Liver Regeneration Research Articles (Page 1)

Liver is endowed with high regenerative activity, so that the tissue regrows in mouse after partial hepatectomy within days. We reason that this requires de novo pyrimidine synthesis to support rapid progression via the cell cycle. We find that suppression of de novo pyrimidine synthesis prevents proliferation in regenerating liver, suppressing liver regrowth. Tracing studies and spatial metabolomics reveal a metabolic shift such that ammonia, normally detoxified to urea in the periportal region under homeostasis, is redirected for generating aspartate and carbamoyl phosphate periportally, and glutamine pericentrally, and these products are utilized as precursors by the de novo pyrimidine synthesis pathway. Our research uncovers a metabolic reprogramming leading to utilization of a toxic byproduct for anabolic pathways that are essential for liver regeneration.

The liver possesses a remarkable capacity for regeneration. Previous studies have shown that SOX9/HNF4α double-positive hepatocytes play a role in chronic liver injury. Furthermore, the deletion of HNF4α results in prolonged hepatocyte proliferation following partial hepatectomy. However, the precise role of SOX9 in liver regeneration remains poorly understood. We established acute liver injury models using standard partial hepatectomy (sHx), extended partial hepatectomy (eHx), and intraperitoneal injection of carbon tetrachloride (CCl4). To investigate the interplay between HNF4α and SOX9, we employed hepatocyte-specific Hnf4α knockout (Hnf4αHKO) and Sox9 knockout (Sox9HKO) mice. We assessed how SOX9 influenced liver regeneration in Sox9HKO and SOX9-overexpressing (Sox9HOE) mice. Our study found that SOX9 expression was increased, while HNF4α expression decreased in the priming phase of acute liver injury. HNF4α suppressed SOX9 expression by upregulating miR-124/381 in hepatocytes. Deletion of SOX9 in hepatocytes resulted in a reduced liver-to-body weight ratio and impaired hepatocyte proliferation in both sHx- and CCl4-treated mice. Conversely, hepatocyte-specific SOX9 overexpression improved survival rates in eHx-treated mice. Single-nucleus RNA sequencing of liver tissue and bulk RNA sequencing of hepatocytes from sHx-treated Sox9HKO mice revealed that SOX9 upregulated TGF-α expression in hepatocytes. Co-culture experiments further indicated that SOX9 overexpression enhanced the hepatocyte proliferation by promoting TGF-α secretion. Importantly, inhibiting TGF-α-induced EGFR activation partially reduced the pro-proliferative effects of SOX9 on hepatocytes and the survival rates by SOX9 overexpression in eHx-treated mice. Our findings revealed that HNF4α negatively regulates SOX9 and demonstrated that SOX9 promotes hepatocyte proliferation by upregulating TGF-α levels, ultimately enhancing liver regeneration.

The therapeutic potential of astaxanthin is limited by its poor water solubility, which restricts its bioavailability and clinical translation. To overcome this limitation, an astaxanthin nanoemulsion (NEAX) was developed to enhance its oral delivery and hepatic targeting. The efficacy was evaluated in a hepatotoxicity model using physiological parameters and 1H-NMR serum metabolomics analyzed through Orthogonal Partial Least-Squares Discrimination Analysis (OPLS-DA). Wistar rats with thioacetamide-induced liver injury (150mg/kg, i.p., twice weekly × 6weeks) received oral astaxanthin (15mg/kg) for 4weeks as oil suspension (AX) or lecithin-based NEAX. Both treatments reduced serum transaminases, but only NEAX significantly increased hepatic antioxidant activity. The metabolomics analysis of biomarkers associated with liver damage and regeneration showed changes promoted by AX and NEAX. It also revealed that NEAX reversed liver damage by promoting restoration of metabolites involved in energy and lipid metabolism while limiting fatty acid β-oxidation and increasing metabolites associated with phospholipid insertion in the cellular membrane during liver regeneration, previously not reported for astaxanthin. These findings demonstrate that nanoemulsion delivery systems enhance the therapeutic effects of AX, advancing the development of hepatoprotective therapies based on nanoformulation strategies. They also highlight the potential of metabolomics to understand the mechanisms of hepatic damage and its treatment.

Constitutive androstane receptor activation modulates YAP expression and activity through ubiquitination and sumoylation.

Scientists around the world are focusing on 'green,' environmentfriendly, and cost-effective green synthesis of nanometals using various plant extracts to combat various ailments. Among nanometals, Silver (Ag) is one of the most commercialised nanomaterials due to its wide applications in biotechnology and biomedical fields. The present study reports the first facile synthesis, characterization, and process optimisation of Ag nanoparticles (NPs) using aqueous Grewia tiliaefolia leaf extract (Gt) as a reducing and surface functionalising agent. Characterisation of Gt-mediated Ag-NPs was performed using FTIR. The morphology and microstructures of Gt-derived Ag-NPs were analysed using TEM and FE-SEM. In vitro, antioxidant activity was evaluated against DPPH radicals, hydrogen peroxide radicals, and ferric ions. In vitro, anticancer activity was assessed on MCF-7 and HepG2 cell lines. In vivo, hepatoprotective activity was tested against paracetamol-induced liver toxicity in rats. FTIR analysis confirmed the interaction between Ag-NPs and Gt. The optimal conditions for Gt-derived Ag-NPs were found to be 4 mM AgNO3, 5% Gt, at 90°C for 60 minutes, at pH 9. UV-Visible spectroscopy, XRD, FE-SEM, and TEM revealed the phase formation, spherical morphology, and surface functionalisation of Gt-derived Ag-NPs, which were stable (-28.3 mV) with an average particle size of 14.5±0.05 nm. The Gt-derived Ag-NPs were found to be highly effective in significantly inhibiting DPPH radical, ferric ions, and hydroxyl radicals. Additionally, the cytotoxicity of Gt-derived Ag-NPs was more effective against MCF-7 cells compared to HepG2 cells. They also exhibited dose-dependent protection against hepatoprotective activity in albino rats. The hepatoprotective effects of Gt-mediated Ag-NPs likely result from the combined action of bioactive phytochemicals (such as α/β-amyrin, γ-lactones, betulin, and lupeol), and their ability to scavenge ROS, reduce oxidative stress, and modulate inflammatory pathways. These mechanisms, supported by reduced lipid peroxidation and increased antioxidant activity in paracetamol-induced hepatotoxicity, suggest their therapeutic potential in liver protection and regeneration. Overall, Gt proves to be an eco-friendly and non-toxic source for synthesizing bioactive Ag-NPs at optimal conditions.

Remnant-liver surface delivery of pHGF via dissolving hyaluronic-acid microneedle patches for post-hepatectomy liver regeneration.

The immunomodulatory oligodeoxynucleotide (ODN) IMT504 exhibits antifibrotic and pro-regenerative properties in the context of liver fibrosis. It also enhances the contribution of GLAST+ Wnt1+ bone marrow stromal progenitors (BMSPs) to liver regeneration in a mouse model of chronic liver disease. In this study, partial hepatectomy (PHx) was performed in CD1 mice. In parallel, Cre-loxP mice were used to identify GLAST+ Wnt1+ BMSPs and assess their contribution to liver cells populations. A combination of in vivo and in vitro assays was conducted. IMT504 significantly enhanced liver mass recovery following PHx by promoting both early and late induction of hepatocyte proliferation. The expression dynamics of genes associated with proliferation, liver function, and liver progenitor identity were analyzed. Moreover, IMT504 stimulated the pro-regenerative activity of GLAST+ Wnt1+ BMSPs by promoting their differentiation into liver cells. In summary, our findings identify IMT504 as a promising therapeutic candidate with strong pro-regenerative potential. Additionally, our data suggest that GLAST+ Wnt1+ BMSPs represent a unique bone marrow-derived population capable of giving rise to liver cells, further supporting their pro-regenerative role in liver regeneration.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-22097-w.

The liver is a highly versatile and resilient organ that is crucial for metabolism, detoxification, digestion, and immune regulation. Its remarkable regenerative capacity is driven primarily by two key cellular processes: hepatocyte polyploidy and cellular senescence. This review explores the complex roles of polyploidy, in which hepatocytes possess multiple chromosome sets, and senescence, characterized by irreversible cell cycle arrest, in maintaining liver homeostasis and facilitating regeneration. Polyploid hepatocytes increase genetic and metabolic diversity, enabling the liver to withstand stress and recover from injury through mechanisms such as compensatory regeneration, depolyploidization, and the fusion of extrinsic stem cells. Concurrently, cellular senescence acts as a protective barrier against uncontrolled cell proliferation and genomic instability while also promoting tissue repair via the senescence-associated secretory phenotype (SASP). The interplay between polyploidy and senescence is regulated by critical molecular pathways, including the Hippo, PI3K/Akt, and p53 signaling pathways, which balance cell proliferation, differentiation, and apoptosis. Additionally, this review discusses the therapeutic potential of targeting these processes to increase liver regeneration, prevent fibrosis, and reduce the risk of hepatocellular carcinoma (HCC). Emerging strategies such as senolytic drugs, stem cell therapies, and cytokine modulation offer promising avenues for treating chronic liver diseases. However, challenges remain in fully understanding the functional distinctions between diploid and polyploid hepatocytes and managing the dual roles of senescence. Future research should focus on molecular insights and targeted interventions to optimize liver health and regenerative outcomes.

BackgroundThe liver is an organ with a strong regenerative capacity. Currently, partial hepatectomy (PHx) remains the most effective treatment option within various therapeutic strategies for liver diseases. When the liver undergoes acute injury, such as PHx, the remaining hepatocytes become hypertrophic, re-enter the cell cycle, initiate proliferation, and restore liver function. However, identifying the role of adult hepatic stem/progenitor cells (HSPCs) in this repair process remains challenging.MethodsIn this study, liver fibrosis was induced in mice by subcutaneous injection of carbon tetrachloride (CCl4) into the back for 8 weeks. Subsequently, 2/3 PHx was used to establish a fibrotic PHx model. Samples were collected at 12 h, 24 h, 48 h, 4 d, and 7 d after PHx. The expression of HSPC-associated markers, including Afp, Dlk1, Ki67, and Lgr5, was analysed using quantitative real-time PCR (qRT-PCR) and immunofluorescence.ResultsGene expression analysis revealed that the higher concentration of AFP⁺/DLK1⁺ double-positive cells was in the 50–70% Percoll layer, isolated via density gradient differential centrifugation. Pre-injection of CCl4 promoted liver regeneration after 2/3 PHx, with a peak regenerative phase observed at 24–48 h. Experimental results demonstrated that AFP+/DLK1+ double-positive cells exhibit stem cell-like properties and are involved in liver regeneration. Interestingly, adult and embryonic HSPCs were found in distinct Percoll layers and required different in vitro culture conditions.ConclusionsAFP and DLK1 serve as potential markers for selecting HSPC-like populations from the fibrotic PHx model. Our findings indicate that the fibrotic liver exhibits the most vigorous regenerative activity at 48 h after PHx, making it the optimal period for the isolation and extraction of HSPC-like cells which refers only to marker expression and proliferation, the relevance of the findings presented herein remains to be further verified.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13287-025-04728-1.

Background/AimDespite advances in critical care, postoperative liver failure remains a substantial complication of liver resection, with high mortality rates. Adipose-derived stem cells (ADSCs) have demonstrated potential in various regenerative applications; however, their precise mechanisms in liver repair remain unclear. This study investigated the effects of ADSC sheets on the vascular and cellular responses in a mouse model of partial hepatectomy.Materials and MethodsHuman ADSCs were cultured with magnetic nanoparticle-containing liposomes and formed multilayered cell sheets. Following partial hepatectomy in BALB/c nude mice, ADSC or collagen control sheets were attached to liver resection sites. Immunohistochemical analysis assessed angiogenesis (CD31), hepatic stellate cell activation (α-SMA), and cellular origin. Mice were sacrificed on postoperative days 4 and 7. Statistical analysis was conducted using Bonferroni's method (p<0.05).ResultsCompared to cell-free collagen sheets (control), ADSC sheets demonstrated significantly enhanced neovascularization, with higher CD31 expression on postoperative days 4 and 7. Immunohistochemical analysis revealed that these CD31-positive cells were predominantly of mouse origin, rather than differentiated from transplanted human ADSCs, indicating host cell migration into the sheets. Additionally, ADSC sheets significantly increased α-SMA expression compared to that with collagen sheets, with expression levels progressively increasing from day 4 to 7, suggesting continuous activation of hepatic stellate cells. These findings indicate that ADSC sheets induce angiogenesis and hepatic stellate cell activation during liver regeneration, likely through paracrine mechanisms that recruit host cells, rather than through direct differentiation of transplanted ADSCs.ConclusionThis study lays the groundwork for the clinical application of ADSC sheets, demonstrating their potential to enhance liver regeneration after hepatectomy by promoting host cell-mediated angiogenesis and hepatic stellate cell activation.

Liver diseases are leading causes of death and disability worldwide. Therefore, the development of new treatments for liver disease is urgent. An integral part of the treatment of any liver disease is the process of regeneration of its parenchyma. However, the current approach to studying mammalian liver regeneration is one-sided, focusing solely on the liver itself and neglecting its interactions with other organs. This includes organs of the functional excretory system, such as the lungs and kidneys, which can secrete factors, including HGF, EGF, TGFβ, IL6, and others, into the bloodstream, which influence reparative processes in the liver. Only a few studies exist in this area. However, without a systematic approach to studying liver regeneration, it is impossible to develop new and effective methods to stimulate its regeneration. This review presents data on the interaction of the regenerating liver with the nervous, endocrine, and immune systems, as well as with the lungs, kidneys, and intestines.

Cell networks in the mouse liver during partial hepatectomy.

This study investigates the morphofunctional changes in two primary lymphoid organs of birds, the thymus and the bursa of Fabricius, during liver regeneration following partial hepatectomy. As a central immune organ, the thymus exhibited pronounced reactive responses as early as the first postoperative day, including cortical aplasia, apoptotic cell death, increased cyst formation. By days 3–5, signs of structural restoration appeared, marked by lymphocyte proliferation, formation of follicle-like clusters, and active mitotic division of lymphoblasts, resembling germinal centers typically found in peripheral lymphoid tissues. These regenerative processes became less prominent by day 10 but remained detectable up to day 30. In the bursa of Fabricius, an initial decrease in organ mass and lymphocyte density within follicles was observed, indicative of a stress-induced involutional response. However, by days 10–20, a significant increase in bursal mass (up to 174% of baseline) was recorded, along with epithelial hyperplasia and recovery of lymphoid components, pointing to functional activation of the organ. Together, these findings demonstrate that both the thymus and the bursa of Fabricius actively participate in the systemic immune response during liver regeneration. Their coordinated involvement suggests a complex immunomodulatory role, emphasizing the interdependence between the immune and hepatic systems in birds and highlighting potential directions for future studies in avian regenerative biology and immunology.

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.

Various methionine metabolites used in the treatment of experimental liver diseases in animals demonstrate hepatoprotective properties. The prophylactic use of choline was shown to provide intensive liver regeneration. In this study, we aim to evaluate the hepatoprotective effects of choline bitartrate in piglets, with an assessment of cytokine expression associated with the hepatobiliary system. The research was conducted using experimental pigs reared at the age of 45 days, which corresponds to the period of their early development. The use of choline bitartrate significantly reduces the expression of β transforming growth factor (TGF-β1) and pro-inflammatory interleukin 6 (IL-6) genes, at the same time as providing a significant reduction in total cholesterol and a proportional increase in HDL concentration, which is a classical anti-atherogenic factor.

Background Posthepatectomy liver failure (PHLF) remains a leading cause of morbidity and mortality following major liver resection. Despite advances in surgical techniques and perioperative care, treatment options for PHLF are limited. Pharmacological interventions targeting ischemia-reperfusion injury and portal flow modulation have gained interest as potential therapeutic strategies. Summary This review provides a clinically applicable overview of the current evidence on pharmacological management of PHLF. Perioperative glucocorticoids may reduce inflammatory complications and lower PHLF incidence, though patient selection is crucial. N-acetylcysteine demonstrates antioxidant effects in experimental models and omega-3 fatty acids reduce inflammation, but both lack clinical efficacy. Somatostatin and terlipressin, which modulate portal hemodynamics, have shown promise in preclinical and early-phase clinical studies; however, randomized trials have yet to confirm their benefit in reducing PHLF. Non-selective beta-blockers impair liver regeneration in preclinical models and are not recommended post-hepatectomy. Early postoperative heparin administration and hyperinsulinemic-normoglycemic strategies have been associated with reduced PHLF but require further validation. Key Messages While perioperative glucocorticoids may reduce PHLF risk in selected patients, other pharmacological agents show theoretical or preliminary promise, but cannot be routinely recommended based on current evidence. Prospective clinical trials are needed to establish effective pharmacological strategies for the prevention and treatment of PHLF.

ABSTRACT Being a major contributor to cell senescence and aging, DNA damage activates macroautophagy/autophagy, but how this process is affected by aging-rewired metabolism in normal biological systems remains to be explored. Here in cultured human umbilical cord-derived mesenchymal stem cells (HsMSCs) and the mouse liver that accumulate DNA damage during aging, we found an elevation of DRAM1 (DNA damage regulated autophagy modulator 1) and DRAM1-mediated pro-senescent autophagy (DMPA). Confirming that DRAM1 activated AMPK, we sought DMPA-associated metabolic features and noted substantial enrichment of N-acetylhistamine (N-AcHA) and phosphatidylethanolamine (PE) products in the aging HsMSCs and mouse liver. Elevating DNA damage and senescence, N-AcHA supplements were sufficient to upregulate DRAM1 and DMPA in primary hepatocytes from young mice but not even in pre-senescent HsMSCs, hence reflecting the differential tolerance of these cell models toward cytotoxic metabolic cues. The effects of N-AcHA were further verified in mouse aging and post-hepatectomy liver regeneration models. In contrast, accumulating cellular PE contents via ethanolamine supplements augmented autophagy but not DNA damage and senescence despite tending to induce DRAM1. Combined treatments with N-AcHA and ethanolamine were sufficient to trigger DMPA in HsMSCs. Despite their differential cellular responses toward N-AcHA and ethanolamine supplements, in primary HsMSCs and mouse hepatocytes DMPA did not notably downregulate SQSTM1/p62 proteins, which differed from general macroautophagy and may constitutively support the fusion of SQSTM1-modified cargo-containing autophagosomes with lysosomes. Overall, this study reveals DMPA-promoting metabolic and molecular features. Thus, targeting certain metabolic pathways and DMPA may promote DNA repair and delay senescence/aging. Abbreviations: ATM: ATM serine/threonine kinase; ATG5: autophagy related 5; ACTB: actin beta; BaFA1: bafilomycin A1; CDKN1A/p21: cyclin dependent kinase inhibitor 1A; DDR: DNA damage response; DEGs: differentially expressed genes; DRAM1: DNA damage regulated autophagy modulator 1; DMPA: DRAM1-mediated pro-senescent autophagy; DPMPs: differentially presented metabolic products; ETO: etoposide; Eth: ethanolamine; GL: glycerolipids; GP: glycerophospholipids; γ-H2AX: phosphorylated H2A.X variant histone; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HsMSC: human mesenchymal stem cell; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MSA: methanesulfonic acid; N-AcHA: N-acetylhistamine; PE: phosphatidylethanolamine; PHx: partial hepatectomy; PCYT2: phosphate cytidyltransferase 2, ethanolamine; SASP: senescence-associated secretory phenotype; SA-GLB1/β-gal: senescence-associated galactosidase beta 1; SQSTM1/p62: sequestosome 1; TAF: telomere-associated foci; TP53/p53: tumor protein p53.

Crosstalk via ICAM-1 enhances supportive phenotype of stellate cells and drives hepatocyte proliferation in iPSC-derived hepatic organoids.

Translational research using animal models is essential for addressing the clinical issues in organ transplantations. Although mouse orthotopic liver transplantation (LT) is a useful tool for investigating the mechanisms of liver regeneration, ischemia-reperfusion injury, and immune responses following LT, technical challenges in this procedure restrict its feasibility. The key aspects for successful mouse orthotopic LT are vascular reconstruction in recipients, including the suprahepatic inferior vena cava (SHIVC), portal vein (PV), and infrahepatic inferior vena cava (IHIVC). In addition to the technical difficulties in reconstructing these vessels, the time limitation of the anhepatic phase to within 20 min makes this procedure more challenging. Although a cuff technique can be used for PV reconstruction, a safe and quick suture technique is required to reconstruct the SHIVC during the anhepatic phase. For IHIVC reconstruction, while both cuff and suture techniques are applicable, the suture technique leads to a shorter operation time in donor surgery and back-table preparation and can maintain a larger vascular lumen than the cuff technique. We herein provide guidelines for SHIVC and IHIVC reconstruction using a suture technique to facilitate mouse orthotopic LT.

The liver serves as a central hub for a diverse set of functions including metabolic homeostasis, detoxification, and protein synthesis. While appearing homogeneous, hepatocytes, the major workhorse in the liver, demonstrate spatial identity within the lobule, which in turn dictates gene and protein expression and, eventually, function. Presenting as an axis from the portal triad to the central vein, this organization has been conventionally referred to as metabolic zonation. In recent years, the heterogeneity in expression and function is now understood to extend well beyond hepatocytes and metabolism to include nonparenchymal cells and diverse functions. Although the lobule is conventionally divided into three zones, spatial multi-omics technologies reveal a more nuanced picture, where zonation provides a coordinate system for an eclectic but highly functional hepatic milieu. We summarize the current understanding of liver zonation as it contributes to division of labor, injury compartmentalization, and stepwise arrangement of metabolic pathways and discuss the implications of this framework for liver homeostasis, regeneration, and disease.