Associations between PRF1 Ala91Val polymorphism and risk of hemophagocytic lymphohistiocytosis: a meta-analysis based on 1366 subjects

Screening of four lysosome-related genes in sepsis based on RNA sequencing technology

PURPOSE

Screening of lysosome-related genes in sepsis patients to provide direction for lysosome-targeted therapy.

METHODS

Peripheral blood samples were obtained from 22 patients diagnosed with sepsis and 10 normal controls for the purpose of RNA sequencing and subsequent analysis of differential gene expression. Concurrently, lysosome-related genes were acquired from the Gene Ontology database. The intersecting genes between the differential genes and lysosome-related genes were then subjected to PPI, GO and KEGG analyses. Core genes were identified through survival analysis, and their expression trends in different groups were determined using meta-analysis. Single-cell RNA sequencing was used to clarify the cellular localization of core genes.

RESULTS

The intersection of 1328 sepsis-differential genes with 878 lysosome-related genes yielded 76 genes. PPI analysis showed that intersecting genes were mainly involved in Cellular process, Response to stimulus, Immune system process, Signal transduction, Lysosome. GO and KEGG analysis showed that intersecting genes were mainly involved in leukocyte mediated immunity, cell activation involved in immune response, lytic vacuole, lysosome. Survival analysis screened four genes positively correlated with sepsis prognosis, namely GNLY, GZMB, PRF1 and RASGRP1. The meta-analysis revealed that the expression levels of these four genes were significantly higher in the normal control group compared to the sepsis group, which aligns with the findings from RNA sequencing data. Furthermore, single-cell RNA sequencing demonstrated that T cells and NK cells exhibited high expression levels of GNLY, GZMB, PRF1, and RASGRP1.

CONCLUSION

GNLY, GZMB, PRF1, and RASGRP1, which are lysosome-related genes, are closely linked to the prognosis of sepsis and could potentially serve as novel research targets for sepsis, offering valuable insights for the development of lysosome-targeted therapy. The clinical trial registration number is ChiCTR1900021261, and the registration date is February 4, 2019.

Hemophagocytic lymphohistiocytosis with a hemizygous PRF1 c.674G>A mutation

Hemophagocytic lymphohistiocytosis(HLH) is a rare highly-fatal disease presenting with fever, hepatosplenomegaly, and pancytopenia and has a poor prognosis. Homozygous or semi-zygous or complex heterozygous variants can cause familial HLH and heterozygous carriers are frequently seen in secondary HLH. A 42-year-old male patient was admitted to the hospital for persistent fever, fatigue, and splenomegaly. Investigations revealed hypertriglyceridemia, hyperlactatemia dehydrogenaseemia, hyperferritinemia, and elevated levels of soluble cluster of differentiation 25. We found a heterozygous mutation of PRF1: c.674G>A (p.R225Q) through next-generation sequencing technology of hemophagocytic-lymphohistiocytosis-related genes. After a brief remission with dexamethasone and etoposide-based therapy, the disease relapsed quickly, and an allogeneic hematopoietic stem cell transplant was performed to achieve complete remission. To date, the patient's condition was in complete remission. Our study detected a rare missense mutation in the PRF1 gene in a patient with HLH disease and the c.674G>A mutation may be rated as a possible pathogenic variant.

Transcriptome analysis of novel macrophage M1-related biomarkers and potential therapeutic agents in ischemia-reperfusion injury after lung transplantation based on the WGCNA and CIBERSORT algorithms

Lung transplantation is the last effective treatment for end-stage respiratory failure, however, with ischemia-reperfusion injury (IRI) inevitably occurring in postoperative period. IRI is the major pathophysiologic mechanism of primary graft dysfunction, a severe complication that contributes to prolonged length of stay and overall mortality. The understanding of pathophysiology and etiology remain limited and the underlying molecular mechanism, as well as novel diagnostic biomarkers and therapeutic targets, urgently require exploration. Excessive uncontrolled inflammatory response is the core mechanism of IRI. In this research, a weighted gene co-expression network was established using the CIBERSORT and WGCNA algorithms in order to identify macrophage-related hub genes based on the data downloaded from the GEO database (GSE127003, GSE18995). 692 differentially expressed genes (DEGs) in reperfused lung allografts were identified, with three genes recognized as being related to M1 macrophages and validated as differentially expressed using GSE18995 dataset. Of these putative novel biomarker genes, TCRα subunit constant gene (TRAC) were downregulated, while Perforin-1 (PRF1) and Granzyme B (GZMB) were upregulated in reperfused vs. ischemic lung allografts. Furthermore, we obtained 189 potentially therapeutic small molecules for IRI after lung transplantation from the CMap database among which PD-98059 was the top molecule with the highest absolute correlated connectivity score (CS). Our study provides the novel insights into the impact of immune cells on the etiology of IRI and potential targets for therapeutic intervention. Nevertheless, further investigation of these key genes and therapeutic drugs is needed to validate their effects.

Role of Genetic Polymorphism Present in Macrophage Activation Syndrome Pathway in Post Mortem Biopsies of Patients with COVID-19

COVID-19 is a viral disease associated with an intense inflammatory response. Macrophage Activation Syndrome (MAS), the complication present in secondary hemophagocytic lymphohistiocytosis (sHLH), shares many clinical aspects observed in COVID-19 patients, and investigating the cytolytic function of the responsible cells for the first line of the immune response is important. Formalin-fixed paraffin-embedded lung tissue samples obtained by post mortem necropsy were accessed for three groups (COVID-19, H1N1, and CONTROL). Polymorphisms in MAS cytolytic pathway (PRF1; STX11; STXBP2; UNC13D and GZMB) were selected and genotyping by TaqMan^® assays (Thermo Fisher Scientific, MA, USA) using Real-Time PCR (Applied Biosystems, MA USA). Moreover, immunohistochemistry staining was performed with a monoclonal antibody against perforin, CD8+ and CD57+ proteins. Histopathological analysis showed high perforin tissue expression in the COVID-19 group; CD8+ was high in the H1N1 group and CD57+ in the CONTROL group. An association could be observed in two genes related to the cytolytic pathway (PRF1 rs885822 G/A and STXBP2 rs2303115 G/A). Furthermore, PRF1 rs350947132 was associated with increased immune tissue expression for perforin in the COVID-19 group. The genotype approach could help identify patients that are more susceptible, and for this reason, our results showed that perforin and SNPs in the PRF1 gene can be involved in this critical pathway in the context of COVID-19.

NLRC4 Gene Single Nucleotide Polymorphisms Are Associated with the Prognosis of Hemophagocytic Lymphohistiocytosis

OBJECTIVE

To analyze and study the correlation between NLR family CARD domain-containing 4 (NLRC4) gene single nucleotide polymorphisms and the prognosis of patients with hemophagocytic lymphohistiocytosis (HLH).

METHODS

In this study, we retrospectively studied the clinical data of 62 HLH patients, including 40 males and 22 females. The genomic DNA was extracted, and the genotypes at rs385076 locus and rs479333 locus of the NLRC4 gene were analyzed. The level of blood interleukin-18 (IL-18) was analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with the TT genotype at the NLRC4 gene rs385076 locus, the mortality of HLH patients with TC genotype and CC genotype was higher (RR = 3.205, 95% CI: 1.277-4.788, p = 0.012; RR = 3.052, 95% CI: 1.098-4.753, p = 0.031). Taking the CC genotype at rs479333 of the NLRC4 gene as a reference, HLH patients with CG genotype and GG genotype had a higher risk of death (RR = 3.475, 95% CI: 1.488-5.775, p = 0.003; RR = 2.986, 95% CI: 1.014-5.570, p = 0.047). NLRC4 gene rs385076 T>C and rs479333 C>G were significantly related to the poor prognosis of HLH patients. The area under the curve (AUC) of the receiver operating curve (ROC) for the prognostic outcome of HLH with serum IL-18 level was 0.6813 (95% CI: 0.5365-0.8260, p = 0.0189). NLRC4 gene rs385076 T>C and rs479333 C>G were related to higher serum IL-18 levels.

CONCLUSION

NLRC4 gene rs385076 T>C and rs479333 C>G are related to the poor prognosis of HLH patients.