Antiretrovirals Promote Insulin Resistance in HepG2 Liver Cells through miRNA Regulation and Transcriptional Activation of the NLRP3 Inflammasome.

Metabolic syndrome (MetS) is a non-communicable disease characterized by a cluster of metabolic irregularities. Alarmingly, the prevalence of MetS in people living with Human Immunodeficiency Virus (HIV) and antiretroviral (ARV) usage is increasing rapidly. Insulin resistance is a common characteristic of MetS that leads to the development of Type 2 diabetes mellitus (T2DM). The progression of insulin resistance is strongly linked to inflammasome activation. This study aimed to draw links between the combinational use of Tenofovir disoproxil fumarate (TDF), Lamivudine (3TC), and Dolutegravir (DTG), and inflammasome activation and subsequent promotion of insulin resistance following a 120 h treatment period in HepG2 liver in vitro cell model. Furthermore, we assess microRNA (miR-128a) expression as a negative regulator of the IRS1/AKT signaling pathway. The relative expression of phosphorylated IRS1 was determined by Western blot. Transcript levels of NLRP3, IL-1ß, JNK, IRS1, AKT, PI3K, and miR-128a were assessed using quantitative PCR (qPCR). Caspase-1 activity was measured using luminometry. Following exposure to ARVs for 120 h, NLRP3 mRNA expression (p = 0.0500) and caspase-1 activity (p < 0.0001) significantly increased. This was followed by a significant elevation in IL-1ß in mRNA expression (p = 0.0015). Additionally, JNK expression (p = 0.0093) was upregulated with coinciding increases in p-IRS1 protein expression (p < 0.0001) and decreased IRS1 mRNA expression (p = 0.0004). Consequently, decreased AKT (p = 0.0005) and PI3K expressions (p = 0.0007) were observed. Interestingly miR-128a expression was significantly upregulated. The results indicate that combinational use of ARVs upregulates inflammasome activation and promotes insulin resistance through dysregulation of the IRS1/PI3K/AKT insulin signaling pathway.

A Critical Review of the Biochemical Mechanisms and Epigenetic Modifications in HIV- and Antiretroviral-Induced Metabolic Syndrome.

Metabolic syndrome (MetS) is a non-communicable disease characterised by a cluster of metabolic irregularities. Alarmingly, the prevalence of MetS in people living with Human Immunodeficiency Virus (HIV) and antiretroviral (ARV) usage is increasing rapidly. This study aimed to look at biochemical mechanisms and epigenetic modifications associated with HIV, ARVs, and MetS. More specifically, emphasis was placed on mitochondrial dysfunction, insulin resistance, inflammation, lipodystrophy, and dyslipidaemia. We found that mitochondrial dysfunction was the most common mechanism that induced metabolic complications. Our findings suggest that protease inhibitors (PIs) are more commonly implicated in MetS-related effects than other classes of ARVs. Furthermore, we highlight epigenetic studies linking HIV and ARV usage to MetS and stress the need for more studies, as the current literature remains limited despite the advancement in and popularity of epigenetics.

Antiretrovirals Promote Metabolic Syndrome through Mitochondrial Stress and Dysfunction: An In Vitro Study.

The prevalence of metabolic syndrome MetS in HIV-infected patients on chronic antiretroviral (ARV) therapy continues to rise rapidly, with an estimated 21% experiencing insulin resistance. The progression of insulin resistance is strongly related to mitochondrial stress and dysfunction. This study aimed to draw links between the singular and combinational use of Tenofovir disoproxil fumarate (TDF), Lamivudine (3TC), and Dolutegravir (DTG) on mitochondrial stress and dysfunction as an underlying mechanism for insulin resistance following a 120 h treatment period using an in vitro system of human liver cells (HepG2). The relative protein expressions of pNrf2, SOD2, CAT, PINK1, p62, SIRT3, and UCP2, were determined using Western blot. Transcript levels of PINK1 and p62 were assessed using quantitative PCR (qPCR). ATP concentrations were quantified using luminometry, and oxidative damage (malondialdehyde (MDA) concentration) was measured using spectrophotometry. The findings suggest that despite the activation of antioxidant responses (pNrf2, SOD2, CAT) and mitochondrial maintenance systems (PINK1 and p62) in selected singular and combinational treatments with ARVs, oxidative damage and reduced ATP production persisted. This was attributed to a significant suppression in mitochondrial stress responses SIRT3 and UCP2 for all treatments. Notable results were observed for combinational treatments with significant increases in pNrf2 (p = 0.0090), SOD2 (p = 0.0005), CAT (p = 0.0002), PINK1 (p = 0.0064), and p62 (p = 0.0228); followed by significant decreases in SIRT3 (p = 0.0003) and UCP2 (p = 0.0119) protein expression. Overall there were elevated levels of MDA (p = 0.0066) and decreased ATP production (p = 0.0017). In conclusion, ARVs induce mitochondrial stress and dysfunction, which may be closely associated with the progression of insulin resistance.

A comprehensive review on the global efforts on vaccines and repurposed drugs for combating COVID-19.

The recently discovered coronavirus, known as SARS-CoV-2, is a highly contagious and potentially lethal viral infection that was declared a pandemic by the World Health Organization on March 11, 2020. Since the beginning of the pandemic, an unprecedented number of COVID-19 vaccine candidates have been investigated for their potential to manage the pandemic. Herein, we reviewed vaccine development and the associated research effort, both traditional and forward-looking, to demonstrate the advantages and disadvantages of their technology, in addition to their efficacy limitations against mutant SARS-CoV-2. Moreover, we report repurposed drug discovery, which mainly focuses on virus-based and host-based targets, as well as their inhibitors. SARS-CoV-2 targets include the main protease (Mpro), and RNA-dependent RNA-polymerase (RdRp), which are the most well-studied and conserved across coronaviruses, enabling the development of broad-spectrum inhibitors of these enzymes.

Spirulina platensis Mitigates the Inhibition of Selected miRNAs that Promote Inflammation in HAART-Treated HepG2 Cells.

The introduction of highly active antiretroviral therapy (HAART) in the treatment of HIV/AIDS has recently gained popularity. In addition, the significant role of microRNA expression in HIV pathogenesis cannot be overlooked; hence the need to explore the mechanisms of microRNA expression in the presence of HAART and Spirulina platensis (SP) in HepG2 cells. This study investigates the biochemical mechanisms of microRNA expression in HepG2 cells in the presence of HAART, SP, and the potential synergistic effect of HAART−SP. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine cell viability following SP treatment. The cellular redox status was assessed using the quantification of intracellular reactive oxygen species (ROS), lipid peroxidation, and a lactate dehydrogenase (LDH) assay. The fluorometric JC-1 assay was used to determine mitochondrial polarisation. The quantitative polymerase chain reaction (qPCR) was also employed for micro-RNA and gene expressions. The results show that MiR-146a (p < 0.0001) and miR-155 (p < 0.0001) levels increased in SP-treated cells. However, only miR-146a (p < 0.0001) in HAART−SP indicated an increase, while miR-155 (p < 0.0001) in HAART−SP treatment indicated a significant decreased expression. Further inflammation analysis revealed that Cox-1 mRNA expression was reduced in SP-treated cells (p = 0.4129). However, Cox-1 expression was significantly increased in HAART−SP-treated cells (p < 0.0001). The investigation revealed that HepG2 cells exposed to HAART−SP treatment showed a significant decrease in Cox-2 (p < 0.0001) expression. mRNA expression also decreased in SP-treated cells (p < 0.0001); therefore, SP potentially controls inflammation by regulating microRNA expressions. Moreover, the positive synergistic effect is indicated by normalised intracellular ROS levels (p < 0.0001) in the HAART−SP treatment. We hereby recommend further investigation on the synergistic roles of SP and HAART in the expression of microRNA with more focus on inflammatory and oxidative pathways.

Spirulina platensis Ameliorates Oxidative Stress Associated with Antiretroviral Drugs in HepG2 Cells.

Lately, Spirulina platensis (SP), as an antioxidant, has exhibited high potency in the treatment of oxidative stress, diabetes, immune disorder, inflammatory stress, and bacterial and viral-related diseases. This study investigated the possible protective role of Spirulina platensis against ARV-induced oxidative stress in HepG2 cells. Human liver (HepG2) cells were treated with ARVs ((Lamivudine (3TC): 1.51 µg/mL, tenofovir disoproxil fumarate (TDF): 0.3 µg/mL and Emtricitabine (FTC): 1.8 µg/mL)) for 96 h and thereafter treated with 1.5 µg/mL Spirulina platensis for 24 h. After the treatments, the gene and protein expressions of the antioxidant response pathway were determined using a quantitative polymerase chain reaction (qPCR) and Western blots. The results show that Spirulina platensis decreased the gene expressions of Akt (p < 0.0001) and eNOS (↓p < 0.0001) while, on the contrary, it increased the transcript levels of NRF-2 (↑p = 0.0021), Keap1 (↑p = 0.0002), CAT (↑p < 0.0001), and NQO-1 (↑p = 0.1432) in the HepG2 cells. Furthermore, the results show that Spirulina platensis also decreased the protein expressions of NRF-2 (↓p = 0.1226) and pNRF-2 (↓p = 0.0203). Interestingly, HAART-SP induced an NRF-2 pathway response through upregulating NRF-2 (except for FTC-SP) (↑p < 0.0001), CAT (↑p < 0.0001), and NQO-1 (except for FTC-SP) (↑p < 0.0001) mRNA expression. In addition, NRF-2 (↑p = 0.0085) and pNRF-2 (↑p < 0.0001) protein expression was upregulated in the HepG2 cells post-exposure to HAART-SP. The results, therefore, allude to the fact that Spirulina platensis has the potential to mitigate HAART-adverse drug reactions (HAART toxicity) through the activation of antioxidant response in HepG2 cells. We hereby recommend further studies on Spirulina platensis and HAART synergy.

Fumonisin B2 Induces Mitochondrial Stress and Mitophagy in Human Embryonic Kidney (Hek293) Cells-A Preliminary Study.

Ubiquitous soil fungi parasitise agricultural commodities and produce mycotoxins. Fumonisin B2 (FB2), the structural analogue of the commonly studied Fumonisin B1 (FB1), is a neglected mycotoxin produced by several Fusarium species. Mycotoxins are known for inducing toxicity via mitochondrial stress alluding to mitochondrial degradation (mitophagy). These processes involve inter-related pathways that are regulated by proteins related to SIRT3 and Nrf2. This study aimed to investigate mitochondrial stress responses in human kidney (Hek293) cells exposed to FB2 for 24 h. Cell viability was assessed via the methylthiazol tetrazolium (MTT) assay, and the half-maximal inhibitory concentration (IC50 = 317.4 µmol/L) was estimated using statistical software. Reactive oxygen species (ROS; H2DCFDA), mitochondrial membrane depolarisation (JC1-mitoscreen) and adenosine triphosphate (ATP; luminometry) levels were evaluated to assess mitochondrial integrity. The relative expression of mitochondrial stress response proteins (SIRT3, pNrf2, LONP1, PINK1, p62 and HSP60) was determined by Western blot. Transcript levels of SIRT3, PINK1 and miR-27b were assessed using quantitative PCR (qPCR). FB2 reduced ATP production (p = 0.0040), increased mitochondrial stress marker HSP60 (p = 0.0140) and suppressed upregulation of mitochondrial stress response proteins SIRT3 (p = 0.0026) and LONP1 (p = 0.5934). FB2 promoted mitophagy via upregulation of pNrf2 (p = 0.0008), PINK1 (p = 0.0014) and p62 (p < 0.0001) protein expression. FB2 also suppressed miR-27b expression (p < 0.0001), further promoting the occurrence of mitophagy. Overall, the findings suggest that FB2 increases mitochondrial stress and promotes mitophagy in Hek293 cells.