Time-delayed effects of a single application of AgNPs on structure of testes and functions in Blaps polychresta Forskal, 1775 (Coleoptera: Tenebrionidae).

Silver nanoparticles (AgNPs) are currently the most frequently used engineered nanoparticles. The penetration of AgNPs into ecosystems is undeniable, and their adverse effects on organism reproduction are of fundamental importance for ecosystem stability. In this study, the survival time of the Egyptian beetle Blaps polychresta Forskal, 1775 (Coleoptera: Tenebrionidae), after a single application of 7 different doses, was calculated for 30 days. Then, for the group for which the effect on mortality was calculated as LOAEL - the Lowest Observed Adverse Effect Level, namely, 0.03 mg AgNPs/g body weight (b.w.t.), the following were assessed: structure and ultrastructure of gonads by TEM and SEM, cell viability by cytometry, DNA damage by the comet assay, and a variety of stress markers by spectrophotometric methods. A dose-dependent reduction in the survival time of the insects was revealed. Detailed analysis of the testes of beetles treated with 0.03 mg AgNPs/g b.w.t. revealed numerous adverse effects of nanoparticles in structure and ultrastructure, accompanied by increased apoptosis (but not necrosis), increased DNA damage, increased lipid peroxidation, and decreased levels of antioxidant enzymes. Most likely, the observed results are connected with the gradual release of Ag+ from the surface of the nanoparticles, which, once applied, are internalized in cells and become a long-lasting, stable source of Ag+ ions. Thus, a single exposure to AgNPs may have the effects of chronic exposure and lead to structural damage and dysfunction of the gonads of B. polychresta.

Relative gene expression, micronuclei formation, and ultrastructure alterations induced by heavy metal contamination in Pimelia latreillei (Coleoptera: Tenebrionidae) in an urban-industrial area of Alexandria, Egypt.

The present research aims to evaluate the impact of industrial processes and anthropogenic activities on the beetle Pimelia latreillei inhabiting the polluted site at Zawya Abd El- Qader, Alexandria, Egypt. Beetles were collected from the vicinity of five factories. The genotoxic effects of environmental exposures to industrial heavy metals were monitored using a broad range of assays, including energy-dispersive X ray microanalysis and X-ray diffraction (SEM and EDX)), qRT-PCR gene expression assay, micronuclei formation, and transmission electron microscope (TEM). Energy dispersive X-ray microanalysis for the soil and testicular tissues of beetles collected from the polluted site revealed a higher percentage of heavy metals than the beetles collected from the reference site (Sidi Kirier, Alexandria, Egypt). To analyze/monitor genotoxicity in P. latreillei sampled from the polluted site, the transcription levels of levels of heat shock proteins (Hsps) and accessory gland seminal fluid protein (AcPC01) in testicular tissues were recorded. The incidence of micronuclei (MN) formation in the testicular cells was also observed. Quantitative RT-PCR (RT-qPCR) analysis was carried out to detect the changes in the gene expression of the aforementioned proteins. Genes encoding heat shock proteins (Hsp60, Hsp70, and Hsp90) were significantly overexpressed (> 2-fold) in specimens sampled from the polluted site; however, AcPC01 gene expression was under-expressed (<1.5-folds). The incidence of MN was significantly increased in specimens sampled from the polluted site. Ultrastructure anomalies (nuclear and cytoplasmic disruption) were also observed in the testicular cells of the beetles sampled from the polluted site compared to those sampled from the unpolluted site. Our results, therefore, advocate a need for adequate measures to reduce increasing environmental pollution in the urban-industrial areas.

Active immunization against tumor necrosis factor-alpha decreases proinflammatory cytokines, oxidative stress mediators and adhesion molecules risk factors in streptozotocin-induced diabetic rats.

UNLABELLED: Diabetes is now one of the most common un-communicable diseases worldwide. Few studies have dealt specifically with the potential therapeutic effect of TNF-α suppressor to decrease oxidative stress markers in patients with diabetes. The aim of this study was to investigate the potential therapeutic and toxic effect of the direct injection of the anti-TNF-α on oxidative stress mediators, proinflammatory cytokines and vascular risk factors associated with diabetes on diabetic rats. METHODS: diabetes was induced by streptozotocin, three weeks after the - induction of diabetes, a polyclonal anti-mouse/rat TNF-α rabbit serum was injected in the treated group and sacrificed after 4 weeks. The expression of TNF-α mRNA was measured by RT-PCR. The levels of TNF-α, VEGF, IL-2, IL- 6, HSP-70, troponin-t, 8-OHdG, ICAM-1 and VCAM-1 were evaluated using ELISA. Myeloperoxiase (MPO) and total peroxides (TPs) levels were estimated by biochemical reactions. RESULTS: the treatment of diabetic rats with the anti-TNF-α caused a significant decrease in the TNF-α mRNA expression, which were paralleled with the decreased levels of TNF-α, IL-6, MOP, HSP-70, ICAM-1, VCAM-1, troponin-t and 8-OHdG in the blood serum. On the contrary, all were highly expressed in the diabetic group that may be the leading reasons for the DNA damage and cell loss. Data revealed that TNF-α, HSP-70, IL-6, MPO and adhesion molecules when expressed in diabetic rats, collectively induce dramatic changes. CONCLUSION: these new findings suggested that targeting TNF-α could effectively reduce expressions of MCP-1, HSP-70, troponin-t, 8-OHdG and VCAM- 1, along with prominent reduction in MPO and IL-6 levels.

Targeting tumor necrosis factor alpha (TNF-α) in diabetic rats could approve avenues for an efficient strategy for diabetic therapy.

BACKGROUND: Several studies held belief that downregulation of TNF-α may be effective for preventing diabetes and it's complications. However, it is not known whether TNF-α downregulation in long-term can generate any biological adverse. AIM: The aim of the present study was to clarify what the impact is for such treatment with specific antibody for TNF-α on the other biological activities after 4weeks. METHODS: Using western blot, IHC, Elisa, biochemical assays and scanning electron microscope. RESULTS: Results show that TNF-α, FOXO-1, IL-6 and MPO, when expressed in diabetic rats, collectively induce dramatic changes in diabetic rats. Since, TNF-α is involved in activation of transcription factor FOXO1 along with oxidative stress mediated by neutrophils. On one hand, IL-6 mediates neutrophils activation leading to an augmentation in stress mediators. And FOXO1 is activated in order to eliminate these oxidative mediators, on the other hand. Data show also that the prominent defect in mucosal IgA and IL-2 secretions may be the leading reasons for digestive atrophy. Finally, Akt-1 inhibits the cleavage of caspase 3, so, it could prevent the incidence of apoptosis. CONCLUSION: Findings of this study reveal how TNF-α can be mechanistically coupled to greater diabetic complications potential.