Liver sinusoidal endothelial cells: Physiology and role in liver diseases

A novel off-liver sinusoidal progenitor cells in supporting transplantable bioliver engineering

Liver transplantation is the only curative option for liver failure, which is currently limited by organ shortages. Although liver tissue engineering (LTE) with a strategy of decellularization/recellularization opens a new window to overcome this limitation, its challenges include the lack of specific seed cell sources and appropriate methods to support recellularization. In this preliminary study, both in vitro and in vivo experiments were performed. In vitro, we used novel off-liver progenitors of liver sinusoidal endothelial cells (LSECs) isolated from bone marrow mesenchymal stem cells (NG2/BMMSCs) and a method to establish transplantable biolivers in an advanced decellularized liver scaffold (rDLS). This partial liver scaffolds (rDLS) shows advantages over whole liver scaffolds (nDLS) and also maintains both microvascular network and naturally regenerative microenvironmental niche, enhancing effective recellularization of the NG2/BMMSCs compared to nDLS in reconstructing hepatic main architectures of endothelial, sinusoidal and biliary tree before seeding hepatic stem cells (MLpvNG2 and ratOv cells). The recellularized hepatic stem cells-mediated bioliver was subsequently induced in a 3D bioreactor-like system with three different conditioned media (CM1-CM3) for different culture durations. Importantly, the NG2/BMMSC-lined rDLSs effectively supported the functional bioliver engineering. In vivo, compared with control recipient pigs that underwent ∼90 % hepatectomy only, the recipients subjected to the same hepatectomy and received the bioliver presented greater survival durations. Overall, this study presents a new technology for fabricating a NG2/BMMSC-based transplantable bioliver that may become a promising treatment for liver failure.

Bio-orthogonal-labeled exosomes reveals specific distribution in vivo and provides potential application in ARDS therapy

Exosomes derived from specific cells may be useful for targeted drug delivery, but tracking them in vivo is essential for their clinical application. However, their small size and complex structure challenge the development of exosome-tracking techniques, and traditional labeling methods are limited by weak affinity and potential toxicity. To address these issues, here we developed a novel bio-orthogonal labeling strategy based on phosphatidylinositol derivatives to fluorescently label exosomes from various human and mouse cell types. The different cell-derived exosomes revealed organ-specific distribution patterns and a favorable safety profile. Notably, 4T1 cell-derived exosomes specifically targeted the lungs. When used as drug carriers loaded with anti-inflammatory resveratrol, these exosomes showed significant therapeutic efficacy in mice with acute respiratory distress syndrome (ARDS), effectively reducing inflammatory responses, mitigating pulmonary fibrosis, and restoring lung tissue morphology and function. Our findings provide a novel exosome labeling strategy and an invaluable tool for their in vivo tracking and targeting screening, while exosomes that specifically target the lungs offer a potential therapeutic strategy for organ-specific diseases such as ARDS.

Liver sinusoidal endothelial cells in hepatic fibrosis: opportunities for future strategies

Liver sinusoidal endothelial cells (LSECs) are highly specialized endothelial cells that form the interface between the hepatic vasculature and parenchymal cells, playing a crucial role in maintaining hepatic homeostasis. Under pathological conditions, LSECs undergo capillarization, marked by the loss of fenestrae and formation of a basement membrane, thereby impairing microcirculation and promoting fibrosis. Beyond capillarization, LSECs experience a spectrum of pathological changes-including angiogenesis, endothelial-to-mesenchymal transition (EndMT), autophagy, and senescence-all of which contribute to fibrogenesis through distinct molecular pathways. Moreover, LSECs orchestrate liver fibrotic remodeling through dynamic crosstalk with hepatic stellate cells (HSCs), hepatocytes, Kupffer cells, and immune cells, exerting both pro- and anti-fibrotic effects. This review comprehensively summarizes LSECs dysfunction in hepatic fibrosis, with a particular focus on intercellular communication and emerging therapeutic strategies. Elucidating the regulatory networks that govern LSECs behavior may uncover new opportunities for the diagnosis and treatment of chronic liver disease.

Dimethylamino-based synthetic lipidoid nanoparticles for selective mRNA delivery to splenic antigen-presenting cells

Targeted systemic mRNA delivery to extrahepatic tissues remains a formidable challenge, especially in the absence of targeting ligands on lipid nanoparticles. In this study, we introduce a series of dimethylamino-based ionizable lipidoids (DMA-Lipidoids) engineered for selective mRNA delivery to the spleen. Using a combinatorial approach, we synthesized 48 chemically distinct lipidoids by pairing four DMA-containing amine heads with 12 newly designed hyperbranched tails. Remarkably, lipidoids with tails H228, H226x, H246x, and H446x demonstrated exceptional spleen-targeting efficiency. To refine the lipidoid design, we constructed and screened a secondary library of 36 lipidoids containing DMA analogues. Through this two-round screening process, we identified lipidoids with both high potency and spleen selectivity. The lead candidate, DMA4-H228, achieved precise delivery of ovalbumin mRNA to antigen-presenting cells (APCs), driving interferon-α (IFN α) production and APC activation. This robust immune response effectively inhibited tumor growth. Overall, these innovative DMA-lipidoids demonstrate strong spleen-targeting capabilities, offering a transformative platform for mRNA vaccine development.

Innovative nanomedicine approaches for the management of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver disorder globally. The prevalence of NAFLD in the general population is estimated to be 25-30 %, making it the most common chronic liver condition in China as well as worldwide. Given the escalating disease burden and the scarcity of effective therapeutic interventions, there is a pressing unmet clinical need. Consequently, the development of novel pharmaceuticals has emerged as a pivotal research focus in recent years. Moreover, the advent of nano-delivery technology offers innovative solutions for NAFLD drug therapy. This paper presents a comprehensive examination of the pathogenesis and therapeutic targets of NAFLD. It critically reviews the latest advancements in nanomedicine research pertinent to NAFLD treatment. The review synthesizes a broad range of research findings to bridge the gap between current knowledge and emerging therapeutic strategies, and aims to inform and guide future research directions in NAFLD management.

Ultrasound-Mediated Biomimetic Microbubbles Effectively Reverse LSECs Capillarization and Exert Antiplatelet Therapy in Liver Fibrosis

Liver fibrosis, characterized by excessive tissue remodeling as a response to chronic liver injury, is accompanied by capillarization of liver sinusoidal endothelial cells (LSECs) and activated hepatic stellate cells (HSCs). Simvastatin (Sim) can modulate endothelial function by increasing endothelial nitric oxide synthase (eNOS)-dependent nitric oxide (NO) release, thereby reversing capillarization and attenuating liver fibrosis. However, monotherapy often demonstrates limited therapeutic effectiveness given the complex pathophysiology of liver fibrosis. Herein, a type of multifunctional liposomal microbubbles (MBs) carrying both Sim and platelet membrane (PM) has been designed for drug delivery targeting the inflammatory LSECs, with ultrasound-targeted microbubble destruction (UTMD) to mediate efficient release of these therapeutic agents inside the liver sinusoidal. In rat liver fibrosis model, the multifunctional MBs reverses capillarization through the increase of eNOS-dependent NO production. Subsequently, the MBs adhering to the inflammatory LSECs block the adhesion and activation of inherent platelet (PLT), thereby decreasing platelet-derived growth factor β (PDGF-β) to inhibit the HSCs activation. This study demonstrates the strong therapeutic efficacy of the multifunctional MBs integrating Sim and PLT against liver fibrosis, which highlights a great potential for effectively managing this intractable chronic disease.

Immune-endothelial cell crosstalk in hepatic endothelial injury of liver fibrotic mice

INTRODUCTION

Liver fibrosis is a common pathological process in chronic liver disease, reflecting the advanced stage of the disease. Liver endothelial cells (ECs), especially liver sinusoidal endothelial cells (LSECs), are recognized as critical modulators of liver homeostasis and play essential roles in the recruitment and function of liver immune cells. In this study, we aimed to explore the mechanism of hepatic EC injury and the potential regulatory pathways of intercellular communication in liver fibrosis.

METHODS

In this study, C57BL/6 male mice were treated with CCl4 for 6 weeks to establish a liver fibrosis model. Masson staining and immunohistochemistry were performed to assess the extent of liver fibrosis. Hepatic endothelial injury was detected by using scanning electron microscopy (SEM) and PCR technology. Single-cell RNA sequencing (scRNA-seq) was performed to analyze phenotypic changes in nonparenchymal cells and dissect intercellular crosstalk.

RESULTS

A total of 24,534 cells were clustered into 10 main cell subsets. The LSEC fenestrae and surface receptor expression were reduced, and the expression of Cd34 was upregulated. Liver ECs exhibited dense cellular crosstalk with immune cells (macrophages, T and B cells). The analysis of intercellular signaling pathways revealed that immune cells targeted liver ECs through the Ptprc-Mrc1 and Sell-Podxl signaling pathways to maintain cellular interactions during liver fibrosis.

CONCLUSION

We revealed apparent damage and capillarization of liver ECs and demonstrated the cell-cell communications among liver immune cells and ECs during the development of liver fibrosis. The Ptprc-Mrc1 and Sell-Podxl signaling pathways exerted prominent roles in liver immune cell-EC interactions.

NSun2-Mediated tsRNAs Alleviate Liver Fibrosis via FAK Dephosphorylation

Sinusoidal capillarization - key symptoms of liver fibrosis progression - represents potential therapeutic targets. tRNA modification-mediated tRNA-derived small RNAs (tsRNAs) play a role in angiogenesis. NSun2, an RNA methyltransferase, generates a significant number of tsRNAs. However, the role of NSun2 and its mediated tsRNAs in liver fibrosis remains unclear. In this study, NSun2 deficiency was found to inhibit sinusoidal capillarization, alleviating liver fibrosis. Furthermore, endothelial cell angiogenesis and migration were disrupted in NSun2 knockout mice. Mechanistically, reduced NSun2 expression led to alterations in the functional tsRNAs tRF-1-S25 and tRF-5-V31, which regulate sinusoidal capillarization by targeting key proteins, including DUSP1 and FAK - crucial clinical targets. Moreover, intravenous injection of tRF-1-S25 and tRF-5-V31 inhibitor rescued liver fibrosis in mice. In conclusion, tsRNAs generated by NSun2-mediated modification of tRNAs inhibit sinusoidal capillarization. Furthermore, targeting the DUSP1/FAK/p-FAK pathway offers an innovative approach to treat this disease.

Physics-driven self-supervised learning for fast high-resolution robust 3D reconstruction of light-field microscopy

Light-field microscopy (LFM) and its variants have significantly advanced intravital high-speed 3D imaging. However, their practical applications remain limited due to trade-offs among processing speed, fidelity, and generalization in existing reconstruction methods. Here we propose a physics-driven self-supervised reconstruction network (SeReNet) for unscanned LFM and scanning LFM (sLFM) to achieve near-diffraction-limited resolution at millisecond-level processing speed. SeReNet leverages 4D information priors to not only achieve better generalization than existing deep-learning methods, especially under challenging conditions such as strong noise, optical aberration, and sample motion, but also improve processing speed by 700 times over iterative tomography. Axial performance can be further enhanced via fine-tuning as an optional add-on with compromised generalization. We demonstrate these advantages by imaging living cells, zebrafish embryos and larvae, Caenorhabditis elegans, and mice. Equipped with SeReNet, sLFM now enables continuous day-long high-speed 3D subcellular imaging with over 300,000 volumes of large-scale intercellular dynamics, such as immune responses and neural activities, leading to widespread practical biological applications.

Quantitative Total-Body Imaging of Blood Flow with High-Temporal-Resolution Early Dynamic 18F-FDG PET Kinetic Modeling

Past efforts to measure blood flow with the widely available radiotracer 18F-FDG were limited to tissues with high 18F-FDG extraction fraction. In this study, we developed an early dynamic 18F-FDG PET method with high-temporal-resolution (HTR) kinetic modeling to assess total-body blood flow based on deriving the vascular phase of 18F-FDG transit and conducted a pilot comparison study against a 11C-butanol flow-tracer reference. Methods: The first 2 min of dynamic PET scans were reconstructed at HTR (60 × 1 s/frame, 30 × 2 s/frame) to resolve the rapid passage of the radiotracer through blood vessels. In contrast to existing methods that use blood-to-tissue transport rate as a surrogate of blood flow, our method directly estimated blood flow using a distributed kinetic model (adiabatic approximation to tissue homogeneity [AATH] model). To validate our 18F-FDG measurements of blood flow against a reference flow-specific radiotracer, we analyzed total-body dynamic PET images of 6 human participants scanned with both 18F-FDG and 11C-butanol. An additional 34 total-body dynamic 18F-FDG PET images of healthy participants were analyzed for comparison against published blood-flow ranges. Regional blood flow was estimated across the body, and total-body parametric imaging of blood flow was conducted for visual assessment. AATH and standard compartment model fitting was compared using the Akaike information criterion at different temporal resolutions. Results: 18F-FDG blood flow was in quantitative agreement with flow measured from 11C-butanol across same-subject regional measurements (Pearson correlation coefficient, 0.955; P < 0.001; linear regression slope and intercept, 0.973 and -0.012, respectively), which was visually corroborated by total-body blood-flow parametric imaging. Our method resolved a wide range of blood-flow values across the body in broad agreement with published ranges (e.g., healthy cohort values of 0.51 ± 0.12 mL/min/cm3 in the cerebral cortex and 2.03 ± 0.64 mL/min/cm3 in the lungs). HTR (1-2 s/frame) was required for AATH modeling. Conclusion: Total-body blood-flow imaging was feasible using early dynamic 18F-FDG PET with HTR kinetic modeling. This method may be combined with standard 18F-FDG PET methods to enable efficient single-tracer multiparametric flow-metabolism imaging, with numerous research and clinical applications in oncology, cardiovascular disease, pain medicine, and neuroscience.

Acoustofluidic bioassembly induced morphogenesis for therapeutic tissue fabrication

To build in vitro tissues for therapeutic applications, it is essential to replicate the spatial distribution of cells that occurs during morphogenesis in vivo. However, it remains technically challenging to simultaneously regulate the geometric alignment and aggregation of cells during tissue fabrication. Here, we introduce the acoustofluidic bioassembly induced morphogenesis, which is the combination of precise arrangement of cells by the mechanical forces produced by acoustofluidic cues, and the morphological and functional changes of cells in the following in vitro and in vivo cultures. The acoustofluidic bioassembly can be used to create tissues with regulated nano-, micro-, and macro-structures. We demonstrate that the neuromuscular tissue fabricated with the acoustofluidic bioassembly exhibits enhanced contraction dynamics, electrophysiology, and therapeutic efficacy. The potential of the acoustofluidic bioassembly as an in situ application is demonstrated by fabricating artificial tissues at the defect sites of living tissues. The acoustofluidic bioassembly induced morphogenesis can provide a pioneering platform to fabricate tissues for biomedical applications.

G protein-coupled receptor GPR182 negatively regulates sprouting angiogenesis via modulating CXCL12-CXCR4 axis signaling

Angiogenesis is a critical process for tumor progression, regulated by various signaling pathways. Although antiangiogenic therapies targeting the VEGF pathway have shown potential, their effectiveness is inconsistent across different tumor types. GPR182, an endothelial cell-specific G protein-coupled receptor, is frequently downregulated in hypervascular tumors, but its specific role in angiogenesis has not been well defined. Our study reveals that GPR182 expression is markedly reduced in hepatocellular carcinoma (HCC) and inversely correlates with CD31, a pan-endothelial marker. In zebrafish embryos, Gpr182 deficiency resulted in enhanced angiogenic sprouting and hypervascularization, and GPR182-deficient human umbilical vein endothelial cells (HUVECs) showed increased migration and proliferation. At the molecular level, GPR182 acts as a decoy receptor, binding CXCL12 and regulating its gradient, which in turn suppresses CXCR4-mediated angiogenesis. The pharmacological blockade of CXCR4 with AMD3100 corrected the abnormal angiogenic phenotype in Gpr182-deficient zebrafish embryos and in the livers of a zebrafish HCC model. This work uncovers GPR182 as a negative regulator of angiogenesis, a key process in tumor growth and metastasis, and proposes that targeting GPR182 may offer a novel therapeutic approach for antiangiogenic strategies in cancer treatment.

EGFR-mediated crosstalk between vascular endothelial cells and hepatocytes promotes Piezo1-dependent liver regeneration

Hepatocyte proliferation is essential for recovering liver function after injury. In liver surgery, the mechanical stimulation induced by hemodynamic changes triggers vascular endothelial cells (VECs) to secrete large amounts of cytokines that enhance hepatocyte proliferation and play a pivotal role in liver regeneration (LR). Piezo1, a critical mechanosensory ion channel, can detect and convert mechanical forces into chemical signals, importing external stimuli into cells and triggering downstream biological effects. However, the precise role of Piezo1 in VECs, especially in terms of mediating LR, remains unclear. Here, we report on a potential mechanism by which early changes in hepatic portal hemodynamics activate Piezo1 in VECs to promote hepatocyte proliferation during the process of LR induced by portal vein ligation in rats. In this LR model, hepatocyte proliferation is mainly distributed in zone 1 and zone 2 of liver lobules at 24-48 h after surgery, while only a small number of Ki67-positive hepatocytes were observed in zone 3. Activation of Piezo1 promotes increased secretion of epiregulin and amphiregulin from VECs via the PKC/ERK1/2 axis, further activating epidermal growth factor receptor (EGFR) and ERK1/2 signals in hepatocytes and promoting proliferation. In the liver lobules, the expression of EGFR in hepatocytes of zone 1 and zone 2 is significantly higher than that in zone 3. The EGFR inhibitor gefitinib inhibits LR by suppressing the proliferation of hepatocytes in the middle zone. These data provide a theoretical basis for the regulation of LR through chemical signals mediated by mechanical stimulation.

Hepatic histopathological and morphometric changes in male mice exposed to rosuvastatin from pre-puberty to adulthood: a possible adaptive hepatic response

Lifestyle changes, such as poor eating habits and a reduction in physical exercise, have impaired human lipid profiles. Statins are widely used to treat dyslipidemias, of which rosuvastatin shows greater improvement in the lipid profile and may be used since childhood. This study aimed to assess the hepatic effects when male mice were given 0.9% saline solution or doses of rosuvastatin of 1.5 or 5.5 mg/kg/day from postnatal day (PND) 23 until PND 80. Body mass gain and water and food consumption were monitored during the treatment. Mice were euthanized on PND 80 when blood was collected for serum obtainment, and several organs were collected and weighed. Serum was used for evaluating lipid profiles and markers of hepatic injuries. The liver was assessed for histopathological, morphometric, and stereological changes. There was a temporary reduction in body mass gain and water and food consumption in the rosuvastatin-exposed groups. Both rosuvastatin-treated groups exhibited reduced total cholesterol levels and showed signs of hepatic tissue adaptation in response to prolonged exposure, such as sinusoidal dilation, inflammatory infiltrates, and cell death of hepatocytes. These results are considered side effects of the treatment and may indicate a hepatic adaptation to the chronic exposure.

Cell therapy for liver disorders: past, present and future

The liver fulfils a plethora of vital functions and, due to their importance, liver dysfunction has life-threatening consequences. Liver disorders currently account for more than two million deaths annually worldwide and can be classified broadly into three groups, considering their onset and aetiology, as acute liver diseases, inherited metabolic disorders and chronic liver diseases. In the most advanced and severe forms leading to liver failure, liver transplantation is the only treatment available, which has many associated drawbacks, including a shortage of organ donors. Cell therapy via fully mature cell transplantation is an advantageous alternative that may be able to restore a damaged organ's functionality or serve as a bridge until regeneration can occur. Pioneering work has shown that transplanting adult hepatocytes can support liver recovery. However, primary hepatocytes cannot be grown extensively in vitro as they rapidly lose their metabolic activity. Therefore, different cell sources are currently being tested as alternatives to primary cells. Human pluripotent stem cell-derived cells, chemically induced liver progenitors, or 'liver' organoids, hold great promise for developing new cell therapies for acute and chronic liver diseases. This Review focuses on the advantages and drawbacks of distinct cell sources and the relative strategies to address different therapeutic needs in distinct liver diseases.

Organoid Vascularization: Strategies and Applications

Organoids provide 3D structures that replicate native tissues in biomedical research. The development of vascular networks within organoids enables oxygen and nutrient delivery while facilitating metabolic waste removal, which supports organoid growth and maturation. Recent studies demonstrate that vascularized organoid models offer insights into tissue interactions and promote tissue regeneration. However, the current limitations in establishing functional vascular networks affect organoid growth, viability, and clinical translation potential. This review examines the development of vascularized organoids, including the mechanisms of angiogenesis and vasculogenesis, construction strategies, and biomedical applications. The approaches are categorized into in vivo and in vitro methods, with analysis of their specific advantages and limitations. The review also discusses emerging techniques such as bioprinting and gene editing for improving vascularization and functional integration in organoid-based therapies. Current developments in organoid vascularization indicate potential applications in modeling human diseases and developing therapeutic strategies, contributing to advances in translational research.

Liver Sinusoidal Endothelial Cells in the Regulation of Immune Responses and Fibrosis in Metabolic Dysfunction-Associated Fatty Liver Disease

Liver Sinusoidal Endothelial Cells (LSECs) play a crucial role in maintaining liver homeostasis, regulating immune responses, and fibrosis in liver diseases. This review explores the unique functions of LSECs in liver pathology, particularly their roles in immune tolerance, antigen presentation, and the modulation of hepatic stellate cells (HSCs) during fibrosis. LSECs act as key regulators of immune balance in the liver by preventing excessive immune activation while also filtering antigens and interacting with immune cells, including Kupffer cells and T cells. Metabolic Dysfunction-Associated Fatty Liver Disease(MAFLD) is significant because it can lead to advanced liver dysfunction, such as cirrhosis and liver cancer. The prevalence of Metabolic Associated Steatohepatitis (MASH) is increasing globally, particularly in the United States, and is closely linked to rising rates of obesity and type 2 diabetes. Early diagnosis and intervention are vital to prevent severe outcomes, highlighting the importance of studying LSECs in liver disease. However, during chronic liver diseases, LSECs undergo dysfunction, leading to their capillarization, loss of fenestrations, and promotion of pro-fibrotic signaling pathways such as Transforming growth factor-beta (TGF-β), which subsequently activates HSCs and contributes to the progression of liver fibrosis. The review also discusses the dynamic interaction between LSECs, HSCs, and other hepatic cells during the progression of liver diseases, emphasizing how changes in LSEC phenotype contribute to liver scarring and fibrosis. Furthermore, it highlights the potential of LSECs as therapeutic targets for modulating immune responses and preventing fibrosis in liver diseases. By restoring LSECs' function and targeting pathways associated with their dysfunction, novel therapies could be developed to halt or reverse liver disease progression. The findings of this review reinforce the importance of LSECs in liver pathology and suggest that they hold significant promises as targets for future treatment strategies aimed at addressing chronic liver diseases.

CLICs Inhibitor IAA94 Alleviates Inflammation and Injury in Septic Liver by Preventing Pyroptosis in Macrophages

Macrophage pyroptosis represents a pivotal mechanism underlying acute liver injury during sepsis. Chloride intracellular channel proteins (CLICs) have been linked to inflammatory reflexes, with IAA94 serving as an inhibitor of channel formation characteristic of CLICs. In a mouse model, IAA94 demonstrated efficacy in reducing pro-inflammatory cytokines in liver tissues, decreasing macrophage in the liver, inhibiting the development of the pro-fibrosis phenotype, and alleviating tissue injury. Additionally, IAA94 exhibited inhibitory effects on the activation of NLRP3 inflammasome, leading to the suppression of pyroptosis in J774A.1 cells and the liver. Additionally, IAA94 was observed to impede the interaction between NEK7 and NLRP3. Furthermore, it was observed that the conditioned medium of pyroptotic macrophages treated with IAA94 induced an attenuated inflammatory response in hepatocytes in comparison to that induced by the conditioned medium of pyroptotic macrophages. However, NLRP3 overexpression impeded the beneficial effects of IAA94. In conclusion, IAA94 has the capacity to impede NLRP3 inflammasome formation-mediated pyroptosis by blocking CLICs-mediated chloride efflux and the inhibition of NEK7-NLRP3 interactions, thereby establishing CLICs as a promising therapeutic target against liver inflammation.

Activin B improves glucose metabolism via induction of Fgf21 and hepatic glucagon resistance

Orchestrated hormonal interactions in response to feeding and fasting play a pivotal role in regulating glucose homeostasis. Here, we show that in obesity, the production of follistatin-like 3 (FSTL3), an endogenous inhibitor of Activin B, in adipose tissue is increased in both mice and humans. The knockdown of FSTL3 improves insulin sensitivity and glucose tolerance in diabetic obese db/db mice. Notably, the overexpression of Activin B, a member of the TGFβ superfamily that is induced in liver sinusoidal endothelial cells by fasting, exerts multiple metabolically beneficial effects, including improvement of insulin sensitivity, suppression of hepatic glucose production, and enhancement of glucose-stimulated insulin secretion, all of which are attenuated by the overexpression of FSTL3. Activin B increases insulin sensitivity and reduces fat by inducing fibroblast growth factor 21 (FGF21) while suppressing glucagon action in the liver by increasing phosphodiesterase 4 B (PDE4B), leading to hepatic glucagon resistance and resultant hyperglucagonemia. Activin B-induced hyperglucagonemia enhances glucose-stimulated insulin secretion by stimulating glucagon-like peptide-1 (GLP-1) receptor in pancreatic β-cells. Thus, enhancing the action of Activin B which improves multiple components of the pathogenesis of diabetes may be a promising strategy for diabetes treatment.

Targeting Polymeric Nanoparticles to Specific Cell Populations in the Liver

Nanoparticles (NPs) are beneficial for delivery of drugs in a variety of settings, serving to protect their cargo and allow for sustained release. Polymeric NPs offer several advantages as therapeutics carriers due to their tunable characteristics like size and shape, ease of manufacturing, and biocompatibility. Despite this, there are no polymeric NPs that are approved for treatment of liver diseases. This is surprising since─when administered intravenously─the majority of NPs accumulate in cells in the liver. NP characteristics like size and surface charge can be altered to affect distribution to the liver, and even cellular distribution, but the conjugation of targeting ligands onto the NP surface for specific receptors on the cells is an important approach for enhancing cell specific delivery. Enhancing cell-specific targeting of conjugated NPs in the liver has two major hurdles: 1) avoiding accumulation of NPs in the liver resident macrophages known as Kupffer cells, which are optimized to phagocytose particulates, and 2) overcoming the transport barriers associated with architectural changes of the diseased liver. To identify the structures and mechanisms most important in NP design, NP administration during ex vivo perfusion (EVP)─achieved by anatomically isolating an organ by perfusing it outside the body─may be the most important and efficient approach. However, EVP is currently underutilized in the NP field, with limited research published on NPs delivered during liver EVP, and therefore representing an opportunity for future investigations.

Cutting-edge biotherapeutics and advanced delivery strategies for the treatment of metabolic dysfunction-associated steatotic liver disease spectrum

Metabolic dysfunction-associated steatotic liver disease (MASLD), a condition with the potential to progress into liver cirrhosis or hepatocellular carcinoma, has become a significant global health concern due to its increasing prevalence alongside obesity and metabolic syndrome. Despite the promise of existing therapies such as thyroid hormone receptor-β (THR-β) agonists, PPAR agonists, FXR agonists, and GLP-1 receptor agonists, their effectiveness is limited by the complexity of the metabolic, inflammatory, and fibrotic pathways that drive MASLD progression, encompassing steatosis, metabolic dysfunction-associated steatohepatitis (MASH), and reversible liver fibrosis. Recent advances in targeted therapeutics, including RNA interference (RNAi), mRNA-based gene therapies, monoclonal antibodies, proteolysis-targeting chimeras (PROTAC), peptide-based strategies, cell-based therapies such as CAR-modified immune cells and stem cells, and extracellular vesicle-based approaches, have emerged as promising interventions. Alongside these developments, innovative drug delivery systems are being actively researched to enhance the stability, precision, and therapeutic efficacy of these biotherapeutics. These delivery strategies aim to optimize biodistribution, improve target-specific action, and reduce systemic exposure, thus addressing critical limitations of existing treatment modalities. This review provides a comprehensive exploration of the underlying biological mechanisms of MASLD and evaluates the potential of these cutting-edge biotherapeutics in synergy with advanced delivery approaches to address unmet clinical needs. By integrating fundamental disease biology with translational advancements, it aims to highlight future directions for the development of effective, targeted treatments for MASLD and its associated complications.

Endothelial RUNX3 controls LSEC dysfunction and angiocrine LRG1 signaling to prevent liver fibrosis

BACKGROUND AND AIMS

Liver fibrosis represents a global health burden, given the paucity of approved antifibrotic therapies. Liver sinusoidal endothelial cells (LSECs) play a major gatekeeping role in hepatic homeostasis and liver disease pathophysiology. In early tumorigenesis, runt-related transcription factor 3 (RUNX3) functions as a sentinel; however, its function in liver fibrosis in LSECs remains unclear. This study aimed to investigate the role of RUNX3 as an important regulator of the gatekeeping functions of LSECs and explore novel angiocrine regulators of liver fibrosis.

APPROACH AND RESULTS

Mice with endothelial Runx3 deficiency develop gradual and spontaneous liver fibrosis secondary to LSEC dysfunction, thereby more prone to liver injury. Mechanistic studies in human immortalized LSECs and mouse primary LSECs revealed that IL-6/JAK/STAT3 pathway activation was associated with LSEC dysfunction in the absence of RUNX3. Single-cell RNA sequencing and quantitative RT-PCR revealed that leucine-rich alpha-2-glycoprotein 1 ( LRG1 ) was highly expressed in RUNX3-deficient and dysfunctional LSECs. In in vitro and coculture experiments, RUNX3-depleted LSECs secreted LRG1, which activated HSCs throughTGFBR1-SMAD2/3 signaling in a paracrine manner. Furthermore, circulating LRG1 levels were elevated in mouse models of liver fibrosis and in patients with fatty liver and cirrhosis.

CONCLUSIONS

RUNX3 deficiency in the endothelium induces LSEC dysfunction, LRG1 secretion, and liver fibrosis progression. Therefore, endothelial RUNX3 is a crucial gatekeeping factor in LSECs, and profibrotic angiocrine LRG1 may be a novel target for combating liver fibrosis.

Stem cell exosomes: new hope and future potential for relieving liver fibrosis

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

Hepatic stellate cells regulate liver fatty acid utilization via plasmalemma vesicle-associated protein

The liver is essential for normal fatty acid utilization during fasting. Circulating fatty acids are taken up by hepatocytes and esterified as triacylglycerols for either oxidative metabolization and ketogenesis or export. Whereas the regulation of fatty acid oxidation in hepatocytes is well understood, the uptake and retention of non-esterified fatty acids by hepatocytes is not. Here, we show that murine hepatic stellate cells (HSCs) and their abundantly expressed plasmalemma vesicle-associated protein (PLVAP) control hepatic substrate preference for fasting energy metabolism. HSC-specific ablation of PLVAP in mice elevated hepatic insulin signaling and improved glucose tolerance. Fasted HSC PLVAP knockout mice showed suppressed hepatic fatty acid esterification into di- and triacylglycerols, shifting fasting metabolism from fatty acid oxidation to reliance on carbohydrates. By super-resolution microscopy, we localized HSC PLVAP to caveolae residing along the sinusoidal lumen, supporting a role for HSCs and PLVAP-diaphragmed caveolae in normal fasting metabolism of the liver.

Quantitative PET imaging and modeling of molecular blood-brain barrier permeability

Neuroimaging of blood-brain barrier permeability has been instrumental in identifying its broad involvement in neurological and systemic diseases. However, current methods evaluate the blood-brain barrier mainly as a structural barrier. Here we developed a non-invasive positron emission tomography method in humans to measure the blood-brain barrier permeability of molecular radiotracers that cross the blood-brain barrier through its molecule-specific transport mechanism. Our method uses high-temporal resolution dynamic imaging and kinetic modeling for multiparametric imaging and quantification of the blood-brain barrier permeability-surface area product of molecular radiotracers. We show, in humans, our method can resolve blood-brain barrier permeability across three radiotracers and demonstrate its utility in studying brain aging and brain-body interactions in metabolic dysfunction-associated steatotic liver inflammation. Our method opens new directions to effectively study the molecular permeability of the human blood-brain barrier in vivo using the large catalogue of available molecular positron emission tomography tracers.

Biophysical and Biochemical Roles of Shear Stress on Endothelium: A Revisit and New Insights

Hemodynamic shear stress, the frictional force exerted by blood flow on the endothelium, mediates vascular homeostasis. This review examines the biophysical nature and biochemical effects of shear stress on endothelial cells, with a particular focus on its impact on cardiovascular pathophysiology. Atherosclerosis develops preferentially at arterial branches and curvatures, where disturbed flow patterns are most prevalent. The review also highlights the range of shear stress across diverse human arteries and its temporal variations, including aging-related alterations. This review presents a summary of the critical mechanosensors and flow-sensitive effectors that respond to shear stress, along with the downstream cellular events that they regulate. The review evaluates experimental models for studying shear stress in vitro and in vivo, as well as their potential limitations. The review discusses strategies targeting shear stress, including pharmacological approaches, physiological means, surgical interventions, and gene therapies. Furthermore, the review addresses emerging perspectives in hemodynamic research, including single-cell sequencing, spatial omics, metabolomics, and multiomics technologies. By integrating the biophysical and biochemical aspects of shear stress, this review offers insights into the complex interplay between hemodynamics and endothelial homeostasis at the preclinical and clinical levels.

Single-cell RNA sequencing advances in revealing the development and progression of MASH: the identifications and interactions of non-parenchymal cells

Developing drugs for the treatment of Metabolic Associated Steatohepatitis (MASH) has always been a significant challenge. Researchers have been dedicated to exploring drugs and therapeutic strategies to alleviate disease progression, but treatments remain limited. This is partly due to the complexity of the pathophysiological processes, and inadequate knowledge of the cellular and molecular mechanisms in MASH. Especially, the liver non-parenchymal cells (NPCs) like Kupffer cells, hepatic stellate cells and sinusoidal endothelial cells which play critical roles in live function, immune responses, fibrosis and disease progression. Deciphering how these cells function in MASH, would help understand the pathophysiological processes and find potential drug targets. In recent years, new technologies have been developed for single-cell transcriptomic sequencing, making cell-specific transcriptome profiling a reality in healthy and diseased livers. In this review, we discussed how the use of single-cell transcriptomic sequencing provided us with an in-depth understanding of the heterogeneous, cellular interactions among non-parenchymal cells and tried to highlight recent discoveries in MASH by this technology. It is hoped that the summarized features and markers of various subclusters in this review could provide a technical reference for further experiments and a theoretical basis for clinical applications.

Combined Esculentin-2CHa Fusion Protein-Coated Au Nanoparticles for Effective Against Non-Alcoholic Fatty Liver Disease in Mice Model

Introduction

Extensive research has focused on identifying effective treatments for NAFLD, with numerous bioactive peptide candidates showing significant promise. In this research, a long-acting esculentin-2CHa(1-30)-coated AuNPs (ESC-ABD-AuNPs) was developed and the applicability was evaluated for their use in the treatment of non-alcoholic fatty liver disease (NAFLD).

Methods

ESC-ABD-AuNPs were synthesized by adopting a 1-step reduction process and the successful preparation of the nanoparticles (NPs) was assessed by various physical characterizations including transmission electron microscopy (TEM), ultraviolet-visible (UV-VIS) absorption spectra, dynamic light scattering (DLS), and Fourier Transform Infrared Spectroscopy (FT-IR). After the ESC-ABD-AuNPs were prepared, cytotoxicity, pharmacokinetics (PK), and biodistribution profiles were identified. Then, with a high-fat diet (HFD)-fed obese mice model, efficacy studies were carried out focused on their effects for anti-hyperglycemia and anti-NAFLD. Furthermore, the feasibility of loading a small molecule onto the NPs was evaluated for potential combination therapy.

Results

ESC-ABD-AuNPs were synthesized with an average hydrodynamic size of 120 (±10) nm and demonstrated good stability and an extended plasma half-life of 28.3 h. The NPs exhibited high liver accumulation and were well tolerated in cell viability tests. In PK and biodistribution studies, ESC-ABD-AuNPs showed prolonged retention in major organs, such as the pancreas and the liver. Therapeutic efficacy was demonstrated in the HFD-fed obese mice, where the ESC-ABD-AuNPs significantly reduced blood glucose levels, improved glucose tolerance, and mitigated liver fat accumulation. The ESC-ABD-AuNPs platform also showed potential for combination therapies, demonstrated by its ability to load obeticholic acid (OCA), a farnesoid X receptor (FXR) agonist, found effective for the treatment of NAFLD in clinical studies.

Conclusion

Overall, this study has demonstrated the promising potential of ESC-ABD-AuNPs as a novel treatment for NAFLD. This research suggests that ESC-ABD-AuNPs could be a significant advancement in drug delivery and liver disease treatment, particularly for combination therapies.

Systemic aging and aging-related diseases

Aging is a biological process along with systemic and multiple organ dysfunction. It is more and more recognized that aging is a systemic disease instead of a single-organ functional disorder. Systemic aging plays a profound role in multiple diseases including neurodegenerative diseases, cardiovascular diseases, and malignant diseases. Aged organs communicate with other organs and accelerate aging. Skeletal muscle, heart, bone marrow, skin, and liver communicate with each other through organ-organ crosstalk. The crosstalk can be mediated by metabolites including lipids, glucose, short-chain fatty acids (SCFA), inflammatory cytokines, and exosomes. Metabolic disorders including hyperglycemia, hyperinsulinemia, and hypercholesterolemia caused by chronic diseases accelerate hallmarks of aging. Systemic aging leads to the destruction of systemic hemostasis, causes the release of inflammatory cytokines, senescence-associated secretory phenotype (SASP), and the imbalance of microbiota composition. Released inflammatory factors further aggregate senescence, which promotes the aging of multiple solid organs. Targeting senescence or delaying aging is emerging as a critical health strategy for solving age-related diseases, especially in the old population. In the current review, we will delineate the mechanisms of organ crosstalk in systemic aging and age-related diseases to provide therapeutic targets for delaying aging.

In vitro liver models for toxicological research

Drug-induced liver injury (DILI) presents a major challenge not only in new drug development but also in post-marketing withdrawals and the safety of food, cosmetics, and chemicals. Experimental model organisms such as the rodents have been widely used for preclinical toxicological testing. However, the tension exists associated with the ethical and sustainable use of animals in part because animals do not necessarily inform the human-specific ADME (adsorption, dynamics, metabolism and elimination) profiling. To establish alternative models in humans, in vitro hepatic tissue models have been proposed, ranging from primary hepatocytes, immortal hepatocytes, to the development of new cell resources such as stem cell-derived hepatocytes. Given the evolving number of novel alternative methods, understanding possible combinations of cell sources and culture methods will be crucial to develop the context-of-use assays. This review primarily focuses on 3D liver organoid models for conducting. We will review the relevant cell sources, bioengineering methods, selection of training compounds, and biomarkers towards the rationale design of in vitro toxicology testing.

Exploring the role of gut microbiota in colorectal liver metastasis through the gut-liver axis

Colorectal liver metastasis (CRLM) represents a major therapeutic challenge in colorectal cancer (CRC), with complex interactions between the gut microbiota and the liver tumor microenvironment (TME) playing a crucial role in disease progression via the gut-liver axis. The gut barrier serves as a gatekeeper, regulating microbial translocation, which influences liver colonization and metastasis. Through the gut-liver axis, the microbiota actively shapes the TME, where specific microbial species and their metabolites exert dual roles in immune modulation. The immunologically "cold" nature of the liver, combined with the influence of the gut microbiota on liver immunity, complicates effective immunotherapy. However, microbiota-targeted interventions present promising strategies to enhance immunotherapy outcomes by modulating the gut-liver axis. Overall, this review highlights the emerging evidence on the role of the gut microbiota in CRLM and provides insights into the molecular mechanisms driving the dynamic interactions within the gut-liver axis.

Why do lipid nanoparticles target the liver? Understanding of biodistribution and liver-specific tropism

Lipid nanoparticles (LNPs) are now highly effective transporters of nucleic acids to the liver. This liver-specificity is largely due to their association with certain serum proteins, most notably apolipoprotein E (ApoE), which directs them to liver cells by binding to the low-density lipoprotein (LDL) receptors on hepatocytes. The liver's distinct anatomy, with its various specialized cell types, also influences how LNPs are taken up from the circulation, cleared, and how effective they are in delivering treatments. In this review, we consider factors that facilitate LNP's effective liver targeting and explore the latest advances in liver-targeted LNP technologies. Understanding how LNPs are targeted to the liver can help for effective design and optimization of nanoparticle-based therapies. Comprehension of the cellular interaction and biodistribution of LNPs not only leads to better treatments for liver diseases but also delivers insight for directing nanoparticles to other tissues, potentially broadening their range of therapeutic applications.

Development of novel nucleic acid therapy aimed at directly controlling liver fibrosis

Currently, no drugs directly treat liver fibrosis. Previously, we have shown that treatment with miR-29a-3p improved liver fibrosis in a mouse model. To investigate the effectiveness of nucleic acid therapy at a lower dose, a modified nucleic acid was prepared based on miR-29a-3p. The original microRNA was changed to an RNA-DNA hybrid structure: the 2' position of the RNA was modified with a fluorine base, and locked nucleic acid and phosphorothioate were crosslinked (hereafter called modified nucleic acid). In a mouse model of chronic liver disease treated with carbon tetrachloride (CCl4), the inhibitory effect on liver fibrosis was evaluated with oral administration of the modified nucleic acid. The modified nucleic acid was detected in the liver and gastrointestinal tract within 15 min of oral administration. After 5 weeks of stimulation with CCl4, oral administration of the modified nucleic acid for 2 weeks improved liver fibrosis; CCl4 stimulation was continued during this period as well. This treatment also suppressed the worsening of liver fibrosis. We developed a method to improve liver fibrosis orally using nuclease-resistant nucleic acids without using a drug delivery system. This method may be used as a new treatment for inhibiting the progression of liver fibrosis.

Advances of dual-organ and multi-organ systems for gut, lung, skin and liver models in absorption and metabolism studies

Drug development is a costly and timely process with high risks of failure during clinical trials. Although in vitro tissue models have significantly advanced over the years, thus fostering a transition from animal-derived models towards human-derived models, failure rates still remain high. Current cell-based assays are still not able to provide an accurate prediction of the clinical success or failure of a drug candidate. To overcome the limitations of current methods, a variety of microfluidic systems have been developed as powerful tools that are capable of mimicking (micro)physiological conditions more closely by integrating physiological fluid flow conditions, mechanobiological cues and concentration gradients, to name only a few. One major advantage of these biochip-based tissue cultures, however, is their ability to seamlessly connect different organ models, thereby allowing the study of organ-crosstalk and metabolic byproduct effects. This is especially important when assessing absorption, distribution, metabolism, and excretion (ADME) processes of drug candidates, where an interplay between various organs is a prerequisite. In the current review, a number of in vitro models as well as microfluidic dual- and multi-organ systems are summarized with a focus on absorption (skin, lung, gut) and metabolism (liver). Additionally, the advantage of multi-organ chips in identifying a drug's on and off-target toxicity is discussed. Finally, the potential high-throughput implementation and modular chip design of multi-organ-on-a-chip systems within the pharmaceutical industry is highlighted, outlining the necessity of reducing handling complexity.

Research Progress on the Immune Function of Liver Sinusoidal Endothelial Cells in Sepsis

Sepsis is a complex clinical syndrome closely associated with the occurrence of acute organ dysfunction and is often characterized by high mortality. Due to the rapid progression of sepsis, early diagnosis and intervention are crucial. Recent research has focused on exploring the pathological response involved in the process of sepsis. Liver sinusoidal endothelial cells (LSECs) are a special type of endothelial cell and an important component of liver non-parenchymal cells. Unlike general endothelial cells, which mainly provide a barrier function within the body, LSECs also have important functions in the clearance and regulation of the immune response. LSECs are not only vital antigen-presenting cells (APCs) in the immune system but also play a significant role in the development of infectious diseases and tumors through their specific immune regulatory pathways. However, in certain disease states, the functions of LSECs may be impaired, leading to immune imbalance and the development of organ failure. Investigating the immune pathways of LSECs in sepsis may provide new solutions for the prevention and treatment of sepsis and is crucial for maintaining microcirculation and improving patient outcomes.

The potential roles of gut microbiome in porto-sinusoidal vascular disease: an under-researched crossroad

Accumulating evidence indicates that patients with liver diseases exhibit distinct microbiological profiles, which can be attributed to the bidirectional relationship of the gut-liver axis. Porto-sinusoidal vascular disease (PSVD) has recently been introduced to describe a group of vascular diseases of the liver, involving the portal venules and sinusoids. Although the pathophysiology of PSVD is not yet fully understood, several predisposing conditions, including immunodeficiency, inflammatory bowel disease, abdominal bacterial infections are associated with the increasing in intestinal permeability and microbial translocation, supporting the role of altered gut microbiota and gut-derived endotoxins in PSVD etiopathogenesis. Recent studies have proposed that the gut microbiome may play a crucial role in the pathophysiology of intrahepatic vascular lesions, potentially influencing the onset and progression of PSVD in this context. This review aims to summarize the current understanding of the gut microbiome's potential role in the pathogenesis of hepatic microvascular abnormalities and thrombosis, and to briefly describe their interactions with PSVD. The insights into gut microbiota and their potential influence on the onset and progression of PSVD may pave the way for new diagnostic, prognostic, and therapeutic strategies.

Chenodeoxycholic acid modulates cholestatic niche through FXR/Myc/P-selectin axis in liver endothelial cells

Cholestatic liver diseases are characterized by excessive bile acid accumulation in the liver. Endothelial cells (ECs) shape the local microenvironment in both normal conditions and liver injury, yet their role in cholestasis is unclear. Through a comparative analysis of single-cell RNA sequencing data from various murine models of liver injury, we identify distinctive Myc activation within ECs during obstructive cholestasis resulting from bile duct ligation (BDL). Myc overexpression in ECs significantly upregulates P-selectin, increasing neutrophil infiltration and worsening cholestatic liver injury. This process occurs through the FXR, activated by chenodeoxycholic acid (CDCA) and its conjugate TCDCA. Inhibiting P-selectin with PSI-697 reduces neutrophil recruitment and alleviates injury. Cholestatic patient liver samples also show elevated Myc and P-selectin in ECs, along with increased neutrophils. The findings identify ECs as key drivers of cholestatic liver injury through a Myc-driven program and suggest that targeting the CDCA/FXR/Myc/P-selectin axis may offer a therapeutic approach.

Endoplasmic reticulum stress in liver fibrosis: Mechanisms and therapeutic potential

This paper reviews the important role of endoplasmic reticulum stress in the patho mechanism of liver fibrosis and its potential as a potential target for the treatment of liver fibrosis. Liver fibrosis is the result of sustained inflammation and injury to the liver due to a variety of factors, triggering excessive deposition of extracellular matrix and fibrous scar formation, which in turn leads to loss of liver function and a variety of related complications. Endoplasmic reticulum stress is one of the characteristics of chronic liver disease and is closely related to the pathological process of chronic liver disease, including alcohol-related liver disease, viral hepatitis, and liver fibrosis. The unfolded protein response is one of the important response mechanisms to endoplasmic reticulum stress. It is associated with several pathological aspects of liver fibrosis and the maintenance of endoplasmic reticulum homeostasis. Interventions targeting endoplasmic reticulum stress for the treatment of liver fibrosis have potential research and application value. An in-depth understanding of the biological basis of endoplasmic reticulum stress is also needed in the treatment of liver fibrosis, as well as the development of more effective drugs and interventions to accurately regulate the endoplasmic reticulum signaling network, to achieve the restoration and maintenance of endoplasmic reticulum homeostasis at the cellular and organ levels, and to further promote the reversal of the pathological process of liver fibrosis.

Pathogenetic development, diagnosis and clinical therapeutic approaches for liver metastasis from colorectal cancer (Review)

Colorectal cancer (CRC) is a prevalent malignancy and a significant proportion of patients with CRC develop liver metastasis (CRLM), which is a major contributor to CRC‑related mortality. The present review aimed to comprehensively examine the pathogenetic development and diagnosis of CRLM and the clinical therapeutic approaches for treatment of this disease. The molecular mechanisms underlying CRLM were discussed, including the role of the tumour microenvironment and epithelial‑mesenchymal transition. The present review also highlighted the importance of early detection and the current challenges in predicting the development of CRLM. Various treatment strategies were reviewed, including surgical resection, chemotherapy and immunotherapy, and the potential of novel therapies, such as selective internal radiation therapy and Traditional Chinese Medicine. Despite recent advancements in treatment options, the treatment of CRLM remains a therapeutic challenge due to the complexity of the liver microenvironment and the heterogeneity of CRC. The present review emphasized the need for a multidisciplinary approach and the integration of emerging therapies to improve patient outcomes.

Anti-Endoglin monoclonal antibody prevents the progression of liver sinusoidal endothelial inflammation and fibrosis in MASH

Liver sinusoidal endothelial inflammation/dysfunction and fibrosis are a crucial part of Metabolic Dysfunction Associated Steatohepatitis (MASH) development. TRC105 and M1043 are anti-endoglin (ENG) monoclonal antibodies that bind ENG. In this study, we hypothesized that treatment with anti-ENG antibodies would prevent the progression of LSECs inflammation and fibrosis in vivo and in vitro. MASH was induced in male C57BL/6 mice fed a choline-deficient L-amino acid-defined high-fat diet (CDAA-HFD) for 4 or 8 weeks. In the rescue study, mice were divided into three groups: a control group (chow diet), a MASH group (CDAA-HFD + IgG), and a rescue group (CDAA-HFD + M1043). Later, two groups received rat IgG1 (10 mg/kg) and M1043 (10 mg/kg). In in vitro experiments, inflammation was induced in human LSECs by ox-LDL (50 μg/mL) and treated with TRC105 (300 μg/mL). Liver sinusoidal endothelial inflammation/dysfunction in MASH animals was characterized by endothelial overexpression of ENG, VCAM-1, and ICAM-1 and reduced VE-cadherin and p-eNOS/eNOS expression. M1043 treatment prevented the overexpression of ENG, VCAM-1, and ICAM-1, the progression of liver fibrosis, and the increase of liver-to-body weight ratio. In vitro experiments with TRC105 confirmed the prevention of LSECs inflammation development by reduced ENG and VCAM-1 expression, as well as decreased THP-1 monocytic cell adhesion in ox-LDL activated LSECs. In conclusion, we demonstrate that anti-ENG antibody treatment can prevent LSECs inflammation and fibrosis progression in a MASH animal model and LSECs inflammation in vitro. Thus, we propose directly targeted ENG may represent a promising pharmacological approach for addressing LSECs inflammation and liver fibrosis.

A guide to pathophysiology, signaling pathways, and preclinical models of liver fibrosis

Liver fibrosis is potentially a reversible form of liver disease that evolved from the early stage of liver scarring as a consequence of chronic liver injuries. Recurrent injuries in the liver without any appropriate medication cause the injuries to get intense and deeper, which gradually leads to the progression of irreversible cirrhosis or carcinoma. Unfortunately, there are no approved treatment strategies for reversing hepatic fibrosis, making it one of the significant risk factors for developing advanced liver disorders and liver disease-associated mortality. Consequently, the interpretation of the fundamental mechanisms, etiology, and pathogenesis is crucial for identifying the potential therapeutic target as well as evaluating novel anti-fibrotic therapy. However, despite innumerable research, the functional mechanism and disease characteristics are still obscure. To accelerate the understanding of underlying disease pathophysiology, molecular pathways and disease progression mechanism, it is crucial to mimic human liver disease through the formation of precise disease models. Although various in vitro and in vivo liver fibrotic models have emerged and developed already, a perfect clinical model replicating human liver diseases is yet to be established, which is one of the major challenges in discovering proper therapeutics. This review paper will shed light on pathophysiology, signaling pathways, preclinical models of liver fibrosis, and their limitations.

Developing mRNA Nanomedicines with Advanced Targeting Functions

The emerging messenger RNA (mRNA) nanomedicines have sprung up for disease treatment. Developing targeted mRNA nanomedicines has become a thrilling research hotspot in recent years, as they can be precisely delivered to specific organs or tissues to enhance efficiency and avoid side effects. Herein, we give a comprehensive review on the latest research progress of mRNA nanomedicines with targeting functions. mRNA and its carriers are first described in detail. Then, mechanisms of passive targeting, endogenous targeting, and active targeting are outlined, with a focus on various biological barriers that mRNA may encounter during in vivo delivery. Next, emphasis is placed on summarizing mRNA-based organ-targeting strategies. Lastly, the advantages and challenges of mRNA nanomedicines in clinical translation are mentioned. This review is expected to inspire researchers in this field and drive further development of mRNA targeting technology.

Molecular mechanisms in liver repair and regeneration: from physiology to therapeutics

Liver repair and regeneration are crucial physiological responses to hepatic injury and are orchestrated through intricate cellular and molecular networks. This review systematically delineates advancements in the field, emphasizing the essential roles played by diverse liver cell types. Their coordinated actions, supported by complex crosstalk within the liver microenvironment, are pivotal to enhancing regenerative outcomes. Recent molecular investigations have elucidated key signaling pathways involved in liver injury and regeneration. Viewed through the lens of metabolic reprogramming, these pathways highlight how shifts in glucose, lipid, and amino acid metabolism support the cellular functions essential for liver repair and regeneration. An analysis of regenerative variability across pathological states reveals how disease conditions influence these dynamics, guiding the development of novel therapeutic strategies and advanced techniques to enhance liver repair and regeneration. Bridging laboratory findings with practical applications, recent clinical trials highlight the potential of optimizing liver regeneration strategies. These trials offer valuable insights into the effectiveness of novel therapies and underscore significant progress in translational research. In conclusion, this review intricately links molecular insights to therapeutic frontiers, systematically charting the trajectory from fundamental physiological mechanisms to innovative clinical applications in liver repair and regeneration.

Liver diseases: epidemiology, causes, trends and predictions

As a highly complex organ with digestive, endocrine, and immune-regulatory functions, the liver is pivotal in maintaining physiological homeostasis through its roles in metabolism, detoxification, and immune response. Various factors including viruses, alcohol, metabolites, toxins, and other pathogenic agents can compromise liver function, leading to acute or chronic injury that may progress to end-stage liver diseases. While sharing common features, liver diseases exhibit distinct pathophysiological, clinical, and therapeutic profiles. Currently, liver diseases contribute to approximately 2 million deaths globally each year, imposing significant economic and social burdens worldwide. However, there is no cure for many kinds of liver diseases, partly due to a lack of thorough understanding of the development of these liver diseases. Therefore, this review provides a comprehensive examination of the epidemiology and characteristics of liver diseases, covering a spectrum from acute and chronic conditions to end-stage manifestations. We also highlight the multifaceted mechanisms underlying the initiation and progression of liver diseases, spanning molecular and cellular levels to organ networks. Additionally, this review offers updates on innovative diagnostic techniques, current treatments, and potential therapeutic targets presently under clinical evaluation. Recent advances in understanding the pathogenesis of liver diseases hold critical implications and translational value for the development of novel therapeutic strategies.

The role of liver sinusoidal endothelial cells in metabolic dysfunction-associated steatotic liver diseases and liver cancer: mechanisms and potential therapies

Liver sinusoidal endothelial cells (LSECs), with their unique morphology and function, have garnered increasing attention in chronic liver disease research. This review summarizes the critical roles of LSECs under physiological conditions and in two representative chronic liver diseases: metabolic dysfunction-associated steatotic liver disease (MASLD) and liver cancer. Under physiological conditions, LSECs act as selective barriers, regulating substance exchange and hepatic blood flow. Interestingly, LSECs exhibit contrasting roles at different stages of disease progression: in the early stages, they actively resist disease advancement and help restore sinusoidal homeostasis; whereas in later stages, they contribute to disease worsening. During this transition, LSECs undergo capillarization, lose their characteristic markers, and become dysfunctional. As the disease progresses, LSECs closely interact with hepatocytes, hepatic stellate cells, various immune cells, and tumor cells, driving processes such as steatosis, inflammation, fibrosis, angiogenesis, and carcinogenesis. Consequently, targeting LSECs represents a promising therapeutic strategy for chronic liver diseases. Relevant therapeutic targets and potential drugs are summarized in this review.

A deep learning framework for in silico screening of anticancer drugs at the single-cell level

Tumor heterogeneity plays a pivotal role in tumor progression and resistance to clinical treatment. Single-cell RNA sequencing (scRNA-seq) enables us to explore heterogeneity within a cell population and identify rare cell types, thereby improving our design of targeted therapeutic strategies. Here, we use a pan-cancer and pan-tissue single-cell transcriptional landscape to reveal heterogeneous expression patterns within malignant cells, precancerous cells, as well as cancer-associated stromal and endothelial cells. We introduce a deep learning framework named Shennong for in silico screening of anticancer drugs for targeting each of the landscape cell clusters. Utilizing Shennong, we could predict individual cell responses to pharmacologic compounds, evaluate drug candidates' tissue damaging effects, and investigate their corresponding action mechanisms. Prioritized compounds in Shennong's prediction results include FDA-approved drugs currently undergoing clinical trials for new indications, as well as drug candidates reporting anti-tumor activity. Furthermore, the tissue damaging effect prediction aligns with documented injuries and terminated discovery events. This robust and explainable framework has the potential to accelerate the drug discovery process and enhance the accuracy and efficiency of drug screening.

Liver organoids: Current advances and future applications for hepatology

The creation of self-organizing liver organoids represents a significant, although modest, step toward addressing the ongoing organ shortage crisis in allogeneic liver transplantation. However, researchers have recognized that achieving a fully functional whole liver remains a distant goal, and the original ambition of organoid-based liver generation has been temporarily put on hold. Instead, liver organoids have revolutionized the field of hepatology, extending their influence into various domains of precision and molecular medicine. These 3D cultures, capable of replicating key features of human liver function and pathology, have opened new avenues for human-relevant disease modeling, CRISPR gene editing, and high-throughput drug screening that animal models cannot accomplish. Moreover, advancements in creating more complex systems have led to the development of multicellular assembloids, dynamic organoid-on-chip systems, and 3D bioprinting technologies. These innovations enable detailed modeling of liver microenvironments and complex tissue interactions. Progress in regenerative medicine and transplantation applications continues to evolve and strives to overcome the obstacles of biocompatibility and tumorigenecity. In this review, we examine the current state of liver organoid research by offering insights into where the field currently stands, and the pivotal developments that are shaping its future.

Advances in intrahepatic and extrahepatic vascular dysregulations in cirrhotic portal hypertension

Cirrhotic portal hypertension, the most prevalent and clinically significant complication of liver cirrhosis, manifests as elevated portal venous pressure and is associated with severe complications. Although much research on the mechanisms of portal hypertension has focused on liver fibrosis, less attention has been given to the role of intrahepatic and extrahepatic vascular dysfunction, particularly with respect to extrahepatic vasculature. While the role of hepatic fibrosis in cirrhotic portal hypertension is undeniable, the underlying mechanisms involving intrahepatic and extrahepatic vasculature are highly complex. Sinusoidal capillarization and endothelial dysfunction contribute to increased intrahepatic vascular resistance. Hemodynamic changes in the extrahepatic circulation, including splanchnic vasodilation and hyperdynamic circulation, play a significant role in the development of portal hypertension. Additionally, therapeutic strategies targeting these vascular mechanisms are diverse, including improvement of sinusoidal microcirculation, therapies targeting hepatic stellate cells activation, and pharmacological modulation of systemic vascular tone. Therefore, in this review, we will discuss the vascular-related mechanisms and treatment progress of portal hypertension in cirrhosis to provide a new theoretical basis and practical guidance for clinical treatment.

Modular cone-and-plate device for mechanofluidic assays in Transwell inserts

In this work, we present a cost effective and open-source modular cone-and-plate (MoCAP) device that incorporates shear stress in the popular Transwell® insert system. This system acts as a lid that incorporates flow into 24-well Transwell® inserts while preserving the ability to conduct molecular profiling assays. Moreover, the MoCAP device can be rapidly reconfigured to test multiple shear stress profiles within a single device. To demonstrate the utility of the MoCAP, we conducted select assays on several different brain microvascular endothelial cell (BMEC) lines that comprise models of the blood-brain barrier (BBB), since shear stress can play an important role in BBB function. Our results characterize how shear stress modulates passive barrier function and GLUT1 expression across the different BMEC lines. Overall, we anticipate this low cost mechanofluidic device will be useful to the mechanobiology community.

Effects of Astragaloside IV and Formononetin on Oxidative Stress and Mitochondrial Biogenesis in Hepatocytes

Over-accumulation of reactive oxygen species (ROS) causes hepatocyte dysfunction and apoptosis that might lead to the progression of liver damage. Sirtuin-3 (SIRT3), the main NAD+-dependent deacetylase located in mitochondria, has a critical role in regulation of mitochondrial function and ROS production as well as in the mitochondrial antioxidant mechanism. This study explores the roles of astragaloside IV (AST-IV) and formononetin (FMR) in connection with SIRT3 for potential antioxidative effects. It was shown that the condition of combined pre- and post-treatment with AST-IV or FMR at all concentrations statistically increased and rescued cell proliferation. ROS levels were not affected by pre-or post-treatment individually with AST-IV or pre-treatment with FMR; however, post-treatment with FMR resulted in significant increases in ROS in all groups. Significant decreases in ROS levels were seen when pre- and post-treatment with AST-IV were combined at 5 and 10 μM, or FMR at 5 and 20 μM. In the condition of combined pre- and post-treatment with 10 μM AST-IV, there was a significant increase in SOD activity, and the transcriptional levels of Sod2, Cat, and GPX1 in all treatment groups, which is indicative of reactive oxygen species detoxification. Furthermore, AST-IV and FMR activated PGC-1α and AMPK as well as SIRT3 expression in AML12 hepatocytes exposed to t-BHP-induced oxidative stress, especially at high concentrations of FMR. This study presents a novel mechanism whereby AST-IV and FMR yield an antioxidant effect through induction of SIRT3 protein expression and activation of an antioxidant mechanism as well as mitochondrial biogenesis and mitochondrial content and potential. The findings suggest these agents can be used as SIRT3 modulators in treating oxidative-injury hepatocytes.