TNFα induces Caspase-3 activity in hematopoietic progenitor cells CD34+, CD33+, and CD41 + of myelodysplastic syndromes

BACKGROUND

Cytopenia is the primary feature of Myelodysplastic Syndrome, even in the presence of hypercellular bone marrow. TNFα is recognized as both a proinflammatory, and proapoptotic cytokine with a well established role in promoting apoptosis in MDS. Therefore, TNFα has the potential to be a valuable biomarker for predicting the progression of cytopenia in MDS. This study aims to establish the role of TNFα exposure in triggering apoptosis through caspase-3 activity in CD34+, CD33+, and CD41 + cells in MDS.

METHODS

This study is an in vitro comparative experimental research. Bone marrow mononuclear cells were isolated as the source of hematopoietic progenitor cells. Subsequently, CD34+, CD33+, and CD41 + cells were exposed to rhTNFα, and the caspase-3 activity was measured using flowcytometry.

RESULTS

In MDS CD33 + and CD41 + caspase-3 activity of rhTNFα exposed cells was significantly higher than without exposed cells. The opposite result was found in CD34 + cells, where the caspase-3 activity without rhTNFα exposed cells was significantly higher than rhTNFα exposed cells.

CONCLUSION

rhTNFα exposure led to an elevation in caspase-3 activity in MDS progenitor cells, especially in those that had differentiated into myeloid cell CD33 + and megakaryocyte cell CD41+, as opposed to the early progenitor cells CD34+.

A novel beneficial role of humanin on intestinal apoptosis and dysmotility in a rat model of ischemia reperfusion injury

A prevalent clinical problem including sepsis, shock, necrotizing enterocolitis, and mesenteric thrombosis is intestinal ischemia/reperfusion (I/R) injury. Humanin (HN), a recently identified mitochondrial polypeptide, exhibits antioxidative and antiapoptotic properties. This work aimed to study the role of HN in a model of experimental intestinal I/R injury and its effect on associated dysmotility. A total of 36 male adult albino rats were allocated into 3 equal groups. Sham group: merely a laparotomy was done. I/R group: for 1 h, clamping of the superior mesenteric artery was done, and then reperfusion was allowed for 2 h later. HN-I/R group: rats underwent ischemia and reperfusion, and 30 min before the reperfusion, they received an intraperitoneal injection of 252 μg/kg of HN. Small intestinal motility was evaluated, and jejunal samples were got for biochemical and histological analysis. I/R group showed elevation of intestinal NO, MDA, TNF- α, and IL-6 and decline of GPx and SOD levels. Furthermore, histologically, there were destructed jejunal villi especially their tips and increased tissue expression of caspase-3 and i-NOS, in addition to reduced small intestinal motility. Compared to I/R group, HN-I/R group exhibited decrease intestinal levels of NO, MDA, TNF- α, and IL-6 and increase GPx and SOD. Moreover, there was noticeable improvement of the histopathologic features and decreased caspase-3 and iNOS immunoreactivity, beside enhanced small intestinal motility. HN alleviates inflammation, apoptosis, and intestinal dysmotility encouraged by I/R. Additionally, I/R-induced apoptosis and motility alterations depend partly on the production of nitric oxide.

Paricalcitol protects against hydrogen peroxide-induced injury in endothelial cells through suppression of apoptosis

The vascular endothelium is one of the main targets of oxidative stress which plays an important role in the pathophysiology of vascular damage. Recent studies show that vitamin D can positively regulate endothelial functions in various chronic diseases and in cases of increased oxidative stress. In our study, we investigated the restorative and protective potentials of paricalcitol which is frequently used in patients with chronic renal failure, a vitamin D analogue, in human umbilical vein endothelial cells (HUVEC) before and after H₂O₂-induced oxidative stress. Paricalcitol treatment after the oxidative stress induced by H₂O₂ increased cell viability in endothelial cells depending on the dose that was used. While paricalcitol (500 nM) decreased caspase-3 activity and mitochondrial membrane potential loss, it increased nitric oxide (NO) production and reduced glutathione (GSH) levels. Paricalcitol treatment before oxidative stress increased cell viability. It increased NO production and mitochondrial membrane potential while significantly reducing caspase-3 activity. While paricalcitol caused a significant inhibition of protein disulfide isomerase (PDI) reductase activity in healthy endothelial cells, it did not cause a significant change on the PDI reductase activity under oxidative stress conditions. Present study showed that paricalcitol has restorative and protective effects on endothelial cells against oxidative injury, but these effects occur at high concentrations of paricalcitol.

Challenges in Platelet Functions in HIV/AIDS Management

The interest in platelet functions in HIV/AIDS is due to the high incidence of microvascular thrombosis in these individuals. A lot of laboratory data have been generated regarding platelet functions in this population. The tests demonstrate platelet hyperactivity but decreased aggregation, though results are inconsistent depending on the study design. Antiretroviral treatments currently in use display complex interactions. Many studies on platelet functions in these patients have been for research purposes, but none have found utility in guiding drug treatment of thrombosis.

Low-Dose Gamma Radiation Modulates Liver and Testis Tissues Response to Acute Whole Body Irradiation

Aim

This work aims to investigate whether the pre-exposure to low dose/low dose rate (40 mGy, 2.2 mGy/hour) γ-radiation as a priming dose can produce a protective effect against the subsequent high one (4 Gy, .425 Gy/minute).

Methods

Rats were divided into Group I (control), Group II (L); exposed to 40 mGy, Group III (H); exposed to 4 Gy, and Group IV (L+H); exposed to 40 mGy 24 hours before the exposure to 4Gy. The molecular and biochemical changes related to oxidative stress, DNA damage, apoptosis, and mitochondrial activity in the liver and testis were studied 4 hours after irradiation.

Results

Exposure to 40 mGy before 4 Gy induced a significant increase in the levels of Nrf2, Nrf2 mRNA, TAC, and mitochondrial complexes I & II accompanied by a significant decrease in the levels of LPO, 8-OHdG, DNA fragmentation, TNF-α, caspase-3, and caspase-3 mRNA compared with H group.

Conclusion

Exposure to low-dose γ-radiation before a high dose provides protective mechanisms that allow the body to survive better after exposure to a subsequent high one via reducing the oxidative stress, DNA damage, and apoptosis-induced early after irradiation. However, further studies are required to identify the long-term effects of this low dose.

The antioxidant, anti-inflammatory, and antiplatelet effects of Ribes rubrum L. fruit extract in the diabetic rats

The prothrombotic and inflammatory state plays a significant role in the occurrence of cardiovascular complications in type 2 diabetes mellitus. In this study, the antidiabetic, anti-inflammatory, and antiplatelet potentials of the extracts obtained from Ribes rubrum were investigated. The antidiabetic, anti-inflammatory, and antioxidant activities of the ethanol and water extracts of R. rubrum were evaluated by in vitro methods. The total phenolic and flavonoid contents were also determined. The experimental diabetes model in rats was induced with streptozotocin (STZ). After hyperglycemia occurred, the ethanol extracts of R. rubrum (RRE, at 100 mg/kg and 500 mg/kg doses) were administered to the treatment groups for 14 days. Blood glucose, lipid profile, plasma, and pancreas tumor necrosis factor-α (TNF-α) levels were determined and compared at the end of the experiments. P-selectin levels and mitochondrial membrane polarization (MMP) of platelets were also measured. In vitro study, the RRE showed potent anti-inflammatory activity. Administration of RRE (at 100 mg/kg doses) to diabetic rats lowered blood glucose level insignificantly. The results showed that there was an increment in levels of TNF-α in plasma and pancreas tissue of the diabetic group compared to the control group. R. rubrum extract regulated and normalized their levels in plasma and pancreatic tissue. RRE at both doses significantly decreased platelet P-selectin levels and prevented STZ-induced loss of MMP in platelets. The results of current research indicate that RRE extract has potent anti-platelet and anti-inflammatory effects and may be beneficial in preventing diabetic complications. PRACTICAL APPLICATIONS: Hyperglycemia causes dyslipidemia, advanced oxidative stress, platelet activation, and inflammation in diabetes mellitus. Plants with various medicinal properties are of worldwide interest for the treatment of diseases due to their biological activities. In this study, the antidiabetic, anti-inflammatory, and antioxidant effects of extracts of Ribes rubrum (%100 ethanol, 50% ethanol, water) were evaluated by in vitro and in vivo methods. The diabetes model was induced with streptozotocin (STZ). The rats were divided into control, diabetic control, R. rubrum-100 mg/kg, and R. rubrum-500 mg/kg doses groups. Blood glucose levels, tumor necrosis factor-α (TNF-α), platelet P-selectin levels, mitochondrial membrane polarization of platelets were examined. The present study has shown that R. rubrum has anti-inflammatory and antiplatelet activity. R. rubrum may be beneficial in the prevention and treatment of DM complications due to its anti-inflammatory and antithrombotic effects.