ISCA2 inhibition decreases HIF and induces ferroptosis in clear cell renal carcinoma.

Clear cell renal cell carcinoma (ccRCC), the most common form of kidney cancer, is typically initiated by inactivation of the von Hippel Lindau (VHL) gene, which results in the constitutive activation of the hypoxia inducible factors, HIF-1α and HIF-2α. Using a high throughput screen, we identify novel compounds that decrease HIF-1/2α levels and induce ferroptosis by targeting Iron Sulfur Cluster Assembly 2 (ISCA2), a component of the late mitochondrial Iron Sulfur Cluster (L-ISC) assembly complex. ISCA2 inhibition either pharmacologically or using siRNA decreases HIF-2α protein levels by blocking iron-responsive element (IRE)-dependent translation, and at higher concentrations, also decreases HIF-1α translation through unknown mechanisms. Additionally, ISCA2 inhibition triggers the iron starvation response, resulting in iron/metals overload and death via ferroptosis. ISCA2 levels are decreased in ccRCC compared to normal kidney, and decreased ISCA2 levels are associated with pVHL loss and with sensitivity to ferroptosis induced by ISCA2 inhibition. Strikingly, pharmacological inhibition of ISCA2 using an orally available ISCA2 inhibitor significantly reduced ccRCC xenograft growth in vivo, decreased HIF-α levels and increased lipid peroxidation, suggesting increased ferroptosis in vivo. Thus, the targeting of ISCA2 may be a promising therapeutic strategy to inhibit HIF-1/2α and to induce ferroptosis in pVHL deficient cells.

Effects of intraguild interactions on Anticarsia gemmatalis and Chrysodeixis includens larval fitness and behavior in soybean.

BACKGROUND: Crop pest management requires an understanding of the complex interactions among species that potentially impact crop yield. In soybean, the velvetbean caterpillar, Anticarsia gemmatalis (Hübner), and the soybean looper, Chrysodeixis includens (Walker), are described as key pests, sharing the same feeding guild. We assessed the intraguild interactions of these species under laboratory conditions. Fitness cost study was conducted to examine the influence of competition on insect development. A video tracking system was used to evaluate behavioral parameters during larval interactions in scenarios with and without food availability. RESULTS: In the fitness cost assay, pupal weight was not significantly affected, regardless of sex. However, larval and pupal survival were influenced by the competition, especially in third versus fifth instar scenarios. We detected 40.00% cannibalism and 46.67% predation when A. gemmatalis and C. includens third instars competed with A. gemmatalis fifth instar, respectively. Distance moved, distance between larvae, body contact (food available) and frequency in food of C. includens larvae were negatively affected by interactions. Anticarsia gemmatalis larvae showed highly active behavior, moving twice or more the distance compared to C. includens larvae, and A. gemmatalis spent more time in body contact with food. CONCLUSION: Our results suggest that A. gemmatalis has a competitive advantage over C. includens. This study provides important information regarding lepidopteran behavior in soybean. We recommended that additional studies are necessary to understand the effects of interactions, especially in field conditions. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

An Erythropoietin-Independent Mechanism of Erythrocytic Precursor Proliferation Underlies Hypoxia Tolerance in Sea Nomads.

The Bajau Sea Nomads were recently demonstrated to have evolved larger spleens as an adaptation to millennia of a marine foraging lifestyle. The large-spleen phenotype appears to derive from increases in thyroid hormone (TH) production as a result of reduced expression of phosphodiesterase 10A (PDE10A), though the exact mechanism remains unknown. Through pharmacological inhibition of PDE10A using the selective inhibitor MP-10 in mice, we were able to mimic the Bajau adaptation and show that treated mice had significantly larger spleens than control animals. This difference appears connected to an excess of early stage erythrocytes and an apparent increase in red blood cell (RBC) precursor proliferation in response to increased TH. However, we determined that the stimulation of RBC production in the mouse model via TH is Erythropoietin (EPO)-independent, unlike in the altitude (chronic hypoxemia) response. We confirmed this using human GWAS data; although the Bajau PDE10A variants are significantly associated with increased TH levels and RBC count, they are not associated with EPO levels, nor are other strongly thyroid-associated SNPs. We therefore suggest that an EPO-independent mechanism of stimulating RBC precursor proliferation via TH upregulation underlies the increase in spleen size observed in Sea Nomad populations.

NHR-14 loss of function couples intestinal iron uptake with innate immunity in C. elegans through PQM-1 signaling.

Iron is essential for survival of most organisms. All organisms have thus developed mechanisms to sense, acquire and sequester iron. In C. elegans, iron uptake and sequestration are regulated by HIF-1. We previously showed that hif-1 mutants are developmentally delayed when grown under iron limitation. Here we identify nhr-14, encoding a nuclear receptor, in a screen conducted for mutations that rescue the developmental delay of hif-1 mutants under iron limitation. nhr-14 loss upregulates the intestinal metal transporter SMF-3 to increase iron uptake in hif-1 mutants. nhr-14 mutants display increased expression of innate immune genes and DAF-16/FoxO-Class II genes, and enhanced resistance to Pseudomonas aeruginosa. These responses are dependent on the transcription factor PQM-1, which localizes to intestinal cell nuclei in nhr-14 mutants. Our data reveal how C. elegans utilizes nuclear receptors to regulate innate immunity and iron availability, and show iron sequestration as a component of the innate immune response.

Excited-State Interaction of Semiconducting Single-Walled Carbon Nanotubes with Their Wrapping Polymers.

We employ photoluminescence and pump-probe spectroscopy on films of semiconducting single-walled carbon nanotubes (CNTs) of different chirality wrapped with either a wide band gap polyfluorene derivative (PF12) or a polythiophene with narrower gap (P3DDT) to elucidate the excited states' interplay between the two materials. Excitation above the polymer band gap gives way to an ultrafast electron transfer from both polymers toward the CNTs. By monitoring the hole polaron on the polymer via its mid infrared signature, we show that also illumination below the polymer band gap leads to the formation of this fingerprint and infer that holes are also transferred toward the polymer. As this contradicts the standard way of discussing the involved energy levels, we propose that polymer-wrapped CNTs should be considered as a single hybrid system, exhibiting states shared between the two components. This proposition is validated through quantum chemical calculations that show hybridization of the first excited states, especially for the thiophene-CNT sample.

Enrofloxacin and Toltrazuril Are Able to Reduce Toxoplasma gondii Growth in Human BeWo Trophoblastic Cells and Villous Explants from Human Third Trimester Pregnancy.

Classical treatment for congenital toxoplasmosis is based on combination of sulfadiazine and pyrimethamine plus folinic acid. Due to teratogenic effects and bone marrow suppression caused by pyrimethamine, the establishment of new therapeutic strategies is indispensable to minimize the side effects and improve the control of infection. Previous studies demonstrated that enrofloxacin and toltrazuril reduced the incidence of Neospora caninum and Toxoplasma gondii infection. The aim of the present study was to evaluate the efficacy of enrofloxacin and toltrazuril in the control of T. gondii infection in human trophoblast cells (BeWo line) and in human villous explants from the third trimester. BeWo cells and villous were treated with several concentrations of enrofloxacin, toltrazuril, sulfadiazine, pyrimethamine, or combination of sulfadiazine+pyrimethamine, and the cellular or tissue viability was verified. Next, BeWo cells were infected by T. gondii (2F1 clone or the ME49 strain), whereas villous samples were only infected by the 2F1 clone. Then, infected cells and villous were treated with all antibiotics and the T. gondii intracellular proliferation as well as the cytokine production were analyzed. Finally, we evaluated the direct effect of enrofloxacin and toltrazuril in tachyzoites to verify possible changes in parasite structure. Enrofloxacin and toltrazuril did not decrease the viability of cells and villous in lower concentrations. Both drugs were able to significantly reduce the parasite intracellular proliferation in BeWo cells and villous explants when compared to untreated conditions. Regardless of the T. gondii strain, BeWo cells infected and treated with enrofloxacin or toltrazuril induced high levels of IL-6 and MIF. In villous explants, enrofloxacin induced high MIF production. Finally, the drugs increased the number of unviable parasites and triggered damage to tachyzoite structure. Taken together, it can be concluded that enrofloxacin and toltrazuril are able to control T. gondii infection in BeWo cells and villous explants, probably by a direct action on the host cells and parasites, which leads to modifications of cytokine release and tachyzoite structure.

Partial 1q Duplications and Associated Phenotype.

Duplications of the long arm of chromosome 1 are rare. Distal duplications are the most common and have been reported as either pure trisomy or unbalanced translocations. The paucity of cases with pure distal 1q duplications has made it difficult to delineate a partial distal trisomy 1q syndrome. Here, we report 2 patients with overlapping 1q duplications detected by G-banding. Array CGH and FISH were performed to characterize the duplicated segments, exclude the involvement of other chromosomes and determine the orientation of the duplication. Patient 1 presents with a mild phenotype and carries a 22.5-Mb 1q41q43 duplication. Patient 2 presents with a pure 1q42.13qter inverted duplication of 21.5 Mb, one of the smallest distal 1q duplications ever described and one of the few cases characterized by array CGH, thus contributing to a better characterization of distal 1q duplication syndrome.

Takayasu arteritis in a Brazilian multicenter study: children with a longer diagnosis delay than adolescents.

OBJECTIVES: To evaluate and compare demographic, clinical, laboratory and angiographic data of Brazilian children and adolescents with Takayasu's arteritis. METHODS: In this Brazilian multicentre, retrospective study which included 10 paediatric rheumatology centres, we identified 71 children and adolescents with Takayasu's arteritis which were diagnosed before their 19th birthday. The patients' demographic, clinical, laboratorial and angiographic data were recorded. The participants were divided into two groups: children, defined by the WHO as younger than 10 years old (group 1: 36 patients) and adolescents, defined as individuals aged 10 to 19 years old (group 2: 35 patients). Features of both groups concerning disease manifestations were compared. RESULTS: A total of 21 (58.3%) patients in group 1 and 30 (85.7%) patients in group 2 were girls (p=0.01). The mean age at disease onset, the mean time to diagnosis, and the mean follow-up time were 5.7 and 12.7, 1.8 and 0.7, 7.2 and 3.6 years, respectively, in groups 1 and 2 (p<0.001, 0.001 and <0.001). At initial evaluation, constitutional symptoms (77.5%) were the most predominant symptoms and decreased peripheral pulses (85.9%) was the most predominant clinical sign without differences between groups. The main laboratory findings were increased erythrocyte sedimentation rate followed by leukocytosis. Anaemia, thrombocytosis and higher platelet levels were significantly more frequent in group 1 (p=0.031, 0.001 and 0.018). Angiographic data were similar in both groups. CONCLUSIONS: Children presented more laboratory abnormalities but clinical and angiographic characteristics were similar to those presented by the adolescents. Diagnosis delay is longer in younger patients.

Association between HLA genes and American cutaneous leishmaniasis in endemic regions of Southern Brazil.

BACKGROUND: The present study sought to investigate the association between HLA-A, HLA-B and HLA-DRB1 genes and susceptibility or resistance to the different clinical manifestations of American cutaneous leishmaniasis (ACL) in southern Brazil. METHODS: The sample consisted of 169 patients with a diagnosis of ACL and 270 healthy subjects for comparison. HLA-A, HLA-B and HLA-DRB1 were typed by PCR-SSO reverse dot blot. RESULTS: Results showed a trend towards susceptibility to cutaneous lesions for alleles HLA-DRB1*13 (P=0.0228; Pc=0.3420; OR=1.66; 95%CI=1.08 - 2.56), HLA-B*35 (P=0.0218; Pc=0.6758; OR=1.67; 95%CI=1.08 - 2.29) and HLA-B*44 (P=0.0290; Pc=0.8990; OR=1.67; 95%CI=1.05 - 2.64). Subjects with allele HLA-B*27 (P=0.0180; Pc=0.5580; OR=7.1111; 95%CI=1.7850 - 28.3286) tended towards susceptibility to mucocutaneous lesions, those with HLA-B*49 (P=0.0101; Pc=0.3131; OR=6.4000; 95%CI=1.8472 - 22.1743) to recurrent ACL, and HLA-B*52 (P=0.0044; Pc=0.1360; OR=12.61; 95%CI=3.08 - 51.66), to re-infection. Presence of HLA-B*45 (P=0.0107; Pc=0.3317) tended to provide protection against the cutaneous form of ACL. The most frequent haplotypes that may be associated with susceptibility to ACL were A*02 B*44 DRB1*07 (P = 0.0236) and A*24 B*35 DRB1*01 (P = 0.0236). CONCLUSION: Some Class I and Class II HLA genes appear to contribute towards susceptibility to and protection against different clinical manifestations of ACL. Other genetic marker studies may contribute toward future prophylactic and therapeutic interventions in ACL.

[Parasitism and superparasitism of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) on Sitotroga cerealella (Oliver) (Lepidoptera: Gelechiidae) eggs]. / Parasitismo e superparasitismo de Trichogramma pretiosum Riley(Hymenoptera: Trichogrammatidae) em ovos de Sitotroga cerealella(Oliver) (Lepidoptera: Gelechiidae).

The parasitoid Trichogramma has been used worldwide as biological control agent due to its wide geographic distribution, high specialization and efficacy against many lepidopteran pests. Biological and behavioral traits of Trichogramma pretiosum Riley parasitizing Sitotroga cerealella (Oliver) eggs were studied aiming to a better understanding of the results from parasitism and superparasitism. The variables investigated were: host acceptance and contact time by T. pretiosum on parasitized host, percentage of parasitoid emergence, number of deformed individuals produced, egg-adult period, sex ratio, offspring female body size and longevity, and number of S. cerealella eggs parasitized/female. Parasitism rejection was observed on parasitized host eggs after 24, 72 and 120 h of parasitism. The rejection was higher for eggs parasitized after 72 h and 120 h of parasitism as compared to the eggs after 24 h of parasitism. T. pretiosum contact time on eggs after 24 h of parasitism was greater than on 72 and 120 h. The offspring produced from hosts from which a single parasitoid emerged were larger, exhibited no deformities and greater capacity of parasitism, different from those produced from eggs where two parasitoids emerged. Offspring longevity, however, was similar for females emerged from hosts from which one or two adults emerged. In conclusion, T. pretiosum was able to recognize previously parasitized eggs and the superparasitism reduced the parasitoid.reproductive success.