Product Citations: 6

Study of the Role of the Tyrosine Kinase Receptor MerTK in the Development of Kidney Ischemia-Reperfusion Injury in RCS Rats.

In International Journal of Molecular Sciences on 9 November 2021 by Pele, T., Giraud, S., et al.

Renal ischaemia reperfusion (I/R) triggers a cascade of events including oxidative stress, apoptotic body and microparticle (MP) formation as well as an acute inflammatory process that may contribute to organ failure. Macrophages are recruited to phagocytose cell debris and MPs. The tyrosine kinase receptor MerTK is a major player in the phagocytosis process. Experimental models of renal I/R events are of major importance for identifying I/R key players and for elaborating novel therapeutical approaches. A major aim of our study was to investigate possible involvement of MerTK in renal I/R. We performed our study on both natural mutant rats for MerTK (referred to as RCS) and on wild type rats referred to as WT. I/R was established by of bilateral clamping of the renal pedicles for 30' followed by three days of reperfusion. Plasma samples were analysed for creatinine, aspartate aminotransferase (ASAT), lactate dehydrogenase (LDH), kidney injury molecule -1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels and for MPs. Kidney tissue damage and CD68-positive cell requirement were analysed by histochemistry. monocyte chemoattractant protein-1 (MCP-1), myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), and histone 3A (H3A) levels in kidney tissue lysates were analysed by western blotting. The phagocytic activity of blood-isolated monocytes collected from RCS or WT towards annexin-V positive bodies derived from cultured renal cell was assessed by fluorescence-activated single cell sorting (FACS) and confocal microscopy analyses. The renal I/R model for RCS rat described for the first time here paves the way for further investigations of MerTK-dependent events in renal tissue injury and repair mechanisms.

  • FC/FACS
  • Rattus norvegicus (Rat)

Ageing is associated with a changing immune system, leading to inflammageing (increased levels of inflammation markers in serum) and immunosenescence (reduced immune cells and reduced responses towards pathogens). This results in reduced vaccination responses and increased infections in elderly. Much is known about the adaptive immune system upon ageing, but less is known about the innate immune system. Therefore, the aim of this study was to compare innate immune function of Toll like receptor (TLR)-mediated responses between elderly and young adult women. To this end, elderly and young adult women were compared to study the effect of ageing on the relative prevalence and reactivity to TLR-mediated responses of myeloid- and plasmacytoid dendritic cells (mDC, pDC). In addition, TLR expression and inflammatory markers in serum were investigated. Elderly women had reduced numbers of circulating pDCs. In addition, pDCs and mDCs of elderly women responded differently towards TLR stimulation, especially TLR7/8 mediated stimulation was reduced, compared to young adults. In serum, markers involved in inflammation were generally increased in elderly. In conclusion, this study confirms and extends the knowledge about immunosenescence and inflammageing on innate immunity in elderly women.

  • Immunology and Microbiology

The latent HIV-1 viral reservoir in resting CD4+ (rCD4+) T cells represents a major barrier to an HIV-1 cure. There is an ongoing effort to identify therapeutic approaches that will eliminate or reduce the size of this reservoir. However, clinical investigators lack an assay to determine whether or not a decrease in the latent reservoir has been achieved. Therefore, it is critical to develop assays that can reproducibly quantify the reservoir size and changes therein, in participant's blood during a therapeutic trial. Quantification of the latent HIV viral reservoir requires a highly sensitive, cost-effective assay capable of measuring the low frequency of rCD4+ T cells carrying functional provirus. Preferably, such an assay should be such that it can be adopted for high throughput and could be adopted under conditions for use in large-scale clinical trials. While PCR-based assays are commonly used to quantify pro-viral DNA or intracellular RNA transcript, they cannot distinguish between replication-competent and defective proviruses. We have recently published a study where a reporter cell-based assay (termed TZA or TZM-bl based quantitative assay) was used to quantify inducible replication-competent latent HIV-1 in blood. This assay is more sensitive, cost-efficient, and faster than available technology, including the quantitative viral outgrowth assay or the Q-VOA. Using this assay, we show that the size of the inducible latent HIV-1 reservoir in virally suppressed participants on ART is approximately 70-fold larger than previous estimates. We describe here in detail an optimized method to quantitate latently infected cells using the TZA.

  • Immunology and Microbiology

Discovery of Mcl-1-specific inhibitor AZD5991 and preclinical activity in multiple myeloma and acute myeloid leukemia.

In Nature Communications on 17 December 2018 by Tron, A. E., Belmonte, M. A., et al.

Mcl-1 is a member of the Bcl-2 family of proteins that promotes cell survival by preventing induction of apoptosis in many cancers. High expression of Mcl-1 causes tumorigenesis and resistance to anticancer therapies highlighting the potential of Mcl-1 inhibitors as anticancer drugs. Here, we describe AZD5991, a rationally designed macrocyclic molecule with high selectivity and affinity for Mcl-1 currently in clinical development. Our studies demonstrate that AZD5991 binds directly to Mcl-1 and induces rapid apoptosis in cancer cells, most notably myeloma and acute myeloid leukemia, by activating the Bak-dependent mitochondrial apoptotic pathway. AZD5991 shows potent antitumor activity in vivo with complete tumor regression in several models of multiple myeloma and acute myeloid leukemia after a single tolerated dose as monotherapy or in combination with bortezomib or venetoclax. Based on these promising data, a Phase I clinical trial has been launched for evaluation of AZD5991 in patients with hematological malignancies (NCT03218683).

  • Homo sapiens (Human)
  • Cancer Research

During aging the immune system is dysregulated. Especially plasmacytoid dendritic cells (pDCs) and myeloid DCs (mDCs) have reduced Toll like receptor (TLR)-mediated responses resulting in increased susceptibility to infections. Consumption of bovine lactoferrin (bLF) has been shown to reduce infections with viruses. Galacto-oligosacharides (GOS) and vitamin D are associated with reduced pro-inflammatory cytokine levels in serum, and increased TLR7/8 responses, respectively. A double-blind placebo-controlled nutritional intervention study in elderly women was performed, to investigate the potential of bLF, GOS, and vitamin D to restore TLR responsiveness of pDCs and mDCs and to reduce inflammatory markers in serum. The nutritional intervention group (n = 15) received bLF for 3 weeks, followed by 3 weeks of bLF + GOS, and subsequently 3 weeks of bLF + GOS + vitamin D. The placebo group (n = 15) received maltodextrin for 9 weeks. Every 3 weeks, blood was collected and TLR responses of pDCs and mDCs, and inflammation-related markers in serum were measured. After 3 weeks of bLF supplementation, increased TLR7/8 and TLR1/2 responses were observed in pDCs of the nutritional intervention group compared to the placebo group. When the effects of the entire nutritional intervention were investigated, increased TLR1/2 mediated responses in mDCs were observed, and in serum sVCAM tended to decrease. Finally, based on the RAND-36 questionnaire physical function tended to improve in the intervention group. Since especially TLR7-mediated responses in pDCs were enhanced after bLF supplementation compared to placebo, this suggests that bLF may contribute to antiviral responses mediated by pDC in elderly women.Clinical trial registry number: NCT03026244, clinicaltrials.gov.

  • Immunology and Microbiology
  • Veterinary Research
View this product on CiteAb