Immunotherapy-based targeting of MSLN+ activated portal fibroblasts is a strategy for treatment of cholestatic liver fibrosis

The possible pathogenesis of liver fibrosis: therapeutic potential of natural polyphenols

Liver fibrosis is the formation of a fibrous scar resulting from chronic liver injury, independently from etiology. Although many of the mechanical details remain unknown, activation of hepatic stellate cells (HSCs) is a central driver of liver fibrosis. Extracellular mechanisms such as apoptotic bodies, paracrine stimuli, inflammation, and oxidative stress are critical in activating HSCs. The potential for liver fibrosis to reverse after removing the causative agent has heightened interest in developing antifibrotic therapies. Polyphenols, the secondary plant metabolites, have gained attention because of their health-beneficial properties, including well-recognized antioxidant and anti-inflammatory activities, in the setting of liver fibrosis. In this review, we present an overview of the mechanisms underlying liver fibrosis with a specific focus on the activation of resident HSCs. We highlight the therapeutic potential and promising role of natural polyphenols to mitigate liver fibrosis pathogenesis, focusing on HSCs activation. We also discuss the translational gap from preclinical findings to clinical treatments involved in natural polyphenols in liver fibrosis.

Thy-1 restricts steatosis and liver fibrosis in steatotic liver disease

BACKGROUND AND AIMS

Steatotic liver disease (SLD) is generally considered to represent a hepatic manifestation of metabolic syndrome and includes a disease spectrum comprising isolated steatosis, metabolic dysfunction-associated steatohepatitis, liver fibrosis and ultimately cirrhosis. A better understanding of the detailed underlying pathogenic mechanisms of this transition is crucial for the design of new and efficient therapeutic interventions. Thymocyte differentiation antigen (Thy-1, also known as CD90) expression on fibroblasts controls central functions relevant to fibrogenesis, including proliferation, apoptosis, cytokine responsiveness, and myofibroblast differentiation.

METHODS

The impact of Thy-1 on the development of SLD and progression to fibrosis was investigated in high-fat diet (HFD)-induced SLD wild-type and Thy-1-deficient mice. In addition, the serum soluble Thy-1 (sThy-1) concentration was analysed in patients with metabolic dysfunction-associated SLD stratified according to steatosis, inflammation, or liver fibrosis using noninvasive markers.

RESULTS

We demonstrated that Thy-1 attenuates the development of fatty liver and the expression of profibrogenic genes in the livers of HFD-induced SLD mice. Mechanistically, Thy-1 directly inhibits the profibrotic activation of nonparenchymal liver cells. In addition, Thy-1 prevents palmitic acid-mediated amplification of the inflammatory response of myeloid cells, which might indirectly contribute to the pronounced development of liver fibrosis in Thy-1-deficient mice. Serum analysis of patients with metabolically associated steatotic liver disease syndrome revealed that sThy-1 expression is correlated with liver fibrosis status, as assessed by liver stiffness, the Fib4 score, and the NAFLD fibrosis score.

CONCLUSION

Our data strongly suggest that Thy-1 may function as a fibrosis-protective factor in mouse and human SLD.

Single-cell RNA sequencing reveals reduced intercellular adhesion molecule crosstalk between activated hepatic stellate cells and neutrophils alleviating liver fibrosis in hepatitis B virus transgenic mice post menstrual blood-derived mesenchymal stem cell transplantation

Liver fibrosis can cause hepatitis B virus (HBV)-associated hepatocellular carcinoma. Menstrual blood-derived mesenchymal stem cells (MenSCs) can ameliorate liver fibrosis through paracrine. Single-cell RNA sequencing (scRNA-seq) may be used to explore the roadmap of activated hepatic stellate cell (aHSC) inactivation to target liver fibrosis. This study established HBV transgenic (HBV-Tg) mouse model of carbon tetrachloride (CCl4)-induced liver fibrosis and demonstrated that MenSCs migrated to the injured liver to improve serological indices and reduce fibrotic accumulation. RNA-bulk analysis revealed that MenSCs mediated extracellular matrix accumulation and cell adhesion. Liver parenchymal cells and nonparenchymal cells were identified by scRNA-seq in the control, CCl4, and MenSC groups, revealing the heterogeneity of fibroblasts/HSCs. A CellChat analysis revealed that diminished intercellular adhesion molecule (ICAM) signaling is vital for MenSC therapy. Specifically, Icam1 in aHSCs acted on Itgal/Itgb2 and Itgam/Itgb2 in neutrophils, causing decreased adhesion. The expression of Itgal, Itgam, and Itgb2 was higher in CCl4 group than in the control group and decreased after MenSC therapy in neutrophil clusters. The Lcn2, Pglyrp1, Wfdc21, and Mmp8 had high expression and may be potential targets in neutrophils. This study highlights interacting cells, corresponding molecules, and underlying targets for MenSCs in treating HBV-associated liver fibrosis.

Aptamer-functionalized nanomaterials (AFNs) for therapeutic management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents one of the deadliest cancers globally, making the search for more effective diagnostic and therapeutic approaches particularly crucial. Aptamer-functionalized nanomaterials (AFNs), an innovative nanotechnology, have paved new pathways for the targeted diagnosis and treatment of HCC. Initially, we outline the epidemiological background of HCC and the current therapeutic challenges. Subsequently, we explore in detail how AFNs enhance diagnostic and therapeutic efficiency and reduce side effects through the specific targeting of HCC cells and the optimization of drug delivery. Furthermore, we address the challenges faced by AFNs in clinical applications and future research directions, with a particular focus on enhancing their biocompatibility and assessing long-term effects. In summary, AFNs represent an avant-garde therapeutic approach, opening new avenues and possibilities for the diagnosis and treatment of HCC.

Mesothelin CAR T Cells Secreting Anti-FAP/Anti-CD3 Molecules Efficiently Target Pancreatic Adenocarcinoma and its Stroma

PURPOSE

Targeting solid tumors with chimeric antigen receptor (CAR) T cells remains challenging due to heterogenous target antigen expression, antigen escape, and the immunosuppressive tumor microenvironment (TME). Pancreatic cancer is characterized by a thick stroma generated by cancer-associated fibroblasts (CAF), which may contribute to the limited efficacy of mesothelin-directed CAR T cells in early-phase clinical trials. To provide a more favorable TME for CAR T cells to target pancreatic ductal adenocarcinoma (PDAC), we generated T cells with an antimesothelin CAR and a secreted T-cell-engaging molecule (TEAM) that targets CAF through fibroblast activation protein (FAP) and engages T cells through CD3 (termed mesoFAP CAR-TEAM cells).

EXPERIMENTAL DESIGN

Using a suite of in vitro, in vivo, and ex vivo patient-derived models containing cancer cells and CAF, we examined the ability of mesoFAP CAR-TEAM cells to target PDAC cells and CAF within the TME. We developed and used patient-derived ex vivo models, including patient-derived organoids with patient-matched CAF and patient-derived organotypic tumor spheroids.

RESULTS

We demonstrated specific and significant binding of the TEAM to its respective antigens (CD3 and FAP) when released from mesothelin-targeting CAR T cells, leading to T-cell activation and cytotoxicity of the target cell. MesoFAP CAR-TEAM cells were superior in eliminating PDAC and CAF compared with T cells engineered to target either antigen alone in our ex vivo patient-derived models and in mouse models of PDAC with primary or metastatic liver tumors.

CONCLUSIONS

CAR-TEAM cells enable modification of tumor stroma, leading to increased elimination of PDAC tumors. This approach represents a promising treatment option for pancreatic cancer.

The Origin and Fate of Liver Myofibroblasts

Liver fibrosis of different etiologies is a serious health problem worldwide. There is no effective therapy available for liver fibrosis except the removal of the underlying cause of injury or liver transplantation. Development of liver fibrosis is caused by fibrogenic myofibroblasts that are not present in the normal liver, but rather activate from liver resident mesenchymal cells in response to chronic toxic or cholestatic injury. Many studies indicate that liver fibrosis is reversible when the causative agent is removed. Regression of liver fibrosis is associated with the disappearance of activated myofibroblasts and resorption of the fibrous scar. In this review, we discuss the results of genetic tracing and cell fate mapping of hepatic stellate cells and portal fibroblasts, their specific characteristics, and potential phenotypes. We summarize research progress in the understanding of the molecular mechanisms underlying the development and reversibility of liver fibrosis, including activation, apoptosis, and inactivation of myofibroblasts.

How to calculate sample size in animal and human studies

One of the most important statistical analyses when designing animal and human studies is the calculation of the required sample size. In this review, we define central terms in the context of sample size determination, including mean, standard deviation, statistical hypothesis testing, type I/II error, power, direction of effect, effect size, expected attrition, corrected sample size, and allocation ratio. We also provide practical examples of sample size calculations for animal and human studies based on pilot studies, larger studies similar to the proposed study-or if no previous studies are available-estimated magnitudes of the effect size per Cohen and Sawilowsky.

Two cases of severe pulmonary toxicity from highly active mesothelin-directed CAR T cells

Multiple clinical studies have treated mesothelin (MSLN)-positive solid tumors by administering MSLN-directed chimeric antigen receptor (CAR) T cells. Although these products are generally safe, efficacy is limited. Therefore, we generated and characterized a potent, fully human anti-MSLN CAR. In a phase 1 dose-escalation study of patients with solid tumors, we observed two cases of severe pulmonary toxicity following intravenous infusion of this product in the high-dose cohort (1-3 × 108 T cells per m2). Both patients demonstrated progressive hypoxemia within 48 h of infusion with clinical and laboratory findings consistent with cytokine release syndrome. One patient ultimately progressed to grade 5 respiratory failure. An autopsy revealed acute lung injury, extensive T cell infiltration, and accumulation of CAR T cells in the lungs. RNA and protein detection techniques confirmed low levels of MSLN expression by benign pulmonary epithelial cells in affected lung and lung samples obtained from other inflammatory or fibrotic conditions, indicating that pulmonary pneumocyte and not pleural expression of mesothelin may lead to dose-limiting toxicity. We suggest patient enrollment criteria and dosing regimens of MSLN-directed therapies consider the possibility of dynamic expression of mesothelin in benign lung with a special concern for patients with underlying inflammatory or fibrotic conditions.

Antifibrotic Soluble Thy-1 Correlates with Renal Dysfunction in Chronic Kidney Disease

Kidney fibrosis is a major culprit in the development and progression of chronic kidney disease (CKD), ultimately leading to the irreversible loss of organ function. Thymocyte differentiation antigen-1 (Thy-1) controls many core functions of fibroblasts relevant to fibrogenesis but is also found in a soluble form (sThy-1) in serum and urine. We investigated the association of sThy-1 with clinical parameters in patients with CKD receiving hemodialysis treatment compared to individuals with a preserved renal function. Furthermore, Thy-1 tissue expression was detected in a mouse model of diabetic CKD (eNOS-/-; db/db) and non-diabetic control mice (eNOS-/-). Serum and urinary sThy-1 concentrations significantly increased with deteriorating renal function, independent of the presence of diabetes. Serum creatinine is the major, independent, and inverse predictor of serum sThy-1 levels. Moreover, sThy-1 is not only predicted by markers of renal function but is also itself an independent and strong predictor of markers of renal function, i.e., serum creatinine. Mice with severe diabetic CKD show increased Thy-1 mRNA and protein expression in the kidney compared to control animals, as well as elevated urinary sThy-1 levels. Pro-fibrotic mediators, such as interleukin (IL)-4, IL-13, IL-6 and transforming growth factor β, increase Thy-1 gene expression and release of sThy-1 from fibroblasts. Our data underline the role of Thy-1 in the control of kidney fibrosis in CKD and raise the opportunity that Thy-1 may function as a renal antifibrotic factor.

The Role of Mesothelin in Activation of Portal Fibroblasts in Cholestatic Liver Injury

Fibrosis is a common consequence of abnormal wound healing, which is characterized by infiltration of myofibroblasts and formation of fibrous scar. In liver fibrosis, activated Hepatic Stellate Cells (aHSCs) and activated Portal Fibroblasts (aPFs) are the major contributors to the origin of hepatic myofibroblasts. aPFs are significantly involved in the pathogenesis of cholestatic fibrosis, suggesting that aPFs may be a primary target for anti-fibrotic therapy in cholestatic injury. aPFs are distinguishable from aHSCs by specific markers including mesothelin (Msln), Mucin 16 (Muc16), and Thymus cell antigen 1 (Thy1, CD90) as well as fibulin 2, elastin, Gremlin 1, ecto-ATPase nucleoside triphosphate diphosphohydrolase 2. Msln plays a critical role in activation of PFs, via formation of Msln-Muc16-Thy1 complex that regulates TGFβ1/TGFβRI-mediated fibrogenic signaling. The opposing pro- and anti-fibrogenic effects of Msln and Thy1 are key components of the TGFβ1-induced activation pathway in aPFs. In addition, aPFs and activated lung and kidney fibroblasts share similarities across different organs with expression of common markers and activation cascade including Msln-Thy1 interaction. Here, we summarize the potential function of Msln in activation of PFs and development of cholestatic fibrosis, offering a novel perspective for anti-fibrotic therapy targeting Msln.

Immunotherapy targeting mesothelin in acute myeloid leukemia

Mesothelin (MSLN) is an emerging target that exists in soluble and membrane-associated forms. It is usually used for the diagnosis and treatment of MSLN-positive solid tumors. Interestingly, recent studies have shown that MSLN is highly expressed in 36% of acute myeloid leukemia (AML) patients and barely expressed in normal hematopoietic cells, which makes MSLN a promising target for the treatment of AML. It has been shown that MSLN is detectable as a diagnostic marker in its soluble form. Although the mechanism of action is unclear, MSLN remains a promising target for immunotherapy. Most MSLN research has been conducted in solid tumors, and less research has been conducted in hematopoietic tumors. Increasing research on MSLN is underway in AML, a hematopoietic neoplasm. For example, MSLN is related to extramedullary disease, minimal residual disease, and relapse in AML patients. Decreasing the expression of MSLN reduces the severity of the disease course. This information suggests that MSLN may be an ideal target for the treatment of many AML-related diseases to improve the prognosis and survival rate. At present, there are a few immunotherapies targeting MSLN in AML in preclinical and clinical trials, such as antibody-drug conjugates, bispecific T-cell engagers, and chimeric antigen receptor-T cells, which opens new room for the treatment of MSLN-related AML.

Thy-1-Integrin Interactions in cis and Trans Mediate Distinctive Signaling

Thy-1 is a cell surface glycosylphosphatidylinositol (GPI)-anchored glycoprotein that bears a broad mosaic of biological roles across various cell types. Thy-1 displays strong physiological and pathological implications in development, cancer, immunity, and tissue fibrosis. Quite uniquely, Thy-1 is capable of mediating integrin-related signaling through direct trans- and cis-interaction with integrins. Both interaction types have shown distinctive roles, even when interacting with the same type of integrin, where binding in trans or in cis often yields divergent signaling events. In this review, we will revisit recent progress and discoveries of Thy-1–integrin interactions in trans and in cis, highlight their pathophysiological consequences and explore other potential binding partners of Thy-1 within the integrin regulation/signaling paradigm.

Structure based innovative approach to analyze aptaprobe-GPC3 complexes in hepatocellular carcinoma

BACKGROUND

Glypican-3 (GPC3), a membrane-bound heparan sulfate proteoglycan, is a biomarker of hepatocellular carcinoma (HCC) progression. Aptamers specifically binding to target biomolecules have recently emerged as clinical disease diagnosis targets. Here, we describe 3D structure-based aptaprobe platforms for detecting GPC3, such as aptablotting, aptaprobe-based sandwich assay (ALISA), and aptaprobe-based imaging analysis.

RESULTS

For preparing the aptaprobe-GPC3 platforms, we obtained 12 high affinity aptamer candidates (GPC3_1 to GPC3_12) that specifically bind to target GPC3 molecules. Structure-based molecular interactions identified distinct aptatopic residues responsible for binding to the paratopic nucleotide sequences (nt-paratope) of GPC3 aptaprobes. Sandwichable and overlapped aptaprobes were selected through structural analysis. The aptaprobe specificity for using in HCC diagnostics were verified through Aptablotting and ALISA. Moreover, aptaprobe-based imaging showed that the binding property of GPC3_3 and their GPC3 specificity were maintained in HCC xenograft models, which may indicate a new HCC imaging diagnosis.

CONCLUSION

Aptaprobe has the potential to be used as an affinity reagent to detect the target in vivo and in vitro diagnosing system.

The role of Mesothelin signaling in Portal Fibroblasts in the pathogenesis of cholestatic liver fibrosis

Liver fibrosis develops in response to chronic toxic or cholestatic injury, and is characterized by apoptosis of damaged hepatocytes, development of inflammatory responses, and activation of Collagen Type I producing myofibroblasts that make liver fibrotic. Two major cell types, Hepatic Stellate Cells (HSCs) and Portal Fibroblasts (PFs) are the major source of hepatic myofibroblasts. Hepatotoxic liver injury activates Hepatic Stellate Cells (aHSCs) to become myofibroblasts, while cholestatic liver injury activates both aHSCs and Portal Fibroblasts (aPFs). aPFs comprise the major population of myofibroblasts at the onset of cholestatic injury, while aHSCs are increasingly activated with fibrosis progression. Here we summarize our current understanding of the role of aPFs in the pathogenesis of cholestatic fibrosis, their unique features, and outline the potential mechanism of targeting aPFs in fibrotic liver.