The C-Type Lectin Receptor CD93 Regulates Platelet Activation and Surface Expression of the Protease Activated Receptor 4

BACKGROUND

 The C-type lectin receptor CD93 is a single pass type I transmembrane glycoprotein involved in inflammation, immunity, and angiogenesis. This study investigates the role of CD93 in platelet function. CD93 knockout (KO) mice and wild-type (WT) controls were compared in this study.

METHODS

 Platelet activation and aggregation were investigated by flow cytometry and light transmission aggregometry, respectively. Protein expression and phosphorylation were analyzed by immunoblotting. Subcellular localization of membrane receptors was investigated by wide-field and confocal microscopy.

RESULTS

 The lack of CD93 in mice was not associated to any evident bleeding defect and no alterations of platelet activation were observed upon stimulation with thromboxane A2 analogue and convulxin. Conversely, platelet aggregation induced by stimulation of the thrombin receptor PAR4 was significantly reduced in the absence of CD93. This defect was associated with a significant reduction of α-granule secretion, integrin αIIbβ3 activation, and protein kinase C (PKC) stimulation. Resting WT and CD93-deficient platelets expressed comparable amounts of PAR4. However, upon stimulation with a PAR4 activating peptide, a more pronounced clearance of PAR4 from the platelet surface was observed in CD93-deficient platelets compared with WT controls. Confocal microscopy analysis revealed a massive movement of PAR4 in cytosolic compartments of activated platelets lacking CD93. Accordingly, platelet desensitization following PAR4 stimulation was more pronounced in CD93 KO platelets compared with WT controls.

CONCLUSION

 These results demonstrate that CD93 supports platelet activation triggered by PAR4 stimulation and is required to stabilize the expression of the thrombin receptor on the cell surface.

Cyclic AMP induces reversible EPAC1 condensates that regulate histone transcription

The second messenger cyclic AMP regulates many nuclear processes including transcription, pre-mRNA splicing and mitosis. While most functions are attributed to protein kinase A, accumulating evidence suggests that not all nuclear cyclic AMP-dependent effects are mediated by this kinase, implying that other effectors may be involved. Here we explore the nuclear roles of Exchange Protein Activated by cyclic AMP 1. We find that it enters the nucleus where forms reversible biomolecular condensates in response to cyclic AMP. This phenomenon depends on intrinsically disordered regions present at its amino-terminus and is independent of protein kinase A. Finally, we demonstrate that nuclear Exchange Protein Activated by cyclic AMP 1 condensates assemble at genomic loci on chromosome 6 in the proximity of Histone Locus Bodies and promote the transcription of a histone gene cluster. Collectively, our data reveal an unexpected mechanism through which cyclic AMP contributes to nuclear spatial compartmentalization and promotes the transcription of specific genes.

Transient receptor potential ankyrin 1 (TRPA1) mediates reactive oxygen species-induced Ca2+ entry, mitochondrial dysfunction, and caspase-3/7 activation in primary cultures of metastatic colorectal carcinoma cells

Colorectal carcinoma (CRC) represents the fourth most common cancer worldwide and is the third most common cause of malignancy-associated mortality. Distant metastases to the liver and lungs are the main drivers of CRC-dependent death. Pro-oxidant therapies, which halt disease progression by exacerbating oxidative stress, represent an antitumour strategy that is currently exploited by chemotherapy and ionizing radiation. A more selective strategy to therapeutically exploit reactive oxygen species (ROS) signaling would consist in targeting a redox sensor that is up-regulated in metastatic cells and is tightly coupled to the stimulation of cancer cell death programs. The non-selective cation channel, Transient Receptor Potential Ankyrin 1 (TRPA1), serves as a sensor of the cellular redox state, being activated to promote extracellular Ca²⁺ entry by an increase in oxidative stress. Recent work demonstrated that TRPA1 channel protein is up-regulated in several cancer types and that TRPA1-mediated Ca²⁺ signals can either engage an antiapoptotic pro-survival signaling pathway or to promote mitochondrial Ca²⁺ dysfunction and apoptosis. Herein, we sought to assess for the first time the outcome of TRPA1 activation by ROS on primary cultures of metastatic colorectal carcinoma (mCRC cells). We found that TRPA1 channel protein is up-regulated and mediates enhanced hydrogen peroxide (H₂O₂)-induced Ca²⁺ entry in mCRC cells as compared to non-neoplastic control cells. The lipid peroxidation product 4-hydroxynonenal (4-HNE) is the main ROS responsible for TRPA1 activation upon mCRC cell exposure to oxidative stress. TRPA1-mediated Ca²⁺ entry in response to H₂O₂ and 4-HNE results in mitochondrial Ca²⁺ overload, followed by mitochondrial depolarization and caspase-3/7 activation. Therefore, targeting TRPA1 could represent an alternative strategy to eradicate metastatic CRC by enhancing its sensitivity to oxidative stress.

Proteomic and functional profiling of platelet-derived extracellular vesicles released under physiological or tumor-associated conditions

During hemostasis, thrombosis, and inflammation, activated blood platelets release extracellular vesicles (PEVs) that represent biological mediators of physiological and pathological processes. We have recently demonstrated that the activation of platelets by breast cancer cells is accompanied by a massive release of PEVs, evidence that matches with the observation that breast cancer patients display increased levels of circulating PEVs. A core concept in PEVs biology is that their nature, composition and biological function are strongly influenced by the conditions that induced their release. In this study we have performed a comparative characterization of PEVs released by platelets upon activation with thrombin, a potent thrombotic stimulus, and upon exposure to the breast cancer cell line MDA-MB-231. By nanoparticle tracking analysis and tandem mass spectrometry we have characterized the two populations of PEVs, showing that the thrombotic and tumoral stimuli produced vesicles that largely differ in protein composition. The bioinformatic analysis of the proteomic data led to the identification of signaling pathways that can be differently affected by the two PEVs population in target cells. Specifically, we have demonstrated that both thrombin- and cancer-cell-induced PEVs reduce the migration and potentiate Ca2+-induced apoptosis of Jurkat cells, but only thrombin-derived PEVs also potentiate cell necrosis. Our results demonstrate that stimulation of platelets by thrombotic or tumoral stimuli induces the release of PEVs with different protein composition that, in turn, may elicit selective biological responses in target cells.

Clinical relevance of Paliperidone Palmitate three-month intramuscular injection formulation: an Italian Real-World, Retrospective, one-year Mirror Image Study

Introduction

Paliperidone Palmitate 3-month (PP3M) formulation, introduced in Italy since 2017, is an effective and safety therapeutic option for patients with schizophrenia, clinically stable with 1-month formulation (PP1M). Only a few “Real World” studies investigated the clinical relevance of PP3M and the long-term clinical and health resource utilization outcomes.

Objectives

The aim of this retrospective, mirror image study was to evaluate the efficacy of PP3M in terms of continuity of care and number of hospitalizations.

Methods

Fifty outpatients treated with Paliperidone Palmitate (PP) were recruited from a Community Mental Health Centre (CMHC) in Milan. Statistical analysis were conducted with SPSS 26. Frequencies of hospitalization 6 months before and after the start of PP3M were compared using the McNemar test, setting the significance to p<0.05.

Results

This study involved 34 patients (68%) treated with PP1M and 16 (32%) treated with PP3M.The median time interval between PP1M and PP3M was 14 months. After the switch to PP3M, 69% of patients continued to visit the CMHC with an unchanged frequency (50% once/month, 6% more than once/month), while 31% with a decreased frequency (once/3 months). No patient increased the frequency of CMHC visits or started visiting it discontinuously. 44% of subjects had had at least one hospitalization prior to the switch and no hospitalizations after (p=0.016). Moreover, no patients showed increased hospitalizations

Conclusions

In this study PP3M clinical relevance was confirmed comparing pre-initiation and post-initiation 6-months time intervals: hospitalizations number significantly decreased, while the continuity of care was preserved. Further studies on a greater sample are necessary to support these preliminary data.

Disclosure

No significant relationships.

Incidence and predictive factors of non adherence to therapy in young adults attending a psycho social center in Milan: a retrospective observational “Real world” study

Introduction

Non adherence to psychotropic drugs is associated with negative outcomes, including hospitalizations, aggressive behaviors, suicide attempts and increased premature mortality. It represents a psychiatric challenge, especially in young adults who show higher risk of non-adherence to treatment

Objectives

Firstly this study evaluates the incidence of non-adherence to therapy in 18-24 years patients from a Psycho-Social Center in Milan; and then to analyze the predictive factors of non-adherence.

Methods

In this retrospective “Real Life” observational study, 120 outpatients aged 18 to 24 years, from Psycho-social Center of L. Sacco University Hospital in Milan, were recruited in 2019. Non-adherence to treatment, according to the World Health Organization, was considered “a modality of assuming medications that does not correspond to healthcare professionals’ recommendations”. Statistical analysis were performed with chi-square, ANOVA and linear regression tests, setting significance to p<0.05.

Results

88 of 120 outpatients (73.3%) received an indication to psychopharmacological treatment. Of these, 23 (26.1%) did not show adherence to therapy. Results showed a positive association between non-adherence and increased hospitalizations (p <.01), oral antipsychotics (p<.05) and drop-out rates (p<.001). A significant correlation was also observed between non-adherence and Intellectual Disability (p<.05), Bipolar Disorder (p<.05), psychotic symptoms (p<.05), alterations in affectivity and mood (p<.005), alterations in sleep pattern (p<.05), school dropout (p<.05) and poor family support (p<.01).

Conclusions

This study confirms that non-adherence has a relevant incidence in young-adults psychiatric population, highlighting the importance of effective and structured assessment in clinical practice to identify predictive factors and risk profiles associated with this phenomenon.

Disclosure

No significant relationships.

Mental health evaluation of patients with Inflammatory Bowel Disease and psychiatric comorbidities during the COVID-19 pandemic

Introduction

The mental health of subjects with chronic medical illnesses, such as Inflammatory Bowel Disease (IBD- Crohn’s Disease and Ulcerative Colitis), is typically compromised and the current COVID-19 pandemic might have additionally increased this burden.

Objectives

The aim of the present study was to investigate, during the COVID-19 pandemic, if the presence of a comorbid psychiatric disorder has played a role as an aggravating factor on mental health in patients with IBD.

Methods

Twenty Five patients with psychiatric comorbidities (PC+) and twenty five without (PC-) comparable for age and gender, were recruited at the Gastroenterology department at Sacco University Hospital in Milan. Participants were assessed a psychiatric evaluation, collecting socio-demographic variables and measures of anxiety and depression [on the Hospital Anxiety Depression Scale (HADS)], sleep patterns [on the Insomnia Severity Index (ISI)] and general health status [on the Short Form Health Survey 36 (SF-36)].

Comparative statistical analyses were performed with t test with Bonferroni correction.

Results

PC+ (n=25) showed more severe anxiety and depressive symptoms compared with PC- (n=25) (p <.001) and worse sleep pattern (p<.05). With respect to general health status, PC+ showed reduced physical activities (p<.05), social activities (p<.05), mental health (p<.01) and role limitations due to physical health (p<.05).

Conclusions

The present findings showed a worse mental health in subjects with IBD and psychiatric comorbidities during Covid-19 pandemic, highlighting the importance of screening and treatment of psychiatric symptoms disorders in these patients.

Disclosure

No significant relationships.

Proline-rich tyrosine kinase Pyk2 regulates deep vein thrombosis

Deep vein thrombosis results from the cooperative action of leukocytes, platelets, and endothelial cells. The proline-rich tyrosine kinase Pyk2 regulates platelet activation and supports arterial thrombosis. In this study, we combined pharmacological and genetic approaches to unravel the role of Pyk2 in venous thrombosis. We found that mice lacking Pyk2 almost completely failed to develop deep venous thrombi upon partial ligation of the inferior vena cava. Pyk2-deficient platelets displayed impaired exposure of phosphatidylserine and tissue factor expression by endothelial cells and monocytes was completely prevented by inhibition of Pyk2. In HUVECs, inhibition of Pyk2 hampered IL-11-induced expression of VCAM and P-selectin, and VWF release. Pyk2-deficient platelets showed defective adhesion on VWF and reduced ability to bind activated HUVECs under flow. Moreover, inhibition of Pyk2 in HUVECs strongly reduced platelet adhesion. Similarly, Pyk2-deficient neutrophils were unable to efficiently roll and adhere to immobilized endothelial cells under venous flow conditions. Moreover, platelets and neutrophils from Pyk2-KO mice showed defective ability to form heterogeneous aggregates upon stimulation, while plateletmonocyte interaction occurred normally. Consequently, platelet-neutrophil aggregates, abundant in blood of WT mice upon inferior vena cava ligation, were virtually undetectable in Pyk2-KO mice. Finally, we found that expression of Pyk2 was required for NETosis induced by activated platelets. Altogether our results demonstrate a critical role of Pyk2 in the regulation of the coordinated thromboinflammatory responses of endothelial cells, leukocytes and platelets leading to venous thrombosis. Pyk2 may represent a novel promising target in the treatment of deep vein thrombosis.

Conjugated polymers mediate intracellular Ca2+ signals in circulating endothelial colony forming cells through the reactive oxygen species-dependent activation of Transient Receptor Potential Vanilloid 1 (TRPV1)

Endothelial colony forming cells (ECFCs) represent the most suitable cellular substrate to induce revascularization of ischemic tissues. Recently, optical excitation of the light-sensitive conjugated polymer, regioregular Poly (3-hexyl-thiophene), rr-P3HT, was found to stimulate ECFC proliferation and tube formation by activating the non-selective cation channel, Transient Receptor Potential Vanilloid 1 (TRPV1). Herein, we adopted a multidisciplinary approach, ranging from intracellular Ca²⁺ imaging to pharmacological manipulation and genetic suppression of TRPV1 expression, to investigate the effects of photoexcitation on intracellular Ca²⁺ concentration ([Ca²⁺]_i) in circulating ECFCs plated on rr-P3HT thin films. Polymer-mediated optical excitation induced a long-lasting increase in [Ca²⁺]_i that could display an oscillatory pattern at shorter light stimuli. Pharmacological and genetic manipulation revealed that the Ca²⁺ response to light was triggered by extracellular Ca²⁺ entry through TRPV1, whose activation required the production of reactive oxygen species at the interface between rr-P3HT and the cell membrane. Light-induced TRPV1-mediated Ca²⁺ entry was able to evoke intracellular Ca²⁺ release from the endoplasmic reticulum through inositol-1,4,5-trisphosphate receptors, followed by store-operated Ca²⁺ entry on the plasma membrane. These data show that TRPV1 may serve as a decoder at the interface between rr-P3HT thin films and ECFCs to translate optical excitation in pro-angiogenic Ca²⁺ signals.

An intensive neurofeedback alpha-training to improve sleep quality and stress modulation in health-care workers during the COVID-19 pandemic: A pilot study

Introduction

During the COVID-19 pandemic, health workers represented a group particularly vulnerable to work-related stress, but prevention and management of psychiatric symptoms are still under evaluation. Neurofeedback is a safe and non-invasive neuromodulation technique with the target of training participants in the self-regulation of neural substrates underlying specific psychiatric disorders. Protocols based on the increase of alpha frequencies, associated with the process of relaxation, are used for the treatment of stress, anxiety and sleep disturbances.

Objectives

The aim of the present study was to assess the effectiveness of an alpha-increase NF protocol for the treatment of stress in healthcare workers exposed to the COVID-19 pandemic.

Methods

Eighteen medical doctors belonging to the Sacco Hospital were recruited during the COVID-19 health emergency and underwent a 10 sessions NF alpha-increase protocol during two consecutive weeks. The level of stress was assessed at the beginning (T0) and at the end (T1) of the protocol through the following questionnaires: Severity of Acute Symptoms Stress (SASS), Copenhagen Burnout Inventory (CBI), Pittsburgh Sleep Quality Index (PSQI), Brief-COPE. Statistical analyses were performed with Paired Samples t-Test for continuous variables, setting significance at p < 0.05.

Results

A significant increase in alpha waves mean values between T0 and T1 was observed. In addition, a significant reduction in the PSQI test score between T0 and T1 was observed.

Conclusions

Alpha-increase protocol showed promising results in terms of stress modulation, sleep quality improvement and safety profile in a pilot sample of health-care workers. Larger controlled studies are warranted to confirm present results.

Blood-based genomics of triple-negative breast cancer progression in patients treated with neoadjuvant chemotherapy

Background

As neoadjuvant chemotherapy (NAC) is increasingly used in triple-negative breast cancer (TNBC), we investigated the value of circulating tumor DNA (ctDNA) for patient monitoring prior, during, and after NAC, and circulating tumor cells (CTCs) for disease characterization at clinical progression.

Materials and methods

Forty-two TNBC patients undergoing NAC were prospectively enrolled. Primary tumor mutations identified by targeted-gene sequencing were validated and tracked in 168 plasma samples longitudinally collected at multiple time-points by droplet digital polymerase chain reaction. At progression, plasma DNA underwent direct targeted-gene assay, and CTCs were collected and analyzed for copy number alterations (CNAs) by low-pass whole genome sequencing.

Results

ctDNA detection after NAC was associated with increased risk of relapse, with 2-year event-free survival estimates being 44.4% [95% confidence interval (CI) 21.4%-92.3%] versus 77.4% (95% CI 57.8%-100%). ctDNA prognostic value remained worthy even after adjusting for age, residual disease, systemic inflammatory indices, and Ki-67 [hazard ratio (HR) 1.91; 95% CI 0.51-7.08]. During follow-up, ctDNA was undetectable in non-recurrent cases with the unique exception of one showing a temporary peak over eight samples. Conversely, ctDNA was detected in 8/11 recurrent cases, and predated the clinical diagnosis up to 13 months. Notably, recurrent cases without ctDNA developed locoregional, contralateral, and bone-only disease. At clinical progression, CTCs presented chromosome 10 and 21q CNAs whose network analysis showed connected modules including HER/PI3K/Ras/JAK signaling and immune response.

Conclusion

ctDNA is not only associated with but is also predictive of prognosis in TNBC patients receiving NAC, and represents an exploitable tool, either alone or with CTCs, for personalized TNBC management.

•

ctDNA was detected in 77% of early-stage TNBC patients undergoing neoadjuvant chemotherapy.

•

Patients with still detectable ctDNA after NAC were more than twice as likely to relapse as those with undetectable levels.

•

Detection of ctDNA during follow-up antedated clinical overt metastases up to 13 months.

•

ctDNA was undetectable in all but one non-recurrent patient with a temporary peak in only 1 of 8 samples tested.

•

CTCs of progressing cases lacked epithelial surface markers and showed therapeutically exploitable molecular features.

Hydrogen Sulfide-Evoked Intracellular Ca2+ Signals in Primary Cultures of Metastatic Colorectal Cancer Cells

Simple Summary

Colorectal cancer (CRC) is the most common type of gastrointestinal cancer and the third most predominant cancer in the world. CRC is potentially curable with surgical resection of the primary tumor. The clinical problem of colorectal cancer, however, is the spread and outgrowth of metastases, which are difficult to eradicate and lead to a patient’s death. The failure of conventional treatment to significantly improved outcomes in mCRC has prompted the search for alternative molecular targets with the goal of ameliorating the prognosis of these patients. The present investigation revealed that exogenous delivery of hydrogen sulfide (H₂S) suppresses proliferation in metastatic colorectal cancer cells by inducing an increase in intracellular Ca²⁺ concentration. H₂S was effective on metastatic, but not normal, cells. Therefore, we propose that exogenous administration of H₂S to patients affected by metastatic colorectal carcinoma could represent a promising therapeutic alternative.

Abstract

Exogenous administration of hydrogen sulfide (H₂S) is emerging as an alternative anticancer treatment. H₂S-releasing compounds have been shown to exert a strong anticancer effect by suppressing proliferation and/or inducing apoptosis in several cancer cell types, including colorectal carcinoma (CRC). The mechanism whereby exogenous H₂S affects CRC cell proliferation is yet to be clearly elucidated, but it could involve an increase in intracellular Ca²⁺ concentration ([Ca²⁺]_i). Herein, we sought to assess for the first time whether (and how) sodium hydrosulfide (NaHS), one of the most widely employed H₂S donors, induced intracellular Ca²⁺ signals in primary cultures of human metastatic CRC (mCRC) cells. We provided the evidence that NaHS induced extracellular Ca²⁺ entry in mCRC cells by activating the Ca²⁺-permeable channel Transient Receptor Potential Vanilloid 1 (TRPV1) followed by the Na⁺-dependent recruitment of the reverse-mode of the Na⁺/Ca²⁺ (NCX) exchanger. In agreement with these observations, TRPV1 protein was expressed and capsaicin, a selective TRPV1 agonist, induced Ca²⁺ influx by engaging both TRPV1 and NCX in mCRC cells. Finally, NaHS reduced mCRC cell proliferation, but did not promote apoptosis or aberrant mitochondrial depolarization. These data support the notion that exogenous administration of H₂S may prevent mCRC cell proliferation through an increase in [Ca²⁺]_i, which is triggered by TRPV1.

Fibrillar amyloid peptides promote platelet aggregation through the coordinated action of ITAM- and ROS-dependent pathways

BACKGROUND

Amyloid peptides Aβ40 and Aβ42, whose deposition in brain correlates with Alzheimer disease, are also present in platelets and have prothrombotic activities.

OBJECTIVE

In this study, we analyze the ability of Aβ peptides to form fibrils and to induce platelet activation and aggregation.

METHODS

Aβ40, Aβ42, and their scrambled peptides were diluted in phosphate buffered saline and fibrillogenesis was investigated by ThioflavinT and Congo Red. Aggregation, protein phosphorylation, and reactive oxygen species (ROS) production were analyzed.

RESULTS

Aβ40 and Aβ42, but not scrambled peptides, were able to form fibrils when diluted in phosphate buffered saline. Fibrillogenesis of Aβ42 was very rapid, whereas fibril formation by Aβ40 was completed only after 48 hours of incubation. Fibrillar Aβ40 and Aβ42 promoted dose-dependent aggregation of washed platelets in the presence of extracellular CaCl2 . Cleavage of GPIbα by mocarhagin or blockade of the ITAM-containing FcγRIIA prevented platelet aggregation induced by fibrillary Aβ40 and Aβ42. Fibrillar Aβ peptides stimulated the phosphorylation of FcγRIIA, resulting in the downstream stimulation of PLC, protein kinase C, and phosphoinositide 3-kinases, whose activity was necessary for full aggregation of platelets. Fibrillar Aβ peptides also induced ROS generation, and NOX inhibitors, as well as ROS scavengers, prevented platelet aggregation. However, Aβ peptide-induced ROS production did not require binding to GPIbα or activation of FcγRIIA, but was initiated by CD36, which provided an important contribution to full platelet aggregation.

CONCLUSION

These results suggest that fibrillar amyloid Aβ40 and Aβ42 induce platelet aggregation through the recruitment of GPIb-IX-V and CD36, which requires the convergence of ITAM- and ROS-dependent pathways.

Platelet-derived extracellular vesicles regulate cell cycle progression and cell migration in breast cancer cells

Platelets have been extensively implicated in the progression of cancer and platelet-derived extracellular vesicles (PEVs) are gaining growing attention as potential mediators of the platelet-cancer interplay. PEVs are shed from platelet membrane in response to extracellular stimuli and carry important biological signals for intercellular communication. In this study we demonstrate that PEVs specifically bind to different breast cancer cells and elicit cell-specific functional responses. PEVs were massively internalized by the metastatic cell lines MDA-MB-231 and SKBR3 and the ductal carcinoma cell line BT474, but not by the MCF-7 cell line. In SKBR3 cells, PEVs decreased mitochondrial dehydrogenase activities and altered cell cycle progression without affecting cell viability. Conversely, PEVs potently stimulated migration and invasion of MDA-MB-231, without affecting the distribution in the different phases of the cell cycle. In all the analyzed breast cancer cells, PEVs triggered a sustained increase of intracellular Ca²⁺, but only in MDA-MB-231 cells, this was associated to the stimulation of selected signaling proteins implicated in migration, including p38MAPK and myosin light chain. Importantly, inhibition of myosin light chain phosphorylation by a Rho kinase inhibitor prevented PEVs-stimulated migration of MDA-MB-231 cells. Our results demonstrate that PEVs are versatile regulators of cancer cell behavior and elicit a variety of different responses depending on the specific breast cancer cell subtype.

The proline-rich tyrosine kinase Pyk2 modulates integrin-mediated neutrophil adhesion and reactive oxygen species generation

Neutrophils are first responders in infection and inflammation. They are able to roll, adhere and transmigrate through the endothelium to reach the site of infection, where they fight pathogens through secretion of granule contents, production of reactive oxygen species, extrusion of neutrophil extracellular traps, and phagocytosis. In this study we explored the role of the non-receptor focal adhesion kinase Pyk2 in neutrophil adhesion and activation. Using a specific Pyk2 pharmacological inhibitor, PF-4594755, as well as Pyk2-deficient murine neutrophils, we found that Pyk2 is activated upon integrin αMβ2-mediated neutrophil adhesion to fibrinogen. This process is triggered by Src family kinases-mediated phosphorylation and supported by Pyk2 autophosphorylation on Y402. In neutrophil adherent to fibrinogen, Pyk2 activates PI3K-dependent pathways promoting the phosphorylation of Akt and of its downstream effector GSK3. Pyk2 also dynamically regulates MAP kinases in fibrinogen-adherent neutrophils, as it stimulates p38MAPK but negatively regulates ERK1/2. Pharmacological inhibition of Pyk2 significantly prevented adhesion of human neutrophils to fibrinogen, and neutrophils from Pyk2-knockout mice showed a reduced ability to adhere compared to wildtype cells. Accordingly, neutrophil adhesion to fibrinogen was reduced upon inhibition of p38MAPK but potentiated by ERK1/2 inhibition. Neutrophil adherent to fibrinogen, but not to polylysine, were able to produce ROS upon lipopolysaccharide challenge and ROS production was completely suppressed upon inhibition of Pyk2. By contrast PMA-induced ROS production by neutrophil adherent to either fibrinogen or polylysine was independent from Pyk2. Altogether these results demonstrate that Pyk2 is an important effector in the coordinated puzzle regulating neutrophil adhesion and activation.

Stimulation of mTORC2 by integrin αIIbβ3 is required for PI3Kβ-dependent activation of Akt but is dispensable for platelet spreading on fibrinogen

Phosphatidylinositol 3 kinase (PI3K) is a major player in platelet activation and regulates thrombus formation and stabilization. The β isoform of PI3K is implicated in integrin αIIbβ3 outside-in signaling, is required for the phosphorylation of Akt, and controls efficient platelet spreading upon adhesion to fibrinogen. In this study we found that during integrin αIIbβ3 outside-in signaling PI3Kβ-dependent phosphorylation of Akt on Serine473 is mediated by the mammalian target of rapamycin complex 2 (mTORC2). The activity of mTORC2 is stimulated upon platelet adhesion to fibrinogen, as documented by increased autophosphorylation. However, mTORC2 activation downstream of integrin αIIbβ3 is PI3Kβ-independent. Inhibition of mTORC2, but not mTORC1, also prevents Akt phosphorylation of Threonine308 and affects Akt activity, resulting in the inhibition of GSK3α/β phosphorylation. Nevertheless, mTORC2 or Akt inhibition does not alter PI3Kβ-dependent platelet spreading on fibrinogen. The activation of the small GTPase Rap1b downstream of integrin αIIbβ3 is regulated by PI3Kβ but is not affected upon inhibition of either mTORC2 or Akt. Altogether, these results demonstrate for the first time the activation of mTORC2 and its involvement in Akt phosphorylation and stimulation during integrin αIIbβ3 outside-in signaling. Moreover, the results demonstrate that the mTORC2/Akt pathway is dispensable for PI3Kβ-regulated platelet spreading on fibrinogen.

Reduced latency to first antidepressant treatment in Italian patients with a more recent onset of major depressive disorder

Introduction

Major depressive disorder (MDD) is a prevalent burdensome disease, which frequently remains untreated. The duration of untreated illness (DUI) is modifiable parameter and a valid predictor of outcome. Previous investigation in patients with MDD revealed a DUI of different years, while recent reports have documented a reduction of DUI across time, in patients with different psychiatric disorders.

Objectives/aims

The present study was aimed to investigate potential differences in terms of DUI and related variables in patients with MDD across time.

Methods

An overall sample of 188 patients with MDD was divided in two subgroups on the basis of their epoch of onset (onset before and after year 2000). DUI and other onset-related variables were assessed through a specific questionnaire and compared between the two subgroups.

Results

The whole sample showed a mean DUI of approximately 4.5 years, with a lower value in patients with more recent onset compared to the other subgroup (27.1 ± 42.6 vs. 75.8 ± 105.2 months, P < .05). Moreover, patients with onset after 2000 reported higher rates of onset-related stressful events and lower ones for benzodiazepines prescription (65% vs. 81%; P = 0.02; 47% vs. 30%; P = 0.02).

Conclusions

The comparison of groups with different epochs of onset showed a significant reduction in terms of DUI and benzodiazepines prescription, and a higher rate of onset-related stressful events in patients with a more recent onset. Reported findings are of epidemiologic and clinical relevance in order to evaluate progress and developments in the diagnostic and therapeutic pathways of MDD in Italian and other countries.

Disclosure of interest

The authors have not supplied their declaration of competing interest.