Signalling of ERK1/2, P38MAPK and P90RSK in HIV-associated pre-eclampsia

P90 ribosomal S6 kinases: A bona fide target for novel targeted anticancer therapies?

The 90 kDa ribosomal S6 kinase (RSK) family of proteins is a group of highly conserved Ser/Thr kinases. They are downstream effectors of the Ras/ERK/MAPK signaling cascade. ERK1/2 activation directly results in the phosphorylation of RSKs, which further, through interaction with a variety of different downstream substrates, activate various signaling events. In this context, they have been shown to mediate diverse cellular processes like cell survival, growth, proliferation, EMT, invasion, and metastasis. Interestingly, increased expression of RSKs has also been demonstrated in various cancers, such as breast, prostate, and lung cancer. This review aims to present the most recent advances in the field of RSK signaling that have occurred, such as biological insights, function, and mechanisms associated with carcinogenesis. We additionally present and discuss the recent advances but also the limitations in the development of pharmacological inhibitors of RSKs, in the context of the use of these kinases as putative, more efficient targets for novel anticancer therapeutic approaches.

Circulating levels of transforming growth factor beta-1, 2 and 3 in HIV associated preeclamptic pregnancies

The active role of transforming growth factor-beta in implantation, embryonic development and decidualization has driven our interest to evaluate circulating TGF-β(1-3) in the synergy of HIV associated pregnancy. Serum TGF-β(1-3) was quantified in normotensive (n = 38) and preeclamptic (n = 38) pregnant women, who were stratified by HIV status, HIV negative (n = 19) and HIV positive (n = 19), using a Bioplex immunoassay.Based on HIV status, we report no significant difference in TGF-β-1 (p = .95) and TGF-β2 (p = .80) however, TGF-β3 was significantly downregulated in HIV positive (p = .03) vs the HIV negative groups. A significant positive correlation (p < .05) was noted between TGF-β3 and gestational age (p = .03) (r = 0.51), birth weight (p = .04) (r = 0.53) and CD4 count (p = .02) (r = 0.53). Bivariate correlation between isoforms based on HIV status showed several significant positive associations. In the synergy of HIV infected PE, we demonstrate an association between TGF-β(1-3) with PE emanating from the hypoxic microenvironment that affects receptor-SMAD activity. Decreased TGF-β3 levels in HIV infected PE, may originate from ARV usage and/or the mutational/physiological dysregulation of SMAD expression. Impact StatementWhat is already known on this subject? TGF-β overexpression can convert its protective functions into pathogenic variants. It has a significant role in the oxidatively stressed and inflammatory condition of tissue fibrosis and hence may also be dysregulated in the microenvironment of PE. In HIV infection, TGF-β promotes viral replication and spreading through the induction of cellular proteins which induce TGF-β production. Also, mononuclear phagocytes infected with HIV also produce increased TGF-β mRNA and proteins.What do the results of the study add? Our results show no association of TGF-β isoforms (1-3) based on pregnancy type (PE vs normotensive pregnant) at term. The lack of association may be linked to TGF-βs dual promoter/suppresser nature or to gestational age.What are the implications of these findings for clinical practice and/or further research? Large-scale comprehensive clinical trials are warranted to elucidate the association and mechanistic role of TGF-β receptor-SMAD signalling, the effect of its inhibitors on cell invasion and angiogenesis as well as to deliver valuable data for the detection of novel therapeutic agents in pregnancies complicated by HIV infection.

Identification of underlying mechanisms and hub gene-miRNA networks of the genomic subgroups in preeclampsia development

Preeclampsia is a hypertensive disorder of pregnancy that can lead to multiorgan complications in the mother and fetus. Our study aims to uncover the underlying mechanisms and hub genes between genomic subgroups of preeclampsia. A total of 180 preeclampsia cases from 4 gene profiles were classified into 3 subgroups. Weighted gene coexpression analysis was performed to uncover the genomic characteristics associated with different clinical features. Functional annotation was executed within the significant modules and hub genes were predicted using Cytoscape software. Subsequently, miRNet analysis was performed to identify potential miRNA-mRNA networks. Three key subgroup-specific modules were identified. Patients in subgroup II were found to develop more severe preeclampsia symptoms. Subgroup II, characterized by classical markers, was considered representative of typical preeclampsia patients. Subgroup I was considered as an early stage of preeclampsia with normal-like gene expression patterns. Moreover, subgroup III was a proinflammatory subgroup, which presented immune-related genomic characteristics. Subsequently, miR-34a-5p and miR-106a-5p were found to be correlated with all 3 significant gene modules. This study revealed the transcriptome classification of preeclampsia cases with unique gene expression patterns. Potential hub genes and miRNAs may facilitate the identification of therapeutic targets for preeclampsia in future.

Inhibition of PKC-δ reduce rhabdomyolysis-induced acute kidney injury

Despite extensive research, the mechanisms underlying rhabdomyolysis-induced acute kidney injury (AKI) remain largely elusive. In this study, we established both cell and murine models of rhabdomyolysis-induced AKI by using myoglobin and glycerin, respectively, and provided evidence that protein kinase Cδ (PKC-δ) was activated in both models and subsequently promoted cell apoptosis. Moreover, we found that this detrimental effect of PKC-δ activation can be reversed by its pharmaceutical inhibitor rottlerin. Furthermore, we detected and confirmed the existence of PKC-δ-mediated myoglobin-induced cell apoptosis and the expression of TNF-α and IL1-β via regulation of the p38MAPK and ERK1/2 signalling pathways. In summary, our research revealed the role of PKC-δ in renal cell apoptosis and suggests that PKC-δ is a viable therapeutic target for rhabdomyolysis-induced AKI.

Systematic and meta-analysis of factors associated with preeclampsia and eclampsia in sub-Saharan Africa

Background

Preeclampsia and eclampsia are common complications of pregnancy globally, including sub-Saharan African (SSA) countries. Although it has a high burden on maternal and neonatal mortality and morbidity, evidence on the risk of the problem is limited. Therefore, the aim of this review was to examine the factors associated with preeclampsia and eclampsia among mothers in SSA countries.

Methods

We searched article from SSA countries using electronic database MEDLINE, EMBASE, PubMed, CINAHL published in English from January 2000 to May 2020. Two reviewers independently screened, extracted and assessed the quality of the articles. Both random and fixed effect model were used for analysis. Heterogeneity of the studies and publication bias were checked. STATA 16 used for analysis.

Results

Fifty-one studies met the inclusion criteria and included in this review. The following factors were identified through meta-analysis: being primiparous (OR: 2.52; 95% CI:1.19, 3.86), previous history of maternal preeclampsia/eclampsia (OR:5.6; 95% CI:1.82, 9.28), family history of preeclampsia/eclampsia (OR:1.68; 95% CI:1.26, 2.11), high maternal body mass index (OR: 1.69; 95% CI:1.17, 2.21), chronic hypertension (OR: 2.52; 95% CI:1.29, 3.74), anaemia during pregnancy (OR: 3.22; 95% CI:2.70, 3.75) and lack of antenatal care visits (OR: 2.71; 95% CI:1.45, 3.96). There was inconclusive evidence for a relationship with a number of other factors, such as nutrition and related factors, antenatal care visits, birth spacing, and other factors due to few studies found in our review.

Conclusions

The risk of preeclampsia and eclampsia is worse among women who have a history of preeclampsia/eclampsia (either themselves or family members), primiparous, obesity and overweight, living with chronic disease, having anaemia during pregnancy and absence from ANC visits. Therefore, investment must be made in women’s health needs to reduce the problem and health service providers need to give due attention to high-risk women.

Pregnancy-associated venous insufficiency course with placental and systemic oxidative stress

The development of lower extremity venous insufficiency (VI) during pregnancy has been associated with placental damage. VI is associated with increased oxidative stress in venous wall. We have investigated potential disturbance/dysregulation of the production of reactive oxygen species (ROS) in placenta and its eventual systemic effects through the measurement of malondialdehyde (MDA) plasma levels in women with VI. A total of 62 women with VI and 52 healthy controls (HCs) were studied. Levels of nicotinamide adenine dinucleotide phosphate-oxidase 1 (NOX1), 2 (NOX2), inducible nitric oxide synthase (iNOS), endothelial (eNOS), poly(ADP-ribose) polymerase PARP (PARP) and ERK were measured in placental tissue with immunohistochemistry and RT-qPCR. Plasma and placental levels of MDA were determined by colorimetry at the two study times of 32 weeks of gestation and post-partum. Protein and gene expression levels of NOX1, NOX2, iNOS, PARP and ERK were significantly increased in placentas of VI. eNOS activity was low in both study groups, and there were no significant differences in gene or protein expression levels. Women with VI showed a significant elevation of plasma MDA levels at 32 weeks of gestation, and these levels remained elevated at 32 weeks post-partum. The MDA levels were significantly higher in placentas of women with VI. Placental damage that was found in the women with VI was characterized by overexpression of oxidative stress markers NOX1, NOX2, and iNOS, as well as PARP and ERK. Pregnant women with VI showed systemic increases in oxidative stress markers such as plasma MDA levels. The foetuses of women with VI had a significant decrease in their venous pH as compared to those from HC women. The situation of oxidative stress and cellular damage created in the placenta is in coexpression with the production of a pH acidification.

The role of Galectin-1 in HIV associated preeclampsia

OBJECTIVE

In this study, the role of Gal1, a regulatory protein involved in receptor binding and gene transcription within trophoblast cells, in the pathophysiology of HIV associated preeclampsia was determined by immunolocalizing its expression in the placenta of a South African cohort.

STUDY DESIGN

this is an analytical study carried out at the Optics and Imaging Center, Neslon R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa. A hundred and twenty HIV negative or positive, Black African primigrad or multigravid women with pre-eclamptic and normotensive pregnancies were involved in the study. Post-delivery, full thickness of centrally located placental tissue obtained was fixed for immunohistochemistry. The expression of Gal1 was immunolocalized using immunohistochemical assay kit and further quantified with using AxioVision Image analysis software package. Student t-test was used to compare the levels of the analytes while One-way ANOVA was used for comparison across the groups.

RESULTS

Gal1 immunoreactivity was observed within the Hofbauer cells, cytotrophoblast, syncytial knots and in the endothelial cells lining blood vessels in both exchange and conducting villi of both normotensive and preeclamptic pregnancies regardless of HIV status. There was a down regulation in Gal1 immunoreactivity in both the exchange and conducting villi of preeclamptic compared to normotensive pregnancies. However, there was no significant effect of HIV infection on Gal1 immunostaining in both villi types.

CONCLUSION

The down regulation of Gal1 in preeclampsia may be due to the inhibition of the MAPK pathway. Since Gal1 influences differentiation and migration, the defective trophoblast invasion in preeclampsia may emanate from its decreased immunoexpression. This highlights the role of Gal1 in angiogenesis and placentation.