Bilirubin, the primary breakdown product of hemoproteins, particularly hemoglobin, plays a key role in the diagnosis, prognosis, and monitoring of liver diseases. In acute liver diseases, such as acute liver failure, drug-induced liver injury, and viral hepatitis, bilirubin serves as a biomarker reflecting the extent of hepatocyte loss and liver damage. Chronic liver diseases, including alcohol-related liver disease, chronic hepatitis C virus infection, metabolic dysfunction-associated fatty liver disease, and autoimmune liver diseases, are marked by persistent liver injury and inflammation. Bilirubin levels in chronic liver diseases provide insight into liver function, disease severity, and prognosis. As a versatile biomarker, bilirubin offers valuable information on the pathophysiology of liver diseases and aids in guiding clinical decision-making regarding the treatment of liver diseases and their complications. This review aimed to explore the multifunctional role of bilirubin in liver diseases by analyzing its biological functions beyond its role as a biomarker of liver damage.

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease, has a high global prevalence and can progress to metabolic dysfunction-associated steatohepatitis, cirrhosis, and hepatocellular carcinoma. The pathogenesis of MASLD is primarily driven by disturbances in hepatic lipid metabolism, involving six key processes: increased hepatic fatty acid uptake, enhanced fatty acid synthesis, reduced oxidative degradation of fatty acids, increased cholesterol uptake, elevated cholesterol synthesis, and increased bile acid synthesis. Consequently, maintaining hepatic lipid metabolic homeostasis is essential for effective MASLD management. Numerous novel molecules and Chinese proprietary medicines have demonstrated promising therapeutic potential in treating MASLD, primarily by inhibiting lipid synthesis and promoting lipid oxidation. In this review, we summarized recent research on MASLD, elucidated the molecular mechanisms by which lipid metabolism disorders contribute to MASLD pathogenesis, and discussed various lipid metabolism-targeted therapeutic approaches for MASLD.

The most prevalent form of dementia, Alzheimer’s disease (AD), is a neurological disorder that causes gradual memory loss. AD is characterized by amyloid-beta plaques, neurofibrillary tangles, and neuron loss. While preclinical and clinical trials are underway to reduce the generation and overall brain disease load, current treatment focuses on alleviating symptoms. Animal studies are essential for advancing our understanding of AD, identifying potential drug targets, and testing experimental therapies. An ideal animal model not only exhibits the same symptoms and pathological changes as a human disease but also follows the same sequence of pathological events. This review highlights the various inducing agents used to model AD in animals, such as streptozotocin, aluminium chloride, trimethyltin, lipopolysaccharide, scopolamine, and others, along with their underlying mechanisms. The outcomes of some studies that used such inducing agents to develop AD are discussed briefly. Among chemically induced models, streptozotocin and amyloid-beta are the most frequently used, while d-galactose, scopolamine, and aluminium-induced models are being used because they are non-invasive, reproducible, and compatible. However, none of the chemical/drug-induced models fully capture the scope of AD pathology and cognitive impairment. Overall, further research is necessary to establish the stability of the models in terms of consistency and reproducibility.

Ketamine, a non-competitive N-methyl-D-aspartate receptor antagonist, has emerged as an effective therapeutic agent for the management of treatment-resistant depression. Repeated treatments with ketamine show rapid, robust, and sustained antidepressant effects. Despite the large body of evidence, key concerns include adverse effects such as dissociative symptoms, hemodynamic instability, and the risk of abuse with long-term ketamine therapy. This narrative review provides an overview of the neurobiological mechanisms underlying ketamine’s antidepressant effects, its basic pharmacodynamics, and its safety profile. The clinical evidence regarding ketamine’s efficacy in depression is also summarized, and the need for further research on the long-term effects of ketamine therapy, the development of agents with similar antidepressant effects but fewer adverse effects or potential for abuse, and the identification of biomarkers to predict the response to ketamine is highlighted.

Bile acids are byproducts of cholesterol metabolism in the liver and constitute the primary components of bile. Disruption of bile flow leads to cholestasis, characterized by the accumulation of hydrophobic bile acids in the liver and bloodstream. Such accumulation can exacerbate liver impairment. This review discussed recent developments in understanding how bile acids contribute to liver damage, including disturbances in mitochondrial function, endoplasmic reticulum stress, inflammation, and autophagy dysfunction. Mitochondria play a pivotal role in cholestatic liver injury by influencing hepatocyte apoptosis and inflammation. Recent findings linking bile acids to liver damage highlight new potential treatment targets for cholestatic liver injury.

Cancer is the leading cause of death globally, with nearly 20 million new cases and 9.7 million deaths in 2022. Due to its vague initial symptoms, cancer is often difficult to detect in its early stages. Liquid biopsy, a revolutionary approach in oncology, provides a minimally invasive, real-time method for cancer detection, monitoring, and characterization by examining circulating tumor components in body fluids. This review presents current technologies and clinical applications of liquid biopsy, focusing particularly on its value for early cancer diagnosis. Liquid biopsy enables molecular profiling of cancer for precision oncology by isolating circulating extracellular nucleic acids (cell-free DNA), circulating tumor DNA, and circulating tumor cells from blood and other body fluids. Cell-free DNA, which circulates freely in the blood, may or may not be tumor-derived, while circulating tumor DNA is specifically of tumor origin. Additionally, circulating tumor cells can be isolated from blood; these cells, shed from tumors into the bloodstream, typically survive only 1–2.5 h before immune clearance, though a small fraction can persist and metastasize to distant sites. Exosomes, small membrane-bound vesicles secreted by tumor cells, also carry molecular information about the tumor and have become a valuable source of biomarkers in liquid biopsy. Advances in detection technologies for these analytes have expanded the utility of liquid biopsy, facilitating the identification of somatic mutations and actionable genomic alterations in tumors. Finally, this review discusses the opportunities and challenges facing liquid biopsy and offers insights into its future development.

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its more advanced form, metabolic dysfunction-associated steatohepatitis, have emerged as the most prevalent liver diseases worldwide. Currently, lifestyle modification is the foremost guideline-recommended management strategy for MASLD. However, it remains unclear which detrimental signals persist in MASLD even after disease remission. Thus, we aimed to examine the persistent changes in liver transcriptomic profiles following this reversal.

Male C57BL/6J mice were divided into three groups: Western diet (WD) feeding, chow diet (CD) feeding, or diet reversal from WD to CD. After 16 weeks of feeding, RNA sequencing was performed on the mice’s livers to identify persistent alterations characteristic of MASLD. Additionally, RNA sequencing databases containing high-fat diet-fed P53-knockout mice and human MASLD samples were utilized.

WD-induced MASLD triggered persistent activation of the DNA damage response (DDR) and its primary transcription factor, P53, long after the resolution of the hepatic phenotype through dietary reversal. Elevated levels of P53 might promote apoptosis, thereby exacerbating metabolic dysfunction-associated steatohepatitis, as they strongly correlated with hepatocyte ballooning, an indicator of apoptosis activation. Moreover, P53 knockout in mice led to downregulated expression of apoptosis signaling in the liver. Mechanistically, P53 may regulate apoptosis by transcriptionally activating the expression of apoptosis-enhancing nuclease (AEN). Consistently, P53, AEN, and the apoptosis process all exhibited persistently elevated expression and showed a strong inter-correlation in the liver following dietary reversal.

The liver demonstrated upregulation of DDR signaling and the P53-AEN-apoptosis axis both during and after exposure to WD. Our findings provide new insights into the mechanisms of MASLD relapse, highlighting DDR signaling as a promising target to prevent MASLD recurrence.

The genome editing technology based on clustered regularly interspaced short palindromic repeats/CRISPR-associated protein-9 (CRISPR/Cas9), is revolutionizing research, particularly in the context of human neurodegenerative disorders. This review examines recent advancements in CRISPR/Cas9 and its potential to address the protein misfolding mechanisms underlying these diseases. Proteins, the fundamental units of life, can misfold due to various changes, resulting in aggregation and contributing to devastating illnesses such as Alzheimer’s disease, Parkinson’s disease, Amyotrophic lateral sclerosis, and Huntington’s disease. Understanding the pathology of these disorders and the methods used for their detection is vital for developing effective treatments. CRISPR/Cas9 offers a powerful tool for combating neurodegenerative disorders at the molecular level. Its groundbreaking gene-editing capabilities are advancing preclinical and animal studies, paving the way for potential human trials and innovative therapeutic strategies. This review explores the complex challenge of protein misfolding and highlights how CRISPR technology could provide a crucial breakthrough in the fight against neurodegenerative disorders. It offers a synthesis of CRISPR advancements for neurodegenerative disorders. However, it is essential to be aware of the review’s limitations, including potential selection bias, the risk of oversimplification, and possible obsolescence in rapidly changing research fields. Despite these considerations, the transformative promise of CRISPR in understanding and potentially treating neurodegenerative diseases warrants continued research and thorough analysis.

Cirrhosis is often characterized by decreased liver function, ranging from a compensated, typically asymptomatic phase to a decompensated phase characterized by the appearance of ascites or variceal bleeding, and ultimately hepatorenal syndrome (HRS) or hepatopulmonary syndrome (HPS). The latter two complications are associated with a poor prognosis and limited treatment efficacy. In cases of ascites or variceal bleeding resistant to medical therapy, transjugular intrahepatic portosystemic shunt (TIPS) is effective and safe. Shunting blood by TIPS diverts portal blood to the systemic circulation, potentially increasing systemic blood volume and benefiting renal function. However, TIPS could also divert nitric oxide to the systemic circulation, potentially worsening systemic hypotension and perfusion, which could be detrimental to renal function. Available evidence indicates that TIPS often improves renal function in patients with portal hypertension, with or without HRS. No studies have shown persistently decreased renal function after TIPS. However, these data are insufficient to support a recommendation for the use of TIPS specifically for HRS. In patients without pre-existing HPS, TIPS does not appear to significantly affect pulmonary gas exchange. Results of TIPS in HPS have been inconsistent; some studies have shown improvement, but effects were transient. No studies have shown a persistent decline in pulmonary function after TIPS. The evidence supports the need for large randomized controlled trials to investigate the beneficial effects of TIPS for HRS. Similar pulmonary function data are less clear regarding TIPS for HPS. The aim of the current report was to review the literature regarding the effects of TIPS on renal and pulmonary function in hepatic decompensation, with or without the development of HRS or HPS.

The incidence and prevalence of inflammatory bowel diseases (IBD), including ulcerative colitis and Crohn’s disease, are rapidly increasing. Currently, colonoscopy is the gold standard for diagnosing and monitoring the course of IBD. However, the recently implemented “treat-to-target” strategy, which involves meticulously pursuing multiple therapeutic objectives, has opened avenues for non-invasive diagnostic and monitoring tools. These tools aim to assess disease activity and predict the likelihood of recurrence. Research studies into serum and fecal biomarkers in IBD have been ongoing for several years. Among the most relevant biomarkers, fecal calprotectin and C-reactive protein have shown the best accuracy, with good-to-optimal correlation with endoscopic, histologic, or transmural activity. Numerous studies have explored the potential advantages of using multi-target tools that combine serum and fecal biomarkers with clinical activity indexes to enhance diagnostic and monitoring effectiveness. Encouraging findings have emerged for fecal lactoferrin, autoantibodies, micro-RNA, gene expression, and many other serological and fecal markers. However, limited evidence has hindered their widespread adoption in routine clinical practice. This review aimed to summarize the available data on the utilization of biomarkers in IBD.