ERG mediates the inhibition of NK cell cytotoxicity through the HLX/STAT4/Perforin signaling pathway, thereby promoting the progression of myocardial infarction

This study aimed to investigate the role of ERG in the HLX/STAT4/Perforin signaling axis, impacting natural killer (NK) cell cytotoxicity and myocardial infarction (MI) progression. NK cell cytotoxicity was assessed via co-culture and 51Cr release assays. Datasets GSE34198 and GSE97320 identified common differentially expressed genes in MI. NK cell gene expression was analyzed in MI patients and healthy individuals using qRT-PCR and Western blotting. ERG's regulation of HLX and STAT4's regulation of perforin were studied through computational tools (MEM) and ChIP experiments. HLX's influence on STAT4 was explored with the MG132 proteasome inhibitor. Findings were validated in a mouse MI model. ERG, a commonly upregulated gene, was identified in NK cells from MI patients and mice. ERG upregulated HLX, leading to STAT4 proteasomal degradation and reduced Perforin expression. Consequently, NK cell cytotoxicity decreased, promoting MI progression. ERG mediates the HLX/STAT4/Perforin axis to inhibit NK cell cytotoxicity, fostering MI progression. These results provide vital insights into MI's molecular mechanisms. (AU)

ERG mediates the inhibition of NK cell cytotoxicity through the HLX/STAT4/Perforin signaling pathway, thereby promoting the progression of myocardial infarction

This study aimed to investigate the role of ERG in the HLX/STAT4/Perforin signaling axis, impacting natural killer (NK) cell cytotoxicity and myocardial infarction (MI) progression. NK cell cytotoxicity was assessed via co-culture and 51Cr release assays. Datasets GSE34198 and GSE97320 identified common differentially expressed genes in MI. NK cell gene expression was analyzed in MI patients and healthy individuals using qRT-PCR and Western blotting. ERG's regulation of HLX and STAT4's regulation of perforin were studied through computational tools (MEM) and ChIP experiments. HLX's influence on STAT4 was explored with the MG132 proteasome inhibitor. Findings were validated in a mouse MI model. ERG, a commonly upregulated gene, was identified in NK cells from MI patients and mice. ERG upregulated HLX, leading to STAT4 proteasomal degradation and reduced Perforin expression. Consequently, NK cell cytotoxicity decreased, promoting MI progression. ERG mediates the HLX/STAT4/Perforin axis to inhibit NK cell cytotoxicity, fostering MI progression. These results provide vital insights into MI's molecular mechanisms. (AU)

Linfohistiocitosis hemofagocítica asociada a infecciones virales: reto diagnóstico y dilema terapéutico / Hemophagocytic lymphohistiocytosis associated with viral infections: diagnostic challenges and therapeutic dilemmas

La linfohistiocitosis hemofagocítica es un síndrome clinicopatológico de evolución potencialmente fatal, en el que una respuesta inmune no controlada e ineficaz conduce a hiperinflamación. Puede aparecer como una enfermedad familiar o esporádica, asociado a diferentes factores desencadenantes: infecciones, neoplasias, enfermedades autoinmunes o inmunodeficiencias adquiridas, pero la asociación más consistente es con infecciones virales, especialmente el virus de Epstein-Barr. Las principales características clínicas son fiebre, disfunción hepática, coagulopatía y pancitopenia. El diagnóstico es difícil debido a la rareza de este síndrome y a la falta de especificidad de los hallazgos clínicos, sin embargo, un diagnóstico y tratamiento precoces son importantes para disminuir la mortalidad. El tratamiento debe ser dirigido al control de la enfermedad subyacente y a suprimir la respuesta inflamatoria exagerada mediante el uso de inmunosupresores (AU)

Hemophagocytic lymphohistiocytosis is a frequently fatal clinicopathologic syndrome in which an uncontrolled and ineffective immune response leads to severe hyperinflammation. It may occur as either a familial disorder or a sporadic condition in association with a variety of triggers: infections, malignancies, autoimmune diseases, and acquired immune deficiencies. However, the most consistent association is with viral infections, especially Epstein-Barr virus. The main clinical features are fever, liver dysfunction, coagulation abnormalities and pancytopenia. Early diagnosis and treatment are important to reducing mortality, but the diagnosis is difficult because of the rarity of the syndrome and the lack of specificity of the clinical findings. Treatment should be directed towards treating the underlying disease and to suppressing the exaggerated inflammatory response through the use of immunosuppressive agents (AU)

Clinical and genetic characteristics in a series of haemophagocytic lymphohistiocytosis patients without perforin defects

Aim: Haemophagocytic lymphohistiocytosis (HLH) is characterised by T cell and macrophage activation and excessive production of inflammatory cytokines. Genetic diagnosis is required to discriminate between primary forms (familial HLH, FHL), due to mutations in genes involved in cytolysis, and secondary forms. We aimed to analyse the genes coding for Munc13-4 (UNC13D) and syntaxin-11 (STX11) proteins in search of mutations that might explain HLH in 5 patients without perforin defects. Materials and methods: Perforin expression was evaluated by flow cytometry, sCD25 was measured by ELISA and NK activity was investigated by the conventional functional assay. Coding regions and exons surroundings were sequenced for PRF1, UNC13D and STX11 genes. Results: P1 and P2 developed severe early-onset HLH, P1 died at 6 months. P3, with a sister who died after HLH, responded well to treatment (HLH-2004), and had a second HLH episode two years later. P2 developed HLH at year 7 while in complete remission after lymphoblastic leukaemia. P4 and P5 were brothers who died at 5 and 6 years old due to an HLH and EBV mononucleosis infection. XLP was discarded because P4 was a girl. P1 and P3 showed mutations in UNC13D previously described as pathogenic. There were no changes in STX11.Conclusions: UNC13D mutations were found in 50% of the HLH families without perforin defects and STX11 defects were not detected. These results agree with published series in which mutations in UNC13D explain up to 50% of FHL without PRF1 mutations, supporting a heterogeneous genetic background for this disease (AU)

Objetivo: La linfohistiocitosis hemofagocítica (HLH) se caracteriza por la activación incontrolada de células T y macrófagos y producción excesiva de citoquinas inflamatorias. El diagnóstico genético es necesario para distinguir entre formas primarias (HLH familiar, FHL),debidas a mutaciones en genes implicados en citolisis, y secundarias. Nuestro objetivo es analizar la presencia de mutaciones en los genes que codifican para Munc13-4 (UNC13D) ysintaxina-11 (STX11) en cinco pacientes con HLH no asociado a defecto de perforina. Materiales y métodos: Se evaluó la expresión de perforina por citometría, CD25s por ELISA y la actividad NK con un ensayo funcional. Se secuenciaron los exones y regiones flanqueantes de los genes PRF1, UNC13D y STX11.Resultados: P1 y P2 desarrollaron HLH severo de inicio temprano, P1 falleció con 6 meses. P3,con una hermana fallecida tras HLH, respondió adecuadamente al tratamiento (HLH-2004),presentando un segundo episodio dos años después. P2 desarrolló HLH a los 7 años de edad estando en remisión completa de una leucemia linfoblástica previa. P4 y P5 son hermanos que fallecieron con 5 y 6 años tras HLH y mononucleosis por infección EBV. Se descartó XLP ya que uno de los pacientes era niña. P1 y P3 presentaron mutaciones en UNC13D previamente descritas como patogénicas. No se encontraron alteraciones en STX11.Conclusiones: Se encontraron mutaciones en UNC13D en el 50% de las familias con HLH sin defectos de perforina y no se detectaron defectos en STX11. Este resultado concuerda con series publicadas en las que mutaciones en UNC13D explican hasta el 50% de la FLH sin mutaciones en PRF1, y apoyan una base genética muy heterogénea para esta enfermedad (AU)