HIF meets NF-κB signaling

T Cell Nrf2/Keap1 Gene Editing Using CRISPR/Cas9 and Experimental Kidney Ischemia-Reperfusion Injury

Aims: T cells play pathophysiologic roles in kidney ischemia-reperfusion injury (IRI), and the nuclear factor erythroid 2-related factor 2/kelch-like ECH-associated protein 1 (Nrf2/Keap1) pathway regulates T cell responses. We hypothesized that clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated Keap1-knockout (KO) augments Nrf2 antioxidant potential of CD4+ T cells, and that Keap1-KO CD4+ T cell immunotherapy protects from kidney IRI. Results: CD4+ T cell Keap1-KO resulted in significant increase of Nrf2 target genes NAD(P)H quinone dehydrogenase 1, heme oxygenase 1, glutamate-cysteine ligase catalytic subunit, and glutamate-cysteine ligase modifier subunit. Keap1-KO cells displayed no signs of exhaustion, and had significantly lower levels of interleukin 2 (IL2) and IL6 in normoxic conditions, but increased interferon gamma in hypoxic conditions in vitro. In vivo, adoptive transfer of Keap1-KO CD4+ T cells before IRI improved kidney function in T cell-deficient nu/nu mice compared with mice receiving unedited control CD4+ T cells. Keap1-KO CD4+ T cells isolated from recipient kidneys 24 h post IR were less activated compared with unedited CD4+ T cells, isolated from control kidneys. Innovation: Editing Nrf2/Keap1 pathway in murine T cells using CRISPR/Cas9 is an innovative and promising immunotherapy approach for kidney IRI and possibly other solid organ IRI. Conclusion: CRISPR/Cas9-mediated Keap1-KO increased Nrf2-regulated antioxidant gene expression in murine CD4+ T cells, modified responses to in vitro hypoxia and in vivo kidney IRI. Gene editing targeting the Nrf2/Keap1 pathway in T cells is a promising approach for immune-mediated kidney diseases.

Plantamajoside inhibits hypoxia-induced migration and invasion of human cervical cancer cells through the NF-κB and PI3K/akt pathways

Plantamajoside (PMS) is a major compound of Plantago asiatica and possesses anti-tumor property in several types of cancers. However, the effect of PMS on cervical cancer has not been investigated. This study aimed to investigate the effect of PMS on the migration and invasion of cervical cancer cell lines under hypoxic condition. Our results demonstrated that PMS significantly inhibited hypoxia-caused increases in cell migration and invasion of cervical cancer cells. The hypoxia-induced epithelial-mesenchymal transition (EMT) process was prevented by PMS with increased E-cadherin expression, and decreased expression levels of N-cadherin and vimentin in cervical cancer cells. Besides, the expression levels of transcription factors slug and snail were suppressed by PMS in hypoxia-induced cervical cancer cells. The increased mRNA and protein levels of hypoxia-inducible factor 1alpha (HIF-1α) in hypoxia-induced cervical cancer cells were prevented by PMS. Furthermore, PMS blocked the hypoxia-induced activation of NF-κB and PI3K/Akt pathway in cervical cancer cells. Taken together, these findings suggest that PMS exerted an anti-tumor activity in cervical cancer through preventing the hypoxia-induced EMT. Thus, PMS might serve as a therapeutic agent for the treatment of cervical cancer.

Co-treatment with nitroglycerin and metformin exhibits physicochemically and pathohistologically detectable anticancer effects on fibrosarcoma in hamsters

We investigated the effect of nitroglycerin with metformin on fibrosarcoma in hamsters. Syrian golden hamsters of both sexes, weighing approximately 60 g, were randomly allocated to control and experimental groups, with 8 animals per group. In all groups, 2 × 10⁶ BHK-21/C13 cells in 1 ml were injected subcutaneously into the animals' backs. Peroral treatment carried out with nitroglycerin 25 mg/kg daily, or with metformin 500 mg/kg daily, or with a combination of nitroglycerin 25 mg/kg and metformin 500 mg/kg daily. Later validation experiments were conducted with double doses of the single therapy and additional rescue doses of mebendazole 460 mg/kg daily, via a gastric probe after tumor inoculation. After 2 weeks, when the tumors were approximately 2-3 cm in the control group, all animals were sacrificed. Blood samples were collected for hematological and biochemical analyses, the tumors were excised and weighed, and their diameters and volumes were measured. The tumor samples were pathohistologically and immunohistochemically assessed for proliferation marker protein Ki-67, proliferating cell nuclear antigen PCNA, hematopoietic progenitor cell antigen CD34, cluster of differentiation 31 (CD31), cytochrome c oxidase subunit 4 (COX4), mitochondria marker Cytochrome C, glucose transporter 1 (GLUT1) and inducible nitric oxide synthase (iNOS), and the main organs were toxicologically tested. The Ki-67 and PCNA positivity and the cytoplasmic marker (CD34, CD31, COX4, Cytochrome C, GLUT1, iNOS) immunoexpression in the tumor samples were quantified. The combination of nitroglycerin and metformin significantly inhibited fibrosarcoma growth in hamsters without toxicity, compared to monotherapy or control. The results were validated and confirmed in the subsequently accomplished experiment with doubled doses of the single drug therapy and in the rescue experiment with addition of mebendazole. The single treatments did not show significant antisarcoma effect, regardless of the dose. Co-treatment with mebendazole inhibited anticancer activity of the nitroglycerin and metformin combination. Mebendazole rescued tumor progression suppressed by the combination of nitroglycerin and metformin. Administration of nitroglycerin with metformin might be an effective and safe approach in novel nontoxic adjuvant and relapse prevention anticancer treatment.

Erythropoietin attenuates LPS-induced microvascular damage in a murine model of septic acute kidney injury

Acute kidney injury (AKI) is a frequent complication of sepsis, with a high mortality. Hallmarks of septic-AKI include inflammation, endothelial injury, and tissue hypoxia. Therefore, it would be of interest to develop therapeutic approaches for improving the microvascular damage in septic-AKI. Erythropoietin (EPO) is a well-known cytoprotective multifunctional hormone. Thus, the aim of this study was to evaluate the protective effects of EPO on microvascular injury in a murine model of endotoxemic AKI. Male Balb/c mice were divided into four groups: control, LPS (8 mg/kg, ip.), EPO (3000 IU / kg, sc.) and LPS + EPO. A time course study (0-48 h) was designed. Experiments include, among others, immunohistochemistry and Western blottings of hypoxia-inducible transcription factor (HIF-1α), erythropoietin receptor (EPO-R), vascular endothelial growth factor system (VEGF/VEGFR-2), platelet and endothelial adhesion molecule-1 (PeCAM-1), inducible nitric oxide synthase (iNOS) and phosphorylated nuclear factor kappa B p65 (NF-κB). Data showed that EPO attenuates renal microvascular damage during septic-AKI progression through a) the decrease of HIF-1 alpha, iNOS, and NF-κB and b) the enhancement of EPO-R, PeCAM-1, VEGF, and VEGFR-2 expression. In summary, EPO renoprotection involves the attenuation of septic-induced renal hypoxia and inflammation as well as ameliorates the endotoxemic microvascular injury.

New perspectives on the regulation of iron absorption via cellular zinc concentrations in humans

Iron deficiency is the most prevalent nutritional deficiency, affecting more than 30% of the total world's population. It is a major public health problem in many countries around the world. Over the years various methods have been used with an effort to try and control iron-deficiency anemia. However, there has only been a marginal reduction in the global prevalence of anemia. Why is this so? Iron and zinc are essential trace elements for humans. These metals influence the transport and absorption of one another across the enterocytes and hepatocytes, due to similar ionic properties. This paper describes the structure and roles of major iron and zinc transport proteins, clarifies iron-zinc interactions at these sites, and provides a model for the mechanism of these interactions both at the local and systemic level. This review provides evidence that much of the massive extent of iron deficiency anemia in the world may be due to an underlying deficiency of zinc. It explains the reasons for predominance of cellular zinc status in determination of iron/zinc interactions and for the first time thoroughly explains mechanisms by which zinc brings about these changes.

Hemorrhage Exacerbates Radiation Effects on Survival, Leukocytopenia, Thrombopenia, Erythropenia, Bone Marrow Cell Depletion and Hematopoiesis, and Inflammation-Associated microRNAs Expression in Kidney

Exposure to high-dose radiation results in detrimental effects on survival. The effects of combined trauma, such as radiation in combination with hemorrhage, the typical injury of victims exposed to a radiation blast, on survival and hematopoietic effects have yet to be understood. The purpose of this study was to evaluate the effects of radiation injury (RI) combined with hemorrhage (i.e., combined injury, CI) on survival and hematopoietic effects, and to investigate whether hemorrhage (Hemo) enhanced RI-induced mortality and hematopoietic syndrome. Male CD2F1 mice (10 weeks old) were given one single exposure of γ- radiation (60Co) at various doses (0.6 Gy/min). Within 2 hr after RI, animals under anesthesia were bled 0% (Sham) or 20% (Hemo) of total blood volume via the submandibular vein. In these mice, Hemo reduced the LD50/30 for 30-day survival from 9.1 Gy (RI) to 8.75 Gy (CI) with a DMF of 1.046. RI resulted in leukocytopenia, thrombopenia, erythropenia, and bone marrow cell depletion, but decreased the caspase-3 activation response. RI increased IL-1β, IL-6, IL-17A, and TNF-α concentrations in serum, bone marrow, ileum, spleen, and kidney. Some of these adverse alterations were magnified by CI. Erythropoietin production was increased in kidney and blood more after CI than RI. Furthermore, CI altered the global miRNAs expression in kidney and the ingenuity pathway analysis showed that miRNAs viz., let-7e, miR-30e and miR-29b that were associated with hematopoiesis and inflammation. This study provides preliminary evidence that non-lethal Hemo exacerbates RI-induced mortality and cell losses associated with high-dose γ-radiation. We identified some of the initial changes occurring due to CI which may have facilitated in worsening the injury and hampering the recovery of animals ultimately resulting in higher mortality.