Search Results (93)

Ursodeoxycholic acid (UDCA) is widely used to treat cholestatic liver diseases such as primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), yet its molecular mechanisms remain unclear. This study investigated the impact of long-term UDCA therapy on circulating levels of the microRNAs miR-34a and miR-506, which are implicated in PBC pathogenesis, and explored associated changes in inflammatory markers and signaling pathways. Serum samples from patients with PBC and PSC were collected before and after UDCA treatment and analyzed for miRNA expression as well as levels of TREM-2 and sCD163. In vitro studies using human cholangiocytes and lipopolysaccharide (LPS) stimulation assessed changes in the expression of miR-34a, TREM-2, and ADAM17. The results showed that the baseline levels of miR-34a and miR-506 were significantly elevated in PBC patients compared to controls and were significantly reduced after UDCA therapy in PBC but not in PSC. UDCA also decreased serum levels of TREM-2 and sCD163. In vitro, it suppressed the LPS-induced expression of miR-34a and ADAM17 while enhancing TREM-2 expression. Single-cell RNA sequencing of liver tissue and immunofluorescence staining confirmed TREM-2 expression in cholangiocytes. These findings suggest that UDCA modulates key inflammatory pathways and miRNAs in PBC, providing mechanistic insights into its therapeutic effect Full article

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a severe hepatocellular cholestasis due to biallelic variations in the ABCB11 (ATP-binding cassette B11) gene encoding the canalicular bile salt export pump (BSEP). Some missense variants identified in patients with PFIC2 do not traffic properly to the canalicular membrane. However, 4-phenybutyrate (4-PB) has been shown in vitro to partially correct the mis-trafficking of selected variants, resulting in an improvement of the medical conditions of corresponding PFIC2 patients. Herein, we report the ability of 4-PB analogous or homologous drugs and of non-4-PB related chemical correctors to rescue the canalicular expression and the activity of the folding-defective Abcb11^R1128C variant. New compounds, either identified by screening a chemical library or designed by structural homology with 4-PB (or its metabolites) and synthesized, were evaluated in vitro for their ability to (i) correct the canalicular localization of Abcb11^R1128C after transfection in hepatocellular polarized cell lines; (ii) restore the ³H-taurocholate transport of the Abcb11^R1128C protein in Madin–Darby canine kidney (MDCK) cells stably co-expressing Abcb11 and the sodium taurocholate co-transporting polypeptide (Ntcp/Slc10A1). Glycerol phenylbutyrate (GPB), phenylacetate (PA, the active metabolite of 4-PB), 3-hydroxy-2-methyl-4-phenylbutyrate (HMPB, a 4-PB metabolite analog chemically synthesized in our laboratory) and 4-oxo-1,2,3,4-tetrahydro-naphthalene-carboxylate (OTNC, from the chemical library screening) significantly increased the proportion of canalicular Abcb11^R1128C protein. GPB, PA, ursodeoxycholic acid (UDCA), alone or in combination with 4-PB, suberoylanilide hydroxamic acid (SAHA), C18, VX-445, and/or VX-661, significantly corrected both the traffic and the activity of Abcb11^R1128C. Such correctors could represent new pharmacological insights for improving the condition of patients with ABCB11 deficiency due to missense variations affecting the transporter’s traffic. Full article

This Letter to the Editor explores synergistic mechanisms enhancing mRNA cancer vaccine efficacy through bile acid metabolism modulation in liver cancer treatment. The latest evidence indicates that bile acids significantly impair T cell function within the liver cancer microenvironment, creating an immunosuppressive milieu that hampers anti-tumor responses. Modulating bile acid composition, particularly increasing ursodeoxycholic acid (UDCA), could reshape the tumor microenvironment (TME) to favor mRNA vaccine-induced T cell activity—a promising strategy to overcome current immunotherapy limitations in liver cancer. Full article

Background: Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by progressive bile duct damage and cholestasis. While ursodeoxycholic acid (UDCA) is the first-line therapy, approximately 40% of patients have incomplete responses, necessitating alternative treatments. This systematic review and meta-analysis evaluate the efficacy and safety of novel oral anti-cholestatic agents for PBC. Methods: A systematic literature search was conducted in electronic databases up to September 2024. Randomized controlled trials, cohort studies, and case-control studies evaluating novel oral anti-cholestatic agents in adult PBC patients were included. The primary outcome was a change in alkaline phosphatase (ALP) levels. Safety was assessed by the incidence of serious adverse events. Random-effect meta-analyses were performed. Results: Ten studies involving 878 patients were analyzed. Novel agents included seladelpar, fenofibrate, saroglitazar, bezafibrate, elafibranor, and budesonide. The meta-analysis showed significant reductions in ALP levels with novel agents compared to the controls (SMD −2.80; 95% CI −3.56, −2.03; p < 0.00001), with high heterogeneity (I² = 93%). Saroglitazar achieved the largest effect size. There was no significant difference in serious adverse events between novel agents and controls (OR 1.21; 95% CI 0.81, 1.83; p = 0.35). Conclusions: Novel oral anti-cholestatic agents show promise in improving biochemical markers in PBC patients with suboptimal UDCA responses, with a safety profile comparable to controls. However, study heterogeneity and limited long-term data restrict direct comparisons. Larger standardized trials with extended follow-up are needed to confirm long-term efficacy and safety. Full article

Ursodeoxycholic acid (UDCA), a critical secondary bile acid in human physiology, demonstrates significant industrial potential through synthetic routes from bisnoralcohol (BA). Current synthetic routes rely on hydroxyl oxidation and Horner–Wadsworth–Emmons reactions as critical initial steps, facing unresolved challenges in reaction scale-up dynamics and impurity evolution. In this work, we systematically investigated the scale-up effects and innovatively addressed the impurity control problem. In the OH-C(22) selective oxidation of BA, the impurity C(22) carboxylic acid was synthesized, the emulsification was eliminated by process optimization, and the yield was increased from 89.0% to 95.2%. In the Horner–Wadsworth–Emmons reaction, the C(20)-methyl racemate and the C(22)-Z-ene isomer were synthesized, followed by the validation of the remaining byproducts. Based on impurity profile analysis, we innovatively modified the reaction feeding protocol, increased the yield from 79.1% to 90.8%, and significantly improved reaction selectivity. This optimized process demonstrates superior scalability and provides valuable insights for the industrial production of plant-derived UDCA. Full article

Background/Objectives: Ursodeoxycholic acid (UDCA), a hydrophilic bile acid, exhibits anti-inflammatory effects and attenuates the process of colon carcinogenesis. Certain healthy diets increase colonic UDCA concentrations, but its anticancer mechanistic actions remain largely unknown. We hypothesize that UDCA preferentially inhibits cancerous colon cell proliferation with a minimal effect on noncancerous colon cells. Methods: With human noncancerous NCM460 colon cell and cancerous HCT116 colon cell culture models, we performed biochemical, western blotting, PCR array, cell cycle, apoptosis, and immunofluorescent assays to determine the effects of UDCA treatment on colon cell proliferation and the underlying molecular mechanisms. Results: The inhibitory potential of UDCA against cell proliferation (via cell cycle arrest and apoptosis) was 90% greater in cancerous HCT116 cells than noncancerous NCM460 cells when treated with UDCA (0 to 0.4 mM) for 48 h. In UDCA-treated HCT116 cells, we identified 18 genes with ≥80% change (compared to untreated cells) in mRNA levels out of 93 apoptotic genes which were involved in caspase, death receptor, and NFκB pathways. At the molecular level, 0.4 mM UDCA reduced the protein level of the proto-oncogenic c-Myc gene but increased the putative tumor suppressor p21 gene (≥100%) via the ERK1/2/c-Myc/p21 pathway, which regulates cell cycle and apoptosis. These data are consistent with lower c-Myc but higher p21 expression in normal colon tissues compared to cancerous colon tissues. Conclusions: Collectively, UDCA inhibits cancerous HCT116 colon cells to a higher degree than in noncancerous NCM460 colon cells through cell cycle and apoptosis involving ERK1/2/c-Myc/p21 signaling. Full article

Objective: Intrahepatic cholestasis of pregnancy (ICP) is associated with an elevated risk of adverse perinatal outcomes, including perinatal morbidity and mortality. The objectives of this study were to evaluate the bile acid (BA) metabolism profiles in the urine of patients with ICP and to investigate the association between specific BAs and maternal and neonatal outcomes in patients with ICP. Methods: A total of 127 Chinese women with ICP and 55 healthy pregnant women were enrolled in our retrospective study. Spot urine samples and clinical data were collected from pregnant women from January 2019 to December 2022 at the First Affiliated Hospital of Chongqing Medical University, Chongqing. Based on total bile acid (TBA) levels, the ICP group was subdivided into mild (10–40 μmol/L) and severe (≥40 μmol/L) ICP groups. Patients in the ICP group were further divided into two categories according to neonatal outcomes: an ICP with adverse pregnancy outcomes group and an ICP with non-adverse pregnancy outcomes group. Metabolites from maternal urine were collected and analyzed using ultra-high-performance liquid chromatography–triple quadrupole time-of-flight mass spectroscopy (UPLC-triple TOF-MS). Results: Significant differences were observed between the mild and severe ICP groups in the onset time of symptoms, gestational weeks at time of ICP diagnosis, the duration of using ursodeoxycholic acid (UDCA) drugs during pregnancy, gestational age at delivery, premature delivery, and cesarean delivery. The expression levels of the composition of different urinary bile acids including THCA, TCA, T-ω-MCA, TCA-3-S, TCDCA-3-S, TDCA-3-S, GCDCA-3-S, DCA-3-G and GDCA-3-G were remarkably higher in the ICP with adverse pregnancy outcomes group than those in the ICP with non-adverse pregnancy outcomes group and the control group. The single-parameter model used to predict adverse pregnancy outcomes in ICP had similar areas under the curve (AUCs) of the receiver operating characteristic (ROC), ranging from 0.755 to 0.869. However, an AUC of 0.886 and 95% CI were obtained by the index of combined urinary bile acids in multiple prediction models (95% CI 0.790 to 0.983, p < 0.05). TCA-3-S in the urinary bile acids had a strong positive correlation with the aspartate aminotransferase (AST) level (r = 0.617, p < 0.05). Furthermore, TCDCA-3-S and GCDCA-3-S in the urinary bile acids had a strong positive correlation with the alanine aminotransferase (ALT) level (r = 0.607, p < 0.05; r = 0.611, p < 0.05) and AST level (r = 0.629, p < 0.05; r = 0.619, p < 0.05). Conclusions: Maternal urinary bile acid profiles were prominent for the prognosis of maternal and neonatal outcomes of ICP. Elevated levels of TCA-3-S, TCDCA-3-S, and GCDCA-3-S in urine might be important predictors for indicating adverse pregnancy outcomes in ICP. Full article

Background and Aims: Primary biliary cholangitis (PBC) leads to the slow, progressive destruction of the small bile ducts with consecutive cholestasis and intrahepatic cholangitis. If this disease remains untreated, liver parenchyma will be damaged resulting in fibrosis and end-stage liver disease with the need for transplantation. The approval of the Farnesoid X receptor agonist obeticholic acid (Ocaliva; OCA) in early 2017 expanded the drug therapy options of PBC, which previously consisted primarily of the administration of ursodeoxycholic acid (UDCA). Patients and Methods: Included in our prospective pilot study were 16 patients with a confirmed diagnosis of PBC who were treated with an add-on therapy with OCA (5 mg/d). None of the patients had an overlap to autoimmune hepatitis. Patients were investigated between 09/2022 and 09/2023. Results: The majority of patients was female (15/16, 93.75%), and the mean age was 57.63 ± 9.59 (43–77) years. OCA treatment led to a statistically significant decrease in aspartate aminotransferase (AST; AST baseline: 38.50 [26.25; 50.00] IU/L vs. AST 6-month follow-up: 23.50 [21.50; 44.25] IU/L, p = 0.0012), alanine aminotransferase (ALT; ALT baseline: 55.50 [28.75; 97.00] IU/L vs. ALT 6-month follow-up: 36.50 [28.00; 57.25] IU/L, p = 0.0035), and gamma-glutamyl transferase (GGT; GGT baseline: 168.00 [100.30; 328.50] IU/L vs. GGT 6-month follow-up: 88.00 [44.50; 259.80] IU/L, p = 0.0063), while the decrease in alkaline phosphatase (AP) was not statistically significant (AP baseline: 197.00 [170.00; 253.30] IU/L vs. AP 6-month follow-up: 196.00 [134.00; 227.00] IU/L, p = 0.0915). In addition, liver stiffness measurement (LSM) showed a statistically significant decrease after six months of treatment with OCA (LSM baseline: 7.85 [5.55; 10.13] kPa vs. LSM 6-month follow-up: 5.95 [4.55; 8.225] kPa, p = 0.0001). However, the increase in enzymatic liver function measured by LiMAx failed to reach statistical significance, but showed a positive trend (LiMAx baseline: 402.50 [341.50; 469.80] μg/kg/h vs. LiMAx 6-month follow-up: 452.50 [412.50; 562.00] μg/kg/h, p = 0.0625). In none of our patients did therapy with obeticholic acid have to be stopped due to pruritus or poor tolerability. Conclusions: In patients with PBC without adequate response to UDCA, OCA is a promising alternative, which in our group of 16 patients led to a significant improvement of liver enzymes, the amelioration of liver fibrosis, and an increase in liver function capacity in a short-term clinical course. Full article

Background: Even though many metabolic liver diseases can now be diagnosed using blood tests and diagnostic imaging, early diagnosis remains difficult. Understanding mechanisms contributing to the progression from Metabolic Dysfunction-Associated Steatohepatitis (MASH) and Alcoholic Hepatitis (AH) to cirrhosis is critical to reduce the burden of end-stage liver disease. Monitoring individual bile acids has been proposed as a way to distinguish various liver disorders. Methods: This study explored bile acid profiles in patients with MASH and AH. Plasma samples from patients with MASH, AH, and a control group were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify bile acid concentrations. Targeted metabolomic analysis was performed to compare bile acid levels between the hepatitis and control groups. Results: Concentrations of ursodeoxycholic acid (UDCA), chenodeoxycholic acid (CDCA), taurocholic acid (TCA), tauroursodeoxycholic acid (TUDCA), taurochenodeoxycholic acid (TCDCA), glycoursodeoxycholic acid (GUDCA), glycochenodeoxycholic acid (GCDCA), and glycocholic acid (GCA) were significantly elevated in the hepatitis group. Correlation analysis revealed strong positive relationships between the total and direct bilirubin levels and TUDCA and GCDCA. Aspartate aminotransferase (AST) showed strong positive correlations with TCDCA and GCDCA. Child–Pugh score, Fibrosis-4 index, and non-alcoholic fatty liver disease fibrosis score were positively correlated with GCA, whereas the aspartate aminotransferase-to-platelet ratio correlated with TCA, TCDCA, and GCA. The model for end-stage liver disease (MELD) score showed a strong positive correlation with GCDCA. Implications: GCDCA may serve as a predictive biomarker for liver damage, potentially enabling early diagnosis and targeted intervention in patients with MASH and AH. Full article

Background: Cholelithiasis is a rare disease in infants, and there is limited data on its risk factors and management. Objectives: To evaluate the risk factors, management, and response to medical treatment of cholelithiasis in infants. Methods: Infants diagnosed with cholelithiasis by ultrasound between 2018 and 2023 were retrospectively analyzed. Details of patient history, imaging findings, current symptoms, and treatments were reviewed. Results: Over 5 years, 98 infants were diagnosed with cholelithiasis. Thirty-three (33.7%) were girls, and the most common risk factors were the use of cephalosporin antibiotic therapy in 46.9%, sepsis in 30.6%, total parenteral nutrition in 29.6%, prematurity in 27.6%, congenital heart disease in 18.4%, and genetic disease (Down syndrome diagnosis in seven patients) in 16.3%. Only fifteen patients (15.3%) were symptomatic. Ursodeoxycholic acid (UDCA) treatment was given to 90.8% of patients, but nine of them used it for a short period or irregularly, and regular users were 81.6%. Gallstones disappeared in 46 patients (46.9%), including 14 (30.4%) without using UDCA regularly. The response rate to UDCA treatment was lower in preterm infants (p = 0.004). Gallstone resolution was higher in the nonusers, 14/18 (77.8%) versus 32/79 (40.5%) (p = 0.03). Acute cholecystitis was observed in only four patients; no other complications were noted. No infant required surgical or endoscopic treatment. Conclusions: UDCA should not be used routinely in children, especially infants, except in symptomatic children with a contraindication to surgery or to reduce clinical symptoms. In the absence of symptoms, patients may be monitored clinically. Full article

Background: Ursodeoxycholic acid (UDCA), chenodeoxycholic acid (CDCA) plus UDCA (C&U), and terpene are widely administered to prevent common bile duct (CBD) stone recurrence and dissolve gallbladder (GB) stones. We evaluated and compared the combined effects of these agents on CBD stone recurrence and GB stone resolution. Methods: This study included patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) at six referral centers, retrospectively. A total of 940 patients who underwent cholecystectomy before or after CBD stone removal by ERCP were evaluated to assess CBD stone recurrence (the CBD recurrence cohort), and 98 patients with GB stones were assessed by abdominal or endoscopic ultrasonography before and 6 months after ERCP to evaluate GB stone resolution (GB cohort). Patients were divided into no-medication, single-agent treatment (UDCA, C&U, or terpene), or dual-agent treatment (terpene plus UDCA or C&U) groups for the analysis. Results: In the CBD recurrence cohort, baseline characteristics were similar in the three groups. CBD stone recurrence rates were 41.5%, 12.7%, and 9.8% in the no-medication, single-agent, and dual-agent groups, respectively (p < 0.001), and the recurrence rate was significantly lower for those administered C&U plus terpene (5.2% vs. 13.2%, p = 0.002). In the GB cohort, baseline characteristics were also similar in the groups. GB stone resolution rates of >30% were observed in 5.3%, 14.3%, and 34.8% of patients in the no-medication, single-agent, and dual-agent groups, respectively (p = 0.028). Conclusions: C&U plus terpene was significantly more effective for preventing CBD stone recurrence and achieving GB stone resolution than no medication or single agents. Full article

Background/Objectives: Primary biliary cholangitis (PBC) is an autoimmune chronic cholestatic disease of the liver that symptomatically can present with pruritus and fatigue. Its established first- and second-line therapies are ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) although they provide limited symptom management. Liver transplantation offers a potentially curative therapeutic option in refractory cases progressing to cirrhosis. Novel research published after the current guidelines highlights the importance of providing an up-to-date analysis of treatment options available. Methods: In this study, we conducted a literature search using Pubmed, Ovid Medline, and SCOPUS to provide a narrative review of first-line, second-line, and emerging therapies in PBC. Results: UDCA has been well established as a long-term, safe therapy within the literature although it is possible that treatment dosage can be further optimised in refractory patients. It has a favourable side effect profile. Despite improving biochemical markers, histopathological profile, and overall outcomes, up to 30–40% of patients are refractory to it. Age and sex are highlighted as independent indicators of non-responsiveness. This necessitates effective second-line therapies. Future trials could aim to investigate UDCA as a co-first-line therapy. Further supporting results for OCA were found in the interim extension trial of the seminal POISE study. The long-term phase 4 COBOLT trial is still awaiting results to further assess the complications, adherence, and potential adverse effects. It is a viable option in UDCA-refractory patients. The high incidence rate of dose-related pruritis indicates that alternative second-line options are needed. Bezafibrate is an off-label antilipemic agent that shows promise as a prospective second-line therapy option. The landmark BEZURSO trial alleviated some efficacy and safety concerns, but it remains associated with elevated serum creatinine; thus, it should be considered with caution. Other prospective second-line therapies are budesonide, triple therapy, and novel agents such as seladelpar and elafibranor. Conclusions: UDCA should remain the treatment of choice for PBC, though perhaps not as monotherapy. With further investigation, BF shows promise as a new second-line therapy alongside OCA, which it may outperform. Full article

Introduction: Hepatic sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) is a major complication following hematopoietic stem cell transplantation, resulting from immune and chemical toxicity in the sinusoidal endothelium and hepatocellular damage. In the most severe cases, multiorgan dysfunction occurs, so it is essential to promptly identify patients at greater risk of SOS/VOD and to adopt prophylactic strategies. Objectives: This study aims to systematize the impact of different approaches as primary prophylaxes against SOS/VOD in patients undergoing hematopoietic stem cell transplantation (HSCT). Methods: A systematic review and meta-analysis of randomized clinical trials evaluating different strategies for primary prophylaxis of SOS/VOD was carried out in pairwise fashion and with a consistent network structure. The odds ratio (OR) and corresponding confidence intervals were calculated using the random-effects model. Heterogeneity was assessed by the I² method and the efficacy of each approach was estimated by SUCRA (surface under the cumulative ranking curve). Results: Considering all patients undergoing HSCT, ursodeoxycholic acid (UDCA) [OR = 0.38, 95%CI 0.14–1.06, SUCRA = 0.720] was associated with a lower incidence of VOD while defibrotide reached a modest reduction in its incidence [OR = 0.64, 95%CI 0.23–1.67; SUCRA = 0.486]. Considering the subgroup of patients undergoing hematopoietic progenitors allotransplantation, defibrotide scored higher [OR = 0.51, 95%CI 0.09–2.85, SUCRA = 0.650] by comparison with UDCA [OR = 0.53, 95%CI 0.14–1.96, SUCRA = 0.639]. Conclusions: This is the first meta-analysis comparing primary prophylaxes against SOS/VOD. UDCA yielded more promising results when considering all patients undergoing hematopoietic stem cell transplantation, yet, in a subgroup analysis of the ones exposed to allogeneic grafts, it becomes not significantly overrun by defibrotide. Full article

The concentrations of fecal and serum bile acids (BAs) are known to be altered in human patients with chronic liver diseases (CLDs), especially those with biliary tract involvement (BTD). Scarce literature is available regarding fecal BA modifications during canine CLDs. This study aimed to evaluate fecal BAs in canine CLDs according to different clinical and clinicopathological variables. Forty-six dogs were enrolled. Canine feces were analyzed by HPLC. Cholic Acid (CA), Chenodeoxycholic Acid (CDCA), Ursodeoxycholic Acid (UDCA), Deoxycholic Acid (DCA), and Lithocholic Acid (LCA) were measured, and primary BAs (CA + CDCA), secondary BAs (UDCA + DCA + LCA), and the primary/secondary (P/S) ratio were calculated. Primary BAs (p < 0.0001), CA (p = 0.0003), CDCA (p = 0.003), the P/S ratio (p = 0.002), and total BAs (p = 0.005) were significatively higher in BTD dogs (n = 18) compared to in non-BTD dogs (n = 28). Fecal secondary BAs did not statistically differ between BTD and non-BTD dogs. Gastrointestinal clinical signs (p = 0.028) and diarrhea (p = 0.03) were significantly more prevalent in BTD dogs compared to in non-BTD dogs, supporting the hypothesis of some pathological mechanisms assimilable to bile acid diarrhea (BAD). Our results could reflect imbalances of the fecal BA metabolism in dogs with CLDs. Further studies involving gut microbiome and metabolomic assessment are needed to better understand the possible clinical implications of BA metabolism disruption and their potential role in canine CLDs. Full article

Erythropoietic protoporphyria (EPP1) results in painful photosensitivity and severe liver damage in humans due to the accumulation of fluorescent protoporphyrin IX (PPIX). While zebrafish (Danio rerio) models for porphyria exist, the utility of ferrochelatase (fech) knockout zebrafish, which exhibit EPP, for therapeutic screening and biological studies remains unexplored. This study investigated the use of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated fech-knockout zebrafish larvae as a model of EPP1 for drug screening. CRISPR/Cas9 was employed to generate fech-knockout zebrafish larvae exhibiting morphological defects without lethality prior to 9 days post-fertilization (dpf). To assess the suitability of this model for drug screening, ursodeoxycholic acid (UDCA), a common treatment for cholestatic liver disease, was employed. This treatment significantly reduced PPIX fluorescence and enhanced bile-secretion-related gene expression (abcb11a and abcc2), indicating the release of PPIX. Acridine orange staining and quantitative reverse transcription polymerase chain reaction analysis of the bax/bcl2 ratio revealed apoptosis in fech^−/− larvae, and this was reduced by UDCA treatment, indicating suppression of the intrinsic apoptosis pathway. Neutral red and Sudan black staining revealed increased macrophage and neutrophil production, potentially in response to PPIX-induced cell damage. UDCA treatment effectively reduced macrophage and neutrophil production, suggesting its potential to alleviate cell damage and liver injury in EPP1. In conclusion, CRISPR/Cas9-mediated fech^−/− zebrafish larvae represent a promising model for screening drugs against EPP1. Full article