Modulation of Heme-Induced Inflammation Using MicroRNA-Loaded Liposomes: Implications for Hemolytic Disorders Such as Malaria and Sickle Cell Disease.

Hemolytic disorders, like malaria and sickle cell disease (SCD), are responsible for significant mortality and morbidity rates globally, specifically in the Americas and Africa. In both malaria and SCD, red blood cell hemolysis leads to the release of a cytotoxic heme that triggers the expression of unique inflammatory profiles, which mediate the tissue damage and pathogenesis of both diseases. MicroRNAs (miRNAs), such as miR-451a and let-7i-5p, contribute to a reduction in the pro-inflammatory responses induced by circulating free hemes. MiR-451a targets both IL-6R (pro-inflammatory) and 14-3-3ζ (anti-inflammatory), and when this miRNA is present, IL-6R is reduced and 14-3-3ζ is increased. Let-7i-5p targets and reduces TLR4, which results in anti-inflammatory signaling. These gene targets regulate inflammation via NFκB regulation and increase anti-inflammatory signaling. Additionally, they indirectly regulate the expression of key heme scavengers, such as heme-oxygenase 1 (HO-1) (coded by the HMOX1 gene) and hemopexin, to decrease circulating cytotoxic heme concentration. MiRNAs can be transported within extracellular vesicles (EVs), such as exosomes, offering insights into the mechanisms of mitigating heme-induced inflammation. We tested the hypothesis that miR-451a- or let-7i-5p-loaded artificial EVs (liposomes) will reduce heme-induced inflammation in brain vascular endothelial cells (HBEC-5i, ATCC: CRL-3245) and macrophages (THP-1, ATCC: TIB-202) in vitro. We completed arginase and nitric oxide assays to determine anti- and pro-inflammatory macrophage presence, respectively. We also assessed the gene expression of IL-6R, TLR4, 14-3-3ζ, and NFκB by RT-qPCR for both cell lines. Our findings revealed that the exposure of HBEC-5i and THP-1 to liposomes loaded with miR-451a or let-7i-5p led to a reduced mRNA expression of IL-6R, TLR4, 14-3-3ζ, and NFκB when treated with a heme. It also resulted in the increased expression of HMOX1 and hemopexin. Finally, macrophages exhibited a tendency toward adopting an anti-inflammatory differentiation phenotype. These findings suggest that miRNA-loaded liposomes can modulate heme-induced inflammation and can be used to target specific cellular pathways, mediating inflammation common to hematological conditions, like malaria and SCD.

Individual and Institutional Factors Contribute to Research Capacity Building for Early-Stage Investigators from Groups Underrepresented in Biomedical Research: A Qualitative Comparative Analysis.

BACKGROUND: Enhancement of diversity within the U.S. research workforce is a recognized need and priority at a national level. Existing comprehensive programs, such as the National Research Mentoring Network (NRMN) and Research Centers in Minority Institutions (RCMI), have the dual focus of building institutional research capacity and promoting investigator self-efficacy through mentoring and training. METHODS: A qualitative comparative analysis was used to identify the combination of factors that explain the success and failure to submit a grant proposal by investigators underrepresented in biomedical research from the RCMI and non-RCMI institutions. The records of 211 participants enrolled in the NRMN Strategic Empowerment Tailored for Health Equity Investigators (NRMN-SETH) program were reviewed, and data for 79 early-stage, underrepresented faculty investigators from RCMI (n = 23) and non-RCMI (n = 56) institutions were included. RESULTS: Institutional membership (RCMI vs. non-RCMI) was used as a possible predictive factor and emerged as a contributing factor for all of the analyses. Access to local mentors was predictive of a successful grant submission for RCMI investigators, while underrepresented investigators at non-RCMI institutions who succeeded with submitting grants still lacked access to local mentors. CONCLUSION: Institutional contexts contribute to the grant writing experiences of investigators underrepresented in biomedical research.

The Role of Mock Reviewing Sessions in the National Research Mentoring Network Strategic Empowerment Tailored for Health Equity Investigators: A Randomized Controlled Study.

The National Research Mentoring Network (NRMN) Strategic Empowerment Tailored for Health Equity Investigators (SETH) study evaluates the value of adding Developmental Network to Coaching in the career advancement of diverse Early-Stage Investigators (ESIs). Focused NIH-formatted Mock Reviewing Sessions (MRS) prior to the submission of grants can significantly enhance the scientific merits of an ESI's grant application. We evaluated the most prevalent design, analysis-related factors, and the likelihood of grant submissions and awards associated with going through MRS, using descriptive statistics, Chi-square, and logistic regression methods. A total of 62 out of 234 applications went through the MRS. There were 69.4% that pursued R grants, 22.6% career development (K) awards, and 8.0% other grant mechanisms. Comparing applications that underwent MRS versus those that did not (N = 172), 67.7% vs. 38.4% were submitted for funding (i.e., unadjusted difference of 29.3%; OR = 4.8, 95% CI = (2.4, 9.8), p-value < 0.0001). This indicates that, relative to those who did not undergo MRS, ESIs who did, were 4.8 times as likely to submit an application for funding. Also, ESIs in earlier cohorts (1-2) (a period that coincided with the pre COVID-19 era) as compared to those who were recruited at later cohorts (3-4) (i.e., during the peak of COVID-19 period) were 3.8 times as likely to submit grants (p-value < 0.0001). The most prevalent issues that were identified included insufficient statistical design considerations and plans (75%), conceptual framework (28.3%), specific aims (11.7%), evidence of significance (3.3%), and innovation (3.3%). MRS potentially enhances grant submissions for extramural funding and offers constructive feedback allowing for modifications that enhance the scientific merits of research grants.

Sickle Cell Hemoglobin Genotypes Affect Malaria Parasite Growth and Correlate with Exosomal miR-451a and let-7i-5p Levels.

Malaria affects a significant portion of the global population, with 247 million cases in 2021, primarily in Africa. However, certain hemoglobinopathies, such as sickle cell trait (SCT), have been linked to lower mortality rates in malaria patients. Hemoglobin (Hb) mutations, including HbS and HbC, can cause sickle cell disease (SCD) when both alleles are inherited (HbSS and HbSC). In SCT, one allele is inherited and paired with a normal allele (HbAS, HbAC). The high prevalence of these alleles in Africa may be attributed to their protective effect against malaria. Biomarkers are crucial for SCD and malaria diagnosis and prognosis. Studies indicate that miRNAs, specifically miR-451a and let-7i-5p, are differentially expressed in HbSS and HbAS compared to controls. Our research examined the levels of exosomal miR-451a and let-7i-5p in red blood cells (RBCs) and infected red blood cells (iRBCs) from multiple sickle Hb genotypes and their impact on parasite growth. We assessed exosomal miR-451a and let-7i-5p levels in vitro in RBC and iRBC supernatants. Exosomal miRNAs exhibited distinct expression patterns in iRBCs from individuals with different sickle Hb genotypes. Additionally, we discovered a correlation between let-7i-5p levels and trophozoite count. Exosomal miR-451a and let-7i-5p could modulate SCD and malaria severity and serve as potential biomarkers for malaria vaccines and therapies.

Impact of COVID-19 on the Research Career Advancement of Health Equity Scholars from Diverse Backgrounds.

The COVID-19 pandemic has significantly taxed scientific research and seems to have exacerbated existing inequities within the research field, particularly for early-stage investigators (ESIs). This study examines the effects of the COVID-19 pandemic on traditionally underrepresented ESIs enrolled in an NIH-supported study evaluating the effectiveness of developmental networks, grant writing coaching, and mentoring on research career advancement. The survey consisted of 24 closed-ended (quantitative) and 4 open-ended questions (qualitative) linked to a participant's ability to meet grant submission deadlines, research and professional development disruptions, stress level, career transition level, self-efficacy and management of scholarly tasks, and familial responsibilities. Results from 32 respondents (53%) suggest that COVID-19 adversely impacted the continuity of research (81%) and grant submissions (63%). On average, grant submissions were delayed by 6.69 months (i.e., greater than one grant cycle). We also conducted additional analyses characterizing nonresponse and found that there were no significant predictors of nonresponse, indicating a limited threat to the validity of our findings. The disruption caused by COVID-19 to the careers of ESIs from underrepresented groups in the biomedical workforce has been profound in the short term. The long-term consequences to the future success of these groups are unknown but is a worthwhile area of research and potential innovation.

Neuregulin-1 attenuates hemolysis- and ischemia induced-cerebrovascular inflammation associated with sickle cell disease.

OBJECTIVES: Individuals with sickle cell disease (SCD) are at severely heightened risk for cerebrovascular injury and acute cerebrovascular events, including ischemic and hemorrhagic stroke, potentially leading to impaired development and life-long physical and cognitive disabilities. Cerebrovascular injury specific to SCD includes inflammation caused by underlying conditions of chronic hemolysis and reduced cerebrovascular perfusion. The objectives of this study were to investigate whether expression of neuregulin-1ß (NRG-1), an endogenous neuroprotective polypeptide, is increased in SCD or experimental conditions mimicking the hemolysis and ischemic conditions of SCD, and to determine if treatment with exogenous NRG-1 reduces markers of cerebrovascular inflammation. MATERIALS AND METHODS: Plasma and brain-specific NRG-1 levels were measured in transgenic SCD mice. Endogenous NRG-1 levels and response to experimental conditions of excess heme and ischemia were measured in cultured human brain microvascular cells and astrocytes. Pre-treatment with NRG-1 was used to determine NRG-1's ability to ameliorate resultant cerebrovascular inflammation. RESULTS: Plasma and brain-specific NRG-1 were elevated in transgenic SCD mice compared to healthy controls. Neuregulin-1 expression was significantly increased in cultured human microvascular cells and astrocytes exposed to excess heme and ischemia. Pre-treatment with NRG-1 reduced inflammatory chemokine (CXCL-1 and CXCL-10) and adhesion molecule (ICAM-1 and VCAM-1) expression and increased pro-angiogenic factors (VEGF-A) in microvascular cells and astrocytes exposed to excess heme and ischemia. CONCLUSIONS: Elevated NRG-1 in SCD is likely a protective endogenous response to ongoing cerebrovascular insults caused by chronic hemolysis and reduced cerebrovascular perfusion. Administration of NRG-1 to reduce cerebrovascular inflammation may be therapeutically beneficial in SCD and warrants continued investigation.

Angiogenic and angiostatic factors present in the saliva of malaria patients.

BACKGROUND: Malaria related mortality is associated with significant deregulation of host inflammatory factors such as interferon-inducible protein 10, a member of the CXC or α-subfamily (CXCL10), and host angiogenic factors such as angiopoietin 1 (Ang-1) and angiopoietin 2 (Ang-2). However, detection of these factors in malaria patients requires the drawing of blood, which is invasive and increases the risk of accidental blood-borne infections. There has been an increased interest in the use of saliva as the body fluid of choice for the diagnosis of many infectious diseases including malaria. Here, saliva levels of CXCL10, Ang-1, and Ang-2 previously shown to be predictive of severe malaria in malaria patients in Ghana were assessed in malaria patients. METHODS: This study was conducted in the Shai-Osudoku District Hospital in Dodowa, Accra, Ghana and the study population comprised 119 malaria patients and 94 non-malaria subjects. The non-malaria subjects are healthy community participants with no malaria infection. Plasma and saliva levels of CXCL10, Ang-1 and Ang-2 of the study participants were measured using an enzyme-linked immunoassay. Complete blood counts of each participant were measured with a haematology autoanalyzer. Pearson correlation was used to evaluate the correlation between plasma and saliva levels of each biomarker in malaria patients. A p-value of < 0.05 was considered significant. Box plots of median biomarker concentrations were plotted. SPSS version 14.2 software was used for statistical analysis. RESULTS: The non-malaria subjects had a median age of 29 years compared to 23 years for malaria patients (p = 0.001). Among the malaria patients, there was a strong significant relationship between CXCL10 (R2 = 0.7, p < 0.0001) and Ang-1 (R2 = 0.7, p < 0.0001). Malaria patients had lower saliva levels of Ang-1 (p = 0.009) and higher saliva levels of CXCL10 (p = 0.004) and Ang-2 (p = 0.001) compared to non-malaria subjects. CONCLUSIONS: This study provides the first evidence of elevated levels of CXCL10 and Ang-2 in the saliva of malaria patients. Detection of CXCL10, Ang-1 and Ang-2 in saliva may have a potential application for non-invasive malaria diagnosis.

Neuregulin-1/ErbB4 signaling modulates Plasmodium falciparum HRP2-induced damage to brain cortical organoids.

Human cerebral malaria (HCM) is a severe complication of Plasmodium falciparum (P.f.) infection that is characterized by capillary occlusions, rupture of the blood-brain barrier (BBB), perivascular cellular injury, and brain swelling. P.f.histidine-rich protein 2 (HRP2), a byproduct of parasitized red blood cell (pRBC) lysis, crosses the BBB when compromised to cause brain injury. We hypothesized that HRP2-induced neuronal damage can be attenuated by Neuregulin-1 (NRG1), an anti-inflammatory neuroprotective factor. Using brain cortical organoids, we determined that HRP2 upregulated cell death and inflammatory markers and disorganized brain organoid tissue. We identified toll-like receptors (TLR1 and 2) as potential mediators of HRP2-induced cellular damage and inflammation. Exogenous acute treatment of organoids with NRG1 attenuated HRP2 effects. The results indicate that HRP2 mediates malaria-associated HRP2-induced brain injury and inflammation and that NRG1 may be an effective therapy against HRP2 effects in the brain.

MicroRNAs miR-451a and Let-7i-5p Profiles in Circulating Exosomes Vary among Individuals with Different Sickle Hemoglobin Genotypes and Malaria.

Sickle cell disease (SCD) occurs when two alleles of mutated hemoglobin (HbS or HbC) are inherited (HbSS and HbSC) rather than one (HbAS or HbAC), which indicates a person carries the sickle cell trait. The high prevalence of these two alleles in Africa have been associated with reduced malaria susceptibility. Recent in vitro research has been shown that microRNAs (miRNAs) miR-451a and let-7i-5p are differentially expressed in HbSS erythrocytes compared to healthy controls (HbAA) and are overexpressed in Plasmodium-infected malaria erythrocytes. However, these miRNAs have not been fully examined in the plasma of people with different sickle hemoglobin genotypes. Plasma circulating miRNAs are commonly encapsulated in extracellular vesicles, such as exosomes, and are thought to play a role in disease development. Circulating exosomal miR-451a and let-7i-5p were quantified from individuals with various hemoglobin genotypes (HbAA, HbAS, HbAC, HbSS, HbSC, and HbCC) with (+) and without (-) malaria. The results showed a higher level of exosomal let-7i-5p and miR-451a in HbSS-. Exosomal let-7i-5p and miR-451a levels were lower in HbSS+ compared to other genotypes. Based on the area under the curve (AUC) of the Receiver Operating Characteristics (ROCs), both exosomal miRNAs may be useful disease biomarkers for SCD with malaria. Finally, miR-451a and let-7i-5p modulate genes involved in inflammation, making them potential biomarkers of pathogenesis for both diseases.

MiR-451a and let-7i-5p loaded extracellular vesicles attenuate heme-induced inflammation in hiPSC-derived endothelial cells.

Hemolysis is associated with many pathologies, including trauma, sepsis, hemorrhagic stroke, malaria, and genetic disorders such as sickle cell disease (SCD). When hemolysis occurs, free-heme drives vascular inflammation, resulting in oxidative tissue damage and cardiometabolic complications. A better understanding of heme clearance and detoxification is essential to preventing sustained tissue damage. Human induced pluripotent stem cell (hiPSC)-derived endothelial cells (hiPSC-ECs) provide a novel source of patient-specific cells and tissues for disease modeling, drug discovery, and regenerative therapeutics. Here we report the use of hiPSC-ECs to elucidate the role of miR-451a and let-7i-5p-loaded extracellular vesicles (EVs, such as exosomes) in the inflammatory response to free-heme as a model for heme-induced inflammation. We provide evidence of a significant correlation between miR-451a and let-7i-5p-loaded circulating exosomes in plasmodium-infected patients with reported clinical benchmarks of malaria-severity (e.g., Hemoglobin (Hb) levels, white blood cell counts). Additionally, we determined that exposure of Plasmodium falciparum (Pf) parasites to EVs, loaded with either miRNA, significantly reduces their counts in vitro. Using hiPSCs derived from individuals with wild-type Hb (HbAA) or homozygous sickle cell mutated Hb (HbSS) genotypes, we demonstrate that heme-treated hiPSC-ECs secreted inflammatory products (cytokines, chemokines and growth factors) into supporting media at concentrations that were similar to that reported in HbAA and HbSS serum. This inflammatory response was attenuated by exposure with miR-451a or let-7i-5p-loaded EVs. We also found a decrease in transcription of ICAM1 and P-Selectin, as well as the secretion of key inflammatory cytokines (e.g., CXCL10, TNF-α, and IFN-γ). Based on these findings, we propose a model in which increased levels of exosomal miR-451a and let-7i-5p in Plasmodium-infected individuals will attenuate inflammatory responses to free-heme and parasite-derived products. As a result, infected erythrocytes will less likely adhere to the endothelium, sequester in brain micro vessels, and reduce vaso-occlusive crises that exacerbate cerebral malaria.

Randomized Controlled Study to Test the Effectiveness of Developmental Network Coaching in the Career Advancement of Diverse Early-Stage Investigators (ESIs): Implementation Challenges and Lessons Learned.

Introduction: Adding developmental networks (DN) to grant-writing coaching can significantly enhance ESIs' research careers. Herein, we present study design, ESIs' characteristics and encountered challenges/lessons learned and their resolutions when deploying/implementing (a) NCR algorithm(s), (b) recruitment/retention and (c) implementing DN intervention. Methods: Nested Cluster Randomization (NCR) design governs this study implementation. The sample size is 220 ESIs intending to submit an NIH K, R, U, and/or Minority Supplement application(s). Primary outcome: intensity/sustainability of grant submission(s)/funding(s), measured by time to/between application(s). Outcome(s) analyses modes: summaries, Kaplan Meir and Cox proportional hazard models as a function of randomization groups and other predictors of outcomes. Results: In the present study, we recruited two cohorts of ESIs (N = 85): 39% African Americans, 18% Latinx, 18% Whites, 20% Asians and 6% Hawaiian/Pacific Islander/other ethnicities; 65% are women; 73% are assistant professors, 4% are Associate Professors and 23% are instructors/scientists/post-doctoral. Participants' disciplines: 32% basic/biomedical, 36% clinical/translational and 32% social/behavioral. Proposal(s) mechanisms: 61% research grants (R series), 31% career development (K series), 7% support of competitive research (SCORE) and 1% National Science Foundation applications. NCR did produce balance in the distribution of ESIs' demographics, sex at birth, ethnicity, professional appointments, background disciplines, and mechanism of sought funding. Lessons learned/challenges: NCR implementation was methodologically challenged during implementation by added constraints (e.g., assigning coaches to the same randomization arm of their participants as well as blinding them to ESIs' randomization group). Recruitment and retention were hampered by the COVID-19 pandemic and more progressive and innovative strategies were needed to heighten the visibility and outreach of this program. DN delivery was also affected by the pandemic and monitoring of ESIs' engagement and facilitation of communications interventions were needed. Resolution of these challenges effectively reconfigured NCR algorithms, recruitment/retention plans, and DN intervention delivery. We intend to recruit an additional 135 ESIs focusing on underrepresented scholars from RCMIs, CTSAs, and other programs. COVID-19 rendered this program 100% virtual, with recruitment/retention challenges and substantial disruption of ESIs' research. We may extend the grant writing period, coaching, and Mock Study Section support.

Effects of Iron Supplements on Heme Scavengers in Pregnancy.

In malaria endemic countries, anemia in pregnant women occurs as a result of erythrocyte destruction by Plasmodium infections and other causes including malnutrition. Iron supplementation is recommended as treatment of iron-deficiency anemia. Erythrocyte destruction results in increased release of cytotoxic free heme that is scavenged by haptoglobin (Hp), hemopexin (Hx) and heme oxygenase-1 (HO-1). Paradoxically, iron supplementation in pregnant women has been reported to enhance parasitemia and increase levels of free heme. The relationship between free heme, heme scavengers, and birth outcomes has not been investigated, especially in women who are on iron supplementation. We hypothesized that parasite-infected pregnant women on routine iron supplementation have elevated heme and altered expression of heme scavengers. A cross-sectional study was conducted to determine the association between plasma levels of free heme, HO-1, Hp, Hx, and malaria status in pregnant women who received routine iron supplementation and their birth outcomes. Heme was quantified by colorimetric assay and scavenger protein concentration by ELISA. We demonstrated that iron-supplemented women with asymptomatic parasitemia had increased free heme (mean 75.6 µM; interquartile range [IQR] 38.8-96.5) compared with nonmalaria iron-supplemented women (mean 34.9 µM; IQR 17.4-43.8, P < 0.0001). Women with preterm delivery had lower levels of Hx (mean 656.0 µg/mL; IQR 410.9-861.3) compared with women with full-term delivery (mean: 860.9 µg/mL; IQR 715.2-1055.8, P = 0.0388). Our results indicate that iron supplementation without assessment of circulating levels of free heme and heme scavengers may increase the risk for adverse pregnancy outcomes.

Analysis of clinical presentation, hematological factors, self-reported bed net usage, and malaria burden in sickle cell disease patients.

BACKGROUND: Sickle cell anemia (SCA) is a severe monogenic disorder, caused by single nucleotide mutations in the hemoglobin (Hb) gene, that is prevalent in malaria endemic regions of the world. Sickle cell trait (SCT) individuals carry only one of the mutated alleles and were shown to be protected against malaria. However, defining the relative contribution of hematological, clinical, and environmental factors to the overall burden of malaria in individuals with hemoglobinopathies such as SCA has been challenging. METHODS: We hypothesized that hematological differences, clinical presentations, and self-reported bed net usage among Plasmodium-infected and uninfected individuals may govern overall malaria burden in individuals with sickle cell disease (SCD). We conducted a cross-sectional study in Ghana from 2014 to 2019 and described clinical presentations, hematological characteristics, and bed net use based on a comprehensive questionnaire. Hematological characteristics were compared using a parametric or nonparametric ANOVA, pending if data passed D'Agostino & Pearson normality test. When comparing only two Hb genotypes hematological characteristics a Mann-Whitney U-test were used. Logistic regressions and Chi-squared tests were used to compare questionnaire responses between Hb genotypes. All statistical significance was set at p < 0.05. FINDINGS: Multiple hematological parameters were significantly (p < 0.05) altered depending on sickle cell genotype and/or malaria status. When compared to other Hb genotypes, SCA individuals with or without malaria had significantly (p < 0.05) higher WBC and platelets counts and lower Hb levels. While the sickle cell genotype may affect malaria severity, SCT and SCA participants were found to significantly (p < 0.007) use bet nets more than HbAA participants. INTERPRETATIONS: Our findings can be utilized to enhance national guidelines for reducing the incidence of malaria especially among individuals with SCD, SCT protection and health disparities among hemoglobinopathies. FUNDING: This study was supported by the National Institute for Health.

Building a Diverse Workforce and Thinkforce to Reduce Health Disparities.

The Research Centers in Minority Institutions (RCMI) Program was congressionally mandated in 1985 to build research capacity at institutions that currently and historically recruit, train, and award doctorate degrees in the health professions and health-related sciences, primarily to individuals from underrepresented and minority populations. RCMI grantees share similar infrastructure needs and institutional goals. Of particular importance is the professional development of multidisciplinary teams of academic and community scholars (the "workforce") and the harnessing of the heterogeneity of thought (the "thinkforce") to reduce health disparities. The purpose of this report is to summarize the presentations and discussion at the RCMI Investigator Development Core (IDC) Workshop, held in conjunction with the RCMI Program National Conference in Bethesda, Maryland, in December 2019. The RCMI IDC Directors provided information about their professional development activities and Pilot Projects Programs and discussed barriers identified by new and early-stage investigators that limit effective career development, as well as potential solutions to overcome such obstacles. This report also proposes potential alignments of professional development activities, targeted goals and common metrics to track productivity and success.

Elevated neuregulin-1ß levels correlate with plasma biomarkers of cerebral injury and high stroke risk in children with sickle cell anemia.

Stroke, or cerebral infarction, is one of the most serious complications of sickle cell anemia (SCA) in childhood, potentially leading to impaired development and life-long physical and cognitive disabilities. About one in ten children with SCA are at risk for developing overt stroke and an additional 25% may develop silent cerebral infarcts. This is largely due to underlying cerebral injury caused by chronic cerebral ischemia and vascular insult associated with SCA. We previously identified two elevated markers of cerebral injury, plasma brain-derived neurotropic factor (BDNF) and platelet-derived growth factor (PDGF)-AA, in children with SCA and high stroke risk. The objective of this study was to investigate whether neuregulin-1ß (NRG-1), an endogenous neuroprotective polypeptide may also be elevated in children with SCA. Neuregulin-1ß is involved in the preservation of blood brain barrier integrity and brain microvascular cell viability and is cytoprotective in conditions of heme-induced injury and ischemia. Since elevated plasma heme and ischemia are signature characteristics of SCA, we hypothesized that NRG-1 would be elevated in children with SCA, and that NRG-1 levels would also correlate with our biomarkers of cerebral injury. Plasma NRG-1, BDNF and PDGF-AA levels were measured in children with SCA and healthy Controls. Plasma NRG-1 was found to be nearly five-fold higher in those children with SCA compared to Controls. Neuregulin-1ß was also positively correlated with both BDNF and PDGF-AA concentrations, but was not associated with degree of anemia, suggesting that NRG-1 production may be an endogenous response to subclinical cerebral ischemia in SCA warranting further exploration.

Lipoprotein(a) and High Sensitivity C-Reactive Protein among Patients with HIV in Ghana: The Study on Cardiovascular Risk Profile of HIV-Infected Patients on HAART (SCRIPT).

Background: Lipoprotein(a) [Lp(a)] and high-sensitivity C-reactive protein (hs-CRP) levels are associated with cardiovascular disease (CVD) in the general population, even after adjusting for conventional CVD risk factors. However, data are limited regarding the distribution of Lp(a) and hs-CRP among patients with HIV in Ghana. We explored levels of Lp(a), hs-CRP and other cardiovascular risk factors among people who were HIV positive (HIV+) on ART (HIV+ART+), HIV+ART-, and HIV-ART- in a Ghanaian population. Methods: We conducted a cross sectional study, recruited individuals who were HIV+ART+ and HIV+ART- from the largest HIV clinic in central Ghana between August 2018 and December 2019. HIV negative controls were recruited from communities and adjoining suburbs of Kumasi. Lipoprotein(a) was measured using Immunoturbidimetric assay and high sensitive-CRP concentrations were determined using particle-enhanced turbidimetric assay. We compared levels of Lp(a), hs-CRP, and conventional CVD risk factors among these groups and used multivariable stepwise logistic regression models to explore associations between them. Results: Among HIV+ART+ (n = 156), HIV+ART- (n = 131), and HIV-ART- (n = 147), mean(SD) ages were 48 (9.1) years, 41 (11.1) years and 45 (11.9) years, p = <0.001, proportion of females were 71.2%, 67.9% and 73.5% respectively. Median(IQR) concentrations of hs-CRP in mg/L were 1.7 (0.8,4.5), 2.03 (0.5,8.58) and 1.0 (0.45,2.74) across respective groups and the proportion of elevated Lp(a) concentrations (Lp[a] > 30mg/dL) were 70%, 48% and 62% among HIV+ART+,HIV+ART- and HIV-ART- participants respectively. Diabetes mellitus, dyslipidemia, waist-to-hip ratio and metabolic syndrome were associated with higher hs-CRP levels. Compared to HIV-ART-, HIV+ patients had higher odds of having hs-CRP > 3mg/L while HIV+ART+ patients had higher odds of elevated Lp(a) than HIV+ART- after multivariable adjustment. Conclusion: PLWHA in Ghana are associated with higher odds of elevated hs-CRP, regardless of ART use. HIV+ART+ is significantly associated with higher odds of elevated Lp(a) levels compared to HIV+ART-; even after multivariable adjustments. Reasons for this and potential clinical implications merit further study.

Association of EPCR Polymorphism rs867186-GG With Severity of Human Malaria.

BACKGROUND: Cerebral malaria (CM) is characterized by the sequestration of Plasmodium-infected erythrocytes (pRBCs) to host brain microvasculature beds via P. falciparum erythrocyte membrane protein 1 (PfEMP1). Under normal conditions, activated protein C (APC) bound to endothelial protein C receptor (EPCR) has cytoprotective properties via the activation of protease-activated receptor 1 (PAR1). During malaria infection, pRBCs transports PfEMP1 to the membranes to bind EPCR in the same region as APC. As a result, APC is less capable of inducing cytoprotective effects via PAR1. Two studies involving adult malaria patients revealed that EPCR rs867186-GG allele is associated with protection against severe malaria, while three other studies involving child malaria patients could not show association between EPCR rs867186-GG genotype and severe malaria or increased mortality among children with CM. METHODS: We examined the association between the EPCR rs867186-GG genotype and the protection against cerebral malaria. Peripheral blood samples were collected from 47 malaria patients and 34 healthy individuals from a study conducted from 2004 to 2007 at the NSCB Medical College Hospital in India. CM and malaria-associated complications were defined based on WHO criteria. Genomic DNA was isolated from the peripheral blood mononuclear cells. Primer sequences were designed to contain rs867186 of the PROCR gene (NM 006404) and were used to amplify a 660 bp product as described before. PCR products were purified, and DNA sequences were determined by Sanger Sequencing (Genewiz, NJ). Nonparametric tests were used to compare the groups. To analyze differences in allele frequencies, we used chi-squared or Fisher's exact tests for categorical variables if the expected values were less than 5. P-value <0.05 was considered statistically significant. RESULTS: Our results showed significantly higher rates of AG and GG genotypes in CM patients compared to mild malaria (P = 0.0034). CONCLUSION: Our results indicate that rs867186-GG or rs867186-AG genotypes are not associated with protection against HCM.

Hemoglobin Genotypes Modulate Inflammatory Response to Plasmodium Infection.

In 2018, 228 million cases and 405,000 malaria-associated deaths were reported worldwide with a majority being in Africa. A wide range of factors, including parasitemia, host immunity, inflammatory responses to infection, and host hemoglobin genotype, mediate the severity of malaria. Among the hemoglobinopathies, hemoglobin S (HbS) is caused by a single amino acid substitution of Glutamic Acid replaced by Valine at the sixth position of the beta-globin chain (E6V). Hemoglobin C (HbC) on the other hand, involves a single amino acid substitution of Glutamic Acid by a Lysine (E6K), which has received the most attention. These substitutions alter the stability of Hb leading to wide-ranging hematological disorders. The homozygous state of hemoglobin S (HbSS) results in sickle cell anemia (SCA) whereas the heterozygous state (HbAS) results in sickle cell trait (SCT). Both mutations are reported to mediate the reduction in the severity and fatality of Plasmodium falciparum malaria. The mechanism underlying this protection is poorly understood. Since both malaria and sickle cell disease (SCD) are associated with the destruction of erythrocytes and widespread systemic inflammation, identifying which inflammatory factor(s) mediate susceptibility of individuals with different hemoglobin genotypes to Plasmodium infection could result in the discovery of new predictive markers and interventions against malaria or SCD severity. We hypothesized that hemoglobin genotypes modulate the inflammatory response to Plasmodium infection. We conducted a cross-sectional study in Ghana, West Africa, between 2014 and 2019 to ascertain the relationships between blood inflammatory cytokines, Plasmodium infection, and hemoglobin genotype. A total of 923 volunteers were enrolled in the study. A total of 74, age and sex-matched subjects were identified with various genotypes including HbAS, HbAC, HbSS, HbSC, HbCC, or HbAA. Complete blood counts and serum inflammatory cytokine expression levels were assessed. The results indicate that differential expression of CXCL10, TNF-α, CCL2, IL-8, and IL-6 were tightly linked to hemoglobin genotype and severity of Plasmodium infection and that these cytokine levels may be predictive for susceptibility to severe malaria or SCD severity.

Modelling heme-mediated brain injury associated with cerebral malaria in human brain cortical organoids.

Human cerebral malaria (HCM), a severe encephalopathy associated with Plasmodium falciparum infection, has a 20-30% mortality rate and predominantly affects African children. The mechanisms mediating HCM-associated brain injury are difficult to study in human subjects, highlighting the urgent need for non-invasive ex vivo human models. HCM elevates the systemic levels of free heme, which damages the blood-brain barrier and neurons in distinct regions of the brain. We determined the effects of heme on induced pluripotent stem cells (iPSCs) and a three-dimensional cortical organoid system and assessed apoptosis and differentiation. We evaluated biomarkers associated with heme-induced brain injury, including a pro-inflammatory chemokine, CXCL-10, and its receptor, CXCR3, brain-derived neurotrophic factor (BDNF) and a receptor tyrosine-protein kinase, ERBB4, in the organoids. We then tested the neuroprotective effect of neuregulin-1 (NRG-1) against heme treatment in organoids. Neural stem and mature cells differentially expressed CXCL-10, CXCR3, BDNF and ERBB4 in the developing organoids and in response to heme-induced neuronal injury. The organoids underwent apoptosis and structural changes that were attenuated by NRG-1. Thus, cortical organoids can be used to model heme-induced cortical brain injury associated with HCM pathogenesis as well as for testing agents that reduce brain injury and neurological sequelae.

Cardiovascular risk factors among Ghanaian patients with HIV: A cross-sectional study.

BACKGROUND: Cardiovascular disease (CVD) poses a significant cause of morbidity and mortality among people living with human immunodeficiency virus (HIV). However, data are limited on CVD risk burden among HIV patients in Ghana. We describe the age- and sex-adjusted prevalence of CVD risk factors among HIV patients in Ghana. METHODS: From January 2013 to May 2014, we identified eligible HIV patients 18 years and older, as well as uninfected adult blood donors presenting to the Komfo Anokye Teaching Hospital as controls. Using a standardized protocol, we collected demographic, clinical, laboratory, and electrocardiographic data. We created multivariable logistic regression models to compare the prevalence of abnormal risk factors between the two groups. RESULTS: We recruited 345 patients with HIV (n = 173 on HAART, n = 172 not on HAART) and 161 uninfected adult blood donors. Patients with HIV were older (mean [SD] age: 41 [11] vs 32 [11] years) and were more likely to be female (72% vs 28%) than blood donors. Among patients on HAART, median (interquartile range) treatment duration was 17 (4-52) months. The prevalence of hypertension, hypercholesterolemia, and diabetes mellitus among HIV patients was 9%, 29%, and 5%, respectively, compared with 5%, 15%, and 0.6% among uninfected blood donors. Smoking was the least prevalent CVD risk factor (1%-2%). After adjustment for age, sex, and body mass index, HIV patients had a 10-fold higher odds of prevalent diabetes compared with controls, (adjusted OR = 10.3 [95% CI: 1.2, 86.7]). CONCLUSION: CVD risk factors are common among HIV patients in Ghana, demonstrating the urgent need for creation and implementation of strategic CVD interventions.