SARS-CoV-2 produces a microRNA CoV2-miR-O8 in patients with COVID-19 infection.

Many viruses produce microRNAs (miRNAs), termed viral miRNAs (v-miRNAs), with the capacity to target host gene expression. Bioinformatic and cell culture studies suggest that SARS-CoV-2 can also generate v-miRNAs. This patient-based study defines the SARS-CoV-2 encoded small RNAs present in nasopharyngeal swabs of patients with COVID-19 infection using small RNA-seq. A specific conserved sequence (CoV2-miR-O8) is defined that is not expressed in other coronaviruses but is preserved in all SARS-CoV-2 variants. CoV2-miR-O8 is highly represented in nasopharyngeal samples from patients with COVID-19 infection, is detected by RT-PCR assays in patients, has features consistent with Dicer and Drosha generation as well as interaction with Argonaute and targets specific human microRNAs.

Safety and Immunogenicity of Live Viral Vaccines in a Multicenter Cohort of Pediatric Transplant Recipients.

Importance: Live vaccines (measles-mumps-rubella [MMR] and varicella-zoster virus [VZV]) have not been recommended after solid organ transplant due to concern for inciting vaccine strain infection in an immunocompromised host. However, the rates of measles, mumps, and varicella are rising nationally and internationally, leaving susceptible immunocompromised children at risk for life-threating conditions. Objective: To determine the safety and immunogenicity of live vaccines in pediatric liver and kidney transplant recipients. Design, Setting, and Participants: This cohort study included select pediatric liver and kidney transplant recipients who had not completed their primary MMR and VZV vaccine series and/or who displayed nonprotective serum antibody levels at enrollment between January 1, 2002, and February 28, 2023. Eligibility for live vaccine was determined by individual US pediatric solid organ transplant center protocols. Exposures: Exposure was defined as receipt of a posttransplant live vaccine. Transplant recipients received 1 to 3 doses of MMR vaccine and/or 1 to 3 doses of VZV vaccine. Main Outcome and Measure: Safety data were collected following each vaccination, and antibody levels were obtained at 0 to 3 months and 1 year following vaccination. Comparisons were performed using Mann-Whitney U test, and factors associated with development of postvaccination protective antibodies were explored using univariate analysis. Results: The cohort included 281 children (270 [96%] liver, 9 [3%] kidney, 2 [1%] liver-kidney recipients) from 18 centers. The median time from transplant to enrollment was 6.3 years (IQR, 3.4-11.1 years). The median age at first posttransplant vaccine was 8.9 years (IQR, 4.7-13.8 years). A total of 202 of 275 (73%) children were receiving low-level monotherapy immunosuppression at the time of vaccination. The majority of children developed protective antibodies following vaccination (107 of 149 [72%] varicella, 130 of 152 [86%] measles, 100 of 120 [83%] mumps, and 124 of 125 [99%] rubella). One year post vaccination, the majority of children who initially mounted protective antibodies maintained this protection (34 of 44 [77%] varicella, 45 of 49 [92%] measles, 35 of 42 [83%] mumps, 51 of 54 [94%] rubella). Five children developed clinical varicella, all of which resolved within 1 week. There were no cases of measles or rubella and no episodes of graft rejection within 1 month of vaccination. There was no association between antibody response and immunosuppression level at the time of vaccination. Conclusions and Relevance: The findings suggest that live vaccinations may be safe and immunogenic after solid organ transplant in select pediatric recipients and can offer protection against circulating measles, mumps, and varicella.

Oesophageal Varices And Associated Factors In Cirrhotic Patients With Hepatitis C.

BACKGROUND: Infection with hepatitis C virus is reported to have infected almost 71 million people worldwide. This study was done to assess the frequency and associated factors leading to oesophageal varices in patients presenting with hepatitis C related liver cirrhosis. METHODS: A cross-sectional study was conducted at Patel Hospital, Karachi, Pakistan from 9th May to 5th October 2019. Patients of either gender having age >20 years presenting with HCV related liver cirrhosis, and Child Pugh class A, B and C were consecutively enrolled in the study. Data on variables like: age, gender, Childs Pugh Score (A/B/C), smoking status, laboratory characteristics like hemoglobulin (Hb), TLC, platelets, serum albumin level, cholesterol, alkaline phosphate (ALK), alkaline transaminase (ALT), ascites and presence of oesophageal varices was recorded and analysed using SPSS-21.0. RESULTS: Out of 167 patients, mean age was 44.86±14.74 years. Eight-nine (53.3%) of the patients were males. The mean duration of cirrhosis was 5.78±1.10 months. Thrombocytopenia was observed in majority (n=130, 77.8%) of the patients. There were 33 (19.8%) patients with Child Pugh score A while Child-Pugh score B and C was found in 67 (40.1%) each. The frequency of oesophageal varices was 141 (84.4%). A significantly higher proportion of oesophageal varices were found among thrombocytopenic patients (p<0.001), ascites (p-0.024), and having "C" Child-Pugh score (p-0.012). CONCLUSIONS: Oesophageal varices were found in a considerable proportion. Thrombocytopenia, ascites and Child-Pugh class C were found as leading contributing factors to oesophageal varices.

Frequency And Factors Leading To Helicobacter Pylori Infection Among Dyspeptic Patients.

BACKGROUND: Helicobacter pylori is infecting 50 percent or more of the world's population, putting it the most ubiquitous infection on the world. This study is done with the objective to determine the frequency and risk factors of Helicobacter pylori infection among dyspepsia patients at Patel Hospital Karachi. METHODS: This cross-sectional study was conducted at the gastroenterology department at the Patel Hospital in Karachi from 10th Jan to 10th July 2021. All patients with dyspepsia for at least 6 months having age 20-60 years of either gender were included. Three samples from stomach (2 from antrum,1 from corpus) for biopsies were collected from each patient. The specimen was sent to the microbiology department of the hospital and was reported as having histopathological confirmation of Helicobacter pylori infection. RESULTS: Of 111 patients with dyspepsia, mean age of the patients was 44.19±16.41 years. Most of the patients (n=65, 58.6%) were males and 46 (41.4%) were females. The mean duration of dyspepsia was 11.48±5.53 months. Helicobacter pylori was discovered to be present in 93 percent of individuals (83.8 percent). The odds of Helicobacter pylori infection were found to be 7.99 times higher among patients over 40 years old (AOR: 7.99, 95 percent CI: 2.02-31.64, p: 0.003), 3.93 times higher among patients with >9 months of dyspepsia (AOR: 3.93, 95 percent CI: 1.09-14.16, p: 0.036), and 11.85 times higher among smokers as compared to non-smokers (AOR: 11.85, 95 percent CI: 1.42-99.08, p-value 0.023). CONCLUSIONS: The rate of Helicobacter pylori infection in patients with dyspepsia was found to be higher. Furthermore, increasing age, increase duration of dyspepsia and smoking is found to be independent risk factors.

Functional high-throughput screen identifies microRNAs that promote butyrate-induced death in colorectal cancer cells.

The gut fermentation product butyrate displays anti-cancer properties in the human proximal colon, including the ability to inhibit proliferation and induce apoptosis in colorectal cancer (CRC) cells. A natural histone deacetylase inhibitor (HDACi), butyrate can alter histone acetylation patterns in CRC cells, and thereby regulate global gene expression, including the non-coding transcriptome and microRNAs (miRNAs). Dysregulated miRNA expression affects CRC development and progression; however, the interplay between miRNA activity and butyrate response remains to be elucidated. A high-throughput functional screen was employed to identify miRNAs that can act as enhancers of the anti-cancer properties of butyrate. Validation studies confirmed that several miRNAs, including miR-125b, miR-181a, miR-593, and miR-1227, enhanced apoptosis, decreased proliferation, and promoted cell-cycle arrest in the presence of butyrate. Pathway analyses of predicted miRNA target genes highlighted their likely involvement in critical cancer-related growth pathways, including WNT and PI3K signaling. Several cancer-associated miRNA targets, including TRIM29, COX2, PIK3R3, CCND1, MET, EEF2K, DVL3, and NUP62 were synergistically regulated by the combination of cognate miRNAs and butyrate. Overall, this study has exposed the potential of miRNAs to act as enhancers of the anti-cancer effects of HDAC inhibition and identifies specific miRNAs that might be exploited for therapeutic benefit.

Predictive Significance of Tumour Size in Patients Undergoing Curative Surgery for Colorectal Cancer: A Retrospective Cohort Study.

Objectives To evaluate the predictive significance of tumour size in patients undergoing curative surgery for colorectal cancer (CRC). Methods All patients undergoing curative surgery for colon or rectum cancer performed by a single colorectal surgeon between January 2013 and January 2020 were considered eligible for inclusion. Linear and binary logistic regression analyses were modelled to assess whether colonic or rectal tumour size could predict R0 resection, specimen length, number of harvested and positive lymph nodes, lymphocytic infiltration, venous invasion, and overall survival. Results A total of 192 patients were eligible for inclusion. In patients with colon cancer, tumour size was the independent predictor of the number of harvested lymph nodes (P<0.001), the number of positive lymph nodes (P=0.001), and lymphocytic infiltration (P=0.009). However, it did not predict R0 resection (P=0.563), specimen length (P=0.111), specimen length >120 mm (P=0.186), >12 harvested lymph nodes (P=0.145), venous invasion (P=0.103), and five-year overall survival (P=0.543). In patients with rectal cancer, tumour size was the independent predictor of the number of harvested lymph nodes (P<0.001) and the number of positive lymph nodes (P<0.001). However, it did not predict R0 resection (P=0.108), specimen length (P=0.774), specimen length >120 mm (P=0.405), >12 harvested lymph nodes (P= 0.069), lymphocytic infiltration (P=0.912), venous invasion (P= 0.105), and five-year overall survival (P=0.413). Conclusions The results of the current study suggest that tumour size on its own may not have a significant predictive value in oncological or survival outcomes in patients undergoing curative surgery for colon or rectum cancer.

Ceramide-induced integrated stress response overcomes Bcl-2 inhibitor resistance in acute myeloid leukemia.

Inducing cell death by the sphingolipid ceramide is a potential anticancer strategy, but the underlying mechanisms remain poorly defined. In this study, triggering an accumulation of ceramide in acute myeloid leukemia (AML) cells by inhibition of sphingosine kinase induced an apoptotic integrated stress response (ISR) through protein kinase R-mediated activation of the master transcription factor ATF4. This effect led to transcription of the BH3-only protein Noxa and degradation of the prosurvival Mcl-1 protein on which AML cells are highly dependent for survival. Targeting this novel ISR pathway, in combination with the Bcl-2 inhibitor venetoclax, synergistically killed primary AML blasts, including those with venetoclax-resistant mutations, as well as immunophenotypic leukemic stem cells, and reduced leukemic engraftment in patient-derived AML xenografts. Collectively, these findings provide mechanistic insight into the anticancer effects of ceramide and preclinical evidence for new approaches to augment Bcl-2 inhibition in the therapy of AML and other cancers with high Mcl-1 dependency.

A functional screen with metformin identifies microRNAs that regulate metabolism in colorectal cancer cells.

Metformin inhibits oxidative phosphorylation and can be used to dissect metabolic pathways in colorectal cancer (CRC) cells. CRC cell proliferation is inhibited by metformin in a dose dependent manner. MicroRNAs that regulate metabolism could be identified by their ability to alter the effect of metformin on CRC cell proliferation. An unbiased high throughput functional screen of a synthetic micoRNA (miRNA) library was used to identify miRNAs that impact the metformin response in CRC cells. Experimental validation of selected hits identified miRNAs that sensitize CRC cells to metformin through modulation of proliferation, apoptosis, cell-cycle and direct metabolic disruption. Among eight metformin sensitizing miRNAs identified by functional screening, miR-676-3p had both pro-apoptotic and cell cycle arrest activity in combination with metformin, whereas other miRNAs (miR-18b-5p, miR-145-3p miR-376b-5p, and miR-718) resulted primarily in cell cycle arrest when combined with metformin. Investigation of the combined effect of miRNAs and metformin on CRC cell metabolism showed that miR-18b-5p, miR-145-3p, miR-376b-5p, miR-676-3p and miR-718 affected glycolysis only, while miR-1181 only regulated CRC respiration. MicroRNAs can sensitize CRC cells to the anti-proliferative effects of metformin. Identifying relevant miRNA targets may enable the design of innovative therapeutic strategies.

Integrative Transcriptomic Network Analysis of Butyrate Treated Colorectal Cancer Cells.

Diet-derived histone deacetylase inhibitor (HDACi), butyrate, alters global acetylation and consequently global gene expression in colorectal cancer (CRC) cells to exert its anticancer effects. Aberrant microRNA (miRNA) expression contributes to CRC development and progression. Butyrate-mediated modulation of microRNA (miRNA) expression remains under-investigated. This study employed a systems biology approach to gain a comprehensive understanding of the complex miRNA-mRNA interactions contributing to the butyrate response in CRC cells. Next-generation sequencing, gene ontology (GO) and pathway enrichment analyses were utilized to reveal the extent of butyrate-mediated gene regulation in CRC cells. Changes in cell proliferation, apoptosis, the cell cycle and gene expression induced by miRNAs and target gene knockdown in CRC cells were assessed. Butyrate induced differential expression of 113 miRNAs and 2447 protein-coding genes in HCT116 cells. Butyrate also altered transcript splicing of 1591 protein-coding genes. GO, and pathway enrichment analyses revealed the cell cycle to be a central target of the butyrate response. Two butyrate-induced miRNAs, miR-139 and miR-542, acted cooperatively with butyrate to induce apoptosis and reduce CRC cell proliferation by regulating target genes, including cell cycle-related EIF4G2 and BIRC5. EIF4G2 RNA interference mimicked the miR-139-mediated reduction in cell proliferation. The cell cycle is a critical pathway involved in the butyrate response of CRC cells. These findings reveal novel roles for miRNAs in the cell cycle-related, anticancer effects of butyrate in CRC cells.

Functional characterization of potential PGPR exhibiting broad-spectrum antifungal activity.

This study describes the biocontrol potential of rhizobacteria against a range of fungal phytopathogens. Out of 227 bacteria isolated from the rhizosphere of maize, rice, wheat, potato, sunflower and soybean crops cultivated in different agro-ecological regions of Pakistan, 48 exhibited >60 % antifungal activity against Fusarium oxysporum, Fusarium moniliforme, Rhizoctonia solani, Colletotrichum gloeosporioides, Colletotrichum falcatum, Aspergillus niger, and Aspergillus flavus. The rhizobacteria inhibiting >65 % pathogen growth were selected for detailed molecular and in planta studies most of which were identified as Pseudomonas and Bacillus species based on 16S rRNA gene sequence analysis. Antifungal metabolites produced by these rhizobacteria analyzed through LCMS were identified as antibiotics (iturin, surfactins, fengycin, DAPG, Phenazine, etc.), cell wall degrading enzymes (protease, chitinase, and cellulase), plant growth promotion enzymes and hormones (indole-3-acetic acid, ACC-deaminase, phosphates, nitrogen fixation), N-acyl-homoserine lactones and siderophores. The growth room experiment validated the potential of these bacteria as biofertilizer and biopesticide agents. Of all, P. aeruginosa strain FB2 and B. subtilis strain RMB5 showed significantly higher potential as antagonistic plant-beneficial bacteria effective against a range of fungal phytopathogens. Both these bacteria can be used to develop a dual-purpose bacterial inoculum as biopesticide and biofertilizer. Rest of the antagonistic PGPR may be exploited for disease control in less-infested soils.

Impact of Histone Deacetylase Inhibitors on microRNA Expression and Cancer Therapy: A Review.

Chromatin-modifying drugs, such as histone deacetylase inhibitors (HDACi), have shown potential as cancer therapeutics, either alone or in combination with other therapies. HDACi have the ability to reverse aberrant epigenetic modifications associated with cancer, namely dysregulated histone acetylation. There are currently three FDA approved HDACi; vorinostat, romidepsin, and panobinostat. Epigenetic modifications can regulate the expression of protein coding genes, and in addition can alter expression of microRNA (miRNA) genes. Many miRNAs play key roles in cell proliferation and apoptosis, and are commonly dysregulated in cancer states. A number of in vitro and in vivo studies have demonstrated the ability of chromatin-modifying drugs to alter miRNA expression, which may provide the basis for further investigation of miRNAs as therapeutic targets or as biomarkers of drug response. This review summarises findings from studies investigating the effects of HDACi on miRNA expression, as well as key clinical trials involving HDACi. Understanding how chromatin-modifying drugs epigenetically modulate miRNA genes provides further insight into the cellular mechanisms that deliver therapeutic responses, and may assist in refining treatment strategies.

Genetic, physiological and biochemical characterization of Bacillus sp. strain RMB7 exhibiting plant growth promoting and broad spectrum antifungal activities.

BACKGROUND: Plant growth promoting rhizobacteria (PGPR) are functionally diverse group of bacteria having immense potential as biofertilizers and biopesticides. Depending upon their function, they may serve as partial replacements for chemical fertilizer or pesticides as an eco-friendly and cost-effective alternatives as compared to their synthetic counterparts. Therefore, isolation, characterization and practical evaluation of PGPRs having the aforementioned multifaceted beneficial characteristics, are essentially required. This study describes the detailed polyphasic characterization of Bacillus sp. strain RMB7 having profound broad spectrum antifungal activity and plant growth promoting potential. RESULTS: Based on 16S rRNA gene sequencing, strain RMB7 was identified as Bacillus specie. This strain exhibited the production of 8 mg. L(-1)of indole-3-acetic acid (IAA) in tryptophan-supplemented medium. It was able to solubilize 50.6 mg. L(-1) tri-calcium phosphate, reduced 601ηmol acetylene h(-1)/vial and inhibited >70% growth of nine fungal phytopathogens tested in vitro. Under natural pathogen pressure, inoculation with strain RMB7 and RMB7-supernatant conferred resistance by arugula plant against Pythium irregulare with a concurrent growth improvement over non-inoculated plants. The T-RFLP analysis based on 16S rRNA gene showed that inoculation with RMB7 or its supernatant have a major impact on the indigenous rhizosphere bacterial population. Mass spectrometric analysis revealed the production of lipopeptide surfactins as well as iturin A presence in crude extract of RMB7. PCR-amplification further confirmed the presence of genes involved in the biosynthesis of these two bioactive lipopeptide compounds. CONCLUSIONS: The data show that Bacillus sp. strain RMB7 has multifaceted beneficial characteristics. It may be an ideal plant growth promoting as well as biocontrol agent, for its integrated use in disease and nutrient management strategies.

Compliance with postexposure screening and treatment of latent tuberculosis infection among healthcare workers in a tertiary care hospital in Saudi Arabia.

BACKGROUND: Controlling tuberculosis (TB) infection among occupationally exposed healthcare workers (HCWs) may be challenging. METHODS: We retrospectively reviewed clinical records of HCWs who were exposed to patients diagnosed with infectious TB at King Abdulaziz Medical City, Riyadh, Saudi Arabia, between 2008 and 2010. The collected data included baseline tuberculin skin test (TST) status, potential predictors of TST positivity, postexposure diagnosis of latent TB infection (LTBI), and postexposure compliance with LTBI therapy. RESULTS: Thirteen patients were diagnosed with infectious pulmonary TB during the study period. A total of 298 HCWs met our definition for exposure. Exposed HCWs tended to be female (62.9%), non-Saudi (83.9%), nurses (68.6%), or respiratory therapists (24.0%) working in critical care locations (72.8%). Baseline (preemployment) TST documentation existed for 41.3% (123/298). Among those with documented baseline TSTs, 51.2% (63/123) were positive, representing 21.1% (63/298) of all HCWs. Only 48.9% (115/235) of exposed HCWs who had negative or unknown preexposure TST status had their TST tested after exposure. Approximately 46.1% (53/115) of them were diagnosed with postexposure LTBI, and 92.5% (49/53) of them were prescribed LTBI therapy. Among those, 93.9% (46/49) started LTBI therapy; however, 82.6% (38/46) failed to complete the recommended course. CONCLUSIONS: We found low rates of baseline TST documentation and postexposure screening among exposed HCWs. Compliance with initiating postexposure isoniazid prophylaxis among HCWs was fair, but only a small fraction of those who started prophylaxis completed the recommended course of therapy. These findings suggest substantial opportunities to implement administrative measures to enhance LTBI management among HCWs.

Root colonization and growth promotion of sunflower (Helianthus annuus L.) by phosphate solubilizing Enterobacter sp. Fs-11.

An Enterobacter sp. Fs-11 was isolated from sunflower rhizosphere, identified on the basis of 16S rRNA gene sequence analysis (GeneBank accession no. GQ179978) and studied for its root colonization and growth promotion ability in sunflower. Morphologically, it was rod shaped Gram-negative, motile bacterium, producing 4.5 µg mL(-1) indole acetic acid in tryptophan-supplemented medium. It utilized 27 out of 95 substrates in BIOLOG GN2 micro plate system. It was able to convert insoluble tri-calcium phosphate to soluble phosphorus up to 43.5 µg mL(-1) with decrease in pH of the medium up to 4.5 after 10 days incubation at 28 ± 2 °C in the Pikovskaya's broth. High performance liquid chromatography of cell free supernatant showed that Fs-11 produced malic acid and gluconic acid (2.43 and 16.64 µg mL(-1), respectively) in Pikovskaya's broth. Analysis of 900 bp fragment of pyrroloquinoline quinine pqqE gene sequence showed 98 % homology with that of E. cloacae pqqE gene. Confocal laser scanning microscope revealed strong colonization of fluorescently labeled Fs-11 with sunflower roots. Sunflower inoculation with Fs-11 and its rifampicin resistant derivative in sterile sand and natural soil showed that Fs-11 colonized sunflower roots up to 30 days after transplanting in both sterile sand as well as natural soil. Moreover, Fs-11 inoculation resulted in increased plant height, fresh weight, dry weight and total phosphorus contents as compared to un-inoculated plants. The data showed that Enterobacter sp. Fs-11 is an efficient phosphate solubilizing and plant growth promoting rhizobacterium and has great potential to be used as bio-inoculant for sunflower under phosphorus deficient conditions.

Requirement for nuclear factor kappa B signalling in the interleukin-1-induced expression of the CCAAT/enhancer binding protein-delta gene in hepatocytes.

Elevated circulating levels of acute phase proteins (APP) are associated with inflammation and inflammatory disorders such as cardiovascular disease. APP are mainly synthesised by hepatocytes and their transcription is induced by pro-inflammatory cytokines such as interleukin-1 (IL-1). The molecular mechanisms underlying the IL-1-induced expression of key transcription factors implicated in the regulation of APP are poorly understood. We have investigated this aspect using the CCAAT/enhancer binding protein-delta (C/EBPdelta) as a model gene. IL-1 induced the expression of C/EBPdelta mRNA and protein in the human hepatoma Hep3B cell line, a widely employed model system for studies on cytokine signalling in relation to the expression of APP. The IL-1-mediated induction of C/EBPdelta expression was attenuated in the presence of pharmacological inhibitors against c-Jun N-terminal kinase (JNK) (curcumin and SP600125), casein kinase 2 (CK2) (apigenin) and nuclear factor-kappaB (NF-kappaB) (NF-kappaB activation inhibitor). RNA interference assays showed significant attenuation of the IL-1-induced expression of C/EBPdelta following knockdown of the p50 and p65 subunits of NF-kappaB. IL-1 induced NF-kappaB DNA binding and activation by this transcription factor and this was attenuated by curcumin and apigenin. Taken together, these results suggest a potentially crucial role for NF-kappaB in the IL-1-induced expression of C/EBPdelta, and thereby downstream APP genes regulated by this transcription factor.

Cd36, a class B scavenger receptor, functions as a monomer to bind acetylated and oxidized low-density lipoproteins.

Cd36 is a small-molecular-weight integral membrane protein expressed in a diverse, but select, range of cell types. It has an equally diverse range of ligands and physiological functions, which has implicated Cd36 in a number of diseases including insulin resistance, diabetes, and, most notably, atherosclerosis. The protein is reported to reside in detergent-resistant microdomains within the plasma membrane and to form homo- and hetero-intermolecular interactions. These data suggest that this class B scavenger receptor may gain functionality for ligand binding, and/or ligand internalization, by formation of protein complexes at the cell surface. Here, we have overexpressed Cd36 in insect cells, purified the recombinant protein to homogeneity, and analyzed its stability and solubility in a variety of nonionic and zwitterionic detergents. Octylglucoside conferred the greatest degree of stability, and by analytical ultracentrifugation we show that the protein is monomeric. A solid-phase ligand-binding assay demonstrated that the purified monomeric protein retains high affinity for acetylated and oxidized low-density lipoproteins. Therefore, no accessory proteins are required for interaction with ligand, and binding is a property of the monomeric fold of the protein. Thus, the highly purified and functional Cd36 should be suitable for crystallization in octylglucoside, and the in vitro ligand-binding assay represents a promising screen for identification of bioactive molecules targeting atherogenesis at the level of ligand binding.

A CD36 nonsense mutation associated with insulin resistance and familial type 2 diabetes.

Mutations in CD36 / fatty acid translocase (FAT) gene are responsible for insulin resistance in the rat but contribution to human Type 2 diabetes is unknown. A nominal evidence for linkage of familial T2D at the CD36 locus led us to identify a rare nonsense mutation c.1079T>G (p.L360X) in one Caucasian pedigree presenting with autosomal dominant diabetes. Adiponectin levels, as marker of insulin sensitivity, were found to be significantly lower in the p.L360X variant carriers compared to homozygous for wild type CD36. Furthermore, expression studies of the truncated protein showed a defective binding of acetylated-LDL. Thus, our findings suggest a possible role for CD36 in the pathogenesis of T2D associated with reduced insulin sensitivity.

Isoimmunization against CD36 (glycoprotein IV): description of four cases of neonatal isoimmune thrombocytopenia and brief review of the literature.

BACKGROUND: Platelet CD36 (glycoprotein [GP] IV) deficiency occurs in 3 to 5 percent of persons of Asian or African ancestry. A subset of these individuals is at risk for immunization against CD36, but the magnitude of this problem and its significance in transfusion medicine have not yet been clarified. STUDY DESIGN AND METHODS: Clinical and laboratory aspects of neonatal thrombocytopenia involving five infants born to four CD36- mothers were characterized. The CD36 gene was sequenced in three mothers. The literature concerning isoimmunization against CD36 was reviewed and summarized. RESULTS: Isoantibodies reactive with CD36 on normal platelets and platelets from the fathers were identified in each of the four mothers. Two African-American mothers were homozygous for a 1264TG mutation in the CD36 gene. A mother of Italian ancestry was homozygous for a previously unidentified deletion of exons 1 through 3. Previously reported cases of isoimmunization against CD36 were reviewed and summarized. CONCLUSION: Isoimmunization against CD36 can cause neonatal isoimmune thrombocytopenia (NITP), refractoriness to platelet transfusions, and post-transfusion purpura. Immunization against this glycoprotein (GP) should be considered in patients with apparent alloimmune platelet disorders not explained by immunization against recognized platelet-specific alloantigens, especially in persons of African, Asian, and, possibly, Mediterranean ancestry.

Radiation hybrid mapping of 70 rat genes from a data set of differentially expressed genes.

The spontaneously hypertensive rat (SHR) is a model of human essential hypertension. Increased blood pressure in SHR is associated with other risk factors associated with cardiovascular disease, including insulin resistance and dyslipidemia. DNA microarray studies identified over 200 differentially expressed genes and ESTs between SHR and normotensive control rats. These clones represent candidate genes that may underlie previously detected QTLs in SHR. This study made use of the publication of two whole-genome maps to identify positional QTL candidates. Radiation hybrid (RH) mapping was used to determine the chromosomal locations of 70 rat genes and ESTs from this dataset. Most of the locations are novel, but in five cases we identified a definitive map location for genes previously mapped by somatic cell hybrids and/or linkage analysis. Genes for which the mouse genome map location was already determined mapped to syntenic segments in the rat genome map, except for two rat genes whose map locations confirmed previous findings. Where synteny comparisons could be made only with the human, 74% of the genes mapped in this study lay in a conserved syntenic segment. Chromosomal localisation of these mouse and human orthologs to syntenic segments produces a high level of confidence in the data presented in this study. The data provide new map locations for rat genes and will aid efforts to advance the rat genome map. The data may also be used to prioritize candidate QTL genes in SHR and other rat strains on the basis of their map location.