Molecular mechanisms of thalidomide effectiveness on COVID-19 patients explained: ACE2 is a new ΔNp63α target gene.

COVID-19 pandemic is caused by the SARS-CoV-2 virus, whose internalization and infection are mediated by the angiotensin-converting enzyme 2 (ACE2). The identification of novel approaches to tackle this step is instrumental for the development of therapies for the management of COVID-19 and other diseases with a similar mechanism of infection. Thalidomide, a drug sadly known for its teratogenic effects, has potent immunomodulatory and anti-inflammatory properties. Treatment with this drug has been shown to improve the immune functions of COVID-19 patients and proposed for the management of COVID-19 in clinical practice through drug repositioning. Here, we investigated the molecular details linking thalidomide to ACE2 and COVID-19, showing that in conditions mimicking SARS-CoV-2-associated cytokine storm, the transcription factor ΔNp63α and ACE2 are stabilized, and IL-8 production is increased. In such conditions, we found p63 to bind to and regulate the expression of the ACE2 gene. We previously showed that ΔNp63α is degraded upon thalidomide treatment and now found that treatment with this drug-or with its analogue lenalidomide-downregulates ACE2 in a p63-dependent manner. Finally, we found that thalidomide treatment reduces in vitro infection by pseudo-SARS-CoV-2, a baculovirus pseudotyped with the SARS-CoV-2 spike protein. Overall, we propose the dual effect of thalidomide in reducing SARS-CoV-2 viral re-entry and inflammation through p63 degradation to weaken SARS-CoV-2 entry into host cells and mitigate lung inflammation, making it a valuable option in clinical management of COVID-19. KEY MESSAGES: Thalidomide treatment results in p63-dependent ACE2 downregulation. ACE2 is a p63 transcriptional target. Thalidomide reduces the "cytokine storm" associated to COVID-19. Thalidomide prevents viral re-entry of SARS-CoV-2 by p63-dependent ACE2 downregulation. Thalidomide is a modulator of SARS-CoV-2 or other ACE2-dependent infections. ACE2 is modulated by a pharmacological substance.

The Role of Thalidomide and Its Analogs in the Treatment of Hereditary Hemorrhagic Telangiectasia: A Systematic Review.

Background: Hereditary hemorrhagic telangiectasia (HHT) is a disease characterized by arteriovenous malformations and telangiectases, in which the endothelium and immune system play a role in the pathophysiology. Therefore, treatments with antiangiogenic properties which are also regarded as immunomodulators were demonstrated to play an important role in treatment. This systematic review aimed to gather the accumulated information of the use of thalidomide and its analogs in the treatment of HHT. Methods: In this systematic review, publications that were published up to March 2024 and met the inclusion criteria were compiled using the keywords 'thalidomide', 'lenalidomide', 'pomalidomide', 'immunomodulatory drugs' and 'HHT' in Medline and Scholars databases. Results: A total of 53 articles were evaluated and 15 were included in the study. Thalidomide was the predominant used agent and was observed to be used in patients with ages ranging from 37 to 77 years, with doses ranging from 50 to 200 mg daily, and the mean follow-up period was observed to be 6-60 months. Assessments regarding efficacy were based on the epistaxis severity score (ESS), hemoglobin level, and transfusion independence. While thalidomide showed significant efficacy, it also had an adverse event rate of any severity of up to 85% of patients. Use of lenalidomide to control bleeding in HHT was reported in a single case report, while the use of pomalidomide was observed to be investigated in Phase 1 and Phase 2 studies in patients aged 48 to 70 years, with doses ranging from 1 to 5 mg daily for 6-24 months. This treatment was reported to provide significant improvement in hemoglobin levels and ESS. Adverse events of any severity were observed at a frequency of 60-66%. Conclusions: Antiangiogenic agents such as thalidomide, lenalidomide, and pomalidomide may be effective in managing HHT. However, further studies are needed to optimize the timing, dose, and sequence.

A novel hypothesis about mechanism of thalidomide action on pattern formation.

Morphogenesis, the complex process governing the formation of functional living structures, is regulated by a multitude of molecular mechanisms at various levels. While research in recent decades has shed light on many pathways involved in morphogenesis, none singularly accounts for the precise geometric shapes of organisms and their components in space. To bridge this conceptual gap between specific molecular mechanisms and the creation of definitive morphological forms, we have proposed the "epigenetic code hypothesis" in our previous work. In this framework, "epigenetic" means any inheritable cellular information beyond the genetic code that regulates cell fate alongside genetic information. In this study, we conduct a comprehensive analysis of thalidomide's teratogenic effects through the lens of our proposed "epigenetic code" theory, revealing significant indirect support for our hypothesis. We also explore the structural and functional parallels between thalidomide and auxin.

Thalidomide attenuates radiation-induced apoptosis and pro-inflammatory cytokine secretion in oral epithelial cells by promoting LZTS3 expression.

Radiation-induced oral mucositis (RIOM) is a prevalent oral complication that occurs in individuals undergoing radiotherapy or radiation treatment for head and neck tumors. The presence of oral mucosal rupture and ulcerative lesions, which are the defining features of this condition, can significantly affect the quality of life of patients. Additionally, it can interfere with tumor therapy and contribute to an unfavorable prognosis. Current evidence suggests that cellular inflammation and programmed cell death are important factors in disease development. Moreover, thalidomide (THD) has been revealed to reduce the incidence and severity of RIOM in patients undergoing chemoradiotherapy for nasopharyngeal carcinoma. However, the mechanism through which THD improves RIOM remains unknown. This study aimed to investigate the role of LZTS3 in RIOM by analyzing various sequencing datasets and conducting knockdown and overexpression experiments. We used small interfering RNA transfection and LZTS3 overexpression, followed by validation through polymerase chain reaction, western blotting, flow cytometry, and enzyme-linked immunosorbent assay. In this study, we identified LZTS3 as a potential target for THD regulation in RIOM. Through a series of experiments, we confirmed that LZTS3 has the ability to inhibit the inflammatory response and apoptosis of cells. In addition, we also found that THD can regulate the expression of LZTS3 by upregulating, thereby affecting inflammatory response and apoptosis. We repeated these results in a live animal model. In summary, THD has the potential to reduce the occurrence of oral mucositis in patients by upregulating LZTS3 levels. These findings provide a promising avenue for future drug research and development to treat RIOM.

Efficacy and safety of thalidomide for recurrent aphthous stomatitis: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Recurrent aphthous stomatitis (RAS) is considered as the most common oral mucosal lesion affecting up to 25% of people worldwide. Thalidomide has been reported for the treatment of RAS, but the evidence has not been systematically evaluated. We first systematically reviewed the efficacy and safety of thalidomide for the treatment of RAS. METHODS: We searched The Cochrane Library, PubMed, Scopus, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), Chinese BioMedical Literature Database (CBM), Wanfang Data, and VIP information from inception to December 2023. Randomized controlled trials (RCTs) comparing thalidomide with control for RAS were included in the analysis. The primary outcome were complete response and overall response, and the secondary outcome were recurrence interval (RI), ulcer number and size, healing time, visual analogue scale (VAS), immunological data, and adverse events. Meta-analysis was conducted using the Review Manager 5.4 software. RESULTS: Twenty-one trials involving 1668 patients were included in this review. The results of our meta-analysis showed that thalidomide significantly improved the complete response rate and overall response rate, prolonged the recurrence interval, accelerated the healing process, reduced the number and size of ulcers, and lowered TNF-α levels in the treatment of RAS. However, thalidomide significantly increases adverse events. RESULTS: Thalidomide has a significant benefit in the treatment of RAS. However, considering the potential side effects of thalidomide, it may be an optimal treatment option for major RAS patients or cases that do not respond to topical agents. TRIAL REGISTRATION: PROSPERO registration number: CRD42024495038.

Recent advances in the treatment of refractory gastrointestinal angiodysplasia.

Gastrointestinal angiodysplasia (GIA) is a common, acquired, vascular abnormality of the digestive tract, and a frequent cause of bleeding. Refractory GIA criteria usually include recurrent bleeding, transfusions and/or repeat endoscopy. Pharmacological and interventional treatments have been the subject of recent high-quality publications. This review provides an overview of the latest updates on non-endoscopic management of refractory GIA. Aortic valve replacement has shown its efficacy in Heyde syndrome and should be considered if indicated. Anti-angiogenic drugs, such as Octreotide and Thalidomide, are efficient treatments of refractory GIA-related bleeding. Somatostatin analogs should, based on efficacy and tolerance profile, be considered first. In the future, a better understanding of the physiopathology of GIA might help develop new-targeted therapies.

Trisomy 8 presentation by inflammatory manifestations and its response to thalidomide: two case reports and narrative review.

Objective: It has been recognized that there is a nexus among Trisomy 8 (T8), Behcet's disease (BD), and myelodysplastic syndrome (MDS). We reported a series of inflammatory features in 2 children with T8 without hematological involvement. Methods: 2 children with trisomy 8 who were excluded from MDS were retrospectively collected from the Department of Rheumatology and Immunology, Children's Hospital of Nanjing Medical University, Nanjing. Results: Patients developed a range of inflammatory manifestations before a diagnosis of T8. The clinical manifestations of T8 patients vary from normal to severely disabled. Glucocorticoids and thalidomide can effectively relieve inflammation in patients with T8. Conclusion: The early clinical manifestations of T8 in children lack specificity, and the diagnosis is mainly based on karyotype analysis, gastrointestinal endoscopy and bone marrow aspiration findings. Active and effective immunoregulatory therapy and long-term follow-up can improve the prognosis of patients with T8.

Tofacitinib versus thalidomide for mucocutaneous lesions of systemic lupus erythematosus: A real-world CSTAR cohort study XXVII.

OBJECTIVE: Thalidomide is an effective medication for refractory mucocutaneous lesions of systemic lupus erythematosus (SLE) and can treat arthritis in some autoimmune diseases, but it has some adverse reactions. Recently, the effectiveness of tofacitinib in treating mucocutaneous lesions of SLE has been reported. We aimed to compare the efficacy and safety of tofacitinib with thalidomide in treating mucocutaneous and musculoskeletal lesions in patients with SLE. METHODS: This study was a real-world cohort study based on the Chinese SLE Treatment and Research group (CSTAR) registry. SLE patients who manifested mucocutaneous and/or musculoskeletal symptoms and were prescribed tofacitinib or thalidomide were included. We retrospectively conducted comparisons between the tofacitinib and thalidomide groups regarding clinical improvements, SLE disease activity, serological indicators, glucocorticoid doses, and adverse events at the 1, 3, and 6-months time points. RESULTS: At 3 and 6 months, the tofacitinib group exhibited a higher proportion of patients with improvement in mucocutaneous and musculoskeletal issues. Additionally, a greater percentage of patients in the tofacitinib group achieved remission or a low disease activity state (LLDAS) at these time points. No significant serological improvements were observed in either the tofacitinib or thalidomide groups. Fewer adverse events were observed in the tofacitinib group than in the thalidomide group. CONCLUSIONS: Tofacitinib might be superior to thalidomide in the improvement of mucocutaneous and musculoskeletal lesions in SLE, and had a good safety profile.

Thalidomide and Hydroxyurea in Transfusion-Dependent Thalassemia: Efficacy, Safety Profile and Impact on Quality of Life.

Transfusion-dependent thalassemia (TDT) is a major public health concern in India, requiring regular transfusions for survival. There is also significant morbidity caused by iron overload and transfusion related infections. Novel therapies targeting fetal hemoglobin induction are the need of the hour in resource-poor institutions for patients where transplant is not feasible for various reasons. This single arm, non-randomised prospective trial evaluated the efficacy and safety of a combination of low dose thalidomide and hydroxyurea in TDT along with the impact on quality of life (QoL). It included 41 TDT patients, who failed a reasonable trial of hydroxyurea. Complete response (CR) was defined as transfusion independence and partial response (PR) denoted at least a 50% reduction in transfusion requirement. The rest were defined as non-responders (NR). The mean age of the cohort was 20.78 years (range 12-45 years). There were 13 males and 28 females. Nineteen (46.3%), 7 (17.1%), and 15 (36.6%) patients achieved CR, PR, and no response respectively. The overall response rate (CR + PR) was 63.4%. There was a significant increase in hemoglobin levels with decrement in transfusion burden and ferritin levels. There were no significant adverse reactions. No significant predictors of response were found including amongst genetic modifiers. It improved the health related QoL amongst responders. The combination of thalidomide and hydroxyurea appear safe and effective in the reduction in transfusion requirement of TDT patients. The judicious use of these drugs can improve the quality of life and pave the way for patients not eligible for a stem cell transplant.

Targeted treatments for vascular malformations: current state of the art.

Vascular malformations, which arise from anomalies in angiogenesis, encompass capillary, lymphatic, venous, arteriovenous, and mixed malformations, each affecting specific vessel types. Historically, therapeutic options such as sclerotherapy and surgery have shown limited efficacy in complicated malformations. Most vascular malformations stem from hereditary or somatic mutations akin to oncogenic alterations, activating the PI3K-AKT-mTOR, RAS-MAPK-ERK, and G-protein coupled receptor pathways. Recognizing the parallels with oncogenic mutations, we emphasize the potential of targeted molecular inhibitors in the treatment of vascular malformations by repurposing anticancer drugs. This review delves into the recent development and future use of such agents for the management of slow- and fast-flow vascular malformations, including in more specific situations, such as prenatal treatment and the management of associated coagulopathies.

Penile hemangiosarcoma as a cause of stranguria in a dog: clinical presentation, imaging findings, treatment and outcome.

Background: Penile tumors are rare in dogs and only single case reports or small case series have been reported. Case description: An 11-year-old, cross-breed dog was presented for a two-week history of stranguria. At physical examination, a subcutaneous swelling of the penis was detected. Abdominal radiographs, ultrasonography, and CT showed a subcutaneous penile mass involving the penile urethra and bulbus glandis associated with marked lysis of the os penis. Histological features along with the neoplastic cell positivity to CD31 and FVIII immunohistochemical markers warranted a final diagnosis of penile hemangiosarcoma. Findings/treatment and outcome: The dog was treated with amputation of the penis, scrotal urethrostomy, and five adjuvant doses of doxorubicin along with thalidomide. Cutaneous and omental metastases were found 235 days after surgery. The dog was euthanized at 296 days due to bone and pulmonary metastasis. Conclusion: Penile hemangiosarcoma seems to share the same aggressive behavior with other hemangiosarcomas seen in other anatomical locations. Therefore, surgery and chemotherapy may improve survival time in dogs with penile hemangiosarcoma as well.

Immunomodulatory imide drugs inhibit human detrusor smooth muscle contraction and growth of human detrusor smooth muscle cells, and exhibit vaso-regulatory functions.

BACKGROUND: The immunomodulatory imide drugs (IMiDs) thalidomide, lenalidomide and pomalidomide may exhibit therapeutic efficacy in the prostate. In lower urinary tract symptoms (LUTS), voiding and storage disorders may arise from benign prostate hyperplasia, or overactive bladder. While current therapeutic options target smooth muscle contraction or cell proliferation, side effects are mostly cardiovascular. Therefore, we investigated effects of IMiDs on human detrusor and porcine artery smooth muscle contraction, and growth-related functions in detrusor smooth muscle cells (HBdSMC). METHODS: Cell viability was assessed by CCK8, and apoptosis and cell death by flow cytometry in cultured HBdSMC. Contractions of human detrusor tissues and porcine interlobar and coronary arteries were induced by contractile agonists, or electric field stimulation (EFS) in the presence or absence of an IMID using an organ bath. Proliferation was assessed by EdU assay and colony formation, cytoskeletal organization by phalloidin staining, RESULTS: Depending on tissue type, IMiDs inhibited cholinergic contractions with varying degree, up to 50 %, while non-cholinergic contractions were inhibited up to 80 % and 60 % for U46619 and endothelin-1, respectively, and EFS-induced contractions up to 75 %. IMiDs reduced viable HBdSM cells in a time-dependent manner. Correspondingly, proliferation was reduced, without showing pro-apoptotic effects. In parallel, IMiDs induced cytoskeletal disorganization. CONCLUSIONS: IMiDs exhibit regulatory functions in various smooth muscle-rich tissues, and of cell proliferation in the lower urinary tract. This points to a novel drug class effect for IMiDs, in which the molecular mechanisms of action of IMiDs merit further consideration for the application in LUTS.

A pre-B acute lymphoblastic leukemia cell line model reveals the mechanism of thalidomide therapy-related B-cell leukemogenesis.

Lenalidomide, a thalidomide derivative, is prescribed as maintenance therapy for multiple myeloma (MM). Patients with MM receiving lenalidomide were found to develop a distinct therapy-related B cell acute lymphoblastic leukemia (B-ALL). However, the molecular mechanism by which lenalidomide drives B-ALL is unknown. We show that thalidomide treatment of B cell lines increased CD34 expression and fibronectin adhesion. This resembled the effects of Ikzf1 loss of function mutations in B-ALL. IKZF1 is a transcription factor that can act as both a transcriptional activator and a repressor depending upon the target loci. In our experiments, thalidomide-induced degradation of IKZF1 increased the expression of its transcriptional repression targets Itga5 and CD34 explaining the increased adhesion and stemness. Strikingly, withdrawal of thalidomide lead to the mis-localization of IKZF1 to the cytoplasm. Moreover, chromatin immunoprecipitation data showed a long-term effect of thalidomide treatment on IKZF1 target loci. This included decreased chromatin occupancy at early B cell factor 1 (EBF1) and Spi1 (PU.1). Consequently, B-cell lineage specifying transcription factors including Pax5, Spi1 and EBF1 were downregulated even after 7 days of thalidomide withdrawal. Our study thus provides a molecular mechanism of thalidomide-induced B-ALL whereby thalidomide alters the chromatin occupancy of IKZF1 at key B-cell lineage transcription factors leading to a persistent block in B-cell differentiation.

Clinical efficacy of thalidomide for various genotypes of beta thalassemia.

OBJECTIVE: The objective of this study was to investigate the therapeutic efficacy of thalidomide across various genotype presentations of ß-thalassemia so as to facilitate the early screening of thalidomide-sensitive thalassemia cases and to understand the impact of iron overload on thalidomide. METHODS: From our initial sample of 52 patients, we observed 48 patients with ß-thalassemia for two years after administration of thalidomide. This cohort included 34 patients with transfusion-dependent thalassemia (TDT) and 14 patients with non-transfusion-dependent thalassemia (NTDT). We recorded the values of hemoglobin (Hb), fetal hemoglobin (HbF), and serum ferritin (SF) in the baseline period and at 1, 3, 6, 12, 18, and 24 months after enrollment, as well as the pre- and post-treatment blood transfusion volume in all 48 cases. According to the increase in Hb levels from baseline during the 6-month observation period, the response to thalidomide was divided into four levels: main response (MaR), minor response (MiR), slow response (SLR), and no response (NR). A decrease in serum ferritin levels compared to baseline was considered alleviation of iron overload. We calculated the overall response rate (ORR) as follows: ORR = MaR + MiR + SLR/number of observed cases. RESULTS: The ORR was 91.7% (44/48 cases), and 72.9% showed MaR (35/48 cases). Among the 34 patients with TDT, 21 patients (61.8%) were free of blood transfusion, and the remaining 13 patients still required blood transfusion, but their total blood transfusion volume reduced by 31.3% when compared to the baseline. We found a total of 33 cases with 10 combinations of advantageous genes, which included 5 cases with ßCD41-42/ßCD17 and 6 cases with ßCD41-42/ß-28. Based on the treatment outcomes among the 48 cases in the observation group, there were 33 cases in the MaR group and 15 cases in the SLR/NR group. There was a difference in HbF between the two groups at baseline (P = 0.041). There were significant differences between the two groups in Hb and HbF at the time points of 6 and 12 months, respectively (P < 0.001). Compared to the baseline measurement, there was a significant decrease in the level of SF at months 12 and 24 (P < 0.001). CONCLUSION: In this study, we identified 10 ß-thalassemia gene combinations that were sensitive to thalidomide. These gene combinations can be used for initial screening and to predict the therapeutic effect of thalidomide in clinical practice. We examined the therapeutic response to thalidomide and found that the administration of thalidomide in combination with standardized iron removal was more beneficial in reducing iron overload.

QoL during KTd or KRd induction followed by K maintenance or observation in transplant noneligible patients with newly diagnosed multiple myeloma: Longitudinal and cross-sectional analysis of the randomized AGMT 02 study.

Understanding the impact of induction and maintenance therapy on patients' quality of life (QoL) is important for treatment selection. This study aims to compare patient-reported QoL between patients treated with KTd or KRd induction therapy and K maintenance therapy or observation. QoL was assessed using the EORTC QOL-C 30 and QOL-MY20 questionnaires in the AGMT-02 study, in which 123 patients with newly diagnosed transplant ineligible multiple myeloma were randomized to nine cycles of either KTd or KRd induction therapy, followed by 12 cycles of K maintenance therapy, or observation. Longitudinal assessments showed statistically significant improvements in global health-related QoL, various disease symptoms and pain for both treatment regimens. KTd improved insomnia and fatigue, and KRd improved physical functioning. Cross-sectional comparisons indicated a "slight" superiority of KTd over KRd in several scales, with the exception of higher neuropathy scores with KTd. During maintenance, longitudinal comparisons showed no statistically significant changes. Cross-sectional comparisons revealed a "slight" improvement in cognitive functioning during carfilzomib therapy, but a worsening in most other QoL scales. Induction therapy led to improvements in most QoL items, while maintenance therapy with K maintenance was associated with "slight" or "moderate" impairments in several QoL scales compared with the observation group.

Teratogenicity is more likely a function of primary and secondary pharmacology than caused by chemically reactive metabolites: a critical evaluation of 40 years of scientific research.

The number of therapeutic drugs known to be human teratogens is actually relatively small. This may reflect the rigorous animal testing and well defined labelling. Some of these drugs were identified to have reactive metabolites and this has been postulated, historically, to be their teratogenic mechanism. These drugs include thalidomide, various anticonvulsants and retinoic acid derivatives.Many of these experiments were conducted in a period where chemically reactive metabolites were being intensely investigated and associated with all forms of toxicity. The legacy of this is that these examples are routinely cited as well established mechanisms.Examination of mechanism leads to the conclusion that the teratogenicity in humans of these compounds is likely due to the primary and secondary pharmacology of the parent drug and stable circulating metabolites and that association of reactive metabolites to this toxicity is unwarranted.

The emerging role of targeted protein degradation to treat and study cancer.

The evolution of cancer treatment has provided increasingly targeted strategies both in the upfront and relapsed disease settings. Small-molecule inhibitors and immunotherapy have risen to prominence with chimeric antigen receptor T-cells, checkpoint inhibitors, kinase inhibitors, and monoclonal antibody therapies being deployed across a range of solid organ and haematological malignancies. However, novel approaches are required to target transcription factors and oncogenic fusion proteins that are central to cancer biology and have generally eluded successful drug development. Thalidomide analogues causing protein degradation have been a cornerstone of treatment in multiple myeloma, but a lack of in-depth mechanistic understanding initially limited progress in the field. When the protein cereblon (CRBN) was found to mediate thalidomide analogues' action and CRBN's neo-targets were identified, existing and novel drug development accelerated, with applications outside multiple myeloma, including non-Hodgkin's lymphoma, myelodysplastic syndrome, and acute leukaemias. Critically, transcription factors were the first canonical targets described. In addition to broadening the application of protein-degrading drugs, resistance mechanisms are being overcome and targeted protein degradation is widening the scope of druggable proteins against which existing approaches have been ineffective. Examples of targeted protein degraders include molecular glues and proteolysis targeting chimeras (PROTACs): heterobifunctional molecules that bind to proteins of interest and cause proximity-induced ubiquitination and proteasomal degradation via a linked E3 ligase. Twenty years since their inception, PROTACs have begun progressing through clinical trials, with early success in targeting the oestrogen receptor and androgen receptor in breast and prostate cancer respectively. This review explores important developments in targeted protein degradation to both treat and study cancer. It also considers the potential advantages and challenges in the translational aspects of developing new treatments. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Environmental Signals.

Environmental factors have long been known to play a role in the pathogenesis of congenital heart disease (CHD), but this has not been a major focus of research in the modern era. Studies of human exposures and animal models demonstrate that demographics (age, race, socioeconomic status), diseases (e.g., diabetes, hypertension, obesity, stress, infection, high altitude), recreational and therapeutic drug use, and chemical exposures are associated with an increased risk for CHD. Unfortunately, although studies suggest that exposures to these factors may cause CHD, in most cases, the data are not strong, are inconclusive, or are contradictory. Although most studies concentrate on the effects of maternal exposure, paternal exposure to some agents can also modify this risk. From a mechanistic standpoint, recent delineation of signaling and genetic controls of cardiac development has revealed molecular pathways that may explain the effects of environmental signals on cardiac morphogenesis and may provide further tools to study the effects of environmental stimuli on cardiac development. For example, environmental factors likely regulate cellular signaling pathways, transcriptional and epigenetic regulation, proliferation, and physiologic processes that can control the development of the heart and other organs. However, understanding of the epidemiology and risk of these exposures and the mechanistic basis for any effects on cardiac development remains incomplete. Further studies defining the relationship between environmental exposures and human CHD and the mechanisms involved should reveal strategies to prevent, diagnose, and treat CHD induced by environmental signals.

Whole blood transcriptomics reveals the enrichment of neutrophil activation pathways during erythema nodosum leprosum reaction.

Introduction: Patients with the multibacillary form of leprosy can develop reactional episodes of acute inflammation, known as erythema nodosum leprosum (ENL), which are characterized by the appearance of painful cutaneous nodules and systemic symptoms. Neutrophils have been recognized to play a role in the pathogenesis of ENL, and recent global transcriptomic analysis revealed neutrophil-related processes as a signature of ENL skin lesions. Methods: In this study, we expanded this analysis to the blood compartment, comparing whole blood transcriptomics of patients with non-reactional lepromatous leprosy at diagnosis (LL, n=7) and patients with ENL before administration of anti-reactional treatment (ENL, n=15). Furthermore, a follow-up study was performed with patients experiencing an ENL episode at the time of diagnosis and after 7 days of thalidomide treatment (THAL, n=10). Validation in an independent cohort (ENL=8; LL=7) was performed by RT-qPCR. Results: An enrichment of neutrophil activation and degranulation-related genes was observed in the ENL group, with the gene for the neutrophil activation marker CD177 being the most enriched gene of ENL episode when compared to its expression in the LL group. A more pro-inflammatory transcriptome was also observed, with increased expression of genes related to innate immunity. Validation in an independent cohort indicated that S100A8 expression could discriminate ENL from LL. Supernatants of blood cells stimulated in vitro with Mycobacterium leprae sonicate showed higher levels of CD177 compared to the level of untreated cells, indicating that the leprosy bacillus can activate neutrophils expressing CD177. Of note, suggestive higher CD177 protein levels were found in the sera of patients with severe/moderate ENL episodes when compared with patients with mild episodes and LL patients, highlighting CD177 as a potential systemic marker of ENL severity that deserves future confirmation. Furthermore, a follow-up study was performed with patients at the time of ENL diagnosis and after 7 days of thalidomide treatment (THAL, n=10). Enrichment of neutrophil pathways was sustained in the transcriptomic profile of patients undergoing treatment; however, important immune targets that might be relevant to the effect of thalidomide at a systemic level, particularly NLRP6 and IL5RA, were revealed. Discussion: In conclusion, our study reinforces the key role played by neutrophils in ENL pathogenesis and shed lights on potential diagnostic candidates and novel therapeutic targets that could benefit patients with leprosy.