A Review of Angiogenic Imbalance in HIV-Infected Hypertensive Disorders of Pregnancy

Association of angiogenic factors (placental growth factor and soluble FMS-like tyrosine kinase-1) in preeclamptic women of African ancestry comorbid with HIV infection

BACKGROUND

Preeclampsia is a significant cause of maternal and fetal morbidity and mortality, particularly in low- and middle-income countries like South Africa.

AIM

The aim of our study was to investigate the association between placental growth factor (PlGF) and soluble FMS-like tyrosine kinase-1 (sFlt-1) in South African preeclamptic women of African ancestry, comorbid with HIV infection.

METHODS

The study population consisted of women attending a regional hospital in Durban, South Africa, stratified by pregnancy type (normotensive pregnant and preeclampsia) and HIV status. Preeclampsia was defined as new-onset hypertension and proteinuria. DNA was obtained from whole blood. The SNPs of interest were rs722503 in sFlt-1 and rs4903273 in PlGF.

RESULTS

Our findings suggest that single nucleotide polymorphisms of rs722503 analysis show no significant associations between the genotypic frequencies of rs722503 variants and preeclampsia risk in either HIV-negative or HIV-positive groups of women of African ancestry. Similarly, the rs493273 polymorphism showed no significant association with preeclampsia risk in either HIV-negative or HIV-positive pregnant women. Additionally, comparisons of dominant, recessive, and over-dominant allele models did not reveal significant associations. These findings suggest that these genetic variants may not significantly contribute to preeclampsia development in this African ancestry population. However, significant differences were observed in the rs4903273 genotype frequencies between normotensive and preeclamptic women, regardless of HIV status, over dominant alleles AA + GG vs AG showed a significant difference [OR = 2.706; 95% Cl (1.199-5.979); adjusted p = 0.0234*], also in normotensive compared to EOPE (OR = 2.804; 95% Cl (1.151-6.89) p = 0.0326* and LOPE (OR = 2.601; 95% Cl (1.0310-6.539) p = 0.0492*), suggesting that they may be the potential role of this variant in preeclampsia susceptibility.

CONCLUSION

The findings suggest that the rs722503 and rs493273 polymorphisms do not significantly contribute to preeclampsia susceptibility in HIV-negative or HIV-positive pregnant women. However, the rs4903273 genotype frequencies showed notable differences between normotensive and preeclamptic women, indicating a potential association with preeclampsia development in the African ancestry population irrespective of HIV status.

Neuropilin-1 in the pathogenesis of preeclampsia, HIV-1, and SARS-CoV-2 infection: A review

This review explores the role of transmembrane neuropilin-1 (NRP-1) in pregnancy, preeclampsia (PE), human immunodeficiency virus type 1 (HIV-1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Since these conditions are assessed independently, this review attempts to predict their comorbid clinical manifestations. Dysregulation of NRP-1 contributes to the pathogenesis of PE by (a) impairing vascular endothelial growth factor (VEGF) signaling for adequate spiral artery remodeling and placentation, (b) inducing syncytiotrophoblast (ST) cell apoptosis and increasing ST-derived microparticle circulation and (c) by decreasing regulatory T cell activity predisposing maternal immune intolerance. Although NRP-1 is upregulated in SARS-CoV-2 placentae, its exploitation for SARS-CoV-2 internalization and increased infectivity may alter angiogenesis through the competitive inhibition of VEGF. The anti-inflammatory nature of NRP-1 may aid its upregulation in HIV-1 infection; however, the HIV-accessory protein, tat, reduces NRP-1 expression. Upregulated NRP-1 in macrophages and dendritic cells also demonstrated HIV-1 resistance/reduced infectivity. Notably, HIV-1-infected pregnant women receiving antiretroviral therapy (ART) to prevent vertical transmission may experience immune reconstitution, impaired decidualization, and elevated markers of endothelial injury. Since endothelial dysfunction and altered immune responses are central to PE, HIV-1 infection, ART usage and SARS-CoV-2 infection, it is plausible that an exacerbation of both features may prevail in the synergy of these events. Additionally, this review identifies microRNAs (miRNAs) mediating NRP-1 expression. MiR-320 and miR-141 are overexpressed in PE, while miR-206 and miR-124-3p showed increased expression in PE and HIV-1 infection. Additionally, miR-214 is overexpressed in PE, HIV-1 and SARS-CoV-2 infection, implicating treatment strategies to reduce these miRNAs to upregulate and normalize NRP-1 expression. However, inconsistencies in the data of the role and regulation of miRNAs in PE, HIV-1 and SARS-CoV-2 infections require clarification. This review provides a platform for early diagnosis and potential therapeutic intervention of PE, HIV-1, and SARS-CoV-2 infections independently and as comorbidities.

HIV Associated Preeclampsia: A Multifactorial Appraisal

Introduction: This review explores angiogenesis, vascular dysfunction, the complement system, RAAS, apoptosis and NETosis as potential pathways that are dysregulated during preeclampsia, HIV infection and ART usage. Results: HIV-1 accessory and matrix proteins are protagonists for the elevation of oxidative stress, apoptosis, angiogenesis, and elevation of adhesion markers. Despite the immunodeficiency during HIV-1 infection, HIV-1 exploits our cellular defence arsenal by escaping cell-mediated lysis, yet HIV-1 infectivity is enhanced via C5a release of TNF-α and IL-6. This review demonstrates that PE is an oxidatively stressed microenvironment associated with increased apoptosis and NETosis, but with a decline in angiogenesis. Immune reconstitution in the duality of HIV-1 and PE by protease inhibitors, HAART and nucleoside reverse transcriptase, affect similar cellular pathways that eventuate in loss of endothelial cell integrity and, hence, its dysfunction. Conclusions: HIV-1 infection, preeclampsia and ARTs differentially affect endothelial cell function. In the synergy of both conditions, endothelial dysfunction predominates. This knowledge will help us to understand the effect of HIV infection and ART on immune reconstitution in preeclampsia.

A Narrative Review of the Renin-Angiotensin-Aldosterone System in the Placenta and Placental Bed of HIV Infected Women of African Ancestry with Preeclampsia

PURPOSE OF REVIEW

Both HIV infection and preeclampsia (PE), a pregnancy-specific disorder of hypertension and multi-system organ involvement, have high prevalence rates especially in low-to-middle-income countries. The immunoexpression of specific renin-angiotensin-aldosterone system (RAAS) receptors in the placenta and placental bed interface may forecast the risk of PE.

RECENT FINDINGS

Preeclampsia is a leading risk factor for mortality worldwide and remains a challenge in HIV-infected individuals especially those on antiretroviral therapy (ART). Irregular RAAS stimulation may be linked to the pathophysiology of hypertension in HIV infection and in PE. The AT1 receptor is expressed across all trimesters of pregnancy, within placental tissue, eliciting vasoconstriction. This increased expression is associated with the severity of PE, implying that the increased expression may be involved in the pathogenesis of this pregnancy disorder. The AT2 receptor expression in normotensive pregnancies was shown to be lower as compared to non-pregnant individuals. Furthermore, in the PE placental bed, the AT2 receptor is the predominant receptor subtype and is found in extravillous trophoblast cells where they facilitate vasodilation. However, AT4R in placentae of PE pregnancies are found to be significantly reduced compared to normotensives pregnancies. The data on the role played by the RAAS pathway in pregnancy is conflicting. Investigation into a tissue-based RAAS with emphasis on immune-expression within the placenta and placental bed may help resolve this conundrum.

The role of soluble E-selectin in HIV associated preeclampsia

OBJECTIVE

To determine the serum concentration of soluble E-selectin (sE-selectin) in HIV associated preeclampsia.

STUDY DESIGN

The study population (n = 72) consisted of normotensive pregnant (n = 36) and preeclamptic (n = 36) women stratified by HIV status (negative vs. positive). Serum concentrations of sE-selectin were quantified using the MilliPlex multiplex immunoassay method. Statistical analyses were conducted using GraphPad Prism software.

RESULTS

When stratified by pregnancy type and HIV status, serum sE-selectin levels were elevated in the preeclamptic HIV-negative group compared to the normotensive HIV-negative group (p = 0.0070**). Gestational age, systolic blood pressure, diastolic blood pressure and baby weight were statistically different across the study groups (p < 0.0001).

CONCLUSION

This study demonstrates an elevation of sE-selectin in preeclamptic HIV-negative compared to the normotensive HIV-negative group. However, when stratified by HIV status, there was no significant difference observed in preeclamptic HIV-positive and normotensive HIV-positive groups. The findings of this small-scale study suggest that sE-selectin may be used as a biomarker or an early identifier of preeclampsia. Studies with large numbers should be considered to confirm our findings.