Kdr Gene Research Articles

Preparation of bimetallic calcium chromatite nanocomposite using Stevia rebaudiana leaf extract for inducing apoptosis in human cancer cell lines

Abstract Despite the widespread industrial use of chromium-based compounds, there are concerns regarding their toxicity in biomedical applications. Herein, bimetallic calcium chromatite nanocomposite (CC) was prepared through green synthesis using Stevia rebaudiana leaf extract. A porous nanorod of CC was obtained through calcinations at 800 °C. The formation of CC was confirmed by SEM (scanning electron microscopy), EDAX (Energy-dispersive x-ray spectroscopy), HRTEM (High-resolution transmission electron microscopy), TGA (Thermal gravimetric analysis), and BET (Brunauer–Emmett–Teller). The cytotoxicity of the CC was evaluated by the MTT method against cancer lines (HeLa, U87, A549) and primary cell line (HUVEC). The IC50 value of CC against cancer cell lines was lower than the primary cell lines. The calculated specificity index was greater than one, indicating that this CC might target cancer cells without the use of a targeting moiety. Gene expression studies revealed that CC upregulated the proapoptotic gene, BAX and downregulated the anti-apoptotic gene, Bcl-2, to induce apoptosis. The KDR and VEGF genes responsible for angiogenesis were down-regulated, indicating that CC decreases angiogenesis to promote apoptosis. The findings suggest CC prepared using phytoextract could be considered an adjuvant cancer therapy treatment.

Epidemiological analysis of pediculosis and the distribution of kdr mutation frequency in head lice populations in Torbat Heydarieh city of Khorasan Razavi Province, Northeastern Iran

Head lice infestations are the most prominent ectoparasitic infection in the world, including Iran, particularly among school children. Recently, numerous cases of infestation have been reported in various provinces of the country. This study aimed to investigate the prevalence of head louse infestations and analyze kdr gene sequences in terms of resistance mutations in the Torbat-e Heydarieh, Mahvelat, and Zaveh cities of Khorasan Razavi Province, Northeast Iran. The data related to the epidemiological and demographic history of head lice populations were extracted from their medical records and analyzed in Excel software. After extracting the genomic DNA, the kdr fragment was amplified using specific primers. The sequences were also analyzed using bioinformatics software. The prevalence of head louse infestations was 1.59% and 1.7% during 2016 and 2017, respectively. Sequence analysis revealed the frequency distribution of two kdr haplotypes, I and V, in the study areas. The increase in head louse infestations in recent years and the simultaneous presence of kdr mutations indicate the need for new treatments and monitoring/controlling resistance to head louse insecticides.

Benchmarking of Approaches for Gene Copy-Number Variation Analysis and Its Utility for Genetic Aberration Detection in High-Grade Serous Ovarian Carcinomas.

Objective: The goal of this study was to compare the results of CNV detection by three different methods using 13 paired carcinoma samples, as well as to perform a statistical analysis of the agreement. Methods: CNV was studied using NanoString nCounter v2 Cancer CN Assay (Nanostring), Illumina Infinium CoreExome microarrays (CoreExome microarrays) and digital droplet PCR (ddPCR). Results: There was a good level of agreement (PABAK score > 0.6) between the CoreExome microarrays and the ddPCR results for finding CNVs. There was a moderate level of agreement (PABAK values ≈ 0.3-0.6) between the NanoString Assay results and microarrays or ddPCR. For 83 out of 87 target genes studied (95%), the agreement between the CoreExome microarrays and NanoString nCounter was characterized by PABAK values < 0.75, except for MAGI3, PDGFRA, NKX2-1 and KDR genes (>0.75). The MET, HMGA2, KDR, C8orf4, PAX9, CDK6, and CCND2 genes had the highest agreement among all three approaches. Conclusions: Therefore, to get a better idea of how to genotype an unknown CNV spectrum in tumor or normal tissue samples that are very different molecularly, it makes sense to use at least two CNV detection methods. One of them, like ddPCR, should be able to quantitatively confirm the results of the other.

Molecular Analysis of Renal/Adrenal Angiosarcomas Reveals High Frequency of Recurrent Genetic Alterations.

Angiosarcomas of the kidney and adrenal gland are rare, highly aggressive vascular neoplasms. Their genomic profile has not been systematically studied to date. We report the clinicopathologic and molecular features of six angiosarcomas centered in the kidney/adrenal gland. All patients were male adults, ranging from 58 to 77 years of age. Tumor sizes ranged from 2.5 to 22.5 cm. Half of the cases demonstrated hot spot mutations in the KDR gene, while one-third demonstrated mutations in the PIK3CA gene; both of these gene alterations being previously described, preferentially in breast angiosarcomas. In addition, two cases each demonstrated BRIP1 gene amplification, CTNNB1 and ETV6 mutations, which have not been previously reported in angiosarcoma. Notably, molecular studies were critical in establishing the correct diagnoses in three cases: one was an epithelioid angiosarcoma originally misdiagnosed as metastatic adenocarcinoma to the adrenal gland, the second was a vasoformative angiosarcoma that mimicked hemangioma, and the third was a collision tumor between a high-grade angiosarcoma and a chromophobe renal cell carcinoma which was originally diagnosed as a sarcomatoid renal cell carcinoma. In summary, angiosarcomas of the kidney and adrenal gland have a high frequency of recurrent genetic alterations, some of them being shared with other angiosarcoma subtypes, while other appear to be novel. In particular, activating hot spot KDR and PIK3CA mutations represent potential therapeutic targets for these highly aggressive cancers.

Genetic structure analysis of yak breeds and their response to adaptive evolution

Yaks are crucial genetic resources in the Tibetan Plateau and surrounding regions. Throughout the long process of domestication, natural and artificial selection pressures have enabled yaks to demonstrate adaptive characteristics to the environment in terms of physiological structure and genetic molecules, but no systematic cell analysis has been carried out on this phenomenon of yaks. Here, the population structure and genetic diversity of yak were studied by WGRS, and the genes related to yak adaptability were excavated. Combined with scRNA-seq method, the transcription map of yak lung tissue and skin tissue was constructed, which provided a new comprehensive insight into yak adaptability. The analysis of yak population structure showed that there was obvious genetic differentiation between TZ _ yak and other seven yak populations, while there was significant genetic exchange between PL _ yak and SB _ yak at high altitude. WGRS and scRNA-seq analysis revealed that the gene HIF1A related to high altitude adaptation was expressed in various cell types, while EPAS1 was predominantly expressed in epithelial and endothelial cells of yak lung tissue. Endothelial cells play a critical role in hypoxia-adapted VEGF signaling, which correlates closely with the high expression of KDR and VEGFA genes in endothelial cells and monocytes. Furthermore, in the selection signal of High _ yak vs Low _ yak, 19.8 % of the genes overlapped with the genes screened by skin scRNA-seq, including genes related to coat color such as RORA, BNC2, and KIT. Notably, BNC2 is a gene associated with melanin deposition and shows high expression levels in HS cells. Additionally, GRN in melanocytes and SORT1 in IRS play an important role in cell communication between melanocytes and IRS. These findings offer new insights into the natural polymorphism of yaks and provide a valuable reference for future research on high-altitude mammals, and potentially even human genetics.

TAD border deletion at the Kit locus causes tissue-specific ectopic activation of a neighboring gene

Topologically associated domains (TADs) restrict promoter-enhancer interactions, thereby maintaining the spatiotemporal pattern of gene activity. However, rearrangements of the TADs boundaries do not always lead to significant changes in the activity pattern. Here, we investigated the consequences of the TAD boundaries deletion on the expression of developmentally important genes encoding tyrosine kinase receptors: Kit, Kdr, Pdgfra. We used genome editing in mice to delete the TADs boundaries at the Kit locus and characterized chromatin folding and gene expression in pure cultures of fibroblasts, mast cells, and melanocytes. We found that although Kit is highly active in both mast cells and melanocytes, deletion of the TAD boundary between the Kit and Kdr genes results in ectopic activation only in melanocytes. Thus, the epigenetic landscape, namely the mutual arrangement of enhancers and actively transcribing genes, is important for predicting the consequences of the TAD boundaries removal. We also found that mice without a TAD border between the Kit and Kdr genes have a phenotypic manifestation of the mutation — a lighter coloration. Thus, the data obtained shed light on the principles of interaction between the 3D chromatin organization and epigenetic marks in the regulation of gene activity.

The expression of salivary EGF, VEGF, endothelin, and transferrin in waterpipe and cigarette smokers.

The aim of this study was to evaluate the effects of two forms of tobacco smoking, cigarettes and water pipe smoking (WPS), on the expression of a panel of salivary proteins in healthy adults. Three groups of age and gender-matched participants were enrolled in the study: never-smokers, cigarette smokers and WPS (N = 55 per group). Expression of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), endothelin and transferrin in unstimulated whole saliva was estimated using enzyme-linked immunosorbent assays. Statistical analysis consisted of one-way ANOVA and Tukey's post hoc tests, in addition to bioinformatics analysis. VEGF expression was the least in WPS (51.1 ± 14.5 pg/ml) compared to both controls (150.1 ± 13.8 pg/ml) and cigarette smokers (93 ± 9.9 pg/ml), with a significant difference in WPS (p < 0.001) and cigarette smokers (p < 0.01) compared to controls. Furthermore, transferrin showed the weakest expression in the WPS group (1238 ± 261.4 pg/ml) compared to controls (2205.6 ± 298.6 pg/ml) (p = 0.05) and cigarette smokers (1805.4 ± 244 pg/ml). Neither EGF nor endothelin expression showed any statistical difference between the groups (p > 0.05). Gene-gene interaction network demonstrated that FLT1, TFRC, KDR, VEGFB and PGF genes had the highest potential for interaction with the studied proteins. Further functional annotations on the identified markers in the interaction network were performed to identify HIF-1 pathways among the most relevant pathways. In conclusion, smoking habits alter the expression of salivary VEGF and transferrin, which may correspond to early sub-clinical changes in the oral mucosa. The clinical relevance of these salivary changes requires further research.

CFH (rs1061170, rs1410996), KDR (rs2071559, rs1870377) and KDR and CFH Serum Levels in AMD Development and Treatment Efficacy.

Age-related macular degeneration (AMD) is a major global health problem as it is the leading cause of irreversible loss of central vision in the aging population. Av-vascular endothelial growth factor (anti-VEGF) therapies have been shown to be effective, but they do not respond optimally to all patients. This study investigates the genetic factors associated with susceptibility to AMD and response to treatment, focusing on key polymorphisms in the CFH (rs1061170, rs1410996) and KDR (rs2071559, rs1870377) genes and the association of CFH and KDR serum levels in patients with AMD. A cohort of 255 patients with early AMD, 252 patients with exudative AMD, and 349 healthy controls underwent genotyping analysis, which revealed significant associations between CFH polymorphisms and the risk of exudative AMD. The CFH rs1061170 CC genotype was associated with an increased risk of early AMD (p = 0.046). For exudative AMD, the CFH rs1061170 TC + CC genotype increased odds (p < 0.001), while the rs1410996 GA + AA genotype decreased odds (p < 0.001). Haplotypes of CFH SNPs were associated with decreased odds of AMD. In terms of response to treatment, none of the SNPs were associated with the response to anti-VEGF treatment. We also found that both early and exudative AMD patients had lower CFH serum levels compared to the control group (p = 0.038 and p = 0.006, respectively). Exudative AMD patients with the CT genotype of CFH rs1061170 had lower CFH serum levels compared to the control group (p = 0.035). Exudative AMD patients with the GG genotype of CFH rs1410996 also had lower CFH serum levels compared to the control group (p = 0.021). CFH polymorphisms influence susceptibility to AMD but do not correlate with a response to anti-VEGF therapy. Further research is imperative to fully evaluate the developmental significance, treatment efficacy, and predictive role in influencing susceptibility to anti-VEGF therapy for KDR and CFH.

Single-cell RNA sequencing reveals cellular and molecular landscape of fetal cystic hygroma

BackgroundThe molecular mechanism of fetal cystic hygroma (CH) is still unclear, and no study has previously reported the transcriptome changes of single cells in CH. In this study, single-cell transcriptome sequencing (scRNA-seq) was used to investigate the characteristics of cell subsets in the lesion tissues of CH patients.MethodsLymphoid tissue collected from CH patients and control donors for scRNA-seq analysis. Differentially expressed gene enrichment in major cell subpopulations as well as cell-cell communication were analyzed. At the same time, the expression and interactions of important VEGF signaling pathway molecules were analyzed, and potential transcription factors that could bind to KDR (VEGFR2) were predicted.ResultsThe results of scRNA-seq showed that fibroblasts accounted for the largest proportion in the lymphatic lesions of CH patients. There was a significant increase in the proportion of lymphatic endothelial cell subsets between the cases and controls. The VEGF signaling pathway is enriched in lymphatic endothelial cells and participates in the regulation of cell-cell communication between lymphatic endothelial cells and other cells. The key regulatory gene KDR in the VEGF signaling pathway is highly expressed in CH patients and interacts with other differentially expressed EDN1, TAGLN, and CLDN5 Finally, we found that STAT1 could bind to the KDR promoter region, which may play an important role in promoting KDR up-regulation.ConclusionOur comprehensive delineation of the cellular composition in tumor tissues of CH patients using single-cell RNA-sequencing identified the enrichment of lymphatic endothelial cells in CH and highlighted the activation of the VEGF signaling pathway in lymphoid endothelial cells as a potential modulator.Simple summaryThe molecular and cellular pathogenesis of fetal cystic hygroma (CH) remains largely unknown. This study examined the distribution and gene expression signature of each cell subpopulation and the possible role of VEGF signaling in lymphatic endothelial cells in regulating the progression of CH by single-cell transcriptome sequencing. The enrichment of lymphatic endothelial cells in CH and the activation of the VEGF signaling pathway in lymphatic endothelial cells provide some clues to the pathogenesis of CH from the perspective of cell subpopulations.

Abstract 5665: Native nanopore sequencing of multiple tumor sites reveals genetic and epigenetic intra-tumor heterogeneity in canine osteosarcoma

Abstract Osteosarcoma (OS) is an aggressive bone malignancy affecting children and young adults. Implementation and optimization of neoadjuvant chemotherapy led to significant improvements in outcome, but patients with recurrence or metastases at diagnosis continue to have poor prognosis. Whole genome sequencing (WGS) revealed that a hallmark of OS is a highly rearranged genome with complex copy number aberrations rather than point mutations. A better understanding of the key genomic and epigenetic factors driving clonal evolution may provide insights into the tumor progression and the therapy response. Canine OS recapitulates the majority of the hallmark genetic and molecular factors of human OS and is recognized as an informative model. A significant difference is that initial surgery in canine OS allows us to explore tumor evolution unperturbed by treatment, providing invaluable resources to study the genetic and molecular landscape of tumor evolution. Here, we present the first study to date in which we performed bulk WGS of multiple tumor sites and distal normal tissue in two dogs using nanopore long-read sequencing to analyze the genetic and epigenetic evolution of OS. In both subjects, somatic structural variation detection using Severus revealed chromothripsis-like rearrangements in chr11, leading to the deletion of Cdkn2a, a known cell cycle regulator and tumor suppressor. Interestingly, in one of the subjects, the majority of the SVs (n = 131) shared across all the samples were localized on chr5, coinciding with perturbed copy number profiles and bi-allelic frequency of the SNVs, with all mutations identified using complementary bioinformatics analysis of the same native nanopore reads. The multi-site sample analysis identified subclonal structural alterations in TP53 and ATRX genes. With phased nanopore reads, we observed subject-specific copy-neutral loss-of-heterozygosity events and long identical-by-descent blocks. Haplotype-specific copy-number analysis of tumors showed different aneuploidy patterns in both subjects, highlighted clonal compositions of samples from distinct sites, and identified regions of copy-number heterogeneity. Furthermore, phased nanopore reads also revealed haplotype-specific 5mC and 5hmC methylation differences across tumor samples, where samples from different sites of the same tumor demonstrate distinct methylation patterns that overlap DLG2, RUNX2, KDR, and other genes known as mutational hotspots in canine/human OS. Overall, we showcase how a single sequencing assay allows for a joint analysis of genetic and epigenetic tumor alterations, thus providing a richer understanding of the drivers of somatic evolution and their association with the molecular landscape in the canine OS. These findings can be translated into human disease and shed light on tumor progression and therapy response. Citation Format: Ayse Keskus, Sergey Aganezov, Tanveer Ahmad, Xiaoguang Dai, Robert Walker, John Beaulaurier, Scott Hickey, Sissel Juul, Amy Kathleen LeBlanc, Paul S. Meltzer, Mikhail Kolmogorov. Native nanopore sequencing of multiple tumor sites reveals genetic and epigenetic intra-tumor heterogeneity in canine osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5665.

The frequency of kdr and ace-1 alleles in Anopheles gambiae s.l. before and during indoor residual spraying (IRS) implementation and four years after IRS withdrawal in three districts in Atacora, Benin

BackgroundIndoor residual spraying (IRS) was first implemented in the Atacora department, Benin from 2011 to 2012 using bendiocarb (carbamate) followed by annual spraying with pirimiphos-methyl (organophosphate) from 2013 to 2018. Before and after IRS implementation in Atacora, standard pyrethroid insecticide-treated bed nets were the main method of vector control in the area. This study investigated the knockdown resistance (kdr) gene (L1014F) and the acetylcholinesterase (ace-1) gene (G119S), before and during IRS implementation, and 4-years after IRS withdrawal from Atacora. This was done to assess how changes in insecticide pressure from indoor residual spraying may have altered the genotypic resistance profile of Anopheles gambiae s.l.MethodIdentification of sibling species of An. gambiae s.l. and detection of the L1014F mutation in the kdr gene and G119S mutation in ace-1 genes was done using molecular analysis. Allelic and genotypic frequencies were calculated and compared with each other before and during IRS implementation and 4 years after IRS withdrawal. The Hardy–Weinberg equilibrium and genetic differentiation within and between populations were assessed.ResultsPrevalence of the L1014F mutation in all geographic An. gambiae s.l. (An. gambiae s.s., Anopheles. coluzzii, Anopheles. arabiensis, and hybrids of “An. gambiae s.s. and An. coluzzii”) populations increased from 69% before IRS to 87% and 90% during and after IRS. The G119S allele frequency during IRS (20%) was significantly higher than before IRS implementation (2%). Four years after IRS withdrawal, allele frequencies returned to similar levels as before IRS (3%). Four years after IRS withdrawal, the populations showed excess heterozygosity at the ace-1 gene and deficit heterozygosity at the kdr gene, whereas both genes had excess heterozygosity before and during IRS (FIS < 0). No genetic differentiation was observed within the populations.ConclusionsThis study shows that the withdrawal of IRS with bendiocarb and pirimiphos-methyl may have slowed down the selection of individual mosquitoes with ace-1 resistance alleles in contrast to populations of An. gambiae s.l. with the L1014F resistance allele of the kdr gene. This may suggest that withdrawing the use of carbamates or organophosphates from IRS or rotating alternative insecticides with different modes of action may slow the development of ace-1 insecticide-resistance mutations. The increase in the prevalence of the L1014F mutation of the kdr gene in the population, despite the cessation of IRS, could be explained by the growing use of pyrethroids and DDT in agriculture and for other domestic use. More observational studies in countries where carbamates or organophosphates are still being used as public health insecticides may provide additional insights into these associations.Graphical

Insecticide resistance status of Aedes aegypti in border areas of Yunnan Province.

Aedes aegypti is a main vector of arboviral diseases, principally dengue, chikungunya, and Zika. Insecticides remain the most effective vector control method. Pyrethroid is the main insecticide currently used, and the long-term use of insecticides can cause mosquitoes to develop knockdown resistance. Studying the mutation sites and genotypes of Ae. aegypti can reveal the mutation characteristics and regional distribution of the kdr gene in an Ae. aegypti population. Testing for a correlation between the mutation rate in various populations and pyrethrin resistance can clarify the resistance mechanism. The bioassay results showed that all 15 populations are resistant. In the study of the kdr gene, three non-synonymous mutations were identified in the DNA of first generation females from the wild Ae. aegypti population: S989P (TCC-CCC), V1016G (GTA-GGA), and F1534C (TTC-TGC). The mortality rate of the various populations was correlated with the mutation rate at the V1016G + F1534C locus, but not the S989P + V1016G locus. Aedes aegypti populations in border regions of Yunnan Province are resistant to permethrin and beta-cyfluthrin. The insecticidal effect of beta-cyfluthrin is stronger than that of permethrin. The mutation rate at sites V1016G + F1534C is negatively correlated with the mortality of Ae. aegypti based on bioassays. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Up-regulated mRNA expression of VEGFA receptors (FLT1 and KDR) in placentas after assisted reproductive technology fertilization

Placental angiogenesis is a pivotal process for feto-maternal circulation and ensures efficient development of the placenta throughout pregnancy. Many factors during in vitro fertilization and embryo transfer procedures may affect placental gene expression and fetus development. The present study aimed to identify differences in angiogenesis-related gene (VEGFA, FGF2, FLT1, and KDR) expression profiles in placentas after assisted reproductive technology fertilization and natural conception in healthy women. In a case-control study, term placentas were collected from Caucasian women after assisted reproductive technology fertilization (N = 20) and after natural conception in women with uncomplicated pregnancy (N = 9). The mRNA expression in placentas was examined for VEGFA, FGF2, FLT1, and KDR genes by real-time quantitative polymerase chain reaction (RT-qPCR). Group stratification was performed for comparison of investigated genes between the type of embryo transferred (fresh/frozen), place of tissue donation (center/margin), and newborns’ gender (male/female). In the ART placentas, significant down-regulation of VEGFA gene (p = 0.016) and up-regulation of FLT1 (p = 0.026) and KDR (p < 0.001) gene receptors were observed. Genes encoding VEGFA receptors were up-regulated in both fresh (ET) and frozen (FET) embryo transfer groups compared to controls. For the FLT1 gene, a statistically significant difference was observed between the frozen embryo transfer group and the controls (p = 0.032). Relative expression of KDR was significantly higher for both embryo transfer groups compared to controls (p < 0.001) and between ET and FET (p = 0.002). No statistically significant differences were observed between placental expression in different places of tissue donation and newborns’ gender. We observed differences in the placental expression of VEGFA and its receptors FLT1 and KDR in pregnancies after assisted reproductive technology compared to naturally conceived pregnancies. More research is needed to clarify these alterations that may affect placental development and fetal health.

Exploring the anticancer potential of hydrogen sulfide and BAY‑876 on clear cell renal cell carcinoma cells: Uncovering novel mutations in VHL and KDR genes among ccRCC patients

Exploring the anticancer potential of hydrogen sulfide and BAY‑876 on clear cell renal cell carcinoma cells: Uncovering novel mutations in VHL and KDR genes among ccRCC patients

Expression Status of Rap1 Pathway-Related Genes in Liver Metastases Compared with Corresponding Primary Colorectal Cancer.

Understanding molecular networks of CRLM is an ongoing area of research. In this study, paired CRC tissue and adjacent noncancerous tissue from 15 non-metastatic CRC patients and paired CRC tissue and matched liver metastatic tissues from 15 CRLM patients along with their adjacent noncancerous tissues were evaluated. We assessed Rap1 pathway-related genes including NRAS, FGF-1, NGF, and KDR expression by qRT-PCR and their protein status by Western blot. In CRLM patients, NRAS, FGF1, and KDR mRNA and protein were expressed at higher levels in metastatic than in CRC primary tumor and adjacent noncancerous tissue (p < 0.05). In non-metastatic patients, NRAS, FGF1, KDR, and NGF gene expression did not differ between CRC primary tumor-and adjacent noncancerous tissue (p > 0.05). ROC curve analysis showed a reasonable diagnostic accuracy of NRAS, FGF1, KDR, and FGF for the discrimination of metastatic patients from non- metastatic ones on analysis of their primary tumors. The data suggest that further functional studies on Rap1-related genes' role in CRLM are needed. In conclusion, the present data broaden our knowledge about specific molecular characteristics of CRLM. An increased understanding of the molecular features of metastasis has the potential to create more successful treatment, or prevention, of metastasis, especially in multimodal primary tumor treatment.

Identification of breeding habitats and kdr mutations in Anopheles spp. in South Korea

BackgroundMalaria is still endemic in South Korea. However, limited information is available on the current Anopheles breeding sites and the occurrence of insecticide resistance-associated genetic mutations and their distribution needed to control the malaria vector efficiently.MethodsThis study explored breeding sites of Anopheline adults in Gimpo-si, near the demilitarized zone (DMZ) in Gyeonggi-do province, South Korea, from 2022 to 2023. Genetic diversity was investigated based on the internal transcribed spacer (ITS2), cytochrome c oxidase subunit I (COI), and knockdown resistance (kdr) genes of Anopheles mosquitoes. A natural environment associated with the seasonal abundance of Anopheles larvae was characterized.ResultsTwo breeding sites of Anopheles larvae and adults were found at a stream margin or shallow freshwater near the forest in Wolgot-myeon in Gimpo-si without cattle shed within 1 km and in Naega-myeon in Ganghwa-gun with cow shed within 100 m in 2022 and 2023, respectively. Both sites were located between the newly cultivated lands and the forest. Besides, both breeding sites were in the valley at a slight elevation of 60–70 m from ground lands and maintained the shadow all day. Overall, the Wolgot-myeon breeding site showed various Anopheles spp. larvae, including Anopheles sinensis. Naega-myeon, an additional breeding site found in 2023, had Anopheles sineroides larvae, and approximately 59.7% (89/149) of An. sinensis adults inhabited within a 100-m distance. The total collection, including larvae and adults, revealed that An. sinensis, Anopheles pullus, Anopheles kleini, An. sineroides, Anopheles belenrae, and Anopheles lindesayi accounted for 44.2% (118/267), 0.7% (2/267), 0.7% (2/267), 22.1% (59/267), 1.9% (5/267), and 30.3% (81/267), respectively. Furthermore, various kdr mutant genotypes (F/F, C/C, L/F, L/C and F/C) in An. sinensis, and the first kdr allele mutant (L/F1014) in An. belenrae were identified in South Korea.ConclusionsTwo breeding sites of Anopheles larvae were studied in Wolgot-myeon and Naega-myeon. Various Anopheles spp. larvae were detected in both habitats, but overall, An. sinensis was the most prevalent adults in both study sites. The occurrence of kdr allele mutant of An. belenrae in South Korea was reported. Rigorous larvae monitoring of Anopheles spp., continuously updating information on Anopheles breeding sites, and understanding the environmental conditions of Anopheles habitats are required to develop an effective malaria control programme in South Korea.

Candidate genes related to acute cerebral circulatory disorders in Preeclampsia in the Kazakh Population

BackgroundThe purpose of this study is to conduct a comparative analysis of the population frequencies of alleles and genotypes of polymorphic variants of coagulation and fibrinolysis genes SERPINE1 rs1799889, ITGA2 rs1126643, THBD rs1042580, FII rs1799963, FV rs6025, FVII rs6046, angiogenesis and endothelial dysfunction PGF rs12411, FLT1 rs4769612, KDR rs2071559, ACE rs4340, GWAS associated with the development of acute cerebral circulatory disorders in preeclampsia, in an ethnically homogeneous population of Kazakhs with previously studied populations of the world. MethodsThe genomic database was analysed based on the results of genotyping of 1800 conditionally healthy individuals of Kazakh nationality ∼2.5 million SNPs using OmniChip 2.5 M Illumina chips at the DECODE Iceland Genomic Center as part of the joint implementation of the project “Genetic Studies of Preeclampsia in Populations of Central Asia and Europe” (InterPregGen) within the 7th Framework Programme of the European Commission under Grant Agreement No. 282540. ResultThe study discovered a significantly higher population frequency of carrying the unfavorable rs1126643 allele of the ITGA2 gene polymorphism when compared with European populations. The population frequencies of carrying minor alleles of the SERPINE1 (rs179988) and KDR (rs2071559) genes in the Kazakh population were significantly lower when compared with the previously studied populations of Europe and Asia. An intermediate frequency of unfavorable minor alleles between European and Asian populations was found in Kazakhs for gene polymorphisms: FV rs6025, PGF rs12411, and ACE rs4340. The genomic analysis determined the choice of polymorphisms for their further replicative genotyping in patients with ACCD in PE in the Kazakh population. ConclusionThe obtained results will serve as a basis for the development of effective methods of early diagnosis and treatment of PE in pregnant women, carriers of unfavorable genotypes.

Evolution of knockdown resistance (kdr) mutations of Aedes aegypti and Aedes albopictus in Hainan Island and Leizhou Peninsula, China.

Aedes aegypti and Aedes albopictus are important vectors of human arboviruses, transmitting arboviral diseases such as yellow fever, dengue, chikungunya and Zika. These two mosquitoes coexist on Hainan Island and the Leizhou Peninsula in China. Over the past 40 years, the distribution of Ae. albopictus has gradually expanded in these areas, while the distribution of Ae. aegypti has declined dramatically mainly due to the ecological changes and some other factors such as heavy use of insecticide indoor based on endophagic bloodfeeding of the species. This study focused on the knockdown resistance (kdr) genes of both mosquitoes, investigated their mutations, and analyzed their haplotype and evolutionary diversity combined with population genetic features based on the ND4/ND5 genes to further elucidate the molecular mechanisms underlying the development of insecticide resistance in both mosquitoes. Three mutations, S989P, V1016G and F1534C, were found to be present in Ae. aegypti populations, and the three mutations occurred synergistically. Multiple mutation types (F1534C/S/L/W) of the F1534 locus are found in Ae. albopictus populations, with the three common mutations F1534C, F1534S and F1534L all having multiple independent origins. The F1534W (TTC/TGG) mutation is thought to have evolved from the F1534L (TTC/TTG) mutation. The F1534S (TTC/TCG) mutation has evolved from the F1534S (TTC/TCC) mutation. The most common form of mutation at the F1534 locus found in this study was S1534C, accounting for 20.97%, which may have evolved from the F1534C mutation. In addition, a new non-synonymous mutation M1524I and 28 synonymous mutations were identified in Ae. albopictus populations. Correlation analysis showed that the genetic diversity of Ae. aegypti and Ae. albopictus populations did not correlate with their kdr haplotype diversity (P>0.05), but strong gene flow between populations may have contributed to the evolution of the kdr gene. The study of kdr gene evolution in the two mosquito species may help to identify the evolutionary trend of insecticide resistance at an early stage and provide a theoretical basis for improving the efficiency of biological vector control and subsequent research into new insecticides.

Investigating the breeding habitats and kdr allele frequency of malaria vectors in Anambra Central Senatorial Zone, Southeast Nigeria

Malaria, transmitted by infected female Anopheles mosquitoes, is a parasitic disease of major public health importance in Nigeria. Various classes of insecticides have played significant role in the control and elimination of malaria by attacking the vectors. Unfortunately, the success of the use of insecticides in the control of malaria vectors is threatened by the emergence of insecticidal resistance. This study was therefore aimed at determining the resistance status of Anopheles gambiae s. l. in communities in Anambra State, southeast Nigeria. Larval samples were collected from diverse habitats and reared to adult for susceptibility test. Target site resistance assays were carried out and genotypic differentiation test was performed to assess variability of the allelic frequencies of the kdr (L1014F) mutation. The results showed that Anopheles gambiae was the predominant vector (54.2%), followed by Anopheles coluzzii (45.8%). The distribution of the frequency of resistant allele of the kdr gene F (L1014F) showed that the number of homozygous resistant genotype (RR) in Awka North LGA for An. gambiae and An. coluzzii species was highest (31), followed by Awka South (20), and Njikoka (5) LGAs. Also, the number of Heterozygous resistant genotype (Rr) was highest in Awka South (7), followed by Awka North (2), and none was recorded in Njikoka LGA. Homozygous resistant genotype (RR) was frequently observed in the three study areas of Anambra State and is a threat to the use of pyrethroids for insecticidal control of malaria vectors. There is an urgent need for implementation of insecticide resistance management and monitoring in Anambra State to assess the spread of resistance which may expand malaria vector resistance to the remaining classes of insecticides (organophosphates and carbamates) on the long run.

Association of single nucleotide variants in VEGFA and KDR with the risk and angiogenic features of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype and dependent on angiogenesis (AG), whose main effectors are VEGFA and VEGFR2. Functional single nucleotide variants (SNVs) are described in VEGFA and KDR genes. However, it still unknown whether VEGFA − 2578C/A, −2489C/T, −1154G/A, −634G/C, −460C/T and KDR-604T/C, −271G/A, +1192G/A and +1719A/T SNVs act on DLBCL risk and angiogenic features. Genomic DNA from 168 DLBCL patients and 205 controls was used for SNV genotyping. Angiogenesis was immunohistochemically assessed in tumor biopsies, with reactions for VEGFA, VEGFR2, and CD34. VEGFA –1154GG genotype were associated with 1.6-fold higher DLBCL risk. KDR + 1192GG plus KDR + 1719 TT and KDR + 1192GG plus VEGFA − 2578CC combined genotypes are associated with 2.19- and 2.04-fold higher risks of DLBCL, respectively. VEGFA − 634GG or GC genotypes are associated with increased microvessel density and VEGFA levels. No relationship was observed between SNVs and cell-of-origin classification of DLBCL, but higher VEGFA and VEGFR2 were seen in non-germinal center tumors.