The protein bcl‐xL is able to enhance the secretion of the proinflammatory chemokine interleukin 8 (CXCL8) in human melanoma lines. In this study, we investigate whether the bcl‐xL/CXCL8 axis is ...important for promoting melanoma angiogenesis and aggressiveness in vivo, using angiogenesis and xenotransplantation assays in zebrafish embryos. When injected into wild‐type embryos, bcl‐xL‐overexpressing melanoma cells showed enhanced dissemination and angiogenic activity compared with control cells. Human CXCL8 protein elicited a strong proangiogenic activity in zebrafish embryos and zebrafish Cxcr2 receptor was identified as the mediator of CXCL8 proangiogenic activity using a morpholino‐mediated gene knockdown. However, human CXCL8 failed to induce neutrophil recruitment in contrast to its zebrafish homolog. Interestingly, the greater aggressiveness of bcl‐xL‐overexpressing melanoma cells was mediated by an autocrine effect of CXCL8 on its CXCR2 receptor, as confirmed by an shRNA approach. Finally, correlation studies of gene expression and survival analyses using microarray and RNA‐seq public databases of human melanoma biopsies revealed that bcl‐xL expression significantly correlated with the expression of CXCL8 and other markers of melanoma progression. More importantly, a high level of co‐expression of bcl‐xL and CXCL8 was associated with poor prognosis in melanoma patients. In conclusion, these data demonstrate the existence of an autocrine CXCL8/CXCR2 signaling pathway in the bcl‐xL‐induced melanoma aggressiveness, encouraging the development of novel therapeutic approaches for high bcl‐xL‐expressing melanoma.
What's new?
The protein bcl‐xL is able to enhance the secretion of proinflammatory chemokine interleukin 8 (CXCL8) in human melanoma lines. Using the zebrafish model, here the authors demonstrate that bcl‐xL enhances melanoma in vivo angiogenesis and invasion through the CXCL8/CXCR2 axis. In human biopsies, melanoma bcl‐xL expression correlates with CXCL8, and high bcl‐xL/CXCL8 levels significantly correlate with the poor prognosis of melanoma patients. These findings point to novel markers of melanoma aggressiveness associated with the activated bcl‐xL/CXCL8 axis and support the use of the zebrafish model to study the efficacy of therapeutic compounds inhibiting the CXCL8/CXCR2 axis to counteract tumor progression.
Hematopoiesis is a complex process through which immature bone marrow precursor cells mature into all types of blood cells. Although the association of hematopoietic lineage bias (including anemia ...and neutrophilia) with chronic inflammatory diseases has long been appreciated, the causes involved are obscure. Recently, cytosolic multiprotein inflammasome complexes were shown to activate inflammatory and immune responses, and directly regulate hematopoiesis in zebrafish models; this was deemed to occur via cleavage and inactivation of the master erythroid transcription factor GATA1. Herein summarized are the zebrafish models that are currently available to study this unappreciated role of inflammasome-mediated regulation of hematopoiesis. Novel putative therapeutic strategies, for the treatment of hematopoietic alterations associated with chronic inflammatory diseases in humans, are also proposed.
The activation of the Nlrp1a inflammasome in mouse hematopoietic stem and progenitor cells (HSPCs) triggers their pyroptotic death and prolonged leukopenia upon chemotherapy or viral infection.The NLRP3 inflammasome drives HSPC clonal expansion and pyroptosis in myelodysplastic syndrome patients.Emerging evidence from zebrafish models suggests that the canonical inflammasome autonomously regulates the erythroid–myeloid cell fate decision of HSPCs, and terminal erythroid differentiation through the cleavage of Gata1. This mechanism appears to be evolutionarily conserved since pharmacological inhibition of caspase 1 (Casp1) in mouse hematopoietic stem cells (HSCs) results in a rapid increase in Gata1 protein, leading to erythroid differentiation.Pharmacological inhibition of the canonical inflammasome rescues zebrafish disease models of neutrophilic inflammation, anemia associated with chronic diseases, and Diamond–Blackfan anemia.
Bcl-xL: A Focus on Melanoma Pathobiology Lucianò, Anna Maria; Pérez-Oliva, Ana B; Mulero, Victoriano ...
International journal of molecular sciences,
03/2021, Letnik:
22, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Apoptosis is the main mechanism by which multicellular organisms eliminate damaged or unwanted cells. To regulate this process, a balance between pro-survival and pro-apoptotic proteins is necessary ...in order to avoid impaired apoptosis, which is the cause of several pathologies, including cancer. Among the anti-apoptotic proteins, Bcl-xL exhibits a high conformational flexibility, whose regulation is strictly controlled by alternative splicing and post-transcriptional regulation mediated by transcription factors or microRNAs. It shows relevant functions in different forms of cancer, including melanoma. In melanoma, Bcl-xL contributes to both canonical roles, such as pro-survival, protection from apoptosis and induction of drug resistance, and non-canonical functions, including promotion of cell migration and invasion, and angiogenesis. Growing evidence indicates that Bcl-xL inhibition can be helpful for cancer patients, but at present, effective and safe therapies targeting Bcl-xL are lacking due to toxicity to platelets. In this review, we summarized findings describing the mechanisms of Bcl-xL regulation, and the role that Bcl-xL plays in melanoma pathobiology and response to therapy. From these findings, it emerged that even if Bcl-xL plays a crucial role in melanoma pathobiology, we need further studies aimed at evaluating the involvement of Bcl-xL and other members of the Bcl-2 family in the progression of melanoma and at identifying new non-toxic Bcl-xL inhibitors.
Abstract
Chronic inflammatory diseases are associated with hematopoietic lineage bias, including neutrophilia and anemia. We have recently identified that the canonical inflammasome mediates the ...cleavage of the master erythroid transcription factor GATA1 in hematopoietic stem and progenitor cells (HSPCs). We report here that genetic inhibition of Nlrp1 resulted in reduced number of neutrophils and increased erythrocyte counts in zebrafish larvae. We also found that the NLRP1 inflammasome in human cells was inhibited by LRRFIP1 and FLII, independently of DPP9, and both inhibitors regulated hematopoiesis. Mechanistically, erythroid differentiation resulted in ribosomal stress‐induced activation of the ZAKα/P38 kinase axis which, in turn, phosphorylated and promoted the assembly of NLRP1 in both zebrafish and human. Finally, inhibition of Zaka with the FDA/EMA‐approved drug Nilotinib alleviated neutrophilia in a zebrafish model of neutrophilic inflammation and promoted erythroid differentiation and GATA1 accumulation in K562 cells. In conclusion, our results reveal that the NLRP1 inflammasome regulates hematopoiesis and pave the way to develop novel therapeutic strategies for the treatment of hematopoietic alterations associated with chronic inflammatory and rare diseases.
Synopsis
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Deregulation of inflammasome activity contributes to hematopoietic alterations associated to chronic inflammatory diseases, including neutrophilia and anemia. Zebrafish models and human blood cells were used to identify the critical role of the NLRP1 inflammasome on the regulation of hematopoiesis and possible therapeutic targets for clinical intervention.
Erythroid differentiation resulted in ribosomal stress‐induced activation of the ZAKα/P38 kinase axis.
ZAKα/P38 kinase axis phosphorylated and promoted the assembly of NLRP1 in HSPCs which, in turn, regulates their erythroid‐myeloid lineage decision.
NLRP1 inflammasome in HSPCs was inhibited by LRRFIP1 and FLII, independently of DPP9.
The FDA/EMA‐approved drug Nilotinib inhibited NLRP1 inflammasome activation alleviating neutrophilia and promoting erythroid differentiation.
Chronic inflammatory diseases are associated with altered hematopoiesis that could result in neutrophilia and anemia. Here we report that genetic or chemical manipulation of different inflammasome ...components altered the differentiation of hematopoietic stem and progenitor cells (HSPC) in zebrafish. Although the inflammasome was dispensable for the emergence of HSPC, it was intrinsically required for their myeloid differentiation. In addition, Gata1 transcript and protein amounts increased in inflammasome-deficient larvae, enforcing erythropoiesis and inhibiting myelopoiesis. This mechanism is evolutionarily conserved, since pharmacological inhibition of the inflammasome altered erythroid differentiation of human erythroleukemic K562 cells. In addition, caspase-1 inhibition rapidly upregulated GATA1 protein in mouse HSPC promoting their erythroid differentiation. Importantly, pharmacological inhibition of the inflammasome rescued zebrafish disease models of neutrophilic inflammation and anemia. These results indicate that the inflammasome plays a major role in the pathogenesis of neutrophilia and anemia of chronic diseases and reveal druggable targets for therapeutic interventions.
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•The inflammasome regulates the erythroid-myeloid decision in HSC•Caspase-1 inhibition rapidly upregulates GATA1 protein in HSC•Caspase-1 regulates terminal erythroid differentiation•Caspase-1 inhibition rescues neutrophilic inflammation and anemia
Chronic inflammatory diseases are associated to altered hematopoiesis that could result in neutrophilia and anemia. In this issue of Immunity, Tyrkalska et al. (2019) provide evidence of an evolutionarily conserved mechanism by which inflammasome regulates the erythroid/myeloid decision in HSC, which might contribute to the hematopoietic bias of these diseases.
The zebrafish has unique advantages for understanding the evolution of vertebrate immunity and to model human diseases. In this review, we will firstly give an overview of the current knowledge on ...vertebrate innate immune receptors with special emphasis on the inflammasome and then summarize the main contribution of the zebrafish model to this field, including to the identification of novel inflammasome components and to the mechanisms involved in its activation, assembly and clearance of intracellular bacteria.
Macrophages take center stage in the tumor microenvironment, a niche composed of extracellular matrix and a heterogeneous group of cells, including immune ones. They can evolve during tumor ...progression and acquire Tumor-Associated Macrophage (TAMs) phenotype. The release of cytokines by tumor and stromal cells, influence the secretion of cytokines by TAMs, which can guarantee tumor progression and influence the response to therapy. Among all factors able to recruit and polarize macrophages, we focused our attention on Bcl-xL, a multifaceted member of the Bcl-2 family, whose expression is deregulated in melanoma. It acts not only as a canonical pro-survival and anti-apoptotic protein, but also as a promoter of tumor progression.
Human melanoma cells silencing or overexpressing Bcl-xL protein, THP-1 monocytic cells and monocyte-derived macrophages were used in this study. Protein array and specific neutralizing antibodies were used to analyze cytokines and chemokines secreted by melanoma cells. qRT-PCR, ELISA and Western Blot analyses were used to evaluate macrophage polarization markers and protein expression levels. Transwell chambers were used to evaluate migration of THP-1 and monocyte-derived macrophages. Mouse and zebrafish models were used to evaluate the ability of melanoma cells to recruit and polarize macrophages in vivo.
We demonstrated that melanoma cells overexpressing Bcl-xL recruit macrophages at the tumor site and induce a M2 phenotype. In addition, we identified that interleukin-8 and interleukin-1β cytokines are involved in macrophage polarization, and the chemokine CCL5/RANTES in the macrophages recruitment at the tumor site. We also found that all these Bcl-xL-induced factors are regulated in a NF-kB dependent manner in human and zebrafish melanoma models.
Our findings confirmed the pro-tumoral function of Bcl-xL in melanoma through its effects on macrophage phenotype.
A retrospective study of 200 psoriasis patients and 100 healthy donors in a Spanish cohort was carried out to study the comorbidities associated with psoriasis and their association with the response ...to phototherapy. The results showed a higher incidence of psychiatric disease, liver disease, kidney disease, hypertension, heart disease, vascular disease, diabetes, gastrointestinal disease, autoimmune and infectious diseases, dyslipidemia, and psoriatic arthritis in patients with psoriasis than in the control group. The incidence of comorbidities was higher in psoriasis patients over 40 years old than in the control individuals of the same age, which could be indicative of premature aging. Phototherapy was seen to be an effective treatment in cases of moderate-severe psoriasis, total whitening being achieved in more than 30% of patients, with women showing a better response than men. Narrow-band ultraviolet B was found to be the most effective type of phototherapy, although achievement of PASI100 was lower in patients with liver disease, hypertension, heart disease, vascular disease, or diabetes. Strikingly, liver disease and anemia comorbidities favored therapeutic failure. Finally, zebrafish and human 3D organotypic models of psoriasis point to the therapeutic benefit of inhibiting the glucose transporter GLUT1 and the major regulator of blood glucose dipeptidyl peptidase 4. Our study reveals that specific comorbidities of psoriasis patients are associated to failure of phototherapy and, therefore, need to be considered when planning treatment for these patients.
Deubiquitylases (DUBs) are key regulators of the ubiquitin system which cleave ubiquitin moieties from proteins and polyubiquitin chains. Several DUBs have been implicated in various diseases and are ...attractive drug targets. We have developed a sensitive and fast assay to quantify in vitro DUB enzyme activity using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Unlike other current assays, this method uses unmodified substrates, such as diubiquitin topoisomers. By analysing 42 human DUBs against all diubiquitin topoisomers we provide an extensive characterization of DUB activity and specificity. Our results confirm the high specificity of many members of the OTU and JAB/MPN/Mov34 metalloenzyme DUB families and highlight that all USPs tested display low linkage selectivity. We also demonstrate that this assay can be deployed to assess the potency and specificity of DUB inhibitors by profiling 11 compounds against a panel of 32 DUBs.
Chronic diseases and hematopoietic disorders are associated with dysregulation of the inflammasome. Our group has recently reported the relevance of the inflammasome in the differentiation of ...hematopoietic stem and progenitor cells. However, the impact of the inflammasome of myeloid cells in the regulation of hematopoiesis is largely unknown. In this study, we used the unique advantages of the zebrafish model to demonstrate that genetic inhibition of macrophage inflammasome resulted in increased number of macrophages in larvae with skin inflammation without affecting erythrocyte and neutrophil counts. Similarly, the inhibition of the neutrophil inflammasome by the same strategy resulted in increased number of neutrophils in larvae with skin inflammation but did not affect erythrocytes and macrophages. Consistently, hyperactivation of the inflammasome in neutrophils in this model promoted neutrophil death, which was recovered by pharmacological inhibition of Gasdermin E. We conclude that the myeloid inflammasome autonomously regulates pyroptotic cell death in chronic inflammation through a Gasdermin E-dependent pathway in zebrafish.
•The role of the myeloid inflammasome in hematopoiesis was studied in zebrafish.•The myeloid inflammasome autonomously regulates pyroptosis in chronic inflammation.•Gasdermin E mediates pyroptosis of myeloid cells in chronic inflammation.•The myeloid inflammasome does not regulate hematopoiesis.
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