PIM1 promotes hepatic conversion by suppressing reprogramming-induced ferroptosis and cell cycle arrest

Comprehensive evaluation of phosphoproteomic-based kinase activity inference

Kinases regulate cellular processes and are essential for understanding cellular function and disease. To investigate the regulatory state of a kinase, numerous methods have been developed to infer kinase activities from phosphoproteomics data using kinase-substrate libraries. However, few phosphorylation sites can be attributed to an upstream kinase in these libraries, limiting the scope of kinase activity inference. Moreover, inferred activities vary across methods, necessitating evaluation for accurate interpretation. Here, we present benchmarKIN, an R package enabling comprehensive evaluation of kinase activity inference methods. Alongside classical perturbation experiments, benchmarKIN introduces a tumor-based benchmarking approach utilizing multi-omics data to identify highly active or inactive kinases. We used benchmarKIN to evaluate kinase-substrate libraries, inference algorithms and the potential of adding predicted kinase-substrate interactions to overcome the coverage limitations. Our evaluation shows most computational methods perform similarly, but the choice of library impacts the inferred activities with a combination of manually curated libraries demonstrating superior performance in recapitulating kinase activities. Additionally, in the tumor-based evaluation, adding predicted targets from NetworKIN further boosts the performance. We then demonstrate how kinase activity inference aids characterize kinase inhibitor responses in cell lines. Overall, benchmarKIN helps researchers to select reliable methods for identifying deregulated kinases.

Targeting PIM1 by Bruceine D attenuates skin fibrosis via myofibroblast ferroptosis

Skin pan-fibrosis diseases-such as hypertrophic scar (HS), keloid scar (KS), and systemic sclerosis (SSc)-pose significant threats to patients' health and quality of life. In this study, the authors conducted both in vivo and in vitro experiments and discovered that the serine/threonine kinase PIM1 is upregulated in the myofibroblasts of human HS, KS, and SSc tissues, as well as in various animal models of skin fibrosis. Overexpression of PIM1 enhanced the profibrotic phenotypes of human hypertrophic scar fibroblasts (HSFs), which serve as key effector cells in the pathogenesis of skin pan-fibrosis diseases. Through high-throughput screening and subsequent laboratory assays, we identified the small molecule Bruceine D (BD) as a direct binder of PIM1. BD promoted ferroptosis in HSFs by selectively suppressing the PIM1-KEAP1-NRF2 pathway through augmented degradation of PIM1. In various in vivo models-including a hypertrophic scar mouse model, a rabbit ear hypertrophic scar model, and a bleomycin (BLM)-induced skin fibrosis mouse model-BD effectively attenuated fibrotic phenotypes. Collectively, these findings demonstrate that PIM1 serves as a common biomarker and therapeutic target for skin pan-fibrosis diseases. BD mitigates skin fibrosis by activating ferroptosis via PIM1 inhibition, highlighting its great translational potential and high promise to be developed to a clinical drug in treating these conditions, especially those with abnormally elevated PIM1 expression.

Phosphoproteomics profiling of sorafenib-resistant hepatocellular carcinoma patient-derived xenografts reveals potential therapeutic strategies

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer with poor prognosis. Sorafenib, a first-line treatment for advanced HCC, has shown limited clinical benefits due to the onset of drug resistance. Thus, it is imperative to comprehend the mechanisms underlying sorafenib resistance and explore strategies to overcome or delay it. Here, we established HCC patient-derived xenograft (PDX) models with acquired resistance to sorafenib and performed comprehensive proteomic and phosphoproteomic analyses on these models. The active cell cycle pathway along with the active cyclin-dependent kinase CDK1 and DNA-dependent protein kinase PRKDC was identified through KEGG pathway enrichment and kinase substrate enrichment analyses. Upon investigating the potential of combining sorafenib with putative kinase inhibitors, we found that the combination displays synergistic anti-proliferative effects in the sorafenib-resistant liver cancer cell line, thus providing a proof of concept for phosphoproteomic-guided design of precision medicine.

PIM1 signaling in immunoinflammatory diseases: an emerging therapeutic target

PIM1, the proviral integration site for Moloney murine leukemia virus, is a member of the serine/threonine protein kinase family. It is involved in many biological events, such as cell survival, cell cycle progression, cell proliferation, and cell migration, and has been widely studied in malignant diseases. However, recent studies have shown that PIM1 plays a prominent role in immunoinflammatory diseases, including autoimmune uveitis, inflammatory bowel disease, asthma, and rheumatoid arthritis. PIM1 can function in inflammatory signal transduction by phosphorylating multiple inflammatory protein substrates and mediating macrophage activation and T lymphocyte cell specification, thus participating in the development of multiple immunoinflammatory diseases. Moreover, the inhibition of PIM1 has been demonstrated to ameliorate certain immunoinflammatory disorders. Based on these studies, we suggest PIM1 as a potential therapeutic target for immunoinflammatory diseases and a valid candidate for future research. Herein, for the first time, we provide a detailed review that focuses on the roles of PIM1 in the pathogenesis of immunoinflammatory diseases.

Revitalizing liver function in mice with liver failure through transplantation of 3D-bioprinted liver with expanded primary hepatocytes

The utilization of three-dimensional (3D) bioprinting technology to create a transplantable bioartificial liver emerges as a promising remedy for the scarcity of liver donors. This study outlines our strategy for constructing a 3D-bioprinted liver, using in vitro-expanded primary hepatocytes recognized for their safety and enhanced functional robustness as hepatic cell sources for bioartificial liver construction. In addition, we have developed bioink biomaterials with mechanical and rheological properties, as well as printing capabilities, tailored for 3D bioprinting. Upon heterotopic transplantation into the mesentery of tyrosinemia or 90% hepatectomy mice, our 3D-bioprinted liver effectively restored lost liver functions, consequently extending the life span of mice afflicted with liver injuries. Notably, the inclusion of an artificial blood vessel in our 3D-bioprinted liver allowed for biomolecule exchange with host blood vessels, demonstrating, in principle, the rapid integration of the bioartificial liver into the host vascular system. This model underscores the therapeutic potential of transplantation for the treatment of liver failure diseases.

Kinase PIM1 governs ferroptosis to reduce retinal microvascular endothelial cell dysfunction triggered by high glucose

Previous studies have implicated targeting Pim-1 proto-oncogene, serine/threonine kinase (PIM1) as a preventive measure against high glucose-induced cellular stress and apoptosis. This study aimed to reveal the potential role and regulatory mechanism of PIM1 in diabetic retinopathy. Human retinal microvascular endothelial cells (hRMECs) underwent high glucose induction, and fluctuations in PIM1 levels were assessed. By overexpressing PIM1, its effects on the levels of inflammatory factors, oxidative stress indicators, migration and tube formation abilities, tight junction protein expression levels, and ferroptosis in hRMECs were identified. Afterwards, hRMECs were treated with the ferroptosis-inducing agent erastin, and the effect of erastin on the above PIM1 regulatory functions was focused on. PIM1 was downregulated upon high glucose, and its overexpression inhibited the inflammatory response, oxidative stress, cell migration, and tube formation potential in hRMECs, whereas elevated tight junction protein levels. Furthermore, PIM1 overexpression reduced intracellular iron ion levels, lipid peroxidation, and levels of proteins actively involved in ferroptosis. Erastin treatment reversed the impacts of PIM1 on hRMECs, suggesting the mediation of ferroptosis in PIM1 regulation. The current study has yielded critical insights into the role of PIM1 in ameliorating high glucose-induced hRMEC dysfunction through the inhibition of ferroptosis.

Advancements of 3D bioprinting in regenerative medicine: Exploring cell sources for organ fabrication

3D bioprinting has unlocked new possibilities for generating complex and functional tissues and organs. However, one of the greatest challenges lies in selecting the appropriate seed cells for constructing fully functional 3D artificial organs. Currently, there are no cell sources available that can fulfill all requirements of 3D bioprinting technologies, and each cell source possesses unique characteristics suitable for specific applications. In this review, we explore the impact of different 3D bioprinting technologies and bioink materials on seed cells, providing a comprehensive overview of the current landscape of cell sources that have been used or hold potential in 3D bioprinting. We also summarized key points to guide the selection of seed cells for 3D bioprinting. Moreover, we offer insights into the prospects of seed cell sources in 3D bioprinted organs, highlighting their potential to revolutionize the fields of tissue engineering and regenerative medicine.

PIM3 regulates myocardial ischemia/reperfusion injury via ferroptosis

BACKGROUND

Myocardial ischemia/reperfusion (I/R) injury is closely related with cardiovascular diseases; however, the underlying pathogenic mechanisms remain not fully understood. This study sought to investigate the effect and mechanisms of PIM3 implicated in myocardial I/R injury using a rat model of myocardial I/R injury and a cell model of oxygen-glucose deprivation/reoxygenation (OGD/R) induction.

METHODS

The morphology changes were detected by HE staining while cell viability was accessed by the CCK-8 method. The characteristics of ferroptosis were evaluated by ROS production, MDA content, SOD level, iron content, TfR1, FTH1, and GPX4 expression.

RESULTS

Myocardial I/R operation increased myocardial tissue damage in rats, while OGD/R treatment reduced the viability of H9c2 cells. Both myocardial I/R operation and OGD/R stimulation increased ferroptosis, as demonstrated by elevated ROS, MDA, iron content, decreased SOD level, upregulation of TfR1, and downregulation of FTH1 and GPX4. Additionally, myocardial I/R modeling or OGD/R treatment enhanced the expression of PIM3. Silencing of PIM3 inhibited ferroptosis, which resulted in alleviated myocardial I/R-induced damage and improved H9c2 cell survival.

CONCLUSIONS

Our findings highlight a vital role of PIM3 in myocardial I/R injury, indicating that PIM3-targeting ferroptosis may be a promising target for the development of novel therapies of myocardial I/R injury-associated diseases.