Changes in vimentin,lamin A/C and mitofilin induce aberrant cell organization in fibroblasts from Fanconi anemia complementation group A (FA-A) patients

Growing number of publication has proved an increasing of cellular function of the Fanconi anemia proteins. To chromosome stability and DNA repair new roles have been attributed to FA proteins in oxidative stress response and homeostasis, immune response and cytokines sensibility, gene expression. Our work shows a new role for FA-A protein: the organization of the cellular structure.     

Identification of a SLC19A2 nonsense mutation in Persian families with thiamine-responsive megaloblastic anemia

Thiamine-responsive megaloblastic anemia (TRMA) is an autosomal recessive syndrome characterized by early-onset anemia, diabetes, and hearing loss caused by mutations in the SLC19A2 gene. We studied the genetic cause and clinical features of this condition in patients from the Persian population. A clinical and molecular investigation was performed in four patients from three families and their healthy family members. All had the typical diagnostic criteria. The onset of hearing loss in three patients was at birth and one patient also had a stroke and seizure disorder. Thiamine treatment effectively corrected the anemia in all of our patients but did not prevent hearing loss. Diabetes was improved in one patient who presented at the age of 8 months with anemia and diabetes after 2 months of starting thiamine. The coding regions of SLC19A2 were sequenced in all patients. The identified mutation was tested in all members of the families. Molecular analyses identified a homozygous nonsense mutation c.697C > T (p.Gln233*) as the cause of the disease in all families. This mutation was previously reported in a Turkish patient with TRMA and is likely to be a founder mutation in the Persian population.     

Epigenetic and microenvironmental alterations in bone marrow associated with ROS in experimental aplastic anemia

Aplastic anemia or bone marrow failure often develops as an effect of chemotherapeutic drug application for the treatment of various pathophysiological conditions including cancer. The long-term bone marrow injury affects the basic hematopoietic population including hematopoietic stem/progenitor cells (HSPCs). The present study aimed in unearthing the underlying mechanisms of chemotherapeutics mediated bone marrow aplasia with special focus on altered redox status and associated effects on hematopoietic microenvironment and epigenetic status of hematopoietic cells. The study involves the development of busulfan and cyclophosphamide mediated mouse model for aplastic anemia, characterization of the disease with blood and marrow analysis, cytochemical examinations of bone marrow, flowcytometric analysis of hematopoietic population and microenvironmental components, determination of ROS generation, apoptosis profiling, expressional studies of Notch-1 signaling cascade molecules, investigation of epigenetic modifications including global CpG methylation of DNA, phosphorylation of histone-3 with their effects on bone marrow kinetics and expressional analysis of the anti-oxidative molecules viz; SOD-2 and Sdf-1. Severe hematopoietic catastrophic condition was observed during aplastic anemia which involved peripheral blood pancytopenia, marrow hypocellularity and decreased hematopoietic stem/progenitor population. Generation of ROS was found to play a central role in the cellular devastation in aplastic marrow which on one hand can be correlated with the destruction of hematopoiesis supportive niche components and alteration of vital Notch-1 signaling and on other hand was found to be associated with the epigenetic chromatin modifications viz; global DNA CpG hypo-methylation, histone-3 phosphorylation promoting cellular apoptosis. Decline of anti-oxidant components viz; Sdf-1 and SOD-2 hinted towards the irreversible nature of the oxidative damage during marrow aplasia. Collectively, the findings hinted towards the mechanistic correlation among ROS generation, microenvironmental impairment and epigenetic alterations that led to hematopoietic catastrophe under aplastic stress. The findings may potentiate successful therapeutic strategy development for the dreadful condition concerned.     

Application of Equine Infectious Anemia Virus Core Proteins Produced in a Baculovirus Expression System to Serological Diagnosis

Equine infectious anemia virus (EIAV) core proteins were obtained from a baculovirus expression system. Recombinant baculoviruses (rBVs) highly expressed the Gag precursor and p26 antigens in an rBV-infected Sf21 cell culture supernatant. Enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion (AGID) were conducted using the expressed proteins to detect antibodies from experimentally infected horses. The expressed antigens showed low background levels, high specificity and sensitivity in ELISA and AGID. The results of the serological tests using the expressed antigens were identical to those using a manufactured trial antigen. rBVs containing gag and p26 genes were found to express high quality and large quantities of Gag and p26 antigens, respectively. The antigens were quite useful for detecting anti-EIAV antibodies from virus-infected horses.     

Icariin improves Fanconi anemia hematopoietic stem cell function through SIRT6-mediated NF-kappa B inhibition

Icariin (ICA) is a flavonoid glucoside derived from the Epimedium plant genus, which has potent regenerative properties and is used in western medicine to treat impotence. Recently, ICA has generated great interest in improving hepatic stellate cell function and cardiac rejuvenation. However, how this natural component functions in hematopoiesis remains unexplored. Here we have examined the role of ICA on hematopoietic stem cells (HSCs) using the cancer-prone disease model of Fanconi anemia (FA), an inherited bone marrow failure syndrome with extremely high risk of leukemic predisposition. We show that ICA reverses the less quiescent status of HSCs deficient for the Fanca or Fancd2 gene, and improves the ability of these mutant stem cells to form colony formation units (CFU) in vitro and reconstitutes hematopoiesis in transplanted recipients. Further analysis reveals that ICA upregulates enzyme activity of the chromatin binding protein SIRT6 in Fanca^?/? and Fancd2^?/? HSCs, both of which have an intrinsic low SIRT6 activity. Furthermore, forced expression of SIRT6 blocks the natural decline of quiescent HSCs in Fanca^?/? or Fancd2^?/? mice and improves the repopulating capacity of these mutant HSCs in irradiated recipients. Mechanistically, ICA enhances SIRT6-mediated H3K9 deacetylation on the promoter of NF-κB and represses the expression of NF-κB target genes. Together, our findings indicate that ICA improves the function of HSCs by stimulating SIRT6 activity and contributes to the regenerative effect of ICA.     

Interplay between Fanconi anemia and homologous recombination pathways in genome integrity

The Fanconi anemia (FA) pathway plays a central role in the repair of DNA interstrand crosslinks (ICLs) and regulates cellular responses to replication stress. Homologous recombination (HR), the error‐free pathway for double‐strand break (DSB) repair, is required during physiological cell cycle progression for the repair of replication‐associated DNA damage and protection of stalled replication forks. Substantial crosstalk between the two pathways has recently been unravelled, in that key HR proteins such as the RAD51 recombinase and the tumour suppressors BRCA1 and BRCA2 also play important roles in ICL repair. Consistent with this, rare patient mutations in these HR genes cause FA pathologies and have been assigned FA complementation groups. Here, we focus on the clinical and mechanistic implications of the connection between these two cancer susceptibility syndromes and on how these two molecular pathways of DNA replication and repair interact functionally to prevent genomic instability.     

Developmental stage‐dependent influence of environmental factors on growth of rural Sundanese children in West Java,Indonesia

This study investigated the growth trajectories and the relative relevance levels of nutrition, disease, and hormonal status at various developmental stages among children in adverse environments to provide population‐based empirical evidence for the life history theory. Three years of longitudinal anthropometric data in 1‐year intervals were obtained from 418 boys and girls aged 0 to 12 years at recruitment. Following the final measurement, the main survey, which included blood and feces sampling, 3‐h interval food consumption recall surveys for energy and nutrient intakes and anthropometry, was performed. Blood and feces were used for detecting, respectively, anemia and hormonal (IGF‐I and IGFBP‐3) levels as well as intestinal helminthiasis (Ascaris, Trichuris, and hookworm). The major findings of this study are summarized as follows: 1) the growth velocity of the subject children lagged behind international standards during childhood and juvenility but caught up during early adolescence; 2) diseases, both intestinal helminths and anemia, had significant effects on growth in childhood but not at older ages; and 3) hormonal status significantly affected growth in the children, with its highest significance in early adolescence. A larger growth than international standards in early adolescence likely follows programmed hormonal mechanisms after the onset of puberty. The onset of puberty might be associated with adequate amounts of nutrient intake and be mediated by hormonal function, because the IGF‐IZ score was significantly correlated with energy and protein intakes at the transitional period from juvenility to adolescence, when puberty occurs. Am J Phys Anthropol 157:94–106, 2015. © 2015 Wiley Periodicals, Inc.     

RNA interferences targeting the Fanconi anemia/BRCA pathway upstream genes reverse cisplatin resistance in drug-resistant lung cancer cells

Background

Cisplatin is one of the most commonly used chemotherapy agent for lung cancer. The therapeutic efficacy of cisplatin is limited by the development of resistance.In this study, we test the effect of RNA interference (RNAi) targeting Fanconi anemia (FA)/BRCA pathway upstream genes on the sensitivity of cisplatin-sensitive (A549 and SK-MES-1) and -resistant (A549/DDP) lung cancer cells to cisplatin.

Result

Using small interfering RNA (siRNA), knockdown of FANCF, FANCL, or FANCD2 inhibited function of the FA/BRCA pathway in A549, A549/DDP and SK-MES-1 cells, and potentiated sensitivity of the three cells to cisplatin. The extent of proliferation inhibition induced by cisplatin after knockdown of FANCF and/or FANCL in A549/DDP cells was significantly greater than in A549 and SK-MES-1 cells, suggesting that depletion of FANCF and/or FANCL can reverse resistance of cisplatin-resistant lung cancer cells to cisplatin. Furthermore, knockdown of FANCL resulted in higher cisplatin sensitivity and dramatically elevated apoptosis rates compared with knockdown of FANCF in A549/DDP cells, indicating that FANCL play an important role in the repair of cisplatin-induced DNA damage.

Conclusion

Knockdown of FANCF, FANCL, or FANCD2 by RNAi could synergize the effect of cisplatin on suppressing cell proliferation in cisplatin-resistant lung cancer cells through inhibition of FA/BRCA pathway.     

Evaluation of CD4+CD25+FoxP3+ T cell populations,IL-10 production,and their correlation with clinical and biochemical parameters in sickle cell anemia patients with leg ulcers

Leg ulcers (LUs) are a debilitating complication of sickle cell anemia (SCA), with inflammation known to play a crucial role in their pathogenesis. Many studies have described the roles of T helper type 1 (Th1) and Th2 pathways in SCA; however, defects in anti-inflammatory responses are poorly understood. We evaluated interleukin (IL)-10 levels in serum and peripheral blood mononuclear cells (PBMCs) in SCA patients with leg ulcers (SCALU) and without leg ulcers (SCAWH) in addition to CD4⁺ CD25⁺FoxP3⁺ T cell populations and their its IL-10 expression. In stimulated and unstimulated PBMC cultures, SCALU patients produced higher levels of IL-10 than those in the SCAWH group. Higher levels of IL-10 in SCALU patients correlated with a history of osteonecrosis in stimulated and unstimulated cultures when compared with those in SCAWH. Immunophenotyping revealed that SCALU patients had a higher proportion of CD4⁺CD25⁺FoxP3⁺, Tr1 and CD4⁺CD25⁺FoxP3⁺IL-10⁺ T cells than other groups. Our findings revealed that IL-10 levels were increased in unstimulated cells from the SCALU group, and that this group also presented with a predominant CD4⁺ CD25⁺FoxP3⁺ cell population despite many of those cells being IL-10 negative.