LAG-3 : recent developments in combinational therapies in cancer.

The study of anticancer immune responses and in particular the action of immune checkpoint inhibitors that overcome T cell inhibition has revolutionized metastatic patients' care. Unfortunately, many patients are resistant to these innovative immunotherapies. Over the last decade, several immune checkpoint inhibitors, currently available in the clinic, have been developed, such as anti-PD-1/PD-L1 or anti-CTLA-4. More recently, other immune checkpoints have been characterized, among them lymphocyte activation gene 3 (LAG-3). LAG-3 has been the subject of numerous therapeutic studies and may be involved in cancer-associated immune resistance phenomena. This review summarizes the latest knowledge on LAG-3 as an immunotherapeutic target, particularly in combination with standard or innovative therapies. Indeed, many studies are looking at combining LAG-3 inhibitors with chemotherapeutic, immunotherapeutic, radiotherapeutic treatments, or adoptive cell therapies to potentiate their antitumor effects and/or to overcome patients' resistance. We will particularly focus on the association therapies that are currently in phase III clinical trials and innovative combinations in preclinical phase. These new discoveries highlight the possibility of developing other types of therapeutic combinations currently unavailable in the clinic, which could broaden the therapeutic spectrum of personalized medicine.

The endoplasmic reticulum stress protein GRP94 modulates cathepsin L activity in M2 macrophages in conditions of obesity-associated inflammation and contributes to their pro-inflammatory profile.

BACKGROUND/OBJECTIVES: Adipose tissue macrophages (ATM) are key actors in the pathophysiology of obesity-related diseases. They have a unique intermediate M2-M1 phenotype which has been linked to endoplasmic reticulum (ER) stress. We previously reported that human M2 macrophages treated with the ER stress inducer thapsigargin switched to a pro-inflammatory phenotype that depended on the stress protein GRP94. In these conditions, GRP94 promoted cathepsin L secretion and was co-secreted with complement C3. As cathepsin L and complement C3 have been reported to play a role in the pathophysiology of obesity, in this work we studied the involvement of GRP94 in the pro-inflammatory phenotype of ATM. METHODS: GRP94, cathepsin L and C3 expression were analyzed in CD206 + ATM from mice, WT or obesity-resistant transgenic fat-1, fed a high-fat diet (HFD) or a standard diet. GRP94 colocalization with cathepsin L and C3 and its effects were analyzed in human primary macrophages using thapsigargin as a control to induce ER stress and palmitic acid (PA) as a driver of metabolic activation. RESULTS: In WT, but not in fat-1 mice, fed a HFD, we observed an increase in crown-like structures consisting of CD206 + pSTAT1+ macrophages showing high expression of GRP94 that colocalized with cathepsin L and C3. In vitro experiments showed that PA favored a M2-M1 switch depending on GRP94. This switch was prevented by omega-3 fatty acids. PA-induced GRP94-cathepsin L colocalization and a decrease in cathepsin L enzymatic activity within the cells (while the enzymatic activity in the extracellular medium was increased). These effects were prevented by the GRP94 inhibitor PU-WS13. CONCLUSIONS: GRP94 is overexpressed in macrophages both in in vivo and in vitro conditions of obesity-associated inflammation and is involved in changing their profile towards a more pro-inflammatory profile. It colocalizes with complement C3 and cathepsin L and modulates cathepsin L activity.

Mortality, Functional Status, and Quality of Life after 5 Years of Patients Admitted to Critical Care for Spontaneous Intracerebral Hemorrhage.

BACKGROUND: The objective of this study was to assess long-term outcome in patients with spontaneous intracerebral hemorrhage admitted to the intensive care unit. METHODS: Mortality and Glasgow Outcome Scale, Barthel Index, and 5-level EQ-5D version (EQ-5D-5L) scores were analyzed in a multicenter cohort study of three Spanish hospitals (336 patients). Mortality was also analyzed in the Medical Information Mart for Intensive Care III (MIMIC-III) database. RESULTS: The median (25th percentile-75th percentile) age was 62 (50-70) years, the median Glasgow Coma Score was 7 (4-11) points, and the median Acute Physiology and Chronic Health disease Classification System II (APACHE-II) score was 21 (15-26) points. Hospital mortality was 54.17%, mortality at 90 days was 56%, mortality at 1 year was 59.2%, and mortality at 5 years was 66.4%. In the Glasgow Outcome Scale, a normal or disabled self-sufficient situation was recorded in 21.5% of patients at 6 months, in 25.5% of patients after 1 year, and in 22.1% of patients after 5 years of follow-up (4.5% missing). The Barthel Index score of survivors improved over time: 50 (25-80) points at 6 months, 70 (35-95) points at 1 year, and 90 (40-100) points at 5 years (p < 0.001). Quality of life evaluated with the EQ-5D-5L at 1 year and 5 years indicated that greater than 50% of patients had no problems or slight problems in all items (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression). In the MIMIC-III study (N = 1354), hospital mortality was 31.83% and was 40.5% at 90 days and 56.2% after 5 years. CONCLUSIONS: In patients admitted to the intensive care unit with a diagnosis of nontraumatic intracerebral hemorrhage, hospital mortality up to 90 days after admission is very high. Between 90 days and 5 years after admission, mortality is not high. A large percentage of survivors presented a significant deficit in quality of life and functional status, although with progressive improvement over time. Five years after the hemorrhagic stroke, a survival of 30% was observed, with a good functional status seen in 20% of patients who had been admitted to the hospital.

Eosinophil-mucus interplay in severe asthma: Implications for treatment with biologicals.

Airway mucus is a hydrogel with unique biophysical properties due to its primary water composition and a small proportion of large anionic glycoproteins or mucins. The predominant mucins in human mucus, MUC5AC and MUC5B, are secreted by specialized cells within the airway epithelium both in normal conditions and in response to various stimuli. Their relative proportions are correlated with specific inflammatory responses and disease mechanisms. The dysregulation of mucin expression is implicated in numerous respiratory diseases, including asthma, COPD, and cystic fibrosis, where the pathogenic role of mucus has been extensively described yet often overlooked. In airway diseases, excessive mucus production or impaired mucus clearance leads to mucus plugging, with secondary airway occlusion that contribute to airflow obstruction, asthma severity and poor control. Eosinophils and Charcot Leyden crystals in sputum contribute to the mucus burden and tenacity. Mucin may also contribute to eosinophil survival. Other mechanisms, including eosinophil-independent IL-13 release, mast-cell activation and non-type-2 (T2) cytokines, are also likely to participate in mucus pathobiology. An accurate assessment of mucus and its clinical and functional consequences require a thorough approach that includes evaluation of cellular predominance in sputum, airway cytokines and other inflammatory markers, mucus characteristics and composition and structural and functional impact measured by advanced lung imaging. This review, illustrated with clinical scenarios, provides an overview of current methods to assess mucus and its relevance to the choice of biologics to treat patients with severe asthma.

Heat shock proteins and exosomes in cancer theranostics.

Heat shock proteins (HSPs) are a superfamily of molecular chaperones that were discovered through their ability to be induced by different stresses including heat shock. Other than their function as chaperones in proteins homeostasis, HSPs have been shown to inhibit different forms of cell death and to participate in cell proliferation and differentiation processes. Because cancer cells have to rewire their metabolism, they require a high amount of these stress-inducible chaperones for their survival. Therefore, HSPs are unusually abundant in cancer cells where they have oncogene-like functions. In cancer, HSPs have been involved in the regulation of apoptosis, immune responses, angiogenesis, metastasis and treatment resistance. Recently, HSPs have been shown to be secreted through exosomes by cancer cells. These tumor-derived exosomes can be used as circulating markers: HSP-exosomes have been reported as biomarkers of cancer dissemination, response to therapy and/or patient outcome. A new range of functions, mostly in modulation of anticancer immune responses, have been described for these extracellular HSPs. In this review, we will describe those recently reported functions of HSP-exosomes that makes them both targets for anticancer therapeutics and biomarkers for the monitoring of the disease. We will also discuss their emerging interest in cancer vaccines.

Endoscopic Vacuum Therapy for Upper Gastrointestinal Leaks and Perforations: Analysis From a Multicenter Spanish Registry.

INTRODUCTION: Endoscopic vacuum therapy (EVT) is a novel technique for closing upper gastrointestinal (UGI) defects. Available literature includes single-center retrospective cohort studies with small sample sizes. Furthermore, evidence about factors associated with EVT failure is scarce. We aimed to assess the efficacy and safety of EVT for the resolution of UGI defects in a multicenter study and to investigate the factors associated with EVT failure and in-hospital mortality. METHODS: This is a prospective cohort study in which consecutive EVT procedures for the treatment of UGI defects from 19 Spanish hospitals were recorded in the national registry between November 2018 and March 2022. RESULTS: We included 102 patients: 89 with anastomotic leaks and 13 with perforations. Closure of the defect was achieved in 84 cases (82%). A total of 6 patients (5.9%) had adverse events related to the EVT. The in-hospital mortality rate was 12.7%. A total of 6 patients (5.9%) died because of EVT failure and 1 case (0.9%) due to a fatal adverse event. Time from diagnosis of the defect to initiation of EVT was the only independent predictor for EVT failure (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.05, P = 0.005). EVT failure (OR 24.5, 95% CI 4.5-133, P = 0.001) and development of pneumonia after EVT (OR 246.97, 95% CI 11.15-5,472.58, P = 0.0001) were independent predictors of in-hospital mortality. DISCUSSION: EVT is safe and effective in cases of anastomotic leak and perforations of the upper digestive tract. The early use of EVT improves the efficacy of this technique.

Recent progress in discovery of novel AAK1 inhibitors: from pain therapy to potential anti-viral agents.

Adaptor associated kinase 1 (AAK1), a member of the Ark1/Prk1 family of Ser/Thr kinases, is a specific key kinase regulating Thr156 phosphorylation at the µ2 subunit of the adapter complex-2 (AP-2) protein. Due to their important biological functions, AAK1 systems have been validated in clinics for neuropathic pain therapy, and are being explored as potential therapeutic targets for diseases caused by various viruses such as Hepatitis C (HCV), Dengue, Ebola, and COVID-19 viruses and for amyotrophic lateral sclerosis (ALS). Centreing on the advances of drug discovery programs in this field up to 2023, AAK1 inhibitors are discussed from the aspects of the structure-based rational molecular design, pharmacology, toxicology and synthetic routes for the compounds of interest in this review. The aim is to provide the medicinal chemistry community with up-to-date information and to accelerate the drug discovery programs in the field of AAK1 small molecule inhibitors.

Airway autoimmunity, asthma exacerbations, and response to biologics.

Biologic therapies in asthma are indicated in severe disease, and they are directed against specific inflammatory modulators that contribute to pathogenesis and severity. Currently approved biologics target T2 cytokines (IgE, IL-5, IL-4/IL-13, and TLSP) and have demonstrated efficacy in clinical outcomes such as exacerbation rate and oral corticosteroid dose reductions, blood and airway eosinophil depletion, and lung function improvement. However, a proportion of these patients may show inadequate responses to biologics, with either initial lack of improvement or clinical and functional worsening after an optimal initial response. Exacerbations while on a biologic may be due to several reasons, including imprecise identification of the dominant effector pathway contributing to severity, additional inflammatory pathways that are not targeted by the biologic, inaccuracies of the biomarker used to guide therapy, inadequate dosing schedules, intercurrent airway infections, anti-drug neutralizing antibodies, and a novel phenomenon of autoimmune responses in the airways interfering with the effectiveness of the monoclonal antibodies. This review, illustrated using case scenarios, describes the underpinnings of airway autoimmune responses in driving exacerbations while patients are being treated with biologics, device a strategy to evaluate such exacerbations, an algorithm to switch between biologics, and perhaps to consider two biologics concurrently.

PD-L1 in circulating exosomes of Merkel cell carcinoma.

Exosomes, as potential circulated biomarkers, have recently become a topic of interest in the field of oncology. Immune checkpoint molecule PD-L1 has recently been detected in circulating exosomes from cancer patients. The purpose of this work was to evaluate PD-L1 levels in circulating exosomes (Exo-PD-L1) isolated from patients' plasma suffering from Merkel cell carcinoma (MCC). We conducted a prospective bicentric cohort study. PD-L1 was analysed in circulating exosomes from plasma samples of patients suffering from MCC stage I to IV (according to the AJCC 8). Exosomes from 34 patients corresponding to 66 samples were analysed. PD-L1 was identified in circulating exosomes of MCC patients. Exo-PD-L1 levels of MCC patients were similar to healthy donors and lower than other cancers such as melanoma. Exo-PD-L1 levels tended to be higher in MCC patients with distant metastases. Furthermore, Exo-PD-L1 levels did not significantly vary over the course of the disease whatever the disease course or the response to treatment. This study assessed the presence of PD-L1 in circulating exosomes of MCC patients. The low levels of Exo-PD-L1 and small changes over the course of the disease may be due to the metastatic dissemination of MCC, which is mainly through the skin and lymph nodes rather than blood. PD-L1 was identified in circulating exosomes of MCC patients and tends to be higher in advanced disease. This preliminary study is a proof of concept of PD-L1 detection in circulating exosomes of MCC patients.

Design, synthesis and antitumor efficacy evaluation of a series of novel ß-elemene-based macrocycles.

ß-Elemene is the major constituent of the antitumor drugs elemene extract approved in China. By incorporating macrocyclization strategy into the ß-elemene skeleton, we designed a series of novel macrocycles retaining three key carbon-carbon double bonds. Four different methods have been successfully developed for these challenging ring systems. A total of twenty-eight 14- to 24-membered macrocycles were synthesized. Most of these macrocycles exhibited good antitumor activity against several cancer cell lines (PC-3, A549, U87MG, U251 and HCT116), with up to 40 folds improvement of activity comparing to ß-elemene. Additionally, X-ray single crystal structures of compounds Ic, Ip, and IIh were successfully solved as the proof of macrocycle formation. The results warrant the further investigation of this novel class macrocycles in pharmacokinetic and pharmacodynamics studies, which will be reported in due course.

TFG-ß Nuclear Staining as a Potential Relapse Risk Factor in Early-Stage Non-Small-Cell Lung Cancer.

Nowadays, the impact of the tumor-immune microenvironment (TME) in non-small-cell lung cancer (NSCLC) prognosis and treatment response remains unclear. Thus, we evaluated the expression of PD-L1, tumor-infiltrating lymphocytes (TILs), and transforming growth factor beta (TGF-ß) in NSCLC to identify differences in TME, detect possible new prognostic factors, and assess their relationship. We retrospectively analyzed 55 samples from patients who underwent NSCLC surgery and had over a 5-year follow-up. PD-L1 expression was determined by immunohistochemistry following standard techniques. The presence of TILs was evaluated at low magnification and classified into two categories, "intense" and "non-intense". Cytoplasmic TGF-ß staining visualization was divided into four categories, and unequivocal nuclear staining in >1% of viable tumor cells was defined as "present" or "absent". Our aim was to identify differences in disease-free survival (DFS) and overall survival (OS). Tumor stage was the only objective prognostic factor for OS. PD-L1 expression and the presence of TILs had no prognostic impact, neither their combination. There seems to be a lower expression of PD-L1 and a higher expression of TILs in early stages of the disease. Our TGF-ß nuclear staining analysis was promising, since it was associated with worse DFS, revealing this protein as a possible prognostic biomarker of recurrence for resectable NSCLC.

Progesterone elevation on the day of oocyte retrieval and live birth rate after in vitro fertilisation treatment.

The objective of this study was to evaluate if progesterone elevation (PE) on the day of oocyte retrieval is associated with IVF outcome. A prospective cohort study of 400 IVF-ICSI cycles, with fresh embryo transfer on day 2-3 was performed. We proposed a serum progesterone (P) level on percentile (p) 90 as a threshold.Pregnancy rates were not affected, however there were more miscarriages (25.7% vs 43.8%) and lower live birth rate (LBR) (28% vs 23.1%) in the PE group (not statistically significant). We also found a positive correlation between P levels and retrieved and mature oocytes, total embryos, and good quality embryos. This is the first study to analyse LBR based on P levels on the day of oocyte retrieval. PE is not associated with the IVF outcome, but there is a trend to lower ongoing pregnancy rate and LBR and more miscarriages. Our results also show that P levels have no negative effects on oocyte and embryo quality.Impact statementWhat is already known on this subject? The influence of PE during IVF cycle on pregnancy rates remains controversial.What do the results of this study add? This is the first study to analyse LBR based on P levels on the day of oocyte retrieval.What are the implications of these findings for clinical practice and/or further research? We demonstrated that pregnancy rates were not affected by PE at oocyte retrieval, but there is a trend to lower ongoing pregnancy rate and LBR and more miscarriages. Randomised controlled trials are needed to offer more evidence of these relationships.

[Assessment and follow-up of patients with suspected COVID-19 in the first pandemic wave in an urban area of Andalusia (Spain)]. / Valoración y seguimiento de los pacientes con sospecha de COVID-19 en la primera ola pandémica en una zona urbana de Andalucía.

OBJECTIVE: To know the characteristics of the initial care and telephone follow-up of patients with suspected COVID-19 in the first wave of the pandemic. DESIGN: Observational, retrospective (audit of medical records). LOCATION: Urban Primary Care Center of Andalusia (Spain). PARTICIPANTS: Probable cases of SARS-CoV-2 (from 20/03/15 to 20/06/15). PRINCIPAL MEASUREMENTS: Initial medical assessment (place and modality) and telephone follow-up (number of calls and duration). Sociodemographic variables (including family structure). Clinical course (symptoms, vulnerability, tests, hospital admission and outcome). RESULTS: Three hundred one patients (51.5±17.8 years; 23% vulnerable people; 17% non-nuclear family structure). First assessment in Primary Care by phone (59.8%) and face-to-face (25.2%). At the hospital emergency department (11%), patients were more frequently from non-nuclear families (P<.05 χ2) and more tests were carried out (P<.05 χ2) despite having similar symptoms. Vulnerable elderly patients needed home health care (P<.01 ANOVA). 8.2±4.4 follow-up phone calls were made per patient, for 17.1±10.3 days. It increases after ≥2 face-to-face consultations (OR 4.8), the presence of alarm symptoms (OR 2.3) and age ≥45 years (OR 2.0). Few confirmatory tests were performed (19.3% antigenic, 13% serology). The 15.3% hospital admissions (all assessed previously in Primary Care), with 6.3% severe cases and 2.3% death. CONCLUSION: Population chose to be attended in Primary Care during the pandemic first wave, above all by phone. Telephone follow-up was well accepted and useful to select patients with serious complications. Initial medical assessment in the hospital emergency department was related to a lack of social support but not with greater clinical severity.

Nanofitins targeting heat shock protein 110: An innovative immunotherapeutic modality in cancer.

The presence of an inactivating heat shock protein 110 (HSP110) mutation in colorectal cancers has been correlated with an excellent prognosis and with the ability of HSP110 to favor the formation of tolerogenic (M2-like) macrophages. These clinical and experimental results suggest a potentially powerful new strategy against colorectal cancer: the inhibition of HSP110. In this work, as an alternative to neutralizing antibodies, Nanofitins (scaffold ~7 kDa proteins) targeting HSP110 were isolated from the screening of a synthetic Nanofitin library, and their capacity to bind (immunoprecipitation, biolayer interferometry) and to inhibit HSP110 was analyzed in vitro and in vivo. Three Nanofitins were found to inhibit HSP110 chaperone activity. Interestingly, they share a high degree of homology in their variable domain and target the peptide-binding domain of HSP110. In vitro, they inhibited the ability of HSP110 to favor M2-like macrophages. The Nanofitin with the highest affinity, A-C2, was studied in the CT26 colorectal cancer mice model. Our PET/scan experiments demonstrate that A-C2 may be localized within the tumor area, in accordance with the reported HSP110 abundance in the tumor microenvironment. A-C2 treatment reduced tumor growth and was associated with an increase in immune cells infiltrating the tumor and particularly cytotoxic macrophages. These results were confirmed in a chicken chorioallantoic membrane tumor model. Finally, we showed the complementarity between A-C2 and an anti-PD-L1 strategy in the in vivo and in ovo tumor models. Overall, Nanofitins appear to be promising new immunotherapeutic lead compounds.

Extracellular Heat Shock Proteins as Therapeutic Targets and Biomarkers in Fibrosing Interstitial Lung Diseases.

Interstitial lung diseases (ILDs) include a large number of diseases and causes with variable outcomes often associated with progressive fibrosis. Although each of the individual fibrosing ILDs are rare, collectively, they affect a considerable number of patients, representing a significant burden of disease. Idiopathic pulmonary fibrosis (IPF) is the typical chronic fibrosing ILD associated with progressive decline in lung. Other fibrosing ILDs are often associated with connective tissues diseases, including rheumatoid arthritis-ILD (RA-ILD) and systemic sclerosis-associated ILD (SSc-ILD), or environmental/drug exposure. Given the vast number of progressive fibrosing ILDs and the disparities in clinical patterns and disease features, the course of these diseases is heterogeneous and cannot accurately be predicted for an individual patient. As a consequence, the discovery of novel biomarkers for these types of diseases is a major clinical challenge. Heat shock proteins (HSPs) are molecular chaperons that have been extensively described to be involved in fibrogenesis. Their extracellular forms (eHSPs) have been recently and successfully used as therapeutic targets or circulating biomarkers in cancer. The current review will describe the role of eHSPs in fibrosing ILDs, highlighting the importance of these particular stress proteins to develop new therapeutic strategies and discover potential biomarkers in these diseases.

Neutralization of HSF1 in cells from PIK3CA-related overgrowth spectrum patients blocks abnormal proliferation.

PIK3CA-related overgrowth spectrum is caused by mosaicism mutations in the PIK3CA gene. These mutations, which are also observed in various types of cancer, lead to a constitutive activation of the PI3K/AKT/mTOR pathway, increasing cell proliferation. Heat shock transcription factor 1 (HSF1) is the major stress-responsive transcription factor. Recent findings indicate that AKT phosphorylates and activates HSF1 independently of heat-shock in breast cancer cells. Here, we aimed to investigate the role of HSF1 in PIK3CA-related overgrowth spectrum. We observed a higher rate of proliferation and increased phosphorylation of AKT and p70S6K in mutant fibroblasts than in control cells. We also found elevated phosphorylation and activation of HSF1, which is directly correlated to AKT activation. Specific AKT inhibitors inhibit HSF1 phosphorylation as well as HSF1-dependent gene transcription. Finally, we demonstrated that targeting HSF1 with specific inhibitors reduced the proliferation of mutant cells. As there is currently no curative treatment for PIK3CA-related overgrowth spectrum, our results identify HSF1 as a new potential therapeutic target.

TRIM33 prevents pulmonary fibrosis by impairing TGF-ß1 signalling.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterised by myofibroblast proliferation and abnormal extracellular matrix accumulation in the lungs. Transforming growth factor (TGF)-ß1 initiates key profibrotic signalling involving the SMAD pathway and the small heat shock protein B5 (HSPB5). Tripartite motif-containing 33 (TRIM33) has been reported to negatively regulate TGF-ß/SMAD signalling, but its role in fibrogenesis remains unknown. The objective of this study was to elucidate the role of TRIM33 in IPF. METHODS: TRIM33 expression was assessed in the lungs of IPF patients and rodent fibrosis models. Bone marrow-derived macrophages (BMDM), primary lung fibroblasts and 3D lung tissue slices were isolated from Trim33-floxed mice and cultured with TGF-ß1 or bleomycin (BLM). Trim33 expression was then suppressed by adenovirus Cre recombinase (AdCre). Pulmonary fibrosis was evaluated in haematopoietic-specific Trim33 knockout mice and in Trim33-floxed mice that received AdCre and BLM intratracheally. RESULTS: TRIM33 was overexpressed in alveolar macrophages and fibroblasts in IPF patients and rodent fibrotic lungs. Trim33 inhibition in BMDM increased TGF-ß1 secretion upon BLM treatment. Haematopoietic-specific Trim33 knockout sensitised mice to BLM-induced fibrosis. In primary lung fibroblasts and 3D lung tissue slices, Trim33 deficiency increased expression of genes downstream of TGF-ß1. In mice, AdCre-Trim33 inhibition worsened BLM-induced fibrosis. In vitro, HSPB5 was able to bind directly to TRIM33, thereby diminishing its protein level and TRIM33/SMAD4 interaction. CONCLUSION: Our results demonstrate a key role of TRIM33 as a negative regulator of lung fibrosis. Since TRIM33 directly associates with HSPB5, which impairs its activity, inhibitors of TRIM33/HSPB5 interaction may be of interest in the treatment of IPF.

Macrophage-induced reactive oxygen species promote myometrial contraction and labor-associated mechanisms†.

At labor, the myometrium is infiltrated by a massive influx of macrophages that secrete high levels of pro-inflammatory cytokines inducing the expression of specific labor-associated markers. However, the interactions between myocytes and macrophages and the role of macrophages in the myometrium at labor remain to be elucidated. In this work, we studied the role of myometrium-infiltrated macrophages and their interaction with myocytes in lipopolysaccharide-induced preterm labor. A co-culture model of human primary myometrial cells and macrophages was developed and validated. Collagen lattices were used to evaluate myocyte contraction. Differentiation steps were assessed by (i) phalloidin and vinculin staining for cytoskeleton reorganization, (ii) gap junction protein alpha 1 expression and scrape loading/dye transfer with Lucifer Yellow for gap junction intercellular communication, and (iii) calcium imaging for cell excitability. We demonstrated that macrophages favored lipopolysaccharide-induced contraction and early differentiation of myometrial cells. Transwell assays showed that previous activation of macrophages by lipopolysaccharide was essential for this differentiation and that macrophage/myocyte interactions involved macrophage release of reactive oxygen species (ROS). The effects of macrophage-released ROS in myometrial cell transactivation were mimicked by H2O2, suggesting that superoxide anion is a major intermediate messenger in macrophage/myocyte crosstalk during labor. These novel findings provide the foundation for innovative approaches to managing preterm labor, specifically the use of antioxidants to inhibit the initial stages of labor before the contractile phenotype has been acquired. In addition, the co-culture model developed by our team could be used in future research to decipher pathophysiological signaling pathways or screen/develop new tocolytics.

HSP110 sustains chronic NF-κB signaling in activated B-cell diffuse large B-cell lymphoma through MyD88 stabilization.

Activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL) is an aggressive lymphoproliferative disorder involving chronic NF-κB activation. Several mutations in the BCR and MyD88 signaling pathway components, such as MyD88 L265P, are implicated in this aberrant activation. Among heat shock proteins, HSP110 has recently been identified as a prosurvival and/or proliferation factor in many cancers, but its role in ABC-DLBCL survival mechanisms remained to be established. We observed that short hairpin RNA-mediated HSP110 silencing decreased the survival of several ABC-DLBCL cell lines and decreased immunoglobulin M-MyD88 co-localization and subsequent NF-κB signaling. Conversely, overexpression of HSP110 in ABC-DLBCL or non-DLBCL cell lines increased NF-κB signaling, indicating a tight interplay between HSP110 and the NF-κB pathway. By using immunoprecipitation and proximity ligation assays, we identified an interaction between HSP110 and both wild-type MyD88 and MyD88 L265P. HSP110 stabilized both MyD88 forms with a stronger effect on MyD88 L265P, thus facilitating chronic NF-κB activation. Finally, HSP110 expression was higher in lymph node biopsies from patients with ABC-DLBCL than in normal reactive lymph nodes, and a strong correlation was found between the level of HSP110 and MyD88. In conclusion, we identified HSP110 as a regulator of NF-κB signaling through MyD88 stabilization in ABC-DLBCL. This finding reveals HSP110 as a new potential therapeutic target in ABC-DLBCL.

XPO1 regulates erythroid differentiation and is a new target for the treatment of ß-thalassemia.

ß-thalassemia major (ß-TM) is an inherited hemoglobinopathy caused by a quantitative defect in the synthesis of ß-globin chains of hemoglobin, leading to the accumulation of free a-globin chains that aggregate and cause ineffective erythropoiesis. We have previously demonstrated that terminal erythroid maturation requires a transient activation of caspase-3 and that the chaperone Heat Shock Protein 70 (HSP70) accumulates in the nucleus to protect GATA-1 transcription factor from caspase-3 cleavage. This nuclear accumulation of HSP70 is inhibited in human ß-TM erythroblasts due to HSP70 sequestration in the cytoplasm by free a-globin chains, resulting in maturation arrest and apoptosis. Likewise, terminal maturation can be restored by transduction of a nuclear-targeted HSP70 mutant. Here we demonstrate that in normal erythroid progenitors, HSP70 localization is regulated by the exportin-1 (XPO1), and that treatment of ß-thalassemic erythroblasts with an XPO1 inhibitor increased the amount of nuclear HSP70, rescued GATA-1 expression and improved terminal differentiation, thus representing a new therapeutic option to ameliorate ineffective erythropoiesis of ß-TM.