SARS-CoV-2-associated lymphopenia: possible mechanisms and the role of CD147.

T lymphocytes play a primary role in the adaptive antiviral immunity. Both lymphocytosis and lymphopenia were found to be associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While lymphocytosis indicates an active anti-viral response, lymphopenia is a sign of poor prognosis. T-cells, in essence, rarely express ACE2 receptors, making the cause of cell depletion enigmatic. Moreover, emerging strains posed an immunological challenge, potentially alarming for the next pandemic. Herein, we review how possible indirect and direct key mechanisms could contribute to SARS-CoV-2-associated-lymphopenia. The fundamental mechanism is the inflammatory cytokine storm elicited by viral infection, which alters the host cell metabolism into a more acidic state. This "hyperlactic acidemia" together with the cytokine storm suppresses T-cell proliferation and triggers intrinsic/extrinsic apoptosis. SARS-CoV-2 infection also results in a shift from steady-state hematopoiesis to stress hematopoiesis. Even with low ACE2 expression, the presence of cholesterol-rich lipid rafts on activated T-cells may enhance viral entry and syncytia formation. Finally, direct viral infection of lymphocytes may indicate the participation of other receptors or auxiliary proteins on T-cells, that can work alone or in concert with other mechanisms. Therefore, we address the role of CD147-a novel route-for SARS-CoV-2 and its new variants. CD147 is not only expressed on T-cells, but it also interacts with other co-partners to orchestrate various biological processes. Given these features, CD147 is an appealing candidate for viral pathogenicity. Understanding the molecular and cellular mechanisms behind SARS-CoV-2-associated-lymphopenia will aid in the discovery of potential therapeutic targets to improve the resilience of our immune system against this rapidly evolving virus.

Plasma-derived extracellular matrix for xenofree and cost-effective organoid modeling for hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) causes significant cancer mortality worldwide. Cancer organoids can serve as useful disease models by high costs, complexity, and contamination risks from animal-derived products and extracellular matrix (ECM) that limit its applications. On the other hand, synthetic ECM alternatives also have limitations in mimicking native biocomplexity. This study explores the development of a physiologically relevant HCC organoid model using plasma-derived extracellular matrix as a scaffold and nutritive biomatrix with different cellularity components to better mimic the heterogenous HCC microenvironment. Plasma-rich platelet is recognized for its elevated levels of growth factors, which can promote cell proliferation. By employing it as a biomatrix for organoid culture there is a potential to enhance the quality and functionality of organoid models for diverse applications in biomedical research and regenerative medicine and to better replicate the heterogeneous microenvironment of HCC. METHOD: To generate the liver cancer organoids, HUH-7 hepatoma cells were cultured alone (homogenous model) or with human bone marrow-derived mesenchymal stromal cells and human umbilical vein endothelial cells (heterogeneous model) in plasma-rich platelet extracellular matrix (ECM). The organoids were grown for 14 days and analyzed for cancer properties including cell viability, invasion, stemness, and drug resistance. RESULTS: HCC organoids were developed comprising HUH-7 hepatoma cells with or without human mesenchymal stromal and endothelial cells in plasma ECM scaffolds. Both homogeneous (HUH-7 only) and heterogeneous (mixed cellularity) organoids displayed viability, cancer hallmarks, and chemoresistance. The heterogeneous organoids showed enhanced invasion potential, cancer stem cell populations, and late-stage HCC genetic signatures versus homogeneous counterparts. CONCLUSION: The engineered HCC organoids system offers a clinically relevant and cost-effective model to study liver cancer pathogenesis, stromal interactions, and drug resistance. The plasma ECM-based culture technique could enable standardized and reproducible HCC modeling. It could also provide a promising option for organoid culture and scaling up.

Hepatocellular carcinoma patients serum modulates the regenerative capacities of adipose mesenchymal stromal cells.

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers causing the highest mortality rate worldwide. Treatment options of surgery, radiation, cytotoxic drugs and liver transplantation suffer significant side effects and a high frequency of relapse. Stem cell therapy has been proposed as a new effective therapy, however, controversial reports are emerging on the role of mesenchymal stem cells in cancer. In this work, we aimed to assess the regenerative capacities of adipose mesenchymal stem cells when exposed to serum from HCC patients, by assessing the effect of the sera on modulating the regenerative capacities of h-AMSCs and the cancer properties in HCC cells. This will pave the way for maximizing the efficacy of MSCs in cancer therapy. Our data show that HCC serum-treated hA-MSCs suffered oncogene-induced senescence as shown by their altered morphology and ameliorated proliferation and differentiation. The cells were enlarged with small irregular nuclei, swollen rough endoplasmic reticulum cisternae, and aging lysosomes typified by dark residual bodies. HCC serum-treated Huh-7 cancer cells on the other hand displayed higher tumor aggressiveness as depicted by altered morphology, increased cellular proliferation and migration, and decreased percentage of early and late apoptotic cells. Our findings provide evidence that exposure of hA-MSCs to the serum of HCC patients decreases their regenerative capacities and should be considered when employed as a potential therapy in HCC patients.

The interplay of cells, polymers, and vascularization in three-dimensional lung models and their applications in COVID-19 research and therapy.

Millions of people have been affected ever since the emergence of the corona virus disease of 2019 (COVID-19) outbreak, leading to an urgent need for antiviral drug and vaccine development. Current experimentation on traditional two-dimensional culture (2D) fails to accurately mimic the in vivo microenvironment for the disease, while in vivo animal model testing does not faithfully replicate human COVID-19 infection. Human-based three-dimensional (3D) cell culture models such as spheroids, organoids, and organ-on-a-chip present a promising solution to these challenges. In this report, we review the recent 3D in vitro lung models used in COVID-19 infection and drug screening studies and highlight the most common types of natural and synthetic polymers used to generate 3D lung models.

Hepatocellular carcinoma cell line-microenvironment induced cancer-associated phenotype, genotype and functionality in mesenchymal stem cells.

Mesenchymal stromal cells (MSCs) have shown promise in liver cancer treatment. However, when MSCs are recruited to hepatic site of injury, they acquire cancerous promoting phenotype. AIMS: To assess the influence of Hepatocellular carcinoma (HCC) microenvironment on human adipose MSCs (hA-MSCs) and predict hA-MSCs intracellular miRNAs role. MATERIALS AND METHODS: After indirect co-culturing with Huh-7 cells, hA-MSCs were characterized via cell cycle profile, proliferation and migration potentials by MTT and scratch assays respectively. Functional enrichment analysis of deregulated proteins and miRNA targets was also analyzed. KEY FINDINGS: Co-cultured hA-MSCs could acquire a cancer-associated phenotype as shown by upregulation of CAF, cancer markers, and downregulation of differentiation markers. Migration of these cancer-associated cells was increased concomitantly with upregulation of adhesion molecules, but not epithelial to mesenchymal transition markers. Co-cultured cells showed increased proliferation confirmed by downregulation in cell percentage in G0/G1, G2/M and upregulation in S phases of cell cycle. Upregulation of miR-17-5p and 615-5p in co-cultured hA-MSCs was also observed. Functional enrichment analysis of dysregulated proteins in co-cultured hA-MSCs, including our selected miRNAs targets, showed their involvement in development of cancer-associated characteristics. SIGNIFICANCE: This study suggests an interaction between tumor cells and surrounding stromal components to generate cancer associated phenotype of some CAF-like characteristics, known to favor cancer progression. This sheds the light on the use of hA-MSCs in HCC therapy. hA-MSCs modulation may be partially achieved via dysregulation of intracellular miR17-5P and 615-5p expression, suggesting an important role for miRNAs in HCC pathogenesis, and as a possible therapeutic candidate.

Brown seaweeds protect against azoxymethane-induced hepatic repercussions through up-regulation of peroxisome proliferator-activated receptor gamma and attenuation of oxidative stress.

CONTEXT: Seaweeds of the genera Turbinaria and Padina have long been used as food and in traditional medicine for treating several diseases. OBJECTIVE: The current study determines the protective efficacy of the brown seaweeds Turbinaria ornata (Turner) J. Agardh (Sargassaceae) and Padina pavonia (Linnaeus) J.V. Lamouroux (Dictyotaceae) against liver injury induced by azoxymethane (AOM). MATERIALS AND METHODS: Male Swiss mice received 10 mg/kg AOM once a week for two consecutive weeks and then 100 mg/kg daily dose of either T. ornata or P. pavonia ethanolic extract. Thirteen weeks after the first AOM administration and 24 h after the last treatment, overnight fasted mice were sacrificed and samples collected. RESULTS: Compared with the AOM group, both T. ornata and P. pavonia significantly decreased the activity of aminotransferases and the concentration of bilirubin while increased albumin levels in the serum. The antioxidative effect of both extracts was observed from the increased activity of superoxide dismutase and glutathione peroxidase activities in the liver, both of which were decreased by AOM. Moreover, the levels of malondialdehyde and nitric oxide were reduced, and histological findings also confirmed the antihepatotoxic activity. In addition, treatment with T. ornata and P. pavonia significantly increased PPARγ and decreased NF-κB expression in the liver of AOM-administered mice. DISCUSSION AND CONCLUSION: Our findings indicate that the protective function of T. ornata and P. pavonia on AOM-induced liver injury may be possibly exerted by multiple pathways including abolishment of inflammation and oxidative damage, and activation of PPARγ.

Protective Effects of Turbinaria ornata and Padina pavonia against Azoxymethane-Induced Colon Carcinogenesis through Modulation of PPAR Gamma, NF-κB and Oxidative Stress.

The aim of this study was to investigate the antiproliferative and protective effects of the brown seaweeds, Turbinaria ornata and Padina pavonia, against azoxymethane (AOM)-induced colon carcinogenesis in mice. Both algal extracts showed anti-proliferative effects on the human carcinoma cell line HCT-116 in vitro, with T. ornata demonstrating a more potent effect. Male albino Swiss mice received intraperitoneal injections of AOM (10 mg/kg) once a week for two consecutive weeks and 100 mg/kg of either T. ornata or P. pavonia extracts. AOM-induced mice exhibited alterations in the histological structure of the colon, elevated lipid peroxidation and nitric oxide, declined glutathione content and reduced activity of superoxide dismutase and glutathione peroxidase. In addition, AOM induced downregulation of peroxisome proliferator activated receptor gamma (PPARγ) and p53 mRNA expression, with concomitant upregulation of nuclear factor-kappa B (NF-κB) in colon tissue. Administration of either algal extract markedly alleviated the recorded alterations. In conclusion, the current study suggests that T. ornata and P. pavonia, through their antioxidant and anti-inflammatory effects, are able to attenuate colon inflammation by downregulating NF-κB expression. Furthermore, the protective effects of both algae against AOM-initiated carcinogenesis were attributed, at least in part, to their ability to upregulate colonic PPARγ and p53 expression.