Annexin A5 is essential for PKCθ translocation during T-cell activation

Step by step analysis on gene datasets of growth phases in hematopoietic stem cells

Background

Umbilical cord blood hematopoietic stem cells (UCB-HSCs) have important roles in the treatment of illnesses based on their self-renewal and potency characteristics. Knowing the gene profiles and signaling pathways involved in each step of the cell cycle could improve the therapeutic approaches of HSCs. The aim of this study was to predict the gene profiles and signaling pathways involved in the G0, G1, and differentiation stages of HSCs.

Methods

Interventional (n = 8) and non-interventional (n = 3) datasets were obtained from the Gene Expression Omnibus (GEO) database, and were crossed and analyzed to determine the high- and low-express genes related to each of the G0, G1, and differentiation stages of HSCs. Then, the scores of STRING were annotated to the gene data. The gene networks were constructed using Cytoscape software, and enriched with the KEGG and GO databases.

Results

The high- and low-express genes were determined due to inter and intra intersections of the interventional and non-interventional data. The non-interventional data were applied to construct the gene networks (n = 6) with the nodes improved using the interventional data. Several important signaling pathways were suggested in each of the G0, G1, and differentiation stages.

Conclusion

The data revealed that the different signaling pathways are activated in each of the G0, G1, and differentiation stages so that their genes may be targeted to improve the HSC therapy.

The presence of cytotoxic CD4 and exhausted-like CD8+ T-cells is a signature of active tuberculosis

Chronic infections induce CD4+ T-cells with cytotoxic functions (CD4 CTLs); at present, it is still unknown whether latent tuberculosis (LTB) and active tuberculosis (ATB) induce CD4 CTLs. Plasma and cells from four patient groups-uninfected contact (UC), LTB, and ATB (divided as sensitive [DS-TB]- or resistant [DR-TB]-drug)-were evaluated by flow cytometry, q-PCR, and proteomics. The data showed that ATB patients had an increased frequency of CD4+ T-cells and a decreased frequency of CD8+ T-cells. The latter displays an exhausted-like profile characterized by CD39, CD279, and TIM-3 expression. ATB had a high frequency of CD4 + perforin+ cells, suggesting a CD4 CTL profile. The expression (at the transcriptional level) of granzyme A, granzyme B, granulysin, and perforin, as well as the genes T-bet (Tbx21) and NKG2D (Klrk1), in enriched CD4+ T-cells, confirmed the cytotoxic signature of CD4+ T-cells during ATB (which was stronger in DS-TB than in DR-TB). Moreover, proteomic analysis revealed the presence of HSP70 (in DS-TB) and annexin A5 (in DR-TB), which are molecules that have been associated with favoring the CD4 CTL profile. Finally, we found that lipids from Mycobacterium tuberculosis increased the presence of CD4 CTLs in DR-TB patients. Our data suggest that ATB is characterized by exhausted-like CD8+ T-cells, which, together with a specific microenvironment, favor the presence of CD4 CTLs.

SLIDE: Significant Latent Factor Interaction Discovery and Exploration across biological domains

Modern multiomic technologies can generate deep multiscale profiles. However, differences in data modalities, multicollinearity of the data, and large numbers of irrelevant features make analyses and integration of high-dimensional omic datasets challenging. Here we present Significant Latent Factor Interaction Discovery and Exploration (SLIDE), a first-in-class interpretable machine learning technique for identifying significant interacting latent factors underlying outcomes of interest from high-dimensional omic datasets. SLIDE makes no assumptions regarding data-generating mechanisms, comes with theoretical guarantees regarding identifiability of the latent factors/corresponding inference, and has rigorous false discovery rate control. Using SLIDE on single-cell and spatial omic datasets, we uncovered significant interacting latent factors underlying a range of molecular, cellular and organismal phenotypes. SLIDE outperforms/performs at least as well as a wide range of state-of-the-art approaches, including other latent factor approaches. More importantly, it provides biological inference beyond prediction that other methods do not afford. Thus, SLIDE is a versatile engine for biological discovery from modern multiomic datasets.

The most prominent modulated annexins during parasitic infections

Annexins (ANXs) exert different functions in cell biological and pathological processes and are thus known as double or multi-faceted proteins. These sophisticated proteins might express on both parasite structure and secretion and in parasite-infected host cells. In addition to the characterization of these pivotal proteins, describing their mechanism of action can be also fruitful in recognizing their roles in the pathogenesis of parasitic infections. Accordingly, this study presents the most prominent ANXs thus far identified and their relevant functions in parasites and infected host cells during pathogenesis, especially in the most important intracellular protozoan parasitic infections including leishmaniasis, toxoplasmosis, malaria and trypanosomiasis. The data provided in this study demonstrate that the helminth parasites most probably express and secret ANXs to develop pathogenesis while the modulation of the host-ANXs could be employed as a crucial strategy by intracellular protozoan parasites. Moreover, such data highlight that the use of analogs of both parasite and host ANX peptides (which mimic or regulate ANXs physiological functions through various strategies) might suggest novel therapeutic insights into the treatment of parasitic infections. Furthermore, due to the prominent immunoregulatory activities of ANXs during most parasitic infections and the expression levels of these proteins in some parasitic infected tissues, such multifunctional proteins might be also potentially relevant as vaccine and diagnostic biomarkers. We also suggest some prospects and insights that could be useful and applicable to form the basis of future experimental studies.

Annexin A protein family: Focusing on the occurrence, progression and treatment of cancer

The annexin A (ANXA) protein family is a well-known tissue-specific multigene family that encodes Ca²⁺ phospholipid-binding proteins. A considerable amount of literature is available on the abnormal expression of ANXA proteins in various malignant diseases, including cancer, atherosclerosis and diabetes. As critical regulatory molecules in cancer, ANXA proteins play an essential role in cancer progression, proliferation, invasion and metastasis. Recent studies about their structure, biological properties and functions in different types of cancers are briefly summarised in this review. We further discuss the use of ANXA as new class of targets in the clinical diagnosis and treatment of cancer.

Therapeutic Potential of Annexins in Sepsis and COVID-19

Sepsis is a continuing problem in modern healthcare, with a relatively high prevalence, and a significant mortality rate worldwide. Currently, no specific anti-sepsis treatment exists despite decades of research on developing potential therapies. Annexins are molecules that show efficacy in preclinical models of sepsis but have not been investigated as a potential therapy in patients with sepsis. Human annexins play important roles in cell membrane dynamics, as well as mediation of systemic effects. Most notably, annexins are highly involved in anti-inflammatory processes, adaptive immunity, modulation of coagulation and fibrinolysis, as well as protective shielding of cells from phagocytosis. These discoveries led to the development of analogous peptides which mimic their physiological function, and investigation into the potential of using the annexins and their analogous peptides as therapeutic agents in conditions where inflammation and coagulation play a large role in the pathophysiology. In numerous studies, treatment with recombinant human annexins and annexin analogue peptides have consistently found positive outcomes in animal models of sepsis, myocardial infarction, and ischemia reperfusion injury. Annexins A1 and A5 improve organ function and reduce mortality in animal sepsis models, inhibit inflammatory processes, reduce inflammatory mediator release, and protect against ischemic injury. The mechanisms of action and demonstrated efficacy of annexins in animal models support development of annexins and their analogues for the treatment of sepsis. The effects of annexin A5 on inflammation and platelet activation may be particularly beneficial in disease caused by SARS-CoV-2 infection. Safety and efficacy of recombinant human annexin A5 are currently being studied in clinical trials in sepsis and severe COVID-19 patients.