Search Results (124)

Background/Objectives: Advanced 3D cell culture techniques enhance the physiological relevance of in vitro models, while supporting the 3Rs principles (Reduction, Refinement, and Replacement) of animal experimentation. In this context, 3D collagen-based systems mimic key extracellular matrix properties, enabling more accurate cellular organization and phenotype. However, changes in culture dimensionality can affect RT-qPCR reference gene stability, underscoring the need for careful validation when combining 2D and 3D systems. Methods: AML12 cells were cultured for 7 days under different 2D and collagen-based 3D conditions. The expression stability of nine candidate housekeeping genes was systematically evaluated using established algorithms (BestKeeper, NormFinder, geNorm, RefFinder, and ΔCt method), followed by inter-group statistical and correlation analyses of raw Ct values. Albumin gene expression was used as a target gene. Results: Although all candidate genes initially met acceptable variability thresholds, a stepwise, exclusion-based analysis revealed distinct performance differences. Hprt, Ppia, and Actb emerged as the most stable, showing no intra-group variability or interaction with Albumin expression. Nevertheless, Ywhaz and Rplp0, despite their high stability, were compromised by significant correlation with Albumin. Furthermore, Ywhaz showed significant downregulation under 3D culture conditions. B2M, Gapdh, 18S, and Hmbs exhibited increased variability, likely reflecting metabolic and microenvironmental heterogeneity associated with prolonged 2D cultivation of AML12 cells. Conclusions: Overall, this study highlights the importance of context-dependent, exclusion-based reference gene validation when comparing 2D and 3D models, and demonstrates a new approach for reliable gene expression normalization in complex in vitro culture systems. Full article

The liver is the central organ in metabolism; however, modeling hepatic diseases remains limited by current experimental models. Animal models frequently fail to predict human liver physiology, while primary hepatocytes rapidly dedifferentiate in culture. We performed comprehensive transcriptomic profiling of induced pluripotent stem cells (iPSCs) differentiation into hepatocyte-like cells (HLCs) under two-dimensional (2D) and three-dimensional (3D) culture conditions. RNA sequencing analysis revealed the sequential activation of lineage-specific markers across major developmental stages: definitive endoderm (FOXA2, SOX17, CXCR4, CER1, GATA4), posterior foregut (PROX1, GATA6), and hepatoblasts (HNF4A, AFP). Comparative analysis demonstrated a markedly enhanced hepatic gene expression of 3D organoids, as demonstrated by a 33-fold increase in HNF4A expression and elevated levels of mature hepatocyte markers, including ALB, SERPINA1, and UGT2B15. However, the 3D cultures retained fetal characteristics (290-fold higher AFP expression) and exhibited significantly impaired metabolic function, with CYP3A4 expression levels reduced by 2000-fold compared to the adult human liver. This partial maturation was further supported by a moderate correlation with adult liver tissue (ρ = 0.57). We demonstrated high reproducibility across five biologically distinct iPSCs lines, including those derived from patients with rare monogenic disorders. The establishment of quantitative benchmarks provides a crucial tool for standardizing in vitro liver models. Furthermore, we delineate the specific limitations of the current model, highlighting the need for further protocol optimization to enhance metabolic maturation and P450 enzyme activity. Functional validation of metabolic activity (CYP enzyme assays, albumin secretion) was not performed; therefore, conclusions regarding hepatocyte functionality are based on transcriptomic evidence. Full article

Acute liver injury (ALI) is a potentially life-threatening condition lacking effective clinical drugs. Hypoxia-inducible factor-1α (HIF-1α) is a key regulator of both inflammation and metabolism. In ALI, HIF-1α expressions are upregulated, but the role of HIF-1α in hepatocytes and whether it can be targeted remain unclear. Herein, clinical samples and ALI murine models including lipopolysaccharide/D-galactosamine (LPS/D-GalN), acetaminophen (APAP), and thioacetamide (TAA) revealed an increase in HIF-1α expression and ferroptosis. Using HIF-1α gain and loss of function mouse and hepatocyte culture models, we demonstrated that HIF-1α upregulation exacerbated liver ferroptosis and injury. Mechanistically, HIF-1α/transferrin receptor protein 1 (TFR1) axis drives hepatic iron overload, promoting ferroptotic cell death and liver injury. In addition, TFR1 inhibition reversed HIF-1α-induced ALI. Importantly, pharmacological inhibition of HIF-1α and TFR1 significantly reduced ferroptosis and mitigated liver injury both in vivo and in vitro. Together, our findings demonstrate the pathological role of hepatic HIF-1α, which may serve as a promising target of therapeutic intervention. Full article

Compound yeast culture (CYC) is known to enhance animal health, but its effects on hepatic immune function are unclear. This study systematically examined CYC’s regulatory effects on the liver of weaned lambs using transcriptomics and integrative bioinformatics. Ten lambs were randomly assigned to a control diet or a basal diet supplemented with 30 g/d per head of Saccharomyces cerevisiae and Kluyveromyces marxianus co-culture (CYC group) for 42 days. Histological analysis showed that CYC improved hepatocyte arrangement and sinusoidal integrity, suggesting enhanced hepatic tissue stability. Cytokine analysis revealed CYC significantly increased IL-6 and IL-1β while reducing IL-10, TGF-β1, TNF-α, and CXCL9, indicating a bidirectional modulation of the immune response. Additionally, CYC enhanced antioxidant defenses by increasing T-SOD, GSH-Px, and T-AOC activities and decreasing MDA content. Transcriptomic sequencing indicated that CYC reshaped hepatic gene expression. Upregulated genes were enriched in immune-regulatory and structural pathways, including PI3K-AKT signaling, ECM–receptor interactions, Toll-like receptor pathways, and cell adhesion molecules. Protein-level validation further confirmed activation of PI3K and AKTAKT phosphorylation with limited engagement of NF-κB signaling. Conversely, downregulated genes were mainly associated with oxidative stress and energy metabolism, such as ROS-related pathways and MAPK signaling. WGCNA identified key hub genes (PTPRC, CD86, and ITGAV), which correlate with pro-inflammatory factors and participate in immune recognition, T-cell activation, and cell adhesion. These data suggest that CYC promotes hepatic immune homeostasis by enhancing immune signaling, stabilizing tissue architecture, and modulating oxidative stress/metabolic processes. This study provides mechanistic insights into CYC’s regulation of liver immune function and supports its targeted application as a functional feed additive for ruminants. Full article

Three-dimensional (3D) hepatic tissue engineering holds great potential for liver regeneration, disease modeling, and drug screening. These applications require densely layered hepatic tissues that mimic native 3D liver architecture. However, limited oxygen supply and reduced cell viability in densely layered hepatic constructs remain key challenges. To overcome this, this study developed a photo-crosslinkable, oxygen-releasing hydrogel composed of methacrylated hyaluronic acid (MeHA) and calcium peroxide (CPO). The MeHA/CPO hydrogel exhibited favorable rheological properties and sustained oxygen release. Induced pluripotent stem cell-derived hepatocyte (iHep) sheets were cultured with or without MeHA/CPO hydrogel in single- and double-layer formats. The hydrogel enhanced structural integrity and supported the formation of a multilayer (~33 µm). Double-layered iHep sheets with MeHA/CPO showed the significantly increased expression of paracrine factors (HGF, VEGF, Alb) and improved albumin secretion without loss of hepatocyte identity (AFP, HNF4α). This oxygen-releasing system effectively alleviates hypoxic stress, supporting the structural and functional viability of multilayered iHep sheets. Our platform provides a promising approach for engineering metabolically active hepatic tissues and may serve as a foundation for 3D hepatic tissue engineering. Full article

Bisphenol AF (BPAF) exposure is increasingly linked to metabolic disorders, yet the molecular initiating events (MIE) and key events (KE) leading to hepatic steatosis remain unclear. We constructed an adverse outcome pathway (AOP) to mechanistically connect BPAF-triggered macrophage–hepatocyte crosstalk to liver fat accumulation. Male C57BL/6 mice received daily oral gavage of 0, 0.5, 4, or 32 mg kg⁻¹ BPAF for 90 d, and Transwell co-cultures of RAW264.7 macrophages and AML12 hepatocytes were used for in vitro validation. Targeted metabolomics, western blotting, and lipid staining quantified succinate, pathway proteins, and steatosis. BPAF dose-dependently increased serum succinate (BMD = 6901.95 nM) and hepatic triglyceride (TG) (BMD = 874.26 nM). Cryo-EM docking revealed BPAF binding to SUCNR1 at 2.9 Å, disrupting the inactive-state conformation. In co-culture, BPAF-exposed macrophages released succinate that bound hepatocyte SUCNR1, suppressed Akt phosphorylation, and activated JNK. These KEs led to a 40% increase in lipid droplets and elevated TG, total cholesterol (TC), and free fatty acids (FFA) without liver weight gain. We propose the first AOP for BPAF-induced hepatic steatosis: BPAF–SUCNR1 binding (MIE) → macrophage succinate release (KE1) → SUCNR1-mediated Akt inhibition/JNK activation (KE2–4) → hepatic lipid accumulation (KE5) → steatosis (AO). These findings provide mechanistic insight for chemical risk assessment of BPAF and structurally related bisphenols. Full article

Liver fibrosis (LF) is a progressive and increasingly prevalent condition, yet current therapeutic options remain limited. This underscores the growing demand for advanced three-dimensional (3D) preclinical models that better recapitulate the complex pathophysiology of human LF and overcome the limitations of conventional systems. Although a number of in vitro models have been proposed in recent years, many still rely on two-dimensional (2D) hepatocyte cultures, which fail to represent the multicellular interactions and spatial architecture of the fibrotic liver. In contrast, 3D in vitro models, including spheroids, organoids, and liver-on-a-chip (LoC) platforms, offer more physiologically relevant microenvironments, enabling improved disease modeling and patient-specific drug testing. In this review, we summarize current bioengineering strategies for constructing 3D LF models and highlight their advantages, limitations, and future directions for clinical translation. Full article

Changes in hepatic lipoprotein metabolism are responsible for the majority of metabolic dysfunction-associated disorders, including familial hypercholesterolemia (FH), metabolic syndrome (MetS), metabolic dysfunction-associated fatty liver disease (MAFLD), and age-related diseases such as atherosclerosis, a major health burden in modern society. This review aims to advance the understanding of state-of-the-art mechanistic concepts in lipoprotein metabolism, with a particular focus on lipoprotein uptake and secretion and their dysregulation in disease, and to provide a comprehensive overview of experimental models used to study these processes. Human lipoprotein research faces several challenges. First, significant differences in lipoprotein metabolism between humans and other species hinder the reliability of non-human model systems. Additionally, ethical constraints often limit studies on human lipoprotein metabolism using tracers. Lastly, while 2D hepatocyte cell culture systems are widely used, they are commonly of cancerous origins, limiting their physiological relevance and necessitating the use of more physiologically representative models. In this review, we will elaborate on key findings in lipoprotein metabolism, as well as limitations and challenges of currently available study tools, highlighting mechanistic insights throughout discussion of these models. These include human tracer studies, animal studies, 2D tissue culture-based systems derived from cancerous tissue as well as from induced pluripotent stem cells (iPSCs)/embryonic stem cells (ESCs). Finally, we will discuss precision-cut liver slices, liver-on-a-chip models, and, particularly, improved 3D models: (i) spheroids generated from either hepatoma cancer cell lines or primary human hepatocytes and (ii) organoids generated from liver tissues or iPSCs/ESCs. In the last section, we will explore future perspectives on liver-in-a-dish models in studying mechanisms of liver diseases, treatment options, and their applicability in precision medicine approaches. By comparing traditional and advanced models, this review will highlight the future directions of lipoprotein metabolism research, with a focus on the growing potential of 3D liver organoid models. Full article

Background/Objectives: Liver-on-a-chip (LiOC) technology is increasingly recognized as a transformative platform for modeling liver biology, disease mechanisms, drug metabolism, and toxicity screening. Traditional two-dimensional (2D) in vitro models lack the complexity needed to replicate the liver’s unique microenvironment. This review aims to summarize recent advancements in LiOC systems, emphasizing their potential in biomedical research and translational applications. Methods: This narrative review synthesizes findings from key studies on the development and application of LiOC platforms. We explored innovations in material science and bioengineering, including microfluidic design, 3D printing, stem cell– and tissue-derived liver organoid integration, and co-culture strategies. Commercially available LiOC systems and their regulatory relevance were also evaluated. Results: LiOC systems have evolved from simple PDMS-based chips to complex, multicellular constructs incorporating hepatocytes, endothelial cells, Kupffer cells, and hepatic stellate cells. Recent studies demonstrate their superior ability to replicate liver-specific architecture and functions. Applications span cancer research, drug toxicity assessment (e.g., drug-induced liver injury prediction with >85% sensitivity), disease modeling, and regenerative medicine. Several platforms have gained FDA recognition and are in active use for preclinical drug testing. Conclusions: LiOC technology offers a more physiologically relevant alternative to traditional models and holds promise for reducing reliance on animal studies. While challenges remain, such as vascularization and long-term function, ongoing advancements are paving the way toward clinical and pharmaceutical integration. The technology is poised to play a key role in personalized medicine and next-generation therapeutic development. Full article

The liver plays a pivotal role in metabolism, detoxification, and protein synthesis and comprises several cell types, including hepatocytes and cholangiocytes. Primary human hepatocytes in 2D cultures rapidly dedifferentiate and lose their function, making their use as a reliable cell model challenging. Therefore, developing robust three-dimensional cell culture models is crucial, especially for diseases lacking reliable animal models. The aim of this study was to optimize a protocol for the directed differentiation of induced pluripotent stem cells into liver progenitor cells, achieving the high-level expression of specific markers. As a result, we established a 2D culture of liver progenitor cells capable of differentiating into three cell types: a 3D organoid culture containing hepatocyte- and cholangiocyte-like cells and a 2D cell culture comprising stellate-like cells. To evaluate gene delivery efficiency, liver progenitor cells were transduced with various rAAV serotypes carrying an eGFP reporter cassette at different multiplicities of infection (MOIs). Our results revealed that rAAV serotype 2/2 at MOI of 100,000 achieved the highest transduction efficiency of 93.6%, while electroporation demonstrated a plasmid delivery efficiency of 54.3%. These findings suggest that liver progenitor cells are a promising tissue-like cell model for regenerative medicine and demonstrate high amenability to genetic manipulation, underscoring their potential in gene therapy and genome editing studies. Full article

Citrus lumia Risso is an ancient, cultivated Mediterranean lime belonging to the Rutaceae family. It is a species extremely difficult to retrieve, but it is still found in some private gardens in certain regions of Southern Italy. Citrus fruits are a rich source of bioactive compounds, particularly polyphenols, which have been linked to a reduction in the risk of several metabolic diseases. Here, hesperidium peel extracts were obtained by maceration with ethanol:water mixtures in different proportions (50:50, 80:20, 0:100) and the resulting crude extracts were then passed through a glass column containing adsorbent resins to concentrate the polyphenolic compounds. After phytochemical characterization, the extracts were evaluated for antioxidant activity using electron paramagnetic resonance (EPR) spectroscopy. Finally, the water polyphenolic-rich extract (ClumWp), which was the extract with the highest flavonoid content (18.355 ± 1.607 mg/mL) and the strongest antioxidant activity against hydroxyl radical, was tested to evaluate its potential protective effects on lipid accumulation in both 2D hepatocyte cultures and 3D spheroids. Treatment with 25 and 50 μg/mL resulted in a reduction in intracellular lipid content in the HepG2 liver cell line, while treatment with 100 µg/mL ClumWp resulted in a reduction in the intracellular lipid content in HepG2 + LX2 spheroids. In addition, treatment with ClumWp significantly increased ATP levels in the spheroids compared to those untreated, suggesting its ability to restore and promote ATP production. Our results highlight that the study of neglected species, such as Citrus lumia Risso, remains a valuable opportunity to valorize Mediterranean biodiversity, especially in the context of its potential applications to improve human health. In particular, the polyphenolic fraction of Citrus lumia peel showed promising effects on lipid metabolism and cellular energy balance and may prove valuable in the treatment of metabolic disorders such as MASLD, where lipid accumulation disrupts normal cellular functions. Full article

Objective: Dermo-cosmetics have significantly advanced, focusing on innovative and effective products such as cosmeceuticals—cosmetics infused with bioactive ingredients for skin benefits. Synthetic peptides are prominent among these bioactive molecules, noted for their enhanced effects in cellular processes related to skin physiology. Specifically, the glycoprotein E-cadherin plays a crucial role in cellular adhesion and has shown promise in wound healing studies, although its broader cellular functions remain underexplored. Despite their widespread use, many cosmetic peptides lack genetic validation of their effects. This study focuses on the synthetic, amphiphilic acetyl hexapeptide-1, aimed to possess wound healing and anti-aging properties, with a novel exploration of its molecular mechanisms, specifically its effect on the expression of the CDH-1 gene, which encodes E-cadherin—a key protein in cellular adhesion and wound healing. Methods: In this investigation, the acetyl hexapeptide-1 was synthesized in house, followed by cell culture assessment and molecular evaluation. Human hepatocytes HepG2 were exposed to the synthetic hexapeptide to assess cytotoxic effects and examine its impact on gene expression, specifically targeting the wound healing-associated gene CDH-1, as well as apoptosis-related genes BAX, Bcl-2, Caspase-9, and Cyclin D1. Results: No cytotoxic effects were observed in cell cultures. Gene expression analysis revealed a significant increase in E-cadherin expression, along with the NO modulation of apoptosis-related genes (BAX, Bcl-2, Caspase-9) and the cell cycle-related gene Cyclin D1. These findings suggest peptide’s role in enhancing cellular adhesion, without any cytotoxic effects. Conclusions: The findings of this study provide promising insights into the potential molecular properties of synthetic acetyl hexapeptide-1, implying its applicability in cosmeceuticals. These cosmetic peptides hold enormous potential and diverse applications not only within skincare. To fully understand their benefits and expand their scope, additional investigations are warranted to comprehensively explore their molecular mechanisms across a spectrum of applications. Full article

Metabolic reprogramming is a hallmark of cancer, enabling tumor cells to adapt to and exploit their microenvironment for sustained growth. The liver is a common site of metastasis, but the interactions between tumor cells and hepatocytes remain poorly understood. In the context of liver metastasis, these interactions play a crucial role in promoting tumor survival and progression. This study leverages multiomics coverage of the microenvironment via liquid chromatography and high-resolution, high-mass-accuracy mass spectrometry-based untargeted metabolomics, ¹³C-stable isotope tracing, and RNA sequencing to uncover the metabolic impact of co-localized primary hepatocytes and a colon adenocarcinoma cell line, SW480, using a 2D co-culture model. Metabolic profiling revealed disrupted Warburg metabolism with an 80% decrease in glucose consumption and 94% decrease in lactate production by hepatocyte–SW480 co-cultures relative to SW480 control cultures. Decreased glucose consumption was coupled with alterations in glutamine and ketone body metabolism, suggesting a possible fuel switch upon co-culturing. Further, integrated multiomics analysis indicates that disruptions in metabolic pathways, including nucleoside biosynthesis, amino acids, and TCA cycle, correlate with altered SW480 transcriptional profiles and highlight the importance of redox homeostasis in tumor adaptation. Finally, these findings were replicated in three-dimensional microtissue organoids. Taken together, these studies support a bioinformatic approach to study metabolic crosstalk and discovery of potential therapeutic targets in preclinical models of the tumor microenvironment. Full article

(1) Liver injury caused by an overdose of acetaminophen (APAP) represents a major public health concern. Paeoniflorin (PF) has been reported to have anti-inflammatory and liver-protective effects, but the underlying mechanisms remain unclear. This study aimed to investigate the effect of PF on the crosstalk between pyroptosis and NETs in AILI. (2) APAP-treated C57BL/6J mice were used to demonstrate the protective effect of PF on liver injury. HepG2 and dHL-60 cells were cultured to study the effects of PF on hepatocyte pyroptosis and neutrophil extracellular traps (NETs) in vitro. Moreover, cell co-culture experiments were performed, and mice were treated with a NETs-depleting agent and hepatocyte pyroptosis inhibitor to investigate the improvement of AILI induced by PF through regulating the crosstalk between hepatocyte pyroptosis and NETs. (3) PF significantly alleviated AILI. Additionally, PF inhibited the expression of pyroptosis-related proteins, high-mobility group box 1 (HMGB1), and NETs-associated proteins in vitro and in vivo. The co-culture experiments demonstrated that PF not only inhibited the NETs triggered by hepatocyte pyroptosis, but also suppressed the hepatocyte pyroptosis induced by NETs. In mice with depleted neutrophils, the level of hepatocyte pyroptosis notably decreased, indicating a diminished impact of PF. Similarly, NETs formation was reduced in mice receiving a pyroptosis inhibitor compared to the APAP group. Compared with DNase I alone, the reduction effect of PF combined with DNase I on serum ALT and AST levels decreased from 46.857% and 39.927% to 44.347% and 33.419%, respectively. Compared with DSF alone, PF combined with DSF reduced the ALT and AST levels from 46.857% and 39.927% to 45.347% and 36.419%, respectively. (4) PF demonstrated therapeutic effects on AILI. Its mechanism involves the regulation of the crosstalk between hepatocyte pyroptosis and NETs. This research substantiates the pharmacological promise of PF as a therapeutic intervention for acute AILI. Full article

Insulin receptor substrates (IRSs) are well-known mediators of the insulin and insulin-like growth factor (IGF)-I signaling pathways. We previously reported that the protein levels of IRS-2, a molecular species of IRS, were upregulated in the livers of rats fed a protein-restricted diet. This study aimed to elucidate the physiological role of IRS-2, whose level increases in response to protein restriction in cultured hepatocyte models. Hepatocyte-derived cell lines subjected to amino acid deprivation showed increased IRS2 mRNA and IRS-2 protein levels due to increased IRS2 transcription and translation, respectively. Amino acid deprivation markedly increased vascular endothelial growth factor-D (VEGF-D) secretion. Remarkably, the amino acid deprivation-induced VEGF-D secretion was suppressed by IRS-2 knockdown and enhanced by IRS-2 overexpression. These results suggest that IRS-2 is an intercellular signaling molecule that extracellularly transmits information on amino acid deprivation stress by regulating the secretion of growth factors such as VEGF-D. Moreover, this function of IRS-2 is distinct from its currently accepted function as a mediator of the insulin/IGF-I signaling pathways. This study demonstrates that IRS-2 can modulate protein secretion in an insulin-independent manner and greatly expands our understanding of the role of IRS-2, which is upregulated in response to amino acid deprivation. Full article