abrogates the activation of AC and thereby cAMP formation, and that this dysfunction renders the cells resistant to growth inhibition via the cAMP/PKA pathway.

Inhibitors of AKT kinase increase LDL receptor mRNA expression by two different mechanisms.

Protein kinase B (AKT) is a serine/threonine kinase that functions as an important downstream effector of phosphoinositide 3-kinase. We have recently shown that MK-2206 and triciribine, two highly selective AKT inhibitors increase the level of low density lipoprotein receptor (LDLR) mRNA which leads to increased amount of cell-surface LDLRs. However, whereas MK-2206 induces transcription of the LDLR gene, triciribine stabilizes LDLR mRNA, raising the possibility that the two inhibitors may actually affect other kinases than AKT. In this study, we aimed to ascertain the role of AKT in regulation of LDLR mRNA expression by examining the effect of five additional AKT inhibitors on LDLR mRNA levels. Here we show that in cultured HepG2 cells, AKT inhibitors ARQ-092, AKT inhibitor VIII, perifosine, AT7867 and CCT128930 increase LDLR mRNA levels by inducing the activity of LDLR promoter. CCT128930 also increased the stability of LDLR mRNA. To study the role of AKT isoforms on LDLR mRNA levels, we examined the effect of siRNA-mediated knockdown of AKT1 or AKT2 on LDLR promoter activity and LDLR mRNA stability. Whereas knockdown of either AKT1 or AKT2 led to upregulation of LDLR promoter activity, only knockdown of AKT2 had a stabilizing effect on LDLR mRNA. Taken together, these results provide strong evidence for involvement of AKT in regulation of LDLR mRNA expression, and point towards the AKT isoform specificity for upregulation of LDLR mRNA expression.