Nation-wide investigation of RHD variants in Thai blood donors: Impact for molecular diagnostics.

BACKGROUND: Knowledge of the molecular determinants driving antigen expression is critical to design, optimize, and implement a genotyping approach on a population-specific basis. Although RHD gene variability has been extensively reported in Caucasians, Africans, and East-Asians, it remains to be explored in Southeast Asia. Thus the molecular basis of non-D+ blood donors was investigated in Thailand. STUDY DESIGN AND METHODS: First, 1176 blood samples exhibiting an inconclusive or negative result by automated serological testing were collected in the 12 Regional Blood Centres of the Thai Red Cross located throughout Thailand. Second, the RHD gene was analyzed in all samples by 1) quantitative multiplex PCR of short fluorescent fragments, and 2) direct sequencing, when necessary, for identifying structural variants and single nucleotide variants, respectively. RESULTS: Additional serological typing yielded 51 and 1125 samples with weak/partial D and D-negative (D-) phenotype, respectively. In the first subset, partial RHD*06.03 was the most common variant allele (allele frequency: 18.6%). In the second subset, the whole deletion of the gene is largely the most frequent (allele frequency: 84.9%), followed by the Asian DEL allele found in 15.6% of the samples. Eight novel alleles with various mutational mechanisms were identified. CONCLUSION: We report, for the first time at the national level, the molecular basis of weak/partial D and serologically D- phenotypes in Thai blood donors. The design and implementation of a dedicated diagnostic strategy in blood donors and patients are the very next steps for optimizing the management and supply of RBC units in Thailand.

Genetic association study of interferon lambda 3, CD27, and human leukocyte antigen-DPB1 with dengue severity in Thailand.

BACKGROUND: Dengue patients develop different disease severity ranging from mild (dengue fever [DF]) to severe forms (dengue hemorrhagic fever [DHF] and the fatal dengue shock syndrome [DSS]). Host genetics are considered to be one factor responsible for the severity of dengue outcomes. To identify genes associated with dengue severity that have not been studied yet, we performed genetic association analyses of interferon lambda 3 (IFNL3), CD27, and human leukocyte antigen-DPB1 (HLA-DPB1) genes in Thai dengue patients. METHODS: A case-control association study was performed in 877 children (age ≤ 15 years) with dengue infection (DF, n = 386; DHF, n = 416; DSS, n = 75). A candidate single nucleotide polymorphism of each of IFNL3, CD27, and HLA-DPB1 was selected to be analyzed. Genotyping was performed by TaqMan real-time PCR assay, and the association with dengue severity was examined. RESULTS: The rs9277534 variant of HLA-DPB1 was weakly associated with DHF. The genotype GG and G allele conferred protection against DHF (p = 0.04, odds ratio 0.74 for GG genotype, p = 0.03, odds ratio 0.79 for G allele). The association became borderline significant after adjusting for confounders (p = 0.05, odds ratio 0.82). No association was detected for IFNL3 or CD27. CONCLUSIONS: The present study demonstrated the weak association of the rs9277534 variant of HLA-DPB1 with protection against DHF. This variant is in the 3' untranslated region and affects HLA-DPB1 surface protein expression. Our finding suggests that HLA-DPB1 may be involved in DHF pathogenesis.

Comprehensive Molecular Analysis of Serologically D-Negative and Weak/Partial D Phenotype in Thai Blood Donors.

BACKGROUND: Molecular genetics of the Rh system has been extensively studied in Caucasians, Black Africans, East Asians, and Indians more recently. In this work, we sought to investigate the molecular basis of variant D expression in the Thai population, which remains unknown. MATERIALS AND METHODS: Blood samples from 450 Thai donors showing the variant D phenotype were collected. The RHD gene was analyzed by quantitative multiplex polymerase chain reaction of short fluorescent fragments and/or Sanger sequencing. RESULTS: The most frequent alleles in 200 D-negative and 121 DEL samples were the whole RHD gene deletion and the Asian DEL alleles, respectively. In 129 weak/partial D samples, 36 variant alleles were identified, including eight novel alleles. RHD*06.03, which is common in variant D samples from South China, is the most prevalent variant allele, followed by the recently reported Indian RHD*01W.150 allele. DISCUSSION: For the first time, a comprehensive overview of the nature and distribution of variant RHD alleles in Thailand is reported. It is a milestone to pave the way towards improvement of the current screening strategy to identify DEL donors accurately. The next step will be the design and implementation of a simple molecular test for screening the most frequent alleles, specifically in this population.

TargetAntiAngio: A Sequence-Based Tool for the Prediction and Analysis of Anti-Angiogenic Peptides.

Cancer remains one of the major causes of death worldwide. Angiogenesis is crucial for the pathogenesis of various human diseases, especially solid tumors. The discovery of anti-angiogenic peptides is a promising therapeutic route for cancer treatment. Thus, reliably identifying anti-angiogenic peptides is extremely important for understanding their biophysical and biochemical properties that serve as the basis for the discovery of new anti-cancer drugs. This study aims to develop an efficient and interpretable computational model called TargetAntiAngio for predicting and characterizing anti-angiogenic peptides. TargetAntiAngio was developed using the random forest classifier in conjunction with various classes of peptide features. It was observed via an independent validation test that TargetAntiAngio can identify anti-angiogenic peptides with an average accuracy of 77.50% on an objective benchmark dataset. Comparisons demonstrated that TargetAntiAngio is superior to other existing methods. In addition, results revealed the following important characteristics of anti-angiogenic peptides: (i) disulfide bond forming Cys residues play an important role for inhibiting blood vessel proliferation; (ii) Cys located at the C-terminal domain can decrease endothelial formatting activity and suppress tumor growth; and (iii) Cyclic disulfide-rich peptides contribute to the inhibition of angiogenesis and cell migration, selectivity and stability. Finally, for the convenience of experimental scientists, the TargetAntiAngio web server was established and made freely available online.

Prevalence of Thalassemia Traits and Iron Deficiency Anemia in Sindh, Pakistan.

Among microcytic hypochromic anemias, the most common disorders are iron deficiency anemia and co-pathological conditions such as α- or ß-thalassemia (α- or ß-thal) traits. The aim of the present study was to determine the frequency and prevalence of iron deficiency anemia and α- or ß-thal traits based on clinical laboratory data across different ethnic groups in five districts of Sindh Province, Pakistan. The present retrospective study analyzed 3 years (2012-2015) of encoded and unlinked clinical laboratory data, and identified 3030 microcytic hypochromic anemia cases. The data contained complete blood counts (CBCs) with smear morphology examinations, serum ferritin levels, and hemoglobin (Hb) electrophoreses. After reviewing the data, 994 confirmed subjects (iron deficiency anemia and α- and ß-thal traits) were then selected for the present study. The prevalence of α- and ß-thal traits was highest in Badin district (35.27%), while the prevalence of iron deficiency anemia was highest in Larkana district (30.73%). According to the ethnic-wise distribution, higher numbers of α- and ß-thal trait cases were seen in the Sindhi ethnic group [375 (64.21%) and 283 (69.02%), respectively] than in the other ethnic groups. In addition, a higher distribution of ß-thal trait cases was observed in the Sindhi ethnic group [n = 327 (56%)] in α- and ß-thal cases overall. Findings from the present study strongly suggested that screening is important not only for ß-thal trait but also other traits as well. However, careful monitoring of CBC parameters, including red blood cell (RBC) indices and morphology, along with clinical findings are essential to diagnose carrier cases, especially in high prevalence areas.

Prevalence of Anemia and Hemoglobin Disorders Among School Children in Myanmar.

The prevalence of anemia is high in the population of Myanmar and hypochromic microcytic anemia (HMA) is predominant. The objective of our study was to determine the prevalence of anemia and causes of HMA among school children. A cross-sectional study was conducted on 239 children from Thanlyin and Insein Townships, Yangon Region, Myanmar. Complete blood count (CBC) and blood film morphology was examined on venous blood samples. Hypochromic microcytic anemia cases were subsequently analyzed for serum ferritin and cellulose acetate hemoglobin (Hb) electrophoresis. The prevalence of anemia was 46.4%; 27.6% had mild, while 18.8% had moderate anemia, and no case of severe anemia was detected. The mean Hb concentration was 11.7 ± 0.9 g/dL. The younger age group (8-11 years) had a significantly higher prevalence of anemia than the older age group (12-15 years) (p = 0.029). Blood film morphology revealed a 50.6% red blood cell (RBC) disorder; HMA was the most common type (70.2%). Out of 85 children with HMA, three children (3.5%) had iron deficiency and all had comorbidity with Hb AE (ßA/ßE) (Hb E trait). Hemoglobin electrophoresis illustrated that Hb AA (ßA/ßA) (31, 36.5%) and Hb AE (ßA/ßE) trait (31, 36.5%) were the most common types followed by ß-thalassemia (ß-thal) trait (19, 22.3%) and Hb EE (ßE/ßE) (homozygous Hb E; HBB: c.79G>A) (three, 3.5%). Hematocrit [or packed cell volume (PCV)], mean corpuscular volume (MCV), mean corpuscular Hb (MCH) and mean corpuscular Hb concentration (MCHC), showed a significant difference between Hb AE, Hb EE and ß-thal trait (p = 0.029, 0.023, 0.015 and 0.01, respectively). Our findings will provide valuable information for the management of anemia in the Myanmar school-age population.

Impact of Omicron variant sublineage BA.2.75 on the OnSite COVID-19 Ag Rapid Test: the applicability of rapid antigen test with universal transport media.

BACKGROUND: Rapid antigen testing (RAT) is one of the most powerful tools for SARS-CoV-2 detection. The OnSite COVID-19 Ag Rapid Test is an antigen-based, point-of-care test approved by the WHO for Emergency Use Listing. The Nucleocapsid (N) gene mutations found in the emerging Omicron sublineages lead to the question of RAT performance. OBJECTIVE: To ensure the diagnostic performance of the study RAT during rapidly mutated Omicron variants. RESULTS: We independently evaluated the performance of this assay in 1098 archived samples collected in Thailand during October 2022-February 2023, which were 798 and 300 COVID-19 real-time RT-PCR positive and negative, respectively. The assay performed with 100% sensitivity and 100% specificity using a cycle threshold (Ct) of <20 for the RT-PCR. The sensitivity decreased to 88% when using Ct <30. Most of the SARS-CoV-2 found were Omicron BA.2 (99%), harboring six known N mutations (P13L, E31del, S33del, R203K, G204R and S413R). Eight samples containing hybrid variants (XBB.1*, XBB.2 and XBJ) were detected by the study RAT. This RAT detects all Omicron sublineages known to be circulating in Thailand. CONCLUSIONS: These results confirmed the good performance of the study RAT for detecting Omicron variants and its appropriateness for individual diagnosis and for genomic surveillance.

Serologically D-negative blood donors in Thailand: molecular variants and diagnostic strategy.

BACKGROUND: Discriminating individuals with "Asian type DEL" from those who are "true D-negative" (D-) among serologically D- donors/patients in Asia would be very valuable, as clinical outcomes are different in these groups. Here we investigated the molecular basis of D-negativity in Thai blood donors, designing a specific strategy for this purpose. MATERIALS AND METHODS: After routine testing, a total of 1,270 serologically D- blood donors originating from Central, Northeastern and South Thailand underwent analysis of the RHD gene by (i) quantitative multiplex polymerase chain reaction of short fluorescent fragments (QMPSF); (ii) direct sequencing of exon 9 to identify the c.1227G>A variant defining the Asian type DEL allele; and (iii) direct sequencing of the other exons. RESULTS: The most common observation was whole deletion of the gene (i.e. RHD*01N.01; allele frequency: 86.81%), followed by the Asian type DEL allele (RHD*01EL.01; 7.60%) and a D-negative hybrid allele (RHD*01N.03; 3.46%). Four novel alleles, including one with a 13.1 kilobase-deletion, were identified and characterized. All but one RHD*01EL.01 allele carriers (183/184) were C-positive (C+), suggesting that this latter subset may be screened specifically when investigating the c.1227G>A variant, which can be identified with 100% accuracy by a specific Tm-shift genotyping assay. DISCUSSION: On the basis of our extensive molecular findings, we have designed a dedicated diagnostic strategy based on Rh C antigen typing followed by a genotyping test. Implementation of this method in all or selected groups of serologically D- donors/patients will contribute to improve the management of transfusion and pregnancy in Thailand.

Applicability of a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for SARS-CoV-2 detection in high exposure risk setting.

OBJECTIVES: During the third wave, the growing number of COVID-19 case clusters reported countrywide in Thailand demonstrated the rapidly evolving characteristics of SARS-CoV-2, the causative agent of the COVID-19 pandemic. The rapid spread of COVID-19 infections had been extensively reported in public areas and construction camps, as well as in congested communities with poor sanitation. High demand for SARS-CoV-2 genome testing and quick reporting by an hour for case identification and isolation characterizes the COVID-19 crisis in Thailand. This situation leads to an urgent need for alternative molecular tests which are reliable, rapid, and cost-effective. METHODS: In this study, we assessed colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP), using real-time reverse transcription-polymerase chain reaction (RT-PCR) as a reference standard, for active case finding in suspected (mostly asymptomatic) cases living in high-risk areas of Bangkok. RESULTS: The diagnostic performance of the RT-LAMP compared with real-time RT-PCR in specimens from 549 Thais were computed in a real-world field study setting. Our study demonstrated that RT-LAMP achieved robust identification of SARS-CoV-2 infection, with a diagnostic sensitivity and specificity of 91.67% and 100%, respectively. CONCLUSION: RT-LAMP is a reliable assay for SARS-CoV-2 detection and is scalable for use in the emergency response to a nationwide pandemic, despite resource limitations. The RT-LAMP real-world data derived from this field study validate its potential use in laboratory practice. RT-LAMP is a good choice as a laboratory-based SARS-CoV-2 molecular test when real-time RT-PCR is not available.

Performance of colorimetric reverse transcription loop-mediated isothermal amplification as a diagnostic tool for SARS-CoV-2 infection during the fourth wave of COVID-19 in Thailand.

BACKGROUND: COVID-19, which is caused by SARS-CoV-2 and its variants, poses an ongoing global threat, particularly in low-immunization coverage regions. Thus, rapid, accurate, and easy-to-perform diagnostic methods are in urgent demand to halt the spread of the virus. OBJECTIVES: We aimed to validate the clinical performance of the FastProof 30 min-TTR SARS-CoV-2 reverse transcription loop-mediated isothermal amplification (RT-LAMP) method using leftover RNA samples extracted from 315 nasopharyngeal swabs. The sensitivity and specificity of RT-LAMP were determined in comparison with reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Of 315 nasopharyngeal swabs, viral RNA was detected in 154 samples (48.9%) by RT-PCR assay. Compared with RT-PCR, overall sensitivity and specificity of RT-LAMP were 81.82% (95% CI: 74.81-87.57) and 100% (95% CI: 97.73-100), respectively. A 100% positivity rate was achieved in samples with cycle threshold (Ct) <31 for RT-PCR targeting the ORF1ab gene. However, samples with Ct >31 accounted for false-negative results by RT-LAMP in 28 samples. CONCLUSIONS: RT-LAMP reliably detected viral RNA with high sensitivity and specificity and has potential application for mass screening of patients with acute COVID-19 infection when viral load is high.

Association of ADAMTS13 polymorphism with cerebral malaria.

BACKGROUND: Cerebral malaria is one of the most severe manifestations of Plasmodium falciparum malaria. The sequestration of parasitized red blood cells (PRBCs) to brain microvascular endothelium has been shown to contribute to the pathophysiology of cerebral malaria. Recent studies reported increased levels of von Willebrand factor (VWF) and reduced activity of VWF-cleaving protease, ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13), in patients with cerebral malaria. METHODS: Association of six single nucleotide polymorphisms (SNPs) of the ADAMTS13 gene with cerebral malaria was examined in 708 Thai patients with P. falciparum malaria. RESULTS: Among six SNPs, the derived allele of a SNP located in intron 28, rs4962153-A, was significantly associated with protection against cerebral malaria when 115 cerebral malaria patients were compared with 367 mild malaria patients (Fisher's exact P-value = 0.0057; OR = 0.27; 95% CI = 0.096-0.76). Significant association was also detected between 115 cerebral malaria and 593 non-cerebral malaria (226 non-cerebral severe malaria and 367 mild malaria) patients (Fisher's exact P-value = 0.012; OR = 0.30; 95% CI = 0.11-0.83). CONCLUSIONS: Excessive adhesion of PRBCs to the platelet-decorated ultra-large VWF (ULVWF) appears to enhance the sequestration of PRBCs to cerebral microvascular endothelium. The genetic association observed in the present study implies that the regulation of platelet-decorated ULVWF strings by ADAMTS13 may play a role in the development of cerebral malaria.

Interferon lambda 1 is associated with dengue severity in Thailand.

OBJECTIVES: Patients with dengue exhibit a range of symptoms from an acute febrile illness (dengue fever, DF), to dengue hemorrhagic fever (DHF), and to the most severe outcome, dengue shock syndrome (DSS). This study was performed to determine the host genetic factors responsible for dengue severity. Two single nucleotide polymorphisms (SNPs) of the interferon lambda 1 (IFNL1) gene (rs30461 and rs7247086) were analyzed for their association with dengue severity in a Thai population. METHODS: This was a case-control association study involving 877 patients under the age of 15 years (DF, n = 386; DHF, n = 416; DSS, n = 75). Genotyping was performed by TaqMan real-time PCR assay. RESULTS: It was found that the rs7247086 variant of IFNL1 was associated with DHF, but not DSS. Genotypes CT and TT and the T allele were protective against DHF (p = 0.03, odds ratio 0.62 for CT, odds ratio 0.13 for TT; and p = 0.01, odds ratio 0.54 for the T allele). The other SNP tested was not associated with DHF or DSS. CONCLUSIONS: The rs7247086 variant of IFNL1 (the T allele) was found to be protective against DHF, suggesting that IFNL1 may play a role in the pathogenesis of DHF.

Identification of a haplotype block in the 5q31 cytokine gene cluster associated with the susceptibility to severe malaria.

BACKGROUND: It has been previously demonstrated that a single nucleotide polymorphism (SNP) in the IL13 promoter region, IL13 -1055T>C (rs1800925), was associated with susceptibility to severe malaria in Thais. In the present study, fine association mapping for a cytokine gene cluster including IL4, IL5, and IL13 on chromosome 5q31 was conducted using the same malaria subjects to refine the region containing a primary variant or a haplotype susceptible to severe malaria. METHODS: A total of 82 SNPs spanning 522 kb of the 5q31 region were analysed in 368 patients with Plasmodium falciparum malaria (203 mild malaria and 165 severe malaria patients). RESULTS: Only rs1881457 located in the promoter region of IL13, which is in linkage disequilibrium with rs1800925 (r2 = 0.73), showed a significant association with severe malaria after adjusting for multiple testing (P = 0.046 by permutation test). This SNP was in a haplotype block spanning 97 kb (from rs2069812 to rs2240032). The detected haplotype block contained the RAD50 gene and the promoter of IL13, but not the other genes. CONCLUSION: A haplotype block in which a primary polymorphism associated with severe malaria is likely to be encoded was identified in Thai malaria patients.

microRNA-27a and microRNA-146a SNP in cerebral malaria.

BACKGROUND: During Plasmodium falciparum infection, microRNA expression alters in brain tissue of mice with cerebral malaria compared to noninfected controls. MicroRNA regulates gene expression post-transcriptionally to influence biological processes. Cerebral malaria pathology caused mainly by the immunological disorder. We hypothesize that single-nucleotide polymorphism in a microRNA influences microRNA biogenesis or target gene recognition and altering susceptibility to cerebral malaria. METHODS: We performed a literature search based on immunological mechanism and applied microRNA-related single-nucleotide polymorphisms database to examine candidate microRNA SNPs possibly responsible for cerebral malaria. MicroRNA-27a and microRNA-146a are supposed to involve in cerebral malaria pathology. To assess the relationship of microRNA SNP to cerebral malaria outcome, we performed TaqMan Genotyping Assays in 110 cerebral malaria and 207 uncomplicated malaria cases for three candidate microRNA SNPs (rs895819 of microRNA-27a, rs57095329 and rs2910164 of microRNA-146a). RESULTS: Our study detected no significant difference in genotype and allele frequency of individual microRNA SNPs as well as in haplotypes of microRNA-146a between these two groups of malaria patients in Thailand. Hardy-Weinberg disequilibrium of rs57095329 in the cerebral malaria group showed a heterozygous excess which might be due to natural selection. CONCLUSION: Our data supported that the candidate microRNA SNPs have no major role to develop cerebral malaria.

Proteomics and bioinformatics analysis reveal potential roles of cadmium-binding proteins in cadmium tolerance and accumulation of Enterobacter cloacae.

BACKGROUND: Enterobacter cloacae (EC) is a Gram-negative bacterium that has been utilized extensively in biotechnological and environmental science applications, possibly because of its high capability for adapting itself and surviving in hazardous conditions. A search for the EC from agricultural and industrial areas that possesses high capability to tolerate and/or accumulate cadmium ions has been conducted in this study. Plausible mechanisms of cellular adaptations in the presence of toxic cadmium have also been proposed. METHODS: Nine strains of EC were isolated and subsequently identified by biochemical characterization and MALDI-Biotyper. Minimum inhibitory concentrations (MICs) against cadmium, zinc and copper ions were determined by agar dilution method. Growth tolerance against cadmium ions was spectrophotometrically monitored at 600 nm. Cadmium accumulation at both cellular and protein levels was investigated using atomic absorption spectrophotometer. Proteomics analysis by 2D-DIGE in conjunction with protein identification by QTOF-LC-MS/MS was used to study differentially expressed proteins between the tolerant and intolerant strains as consequences of cadmium exposure. Expression of such proteins was confirmed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Bioinformatics tools were applied to propose the functional roles of cadmium-binding protein and its association in cadmium tolerance mechanisms. RESULTS: The cadmium-tolerant strain (EC01) and intolerant strain (EC07) with the MICs of 1.6 and 0.4 mM, respectively, were isolated. The whole cell lysate of EC01 exhibited approximately two-fold higher in cadmium binding capability than those of the EC07 and ATCC 13047, possibly by the expression of Cd-binding proteins. Our proteomics analysis revealed the higher expression of DUF326-like domain (a high cysteine-rich protein) of up to 220 fold in the EC01 than that of the EC07. Confirmation of the transcription level of this gene by qRT-PCR revealed a 14-fold induction in the EC01. Regulation of the DUF326-like domain in EC01 was more pronounced to mediate rapid cadmium accumulation (in 6 h) and tolerance than the other resistance mechanisms found in the ATCC 13047 and the EC07 strains. The only one major responsive protein against toxic cadmium found in these three strains belonged to an antioxidative enzyme, namely catalase. The unique proteins found in the ATCC 13047 and EC07 were identified as two groups: (i) ATP synthase subunit alpha, putative hydrolase and superoxide dismutase and (ii) OmpX, protein YciF, OmpC porin, DNA protection during starvation protein, and TrpR binding protein WrbA, respectively. CONCLUSION: All these findings gain insights not only into the molecular mechanisms of cadmium tolerance in EC but also open up a high feasibility to apply the newly discovered DUF326-like domain as cadmium biosorbents for environmental remediation in the future.

Lack of association of the HbE variant with protection from cerebral malaria in Thailand.

Hemoglobin E (HbE; beta26Glu --> Lys) is the most common variant of the beta-globin gene in Southeast Asia; it has been suggested that it confers resistance against Plasmodium falciparum malaria. In this study 306 adult patients with P. falciparum malaria (198 mild and 108 cerebral malaria patients) living in northwest Thailand were investigated to examine whether the HbE variant is associated with protection from cerebral malaria. Our results revealed that the sample allele frequency of HbE was not significantly different between mild (7.3%) and cerebral malaria (7.4%) patients. Thus, the HbA/HbE polymorphism would not be a major genetic factor influencing the onset of cerebral malaria in Thailand.

Cervical Cancer Markers: Epigenetics and microRNAs.

Gynecologic malignant neoplasms are a severe health problem among female patients, of which cervical cancer (CC), in particular, is a common disease leading to high mortality rates. Despite extensive attempts by researchers to solve the molecular mystery of CC, the mechanisms of its pathogenesis remain unclear. Tumor markers used in the clinical laboratory, such as squamous cell carcinoma (SCC), cancer antigen (CA)-125, and CA19-9, provide some help in diagnosing patients with CC. However, finding new molecular markers with high sensitivity and specificity is necessary. This review focuses on the role of epigenetic changes, particularly microRNAs (miRNAs), to CC. Several miRNAs that associated with CC potentially have the advantage of being early biomarkers. Moreover, altered serum miRNAs or single nucleotide polymorphisms in miRNA patterns may predict disease progression.

miR-130a and miR-27b Enhance Osteogenesis in Human Bone Marrow Mesenchymal Stem Cells via Specific Down-Regulation of Peroxisome Proliferator-Activated Receptor γ.

Mesenchymal stem cell (MSC) is a type of stem cell that is capable of differentiating into osteoblasts and adipocytes. The pathological perturbation of MSC fate determination is well demonstrated by the replacement of bone tissues with fat in those with osteoporosis and osteopenia. Cell fate determination can be regulated by epigenetic and post-transcriptional mechanisms. MicroRNAs (miRNAs) are small endogenous non-coding RNA molecules that mediates the post-transcriptional regulation of genes expression. We hypothesized that miRNA specified to PPARγ, a major transcription factor of adipogenesis, is responsible for the differentiation of MSCs into osteoblasts. Candidate miRNA that is responsible for target gene inhibition was identified from the miRNA database via bioinformatic analyses. In this study, miR-130a and miR-27b were selected for investigation on their role in specifically binding to peroxisome proliferator-activated receptor γ (PPARγ) via in vitro osteogenesis of human MSCs. During osteogenic differentiation of human MSCs, the expression level of miR-130a and miR-27b were found to be upregulated. In the meanwhile, adipogenic marker genes (PPARγ and C/EBPß) were found to decrease, which is in contrary to the increased expression of osteogenic marker genes (RUNX2 and Osterix). MSCs were transfected with mimics and inhibitors of miR-130a and miR-27b during in vitro osteogenesis followed by evaluation for the presence of osteogenic markers via quantitative gene expression, Western blot analysis and alkaline phosphatase activity assay. The overexpression of miR-130a and miR-27b is shown to enhance osteogenesis by increasing the gene expression of RUNX2 and Osterix, the protein expression of RUNX2, COL1A1, and Osterix as well as the alkaline phosphatase activity. Taken altogether, these results suggested that miR-130a and miR-27b could promote osteogenesis in human MSCs by targeting the PPARγ.

Correction: Sequence variation in Plasmodium falciparum merozoite surface protein-2 is associated with virulence causing severe and cerebral malaria.

[This corrects the article DOI: 10.1371/journal.pone.0190418.].

Sequence variation in Plasmodium falciparum merozoite surface protein-2 is associated with virulence causing severe and cerebral malaria.

Parasite virulence, an important factor contributing to the severity of Plasmodium falciparum infection, varies among P. falciparum strains. Relatively little is known regarding markers of virulence capable of identifying strains responsible for severe malaria. We investigated the effects of genetic variations in the P.f. merozoite surface protein 2 gene (msp2) on virulence, as it was previously postulated as a factor. We analyzed 300 msp2 sequences of single P. falciparum clone infection from patients with uncomplicated disease as well as those admitted for severe malaria with and without cerebral disease. The association of msp2 variations with disease severity was examined. We found that the N allele at codon 8 of Block 2 in the FC27-like msp2 gene was significantly associated with severe disease without cerebral complications (odds ratio = 2.73, P = 0.039), while the K allele at codon 17 of Block 4 in the 3D7-like msp2 gene was associated with cerebral malaria (odds ratio = 3.52, P = 0.024). The data suggests possible roles for the associated alleles on parasite invasion processes and immune-mediated pathogenicity. Multiplicity of infection was found to associate with severe disease without cerebral complications, but not cerebral malaria. Variations in the msp2-FC27-block 2-8N and 3D7-block 4-17K allele appear to be parasite virulence markers, and may be useful in determining the likelihood for severe and cerebral malaria. Their interactions with potential host factors for severe diseases should also be explored.