Metformin, Empagliflozin, and Their Combination Modulate Ex-Vivo Macrophage Inflammatory Gene Expression.

Type-2 Diabetes Mellitus is a complex, chronic illness characterized by persistent high blood glucose levels. Patients can be prescribed anti-diabetes drugs as single agents or in combination depending on the severity of their condition. Metformin and empagliflozin are two commonly prescribed anti-diabetes drugs which reduce hyperglycemia, however their direct effects on macrophage inflammatory responses alone or in combination are unreported. Here, we show that metformin and empagliflozin elicit proinflammatory responses on mouse bone-marrow-derived macrophages with single agent challenge, which are modulated when added in combination. In silico docking experiments suggested that empagliflozin can interact with both TLR2 and DECTIN1 receptors, and we observed that both empagliflozin and metformin increase expression of Tlr2 and Clec7a. Thus, findings from this study suggest that metformin and empagliflozin as single agents or in combination can directly modulate inflammatory gene expression in macrophages and upregulate the expression of their receptors.

Potential Role of Soluble Toll-like Receptors 2 and 4 as Therapeutic Agents in Stroke and Brain Hemorrhage.

Hemolysis is a physiological condition in which red blood cells (RBCs) lyse, releasing their contents into the extracellular environment. Hemolysis can be a manifestation of several diseases and conditions, such as sickle cell disease, hemorrhagic stroke, and trauma. Heme and hemoglobin are among the unique contents of RBCs that are released into the environment. Although these contents can cause oxidative stress, especially when oxidized in the extracellular environment, they can also initiate a proinflammatory response because they bind to receptors such as the Toll-like receptor (TLR) family. This review seeks to clarify the mechanism by which TLRs initiate a proinflammatory response to heme, hemoglobin, and their oxidized derivatives, as well as the possibility of using soluble TLRs (sTLRs) as therapeutic agents. Furthermore, this review explores the possibility of using sTLRs in hemorrhagic disorders in which mitigating inflammation is essential for clinical outcomes, including hemorrhagic stroke and its subtypes, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH).

Analysis of TLR2 in Primary Endocrine Resistant of Breast Cancer.

BACKGROUND: Previous clinical studies have suggested that Toll-like receptor (TLR)2 had predictive function for endocrine resistance in HER2-positive breast cancer (BCa). Nevertheless, it remains unclear whether TLR2 would relate to development of endocrine therapy resistance in triple-positive breast cancer (TPBC). METHODS: Bioinformatic analysis of TLR2 was carried out through a database. Ten tumor tissues were obtained from TPBC patients who underwent surgery, with five patients displaying primary resistance to tamoxifen (TAM) with the remaining 5 being sensitive. Different levels of proteins were identified through mass spectrometry analysis and confirmed through reverse transcription polymerase chain reaction (RT-PCR) and western blot. TAM-resistant cell lines (BT474-TAM) were established by continuous exposure to TAM, and TAM resistance was assessed via IC50. Additionally, TLR2 mRNA was analyzed through western blot and RT-PCR in BT474, BT474-TAM, MCF-7, and MCF10A cells. Furthermore, TLR2-specific interference sequences were utilized to downregulate TLR2 expression in BT474-TAM cells to elucidate its role in TAM resistance. RESULTS: TLR2 had a correlation with decreased relapse-free survival in BCa patients from the GSE1456-GPL96 cohort, and it was involved in cancer development predominantly mediated by MAPK and PI3K pathways. TLR2 protein expression ranked in the top 5 proteins within the TAM-resistant group, and was 1.9 times greater than that in the sensitive group. Additionally, TLR2 mRNA and protein expression increased significantly in the established TAM-resistant BT474/TAM cell lines. The sensitivity of TAM was restored upon TLR2 downregulation in BT474/TAM cells. CONCLUSIONS: TLR2 might have a therapeutic value as it was involved in the TAM resistance in TPBC, with potential to be a marker for primary endocrine resistance.

A critical role for mast cells and mast cell-derived IL-6 in TLR2-mediated inhibition of tumor growth.

Several TLR agonists are effective in tumor immunotherapy, but their early innate mechanisms of action, particularly those of TLR2 agonists, are unclear. Mast cells are abundant surrounding solid tumors where they are often protumorigenic and enhance tumor angiogenesis. However, antitumor roles for mast cells have also been documented. The impact of mast cells may be dependent on their activation status and mediator release in different tumors. Using an orthotopic melanoma model in wild-type C57BL/6 and mast cell-deficient Kit(W-sh/W-sh) mice and a complementary Matrigel-tumor model in C57BL/6 mice, mast cells were shown to be crucial for TLR2 agonist (Pam(3)CSK(4))-induced tumor inhibition. Activation of TLR2 on mast cells reversed their well-documented protumorigenic role. Tumor growth inhibition after peritumoral administration of Pam(3)CSK(4) was restored in Kit(W-sh/W-sh) mice by local reconstitution with wild-type, but not TLR2-deficient, mast cells. Mast cells secrete multiple mediators after Pam(3)CSK(4) activation, and in vivo mast cell reconstitution studies also revealed that tumor growth inhibition required mast cell-derived IL-6, but not TNF. Mast cell-mediated anticancer properties were multifaceted. Direct antitumor effects in vitro and decreased angiogenesis and recruitment of NK and T cells in vivo were observed. TLR2-activated mast cells also inhibited the growth of lung cancer cells in vivo. Unlike other immune cells, mast cells are relatively radioresistant making them attractive candidates for combined treatment modalities. This study has important implications for the design of immunotherapeutic strategies and reveals, to our knowledge, a novel mechanism of action for TLR2 agonists in vivo.