Background. To investigate the impact of intrapatient variability (IPV) in the levels of immunosuppressant drugs on health outcomes after liver transplantation. Methods. A comprehensive systematic review and meta-analysis were conducted, examining literature from MEDLINE/PubMed, Embase, Web of Science, Cochrane Reviews, and Cochrane CENTRAL. Results. The analysis focused on acute rejection, graft survival, acute kidney injury, and cancer risk as health outcomes. Of 2901 articles screened, 10 met the inclusion criteria. The results indicate a 19% reduction in the risk of acute rejection in patients with lower IPV (RR = 0.81; 95% confidence interval, 0.66-0.99), although 6 studies found no significant association between high IPV and acute rejection. Contrasting results were observed for graft survival, with 1 study indicating worse outcomes for high IPV, whereas another reported no significant difference. High IPV was consistently associated with acute kidney injury across 3 studies. One study suggested a link between high IPV and hepatocellular carcinoma, although a meta-analysis for these outcomes was not feasible. Conclusions. These findings point to a marginal but statistically significant association between high IPV and an increased risk of acute rejection, highlighting the importance of precise management of immunosuppressive drugs in liver transplant recipients to enhance patient outcomes. Export

Background/Objectives: Hepatocellular carcinoma (HCC) therapies are limited by poor response, rapid resistance, and recurrence of aggressive disease. Sorafenib, a multi-tyrosine kinase inhibitor, can trigger β-catenin stabilization and activation, contributing to resistance. Overexpression of the chemokine receptor CXCR6 and its ligand CXCL16 and hyperactivation are implicated in HCC progression and β-catenin stabilization. We hypothesized that SBI-457, a small-molecule CXCR6 antagonist we developed, could disrupt CXCR6/β-catenin crosstalk and enhance sorafenib sensitivity. Methods: We tested SBI-457 alone and in combination with sorafenib in SK-Hep-1 xenograft models and a panel of human HCC cell lines. Tumor burden, β-catenin activation, and CXCR6 expression were assessed by tumor volume measurements, immunohistochemistry, Western blotting, and immunofluorescence. Soluble CXCL16 levels were quantified by ELISA, and cell death responses were evaluated using MTT assays. Results: In vivo, SBI-457 combined with sorafenib reduced normalized tumor volume by 55% compared to vehicle controls, modestly exceeding monotherapy effects, and attenuated sorafenib-induced β-catenin upregulation. In vitro, SBI-457 blocked nuclear accumulation of β-catenin and reversed sorafenib-induced increases in β-catenin levels. Enhanced cell death was observed in specific “responder” HCC cell lines (Hep-3B, SNU-398, JHH-5), which correlated with high intracellular β-catenin, secretion of soluble CXCL16, and expression of a high molecular weight form of CXCR6. In contrast, “non-responder” cell lines with conventional CXCR6 expression and low CXCL16 secretion showed no enhanced cell death response. Conclusions: CXCR6 antagonism with SBI-457 can modulate β-catenin activation and may help overcome sorafenib resistance in selected HCC models. These findings support further development of CXCR6 antagonists as single agents or combination therapies to improve treatment outcomes in HCC.

Human induced pluripotent stem cells (hiPSCs) possess broad differentiation potential; however, efficient maturation into functional hepatocytes remains challenging, in part because conventional differentiation strategies rely on 2D culture or partially defined 3D systems that fail to recapitulate key developmental microenvironmental cues. Although 3D culture has been shown to promote hepatic specification and maturation, a fully defined platform that supports the entire differentiation process from hiPSCs in 3D has not been established. Here, we report a scalable synthetic peptide hydrogel (PepGel) platform that enables hiPSCs to self-organize into long-term, proliferative luminal cavity (LC) architectures within 3D colonies (LC-hiPSCs). These LC-hiPSCs exhibited markedly enhanced differentiation efficiency compared to hiPSC aggregates generated via scaffold-free suspension methods. Using a shear-thinning, self-healing hydrogel configuration optimized for suspension culture, we produced large quantities of LC-hiPSCs and directed their differentiation into PepGel-derived hiPSC-derived hepatocyte-like cells (PG-hiHs). PG-hiHs formed polarized, multi-luminal organoid-like structures and exhibited robust expression of hepatocyte-specific genes and proteins, high cytochrome P450 activity, and in vitro metabolic functions comparable to primary human hepatocytes (PHHs). Following live shipment and transplantation into immunocompromised mouse livers, PG-hiHs engrafted efficiently and maintained human-specific albumin and alpha-1 antitrypsin secretion at PHH-equivalent levels. Furthermore, both LC-hiPSCs and PG-hiHs retained viability, structural organization, and phenotype in complex 3D bioprinted constructs for at least 14 days. Together, this work establishes a fully defined, reproducible, and scalable 3D platform that supports the entire differentiation process, overcoming limitations in hiPSC-derived hepatic maturation and enables physiologically relevant hepatocyte-like tissues for disease modeling, regenerative medicine, and biofabrication.

Rapid and high local calcium (Ca ²⁺ ) signals are essential for triggering neurotransmitter release from presynaptic terminals. In specialized bipolar ribbon synapses of the retina, these local Ca ²⁺ signals control multiple processes, including the priming, docking, and translocation of vesicles on the ribbon before exocytosis, endocytosis, and the replenishment of release-ready vesicles to the fusion sites for sustained neurotransmission. However, our knowledge about Ca ²⁺ signals along the axis of the ribbon active zone is limited. Here, we used fast confocal quantitative dual-color ratiometric line-scan imaging of a fluorescently labeled ribbon binding peptide and Ca ²⁺ indicators to monitor the spatial and temporal aspects of Ca ²⁺ transients of individual ribbon active zones in zebrafish retinal rod bipolar cells (RBCs). We observed that a Ca ²⁺ transient elicited a much greater fluorescence amplitude when the Ca ²⁺ indicator was conjugated to a ribeye-binding peptide than when using a soluble Ca ²⁺ indicator, and the estimated Ca ²⁺ levels at the ribbon active zone exceeded 26 μM in response to a 10-millisecond stimulus, as measured by a ribbon-bound low-affinity Ca ²⁺ indicator. Our quantitative modeling of Ca ²⁺ diffusion and buffering is consistent with this estimate and provides a detailed view of the spatiotemporal [Ca ²⁺ ] dynamics near the ribbon. Importantly, our data demonstrates that the local Ca ²⁺ levels may vary between ribbons of different RBCs and within the same cells. The variation in local Ca ²⁺ signals is found to correlate with ribbon size and active zone extent. Our serial electron microscopy results provide new information about the heterogeneity in ribbon size, shape, and area of the ribbon in contact with the plasma membrane.

The global health concern posed by age-related visual impairment highlights the need for further research focused on the visual changes that occur during the process of aging. To date, multiple sensory alterations related to aging have been identified, including morphological and functional changes in inner hair cochlear cells, photoreceptors, and retinal ganglion cells. While some age-related morphological changes are known to occur in rod bipolar cells in the retina, their effect on these cells and on their connection to other cells via ribbon synapses remain elusive. To investigate the effects of aging on rod bipolar cells and their ribbon synapses, we compared synaptic calcium currents, calcium dynamics, and exocytosis in zebrafish ( Danio rerio ) that were middle-aged (MA,18 months) or old-aged (OA, 36 months). The bipolar cell terminal in OA zebrafish exhibited a decreased number of synaptic ribbons, an increased ribbon length, and a decrease in local Ca ²⁺ signals at the tested ribbon location with little change in the overall magnitude of the calcium current or exocytosis in response to brief pulses. Staining of the synaptic ribbons with antibodies specific for PKCα revealed shortening of the inner nuclear and plexiform layers (INL and IPL). These findings shed light on age-related changes in the retina that are related to synaptic ribbons and calcium signals.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, with poor patient outcomes largely attributable to late diagnosis and the frequent development of therapeutic resistance. Although advances in chemotherapy, targeted therapies, immunotherapy, and combination regimens have improved treatment options, durable clinical responses remain limited. This review synthesizes current evidence on the role of β-catenin signaling in HCC progression and therapeutic resistance, emphasizing the molecular mechanisms underlying aberrant pathway activation and its interactions with other oncogenic signaling networks. The review examines how constitutive β-catenin activation promotes tumor growth, cancer stem cell maintenance, metabolic reprogramming, immune evasion, and resistance to chemotherapy, targeted therapies, and immune checkpoint inhibitors. In addition, emerging therapeutic strategies targeting β-catenin are discussed, including inhibition of β-catenin transcriptional activity, modulation of upstream Wnt signaling, direct suppression of CTNNB1 expression using nucleic acid-based approaches, and interventions targeting the immune and metabolic consequences of pathway activation. Collectively, the evidence identifies β-catenin as a central mediator of HCC progression and treatment resistance while highlighting its potential as a therapeutic target. A deeper understanding of β-catenin-driven mechanisms may facilitate the development of more effective therapeutic strategies and improve clinical outcomes for patients with HCC.