Implementation of pre-clinical methodologies to study fibrosis and test anti-fibrotic therapy

Pharmacological manipulation of liver fibrosis progression using novel HDAC6 inhibitors

Chronic liver injury characterized by unresolved hepatitis leads to fibrosis, potentially progressing to cirrhosis and hepatocellular carcinoma. Effective treatments for halting or reversing liver fibrosis are currently lacking. This study investigates the potential of HDAC6 as a therapeutic target in liver fibrosis. We synthesized two selective HDAC6 inhibitors, DR-3 and FDR2, and assessed their effects on hepatic stellate cell (HSC) activation and liver fibrosis using human precision cut liver slices (hPCLS). Molecular docking, deacetylation inhibition assays, and various cellular assays were employed to evaluate the specificity and anti-fibrotic efficacy of these inhibitors. DR-3 and FDR2 demonstrated high selectivity for HDAC6 over HDAC1, significantly inhibiting HSC activation markers and fibrogenic gene expression. Both inhibitors increased acetylation of α-tubulin and suppressed TGF-β1-induced SMAD signaling in HSCs. In human precision cut liver slices (hPCLS), DR-3 and FDR2 reduced fibrogenic protein levels and collagen deposition. The selective inhibition of HDAC6 by DR-3 and FDR2 effectively reduces HSC activation and fibrogenesis in liver models, supporting further investigation of HDAC6 inhibitors as potential anti-fibrotic therapies.

Prolonged use of pentoxifylline increases the life expectancy of patients with compensated cirrhosis: A 20‑year retrospective study

Liver cirrhosis is a pathology of varied etiology with a high prevalence and mortality, resulting in >1 million mortalities per year. Patients with liver cirrhosis typically have a survival time of 12 years following diagnosis. The treatment for this disease is directed at the complications of cirrhosis; however, to the best of our knowledge, the long-term management of patients with cirrhosis has been scarcely studied. Pentoxifylline (PTX) is a non-selective phosphodiesterase inhibitor with rheological activity and antioxidant, anti-inflammatory and antifibrotic properties. PTX has been used in the treatment of peripheral arterial disease, inflammatory liver diseases and hepatocellular carcinoma with encouraging results. The aim of the present study was to evaluate the effect of PTX use on the survival of patients with compensated cirrhosis. For this purpose, a cross-sectional study was performed at the Gastroenterology and Hepatitis C Department of Dr. Valentín Gómez Farias Hospital (Institute for Security and Social Services for State Workers, Zapopan, Mexico) from June, 1996 to December, 2019. The follow-up time for these patients was 22.6 years (up to the end of the study period). In the present study, 326 patient files were analyzed and 118 patients with the disease were identified, 81 of whom (68.64%) died within 12 years after diagnosis. Of the included patients, 26 received PTX combined with PEG IFN-α-2a plus ribavirin, and 11 received PTX plus propranolol, with a median treatment duration of 20.6±0.8 years. Furthermore, 16 patients (43%) did not develop co-morbidities within this time, and the transition to decompensated cirrhosis was 16.6 years, with a survival time of 20 years. Therefore, the results of the present study suggest that PTX may improve the long-term survival of patients with compensated cirrhosis, rendering PTX a candidate for repurposing in the treatment of hepatic cirrhosis.

The Fourth Annual Symposium of the Midwest Aging Consortium

The Midwest Aging Consortium (MAC) has emerged as a critical collaborative initiative aimed at advancing our understanding of aging and developing strategies to combat the rising prevalence of age-related diseases. Founded in 2019, MAC brings together researchers from various disciplines and institutions across the Midwestern United States to foster interdisciplinary geroscience research. This report summarizes the highlights of the Fourth Annual Symposium of MAC, which was held at Iowa State University in May 2023. The symposium featured presentations on a wide array of topics, including studies on slow-aging animals, cellular senescence and senotherapeutics, the role of the immune system in aging, metabolic changes in aging, neuronal health in aging, and biomarkers for measuring the aging process. Speakers shared findings from studies involving a variety of animals, ranging from commonly used species such as mice, rats, worms, yeast, and fruit flies, to less-common ones like naked mole-rats, painted turtles, and rotifers. MAC continues to emphasize the importance of supporting emerging researchers and fostering a collaborative environment, positioning itself as a leader in aging research. This symposium not only showcased the current state of aging biology research but also highlighted the consortium's role in training the next generation of scientists dedicated to improving the healthspan and well-being of the aging population.

Intersection of stem cell biology and engineering towards next generation in vitro models of human fibrosis

Human fibrotic diseases constitute a major health problem worldwide. Fibrosis involves significant etiological heterogeneity and encompasses a wide spectrum of diseases affecting various organs. To date, many fibrosis targeted therapeutic agents failed due to inadequate efficacy and poor prognosis. In order to dissect disease mechanisms and develop therapeutic solutions for fibrosis patients, in vitro disease models have gone a long way in terms of platform development. The introduction of engineered organ-on-a-chip platforms has brought a revolutionary dimension to the current fibrosis studies and discovery of anti-fibrotic therapeutics. Advances in human induced pluripotent stem cells and tissue engineering technologies are enabling significant progress in this field. Some of the most recent breakthroughs and emerging challenges are discussed, with an emphasis on engineering strategies for platform design, development, and application of machine learning on these models for anti-fibrotic drug discovery. In this review, we discuss engineered designs to model fibrosis and how biosensor and machine learning technologies combine to facilitate mechanistic studies of fibrosis and pre-clinical drug testing.

Arecanut-induced fibrosis display dual phases of reorganising glycans and amides in skin extracellular matrix

The habit of chewing arecanut leads to fibrosis in the oral tissues, which can lead to cancer. Despite high mortality, fibrosis has limited clinical success owing to organ-specific variations, genetic predispositions, and slow progression. Fibrosis is a progressive condition that is unresponsive to medications in the severe phase. To understand underlying macromolecular changes we studied the extracellular matrix's (ECM) key molecular modifications in the early and late phase of arecanut-induced fibrosis in skin. To study the fibrosis, we topically applied arecanut extract on the mice skin. We observed that the matrix changes observe early and late phases based on ECM characteristics including the matrix proteins and the glycans. A spike in the levels of proteoglycans and β-sheet structures are noted in the early phase. A significant drop in the proteoglycans and strengthening of amide covalent interactions is observed in the late phase. Although, almost no physical changes are noticeable only in the early phase; the late phase observes thick collagen bundling and a 4-fold stiffening of the skin tissue. The study indicates that the temporal interplay of proteins and glycans determine the matrix's severity state while opening avenues to research directed towards the phase-specific clinical discovery.

TWEAK/Fn14 axis is an important player in fibrosis

Fibrosis is a common pathological condition associated with abnormal repair after tissue injury. However, the etiology and molecular mechanisms of fibrosis are still not well-understood. Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) belongs to the TNF superfamily and acts by binding to its receptor, fibroblast growth factor-inducible 14 (Fn14), thereby activating a variety of intracellular signal transduction pathways in various types of cells. Besides promoting the expression of growth factors, activation of TWEAK/Fn14 signaling after tissue injury can promote the expression of pro-inflammatory cytokines, which trigger the immune response, thereby exacerbating the injury. Severe or repetitive injury leads to a dysregulated tissue repair process, in which the TWEAK/Fn14 axis promotes the activation and proliferation of myofibroblasts, induces the secretion of the extracellular matrix, and regulates profibrotic mediators to further perpetuate and sustain the fibrotic process. In this review, we summarize the available experimental evidence on the underlying molecular mechanisms by which the TWEAK/Fn14 pathway mediates the development and progression of fibrosis. In addition, we discuss the therapeutic potential of the TWEAK/Fn14 pathway in fibrosis-associated diseases based on evidence derived from multiple models and cells from injured tissue and fibrotic tissue.