Oncogenic BRAF induces senescence and apoptosis through pathways mediated by the secreted protein IGFBP7

Therapeutic targeting the cGAS-STING pathway associated with protein and gene: An emerging and promising novel strategy for aging-related neurodegenerative disease

Neurodegenerative diseases (NDDs) represent a rapidly escalating global health challenge, contributing significantly to the worldwide disease burden and posing substantial threats to public health systems across nations. Among the many risk factors for neurodegeneration, aging is the major risk factor. In the context of aging, multiple factors lead to the release of endogenous DNA (especially mitochondrial DNA, mtDNA), which is an important trigger for the activation of the cGAS-STING innate immune pathway. Recent studies have identified an increasing role for activation of the cGAS-STING signaling pathway as a driver of senescence-associated secretory phenotypes (SASPs) in aging and NDDs. The cGAS-STING pathway mediates the immune sensing of DNA and is a key driver of chronic inflammation and functional decline during the aging process. Blocking cGAS-STING signaling may reduce the inflammatory response by preventing mtDNA release and enhancing mitophagy. Targeted inhibition of the cGAS-STING pathway by biological macromolecules such as natural products shows promise in therapeutic strategies for age-related NDDs. This review aims to systematically and comprehensively introduces the role of the cGAS-STING pathway in age-related NDDs in the context of aging while revealing the molecular mechanisms of the cGAS-STING pathway and its downstream signaling pathways and to develop more targeted and effective therapeutic strategies for NDDs.

Prolonged exposure to leisure screen time notably accelerates biological aging: Evidence from observational studies and genetic associations

LST is steadily increasing and is associated with various health issues. However, its impact on aging remains unclear. A total of 7212 participants from NHANES 1999-2002 were included. LTL, ALM, and FI were selected as aging phenotypes. Observational association between LST and aging traits was analyzed using linear regression models. MR analyses based on 112 genetic variants were performed to test the causal estimates from LST on aging. TWAS and PPI analyses were conducted to investigate underlying biological mechanisms. After adjusting for physical activity, per 1 ​h increase in LST, participants had a shorter LTL (β ​= ​-1.39, 95 ​% CI: -2.47 to -0.30), a lower ALM (β ​= ​-1.09, 95 ​% CI: -1.39 to -0.70), and an increased FI (β ​= ​8.22, 95 ​% CI: 4.29 to 12.30). Likewise, TSMR analyses indicated that genetically increased LST was significantly associated with shorter LTL (β ​= ​-2.63, 95 ​% CI: -4.86 to -0.35), lower ALM (β ​= ​-6.56, 95 ​% CI: -9.43 to -3.60), and increased FI (β ​= ​20.16, 95 ​% CI: 15.73 to 24.77). The trend remained robust after tests for pleiotropy and heterogeneity, consistent with the results of MVMR. 4 hub genes and 15 co-localized genes are identified, respectively, from PPI networks and TWAS. Pathways related to immune reactions, oxidative stress, and protein metabolism were significantly enriched. This study revealed that increased LST is significantly associated with adverse aging phenotypes. Reducing LST may help alleviate the burden of aging.

H, Elsayed Ahmed R, Muralidharan P, Paulsamy P. SASP Modulation for Cellular Rejuvenation and Tissue Homeostasis: Therapeutic Strategies and Molecular Insights

Cellular senescence regulates aging, tissue maintenance, and disease progression through the Senescence-Associated Secretory Phenotype (SASP), a secretory profile of cytokines, chemokines, growth factors, and matrix-remodeling enzymes. While transient SASP aids wound healing, its chronic activation drives inflammation, fibrosis, and tumorigenesis. This review examines SASP's molecular regulation, dual roles in health and pathology, and therapeutic potential. The following two main strategies are explored: senescence clearance, which eliminates SASP-producing cells, and SASP modulation, which refines secretion to suppress inflammation while maintaining regenerative effects. Key pathways, including NF-κB, C/EBPβ, and cGAS-STING, are discussed alongside pharmacological, immunotherapeutic, gene-editing, and epigenetic interventions. SASP heterogeneity necessitates tissue-specific biomarkers for personalized therapies. Challenges include immune interactions, long-term safety, and ethical considerations. SASP modulation emerges as a promising strategy for aging, oncology, and tissue repair, with future advancements relying on multi-omics and AI-driven insights to optimize clinical outcomes.

Metabolic anomalies in vitiligo: a new frontier for drug repurposing strategies

Vitiligo is a chronic autoimmune condition characterized by the destruction of melanocytes, leading to patchy loss of skin depigmentation. Although its precise cause remains unclear, recent evidence suggests that metabolic disturbances, particularly oxidative stress and mitochondrial dysfunction, may play a significant role in the pathogenesis of the disease. Oxidative stress is thought to damage melanocytes and trigger inflammatory responses, culminating in melanocyte immune-mediate destruction. Additionally, patients with vitiligo often exhibit extra-cutaneous metabolic abnormalities such as abnormal glucose metabolism, dyslipidemia, high fasting plasma glucose levels, high blood pressure, out of range C-peptide and low biological antioxidant capacity, suggesting a potential link between metabolic impairment and vitiligo development. This implies that the loss of functional melanocytes mirrors a more general systemic targetable dysfunction. Notably, therapies targeting metabolic pathways, particularly those involving mitochondrial metabolism, such as the peroxisome proliferator-activated nuclear receptor γ (PPARγ) agonists, are currently being investigated as potential treatments for vitiligo. PPARγ activation restores mitochondrial membrane potential, mitochondrial DNA copy number and, consequently, ATP production. Moreover, PPARγ agonists counteract oxidative stress, reduce inflammation, inhibit apoptosis, and maintain fatty acid metabolism, in addition to the well-known capability to enhance insulin sensitivity. Additionally, increasing evidence of a strong relationship between metabolic alterations and vitiligo pathogenesis suggests a role for other approved anti-diabetic treatments, like metformin and fibrates, in vitiligo treatment. Taken together, these data support the use of approaches alternative to traditional immune-suppressive treatments for the treatment of vitiligo.

Genetic geroscience and Alzheimer's disease: The pleiotropy is the point!

Geroscience aims to understand how the biology of aging serves as a shared contributor to multiple age-related health conditions. Genetic variants that influence multiple traits are said to exert pleiotropic effects. The study by Pan and colleagues applied a modern statistical model to identify genetic variants with potentially pleiotropic effects by assessing their joint association with Alzheimer's disease and related dementias and another age-related comorbidity (e.g., coronary heart disease, hyperlipidemia, cancer). Motivated by Pan and colleagues, this commentary introduces the concept of genetic geroscience as a paradigm for identifying genetic variants with potentially pleotropic effects on multiple age-related health conditions.

Mechanisms of mitochondrial reactive oxygen species action in bone mesenchymal cells

Mitochondrial (mt)ROS, insufficient NAD+, and cellular senescence all contribute to the decrease in bone formation with aging. ROS can cause senescence and decrease NAD+, but it remains unknown whether these mechanisms mediate the effects of ROS in vivo. Here, we generated mice lacking the mitochondrial antioxidant enzyme Sod2 in osteoblast lineage cells targeted by Osx1-Cre and showed that Sod2ΔOsx1 mice had low bone mass. Osteoblastic cells from these mice had impaired mitochondrial respiration and attenuated NAD+ levels. Administration of an NAD+ precursor improved mitochondrial function in vitro but failed to rescue the low bone mass of Sod2ΔOsx1 mice. Single-cell RNA-sequencing of bone mesenchymal cells indicated that ROS had no significant effects on markers of senescence but disrupted parathyroid hormone signaling, iron metabolism, and proteostasis. Our data supports the rationale that treatment combinations aimed at decreasing mtROS and senescent cells and increasing NAD+ should confer additive effects in delaying age-associated osteoporosis.

Comprehensive investigation of multiple targets in the development of newer drugs for the Alzheimer's disease

Alzheimer's disease, a significant contributor to dementia, is rapidly becoming a serious healthcare concern in the 21st century. The alarming number of patients with Alzheimer's disease is steadily increasing, which is contributed by the dearth of treatment options. The current treatment for Alzheimer's disease is heavily dependent on symptomatic treatment that has failed to cure the disease despite huge investments in the development of drugs. The clinical treatment of Alzheimer's disease with limited drugs is generally targeted towards the inhibition of N-methyl-d-aspartate receptor and acetylcholine esterase, which only elevate cognition levels for a limited period. Beyond the aforementioned molecular targets, β-amyloid was much explored with little success and thus created a feel and palpable growing emphasis on discovering new putative and novel targets for AD. This has inspired medicinal chemists to explore new targets, including microglia, triggering receptors expressed on myeloid cells 2 (Trem-2), and notum carboxylesterase, to discover new lead compounds. This review explores the functions, pathophysiological roles, and importance of all AD-related targets that address therapeutic and preventive approaches for the treatment and protection of Alzheimer's disease.

Uncovering the Signatures of Cellular Senescence in the Human Dorsolateral Prefrontal Cortex

Identifying senescent cells poses challenges due to their rarity, heterogeneity, and lack of a definitive marker. We performed Visium spatial transcriptomics (ST) and single nucleus RNA sequencing (snRNA-seq) on non-pathological human tissue to build a transcriptomic atlas of aging and senescence in the dorsolateral prefrontal cortex (dlPFC). We identified markers characteristic of aging dlPFC cortical layers and cell types. We also observed an increase in astrocyte abundance and decrease in somatostatin expressing inhibitory neurons. Overall, the senescence profile in the dlPFC was highly heterogeneous and heavily influenced by cell type identity and cortical layer. Combined unbiased analysis of ST and snRNA-seq datasets revealed gene expression modules encoding for communities of microglia and endothelial cells in the white matter and regional astrocytes programs that were strongly enriched with age and for senescence-related genes. These findings will help facilitate future studies exploring the function of senescent cell subpopulations in the aging brain.

Molecular Biomarkers in Borderline Ovarian Tumors: Towards Personalized Treatment and Prognostic Assessment

Borderline Ovarian Tumours (BOTs) are a heterogenous group of ovarian neoplasms which have increased mitotic activity but lack stromal invasion. We performed a narrative review of the literature, aiming to identify prognostic molecular biomarkers that can potentially be used for treatment personalisation. We identified and discussed BRAF/KRAS, Cancer Antigen 125 (Ca 125), Calprotectin, p16ink4a, and Microsatellite instability (MSI) as the most studied biomarkers related to BOTs. Overall, BRAF and KRAS mutations are associated with earlier-stage and favourable prognosis; KRASmt may indicate extraovarian disease in serous BOT (sBOT). Ca125, the only currently clinically used biomarker, can be assessed pre-operatively and has an established role in post-operative surveillance, especially when it is raised pre-operatively or a high potential for malignant transformation is suspected post-operatively. p16ink4a expression trends could also indicate the malignant transformation of the tumour. Calprotectin has an inferior specificity to Ca125 and is not yet established as a biomarker, whilst there is very limited evidence available for MSI. As new evidence is coming along with artificial intelligence platforms, these biomarkers can be integrated and used towards the development of a precision model for treatment stratification and counselling in women diagnosed with BOTs.

Proteomic Alterations in Retinal Müller Glial Cells Lacking Interleukin-6 Receptor: A Comprehensive Analysis

Purpose

Interleukin-6 (IL-6) is an inflammatory cytokine implicated in various retinal pathologies and functions primarily through two signaling pathways: cis-signaling via IL-6 binding to its membrane-bound receptor (IL-6Rα), and trans-signaling via IL-6 binding to soluble IL-6 receptor (sIL-6R). Because the differential effects of IL-6 signaling in retinal Müller glial cells (MGCs) remain unclear, we generated an MGC-specific Il6ra-/- knockout (KO) mouse to eliminate IL-6Rα and, consequently, IL-6 cis-signaling in MGCs. In this study, we examined the proteomic changes in MGCs isolated from KO mice lacking a functional IL-6Rα.

Methods

The proteomes of MGCs isolated from wild-type (WT) and KO mice were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and validated by parallel reaction monitoring (PRM). Relevant biological functions and pathways were examined using Gene Ontology and Ingenuity Pathway Analysis.

Results

LC-MS/MS detected 1866 proteins, of which 81 were significantly altered (41 upregulated, 40 downregulated). PRM analysis confirmed differential expression of Ptgis (fold change [FC] = 3.63), Dpep1 (FC = 2.79), Fmo1 (FC = 2.77), Igfbp7 (FC = 2.07), Rpb1 (FC = 1.73), Pygp (FC = 1.46), Niban 1 (FC = 0.58), Mest (FC = 0.48), and Aldh3a1 (FC = 0.30). The significantly altered proteins are involved in oxidative stress balance, inflammation, mitochondrial dysfunction, and regulation of vascular endothelial growth factor (VEGF) signaling.

Conclusions

The absence of IL-6Rα in KO MGCs corresponded to significant changes in their proteomic profile, highlighting the impact of autocrine IL-6 signaling on MGC function. This study provides a basis for future research evaluating distinct roles of IL-6 in MGCs and subsequent effects on retinal pathology.

Histopathologic and Molecular Insights Following the Management of Ameloblastomas via Targeted Therapies - Pathological and Clinical Perspectives

PURPOSE

Current standard of care for ameloblastoma (conventional/unicystic - mural type) usually mandates extensive bone resection that frequently necessitates immediate reconstruction with serious sequelae, especially among young patients. BRAF-mutated ameloblastomas can be targeted by BRAF inhibitors to markedly reduce their size, enabling conservative removal of residual tumor. We aimed to characterize the effect of post-treatment histomorphologic changes.

METHODS

Study included 14 patients, 11 mandibular and three maxillary tumors. Cases with very minimal residual tumor were defined as near-complete response, while those with mostly vital residual tumor as partial response. The epithelium component was scored for architectural and cellular changes, stroma - for fibrosis, inflammation and new bone formation, on a 3-tired score system: 0-no, 1-focal and 3-frequent changes. The mean scores of each parameter, total epithelium and total stroma were calculated and related to duration of treatment. Differences in the mean scores were investigated for mandibular tumors with near-complete response (n = 3) and partial response (n = 8).

RESULTS

There were no significant differences in mean epithelium or stroma scores between tumors with near-complete and those with partial response (2.22 ± 0.68 versus 2.08 ± 0.43, p = 0.55; 1.41 ± 1.04 versus 1.43 ± 0.44, p = 0.27), suggesting that ameloblastomas have potential to undergo complete response to targeted treatment. This is probably dependent upon tumor/patient/treatment-related factors. Response to treatment appears to be predictable with neoplastic epithelium being first, while the stromal response increases during treatment, the entire process expanding over weeks-to-months.

CONCLUSION

Albeit preliminary, these are the first comprehensive histomorphologic findings on BRAF-treated ameloblastomas. Analyzing the suggested parameters in tumors with partial response, should highlight which tumor component has responded/failed to respond. This could serve as a basis for decision-taking toward subsequent steps in adjuvant treatment (e.g., follow-up, conservative surgery, modifications/changes in treatment regimen, combinations of approaches), with a prime aim of jaw preservation and minimal risk of sequelae.

Interplay between epigenetics, senescence and cellular redox metabolism in cancer and its therapeutic implications

There is accumulating evidence indicating a close crosstalk between key molecular events regulating cell growth and proliferation, which could profoundly impact carcinogenesis and its progression. Here we focus on reviewing observations highlighting the interplay between epigenetic modifications, irreversible cell cycle arrest or senescence, and cellular redox metabolism. Epigenetic alterations, such as DNA methylation and histone modifications, dynamically influence tumour transcriptome, thereby impacting tumour phenotype, survival, growth and spread. Interestingly, the acquisition of senescent phenotype can be triggered by epigenetic changes, acting as a double-edged sword via its ability to suppress tumorigenesis or by facilitating an inflammatory milieu conducive for cancer progression. Concurrently, an aberrant redox metabolism, which is a function of the balance between reactive oxygen species (ROS) generation and intracellular anti-oxidant defences, influences signalling cascades and genomic stability in cancer cells by serving as a critical link between epigenetics and senescence. Recognizing this intricate interconnection offers a nuanced perspective for therapeutic intervention by simultaneously targeting specific epigenetic modifications, modulating senescence dynamics, and restoring redox homeostasis.

Cellular Senescence: A Bridge Between Diabetes and Microangiopathy

Cellular senescence is a state of permanent cell cycle arrest and plays an important role in many vascular lesions. This study found that the cells of diabetic patients have more characteristics of senescence, which may cause microvascular complications. Cell senescence, as one of the common fates of cells, links microangiopathy and diabetes. Cell senescence in a high-glucose environment can partially elucidate the mechanism of diabetic microangiopathy, and various types of cellular senescence induced by it can promote the progression of diabetic microangiopathy. Still, the molecular mechanism of microangiopathy-related cellular senescence has not yet been clearly studied. Building on recent research evidence, we herein summarize the fundamental mechanisms underlying the development of cellular senescence in various microangiopathies associated with diabetes. We gradually explain how cellular senescence serves as a key driver of diabetic microangiopathy. At the same time, the treatment of basic senescence mechanisms such as cellular senescence may have a great impact on the pathogenesis of the disease, may be more effective in preventing the development of diabetic microangiopathy, and may provide new ideas for the clinical treatment and prognosis of diabetic microangiopathy.

Treatment of a mutant KRAS lung cancer cell line with polyisoprenylated cysteinyl amide inhibitors activates the MAPK pathway, inhibits cell migration and induces apoptosis

KRAS mutations are the most common oncogenic mutations in lung adenocarcinoma in Black Americans. Polyisoprenylated Cysteinyl amide Inhibitors (PCAIs) constitute a group of potential cancer therapy agents that we designed to specifically disrupt and suppress hyperactive G-protein signaling, such as that caused by mutated RAS proteins. Here we determine the effects of PCAIs on the viability, G-protein levels, downstream mediators, and apoptosis-related proteins on the KRAS-mutated, Black American-derived lung adenocarcinoma cell line, NCI-H23. Of the 17 PCAIs tested, compounds NSL-YHJ-2-27 and NSL-YHJ-2-46 showed the most potency with EC50 values of 2.7 and 3.3 μM, respectively. Western blotting was used to determine the effect of the PCAIs on the phosphorylation levels of MAPK pathway enzymes. After 48 h exposure to 5 μM of the PCAIs, NSL-YHJ-2-46, the MAPK proteins BRAF, MEK1/2, ERK1/2, and p90RSK were activated through phosphorylation by 90, 190, 150 and 120%, respectively. However, CRAF/RAF1 phosphorylation decreased by 40%, suggesting significant changes in the KRAS/MAPK signaling patterns. Furthermore, 5 μM of NSL-YHJ-2-27 depleted the singly polyisoprenylated monomeric G-proteins RAC 1/2/3 and CDC42 by 77 and 76%, respectively. The depletion of these key cytoskeletal proteins may account for the observed inhibition of cell migration and invasion, and spheroid invasion observed on exposure to NSL-YHJ-2-27 and NSL-YHJ-2-46. Treatment with 5 μM of NSL-YHJ-2-27 suppressed full-length inactive caspase 3 and 7 levels by 72 and 91%, respectively. An analysis of cells treated with the fluorescently labeled active caspase 3/7 irreversible inhibitor, CaspaTagTM Caspase-3/7 in situ reagent revealed a 124% increase in active caspase at 3 μM over controls. These findings clearly show the direct effects of the PCAIs on the RAS signaling pathway. Given the profound increases observed in RPS6KA1/p90RSK phosphorylation, future work will involve a determination whether the proapoptotic isoforms of RPS6KA1/p90RSK are phosphorylated due to the PCAIs treatments. These results support the potential use of the PCAIs as targeted therapies against cancers with KRAS mutations.

IGFBP7 regulates cell proliferation and migration through JAK/STAT pathway in gastric cancer and is regulated by DNA and RNA methylation

New biomarkers for early diagnosis of gastric cancer (GC), the second leading cause of cancer-related death, are urgently needed. IGFBP7, known to play various roles in multiple tumours, is complexly regulated across diverse cancer types, as evidenced by our pancancer analysis. Bioinformatics analysis revealed that IGFBP7 expression was related to patient prognosis, tumour clinicopathological characteristics, tumour stemness, microsatellite instability and immune cell infiltration, as well as the expression of oncogenes and immune checkpoints. GSEA links IGFBP7 to several cancer-related pathways. IGFBP7 deficiency inhibited GC cell proliferation and migration in vitro. Furthermore, an in vivo nude mouse model revealed that IGFBP7 downregulation suppressed the tumorigenesis of GC cells. Western blotting analysis showed that the JAK1/2-specific inhibitor ruxolitinib could rescue alterations induced by IGFBP7 overexpression in GC cells. Additionally, our bioinformatics analysis and in vitro assays suggested that IGFBP7 is regulated by DNA methylation at the genetic level and that the RNA m6A demethylase FTO modulates it at the posttranscriptional level. This study emphasizes the clinical relevance of IGFBP7 in GC and its influence on cell proliferation and migration via the JAK/STAT signalling pathway. This study also highlights the regulation of IGFBP7 in GC by DNA and m6A RNA methylation.

HPV-YAP1 oncogenic alliance drives malignant transformation of fallopian tube epithelial cells

High grade serous ovarian carcinoma (HGSOC) is the most common and aggressive ovarian malignancy. Accumulating evidence indicates that HGSOC may originate from human fallopian tube epithelial cells (FTECs), although the exact pathogen(s) and/or molecular mechanism underlying the malignant transformation of FTECs is unclear. Here we show that human papillomavirus (HPV), which could reach FTECs via retrograde menstruation or sperm-carrying, interacts with the yes-associated protein 1 (YAP1) to drive the malignant transformation of FTECs. HPV prevents FTECs from natural replicative and YAP1-induced senescence, thereby promoting YAP1-induced malignant transformation of FTECs. HPV also stimulates proliferation and drives metastasis of YAP1-transformed FTECs. YAP1, in turn, stimulates the expression of the putative HPV receptors and suppresses the innate immune system to facilitate HPV acquisition. These findings provide critical clues for developing new strategies to prevent and treat HGSOC.

Alterations of receptors and insulin-like growth factor binding proteins in senescent cells

The knowledge about cellular senescence expands dynamically, providing more and more conclusive evidence of its triggers, mechanisms, and consequences. Senescence-associated secretory phenotype (SASP), one of the most important functional traits of senescent cells, is responsible for a large extent of their context-dependent activity. Both SASP's components and signaling pathways are well-defined. A literature review shows, however, that a relatively underinvestigated aspect of senescent cell autocrine and paracrine activity is the change in the production of proteins responsible for the reception and transmission of SASP signals, i.e., receptors and binding proteins. For this reason, we present in this article the current state of knowledge regarding senescence-associated changes in cellular receptors and insulin-like growth factor binding proteins. We also discuss the role of these alterations in senescence induction and maintenance, pro-cancerogenic effects of senescent cells, and aging-related structural and functional malfunctions.

Therapy-Induced Cellular Senescence: Potentiating Tumor Elimination or Driving Cancer Resistance and Recurrence?

Cellular senescence has been increasingly recognized as a hallmark of cancer, reflecting its association with aging and inflammation, its role as a response to deregulated proliferation and oncogenic stress, and its induction by cancer therapies. While therapy-induced senescence (TIS) has been linked to resistance, recurrence, metastasis, and normal tissue toxicity, TIS also has the potential to enhance therapy response and stimulate anti-tumor immunity. In this review, we examine the Jekyll and Hyde nature of senescent cells (SnCs), focusing on how their persistence while expressing the senescence-associated secretory phenotype (SASP) modulates the tumor microenvironment through autocrine and paracrine mechanisms. Through the SASP, SnCs can mediate both resistance and response to cancer therapies. To fulfill the unmet potential of cancer immunotherapy, we consider how SnCs may influence tumor inflammation and serve as an antigen source to potentiate anti-tumor immune response. This new perspective suggests treatment approaches based on TIS to enhance immune checkpoint blockade. Finally, we describe strategies for mitigating the detrimental effects of senescence, such as modulating the SASP or targeting SnC persistence, which may enhance the overall benefits of cancer treatment.

Vaccine Therapy for Heart Failure Targeting the Inflammatory Cytokine Igfbp7

BACKGROUND

The heart comprises many types of cells such as cardiomyocytes, endothelial cells (ECs), fibroblasts, smooth muscle cells, pericytes, and blood cells. Every cell type responds to various stressors (eg, hemodynamic overload and ischemia) and changes its properties and interrelationships among cells. To date, heart failure research has focused mainly on cardiomyocytes; however, other types of cells and their cell-to-cell interactions might also be important in the pathogenesis of heart failure.

METHODS

Pressure overload was imposed on mice by transverse aortic constriction and the vascular structure of the heart was examined using a tissue transparency technique. Functional and molecular analyses including single-cell RNA sequencing were performed on the hearts of wild-type mice and EC-specific gene knockout mice. Metabolites in heart tissue were measured by capillary electrophoresis-time of flight-mass spectrometry system. The vaccine was prepared by conjugating the synthesized epitope peptides with keyhole limpet hemocyanin and administered to mice with aluminum hydroxide as an adjuvant. Tissue samples from heart failure patients were used for single-nucleus RNA sequencing to examine gene expression in ECs and perform pathway analysis in cardiomyocytes.

RESULTS

Pressure overload induced the development of intricately entwined blood vessels in murine hearts, leading to the accumulation of replication stress and DNA damage in cardiac ECs. Inhibition of cell proliferation by a cyclin-dependent kinase inhibitor reduced DNA damage in ECs and ameliorated transverse aortic constriction-induced cardiac dysfunction. Single-cell RNA sequencing analysis revealed upregulation of Igfbp7 (insulin-like growth factor-binding protein 7) expression in the senescent ECs and downregulation of insulin signaling and oxidative phosphorylation in cardiomyocytes of murine and human failing hearts. Overexpression of Igfbp7 in the murine heart using AAV9 (adeno-associated virus serotype 9) exacerbated cardiac dysfunction, while EC-specific deletion of Igfbp7 and the vaccine targeting Igfbp7 ameliorated cardiac dysfunction with increased oxidative phosphorylation in cardiomyocytes under pressure overload.

CONCLUSIONS

Igfbp7 produced by senescent ECs causes cardiac dysfunction and vaccine therapy targeting Igfbp7 may be useful to prevent the development of heart failure.

Eosinophilic Cells in Ovarian Borderline Serous Tumors as a Predictor of BRAF Mutation

According to recent reports, ovarian serous borderline tumor (SBT) harboring the BRAF V600E mutation is associated with a lower risk of progression to low-grade serous carcinoma. Preliminary observations suggest that there may be an association between eosinophilic cells (ECs) and the above-mentioned mutation, so this study aimed to evaluate interobserver reproducibility for assessing ECs. Forty-two samples of SBTs were analyzed for ECs with abundant eosinophilic cytoplasm. Immunohistochemical staining and genetic pro-filing were performed in all cases to verify the BRAF V600E mutation. A BRAF V600E mutation was found in 19 of 42 (45%) cases. Inter-observer reproducibility in the assessment of ECs was substantial (κ = 0.7). The sensitivity and specificity for predicting the mutation were 79% and 91%, respectively. Patients with BRAF-mutated SBTs were significantly younger than those without mutation (p = 0.005). SBTs with BRAF mutation were less likely to be accompanied by non-invasive implants than wild-type SBT: 12% (2/17) versus 33% (6/18). Seven cases were excluded due to incomplete cytoreductive surgery. Nevertheless, Fisher's exact test showed no significant differences between the two groups (p = 0.228). Overall, this study strengthens the idea that ECs in ovarian SBTs may represent a mutation with prognostic significance, which can serve as a primary screening test for BRAF V600E mutation in this pathologic entity.

Too big not to fail: emerging evidence for size-induced senescence

Cellular senescence refers to a permanent and stable state of cell cycle exit. This process plays an important role in many cellular functions, including tumor suppression. It was first noted that senescence is associated with increased cell size in the early 1960s; however, how this contributes to permanent cell cycle exit was poorly understood until recently. In this review, we discuss new findings that identify increased cell size as not only a consequence but also a cause of permanent cell cycle exit. We highlight recent insights into how increased cell size alters normal cellular physiology and creates homeostatic imbalances that contribute to senescence induction. Finally, we focus on the potential clinical implications of these findings in the context of cell cycle arrest-causing cancer therapeutics and speculate on how tumor cell size changes may impact outcomes in patients treated with these drugs.

Cellular senescence in cancer: molecular mechanisms and therapeutic targets

Aging exhibits several hallmarks in common with cancer, such as cellular senescence, dysbiosis, inflammation, genomic instability, and epigenetic changes. In recent decades, research into the role of cellular senescence on tumor progression has received widespread attention. While how senescence limits the course of cancer is well established, senescence has also been found to promote certain malignant phenotypes. The tumor-promoting effect of senescence is mainly elicited by a senescence-associated secretory phenotype, which facilitates the interaction of senescent tumor cells with their surroundings. Targeting senescent cells therefore offers a promising technique for cancer therapy. Drugs that pharmacologically restore the normal function of senescent cells or eliminate them would assist in reestablishing homeostasis of cell signaling. Here, we describe cell senescence, its occurrence, phenotype, and impact on tumor biology. A "one-two-punch" therapeutic strategy in which cancer cell senescence is first induced, followed by the use of senotherapeutics for eliminating the senescent cells is introduced. The advances in the application of senotherapeutics for targeting senescent cells to assist cancer treatment are outlined, with an emphasis on drug categories, and the strategies for their screening, design, and efficient targeting. This work will foster a thorough comprehension and encourage additional research within this field.

Network of extracellular vesicles surrounding senescent cells

Extracellular vesicles (EVs) are small lipid bilayers released from cells that contain cellular components such as proteins, nucleic acids, lipids, and metabolites. Biological information is transmitted between cells via the EV content. Cancer and senescent cells secrete more EVs than normal cells, delivering more information to the surrounding recipient cells. Cellular senescence is a state of irreversible cell cycle arrest caused by the accumulation of DNA damage. Senescent cells secrete various inflammatory proteins known as the senescence-associated secretory phenotype (SASP). Inflammatory SASP factors, including small EVs, induce chronic inflammation and lead to various age-related pathologies. Recently, senolytic drugs that selectively induce cell death in senescent cells have been developed to suppress the pathogenesis of age-related diseases. This review describes the characteristics of senescent cells, the functions of EVs released from senescent cells, and the therapeutic effects of EVs on age-related diseases. Understanding the biology of EVs secreted from senescent cells will provide valuable insights for achieving healthy longevity in an aging society.

The role of miR-222-2p in exosomes secreted by hexavalent chromium-induced premature senescent hepatocytes as a SASP component

With the development of world industrialization, the environmental pollution of hexavalent chromium [Cr(VI)] is becoming an increasingly serious problem. In particular, the mechanisms by which long-term and low-dose exposure to Cr(VI) leading the development of related cancers are not well understood. As senescent cells gradually lose their ability to proliferate and divide, they will not be malignantly transformed. However, Senescence-associated secretory phenotype (SASP) released by senescent cells into the cellular microenvironment can act on neighboring cells. Since SASP has a bidirectional regulatory role in the malignant transformation of cells. Hence, It is very necessary to identified the composition and function of SASP which secreted by Cr(VI) induced senescent L02 hepatocytes (S-L02). Exosomes, a vesicle-like substances released extracellularly after the fusion of intracellular multivesicular bodies with cell membrane, are important components of SASP and contain a large number of microRNAs (miRNAs). By establishing Cr(VI)-induced S-L02 model, we collected the exosomes from the supernatants of S-L02 and L02 culture medium respectively, and screened out the highly expressed miRNAs in the exosomes of S-L02, namely the new SASP components. Among them, the increase of miR-222-5p was the most significant. It was validated that as SASP, miR-222-5p can inhibit the proliferation of L02 and S-L02 hepatocytes and at the same time accelerate the proliferation and migration ability of HCC cells. Further mechanistic studies revealed that miR-222-5p attenuated the regulatory effect of protein phosphatase 2A subunit B isoform R2-α (PPP2R2A) on Akt via repressing its target gene PPP2R2A, causing reduced expressions of forkhead box O3 (FOXO3a), p27 and p21, and finally increasing the proliferation of HCC cells after diminishing the negative regulation of on cell cycle. This study certainly provides valuable laboratory evidence as well as potential therapeutic targets for the prevention and further personalized treatment of Cr(VI)-associated cancers.

Single-cell analysis reveals the transcriptional alterations in the submandibular glands of aged mice

OBJECTIVES

Aging-related salivary gland changes, such as lymphocyte infiltration and acinar cell loss decrease saliva secretion, thereby affecting quality of life. The precise molecular mechanisms underlying these changes remain unclear.

METHODS

We here performed single-cell RNA sequencing to clarify gene expression changes in each cell type comprising the submandibular glands (SMGs) of adult and aged mice.

RESULTS

The proportion of acinar cells decreased in various epithelial clusters annotated with cell type-specific marker genes. Expression levels of the cellular senescence markers, Cdkn2a/p16 and Cdkn1a/p21, were increased in the basal and striated ducts of aged SMGs relative to their levels in those of adult SMGs. In contrast, senescence-associated secretory phenotype-related genes, except transforming growth factor-β, exhibited little change in expression in aged SMGs relative to adult SMGs.

CONCLUSIONS

Gene Ontology analysis revealed increased expression levels of genes encoding major histocompatibility complex (MHC) class I components in the ductal component cells of aged SMGs. MHC class I expression may thus be associated with salivary gland aging.

Transplanting old organs promotes senescence in young recipients

In clinical organ transplantation, donor and recipient ages may differ substantially. Old donor organs accumulate senescent cells that have the capacity to induce senescence in naïve cells. We hypothesized that the engraftment of old organs may induce senescence in younger recipients, promoting age-related pathologies. When performing isogeneic cardiac transplants between age-mismatched C57BL/6 old donor (18 months) mice and young and middle-aged C57BL/6 (3- or 12- month-old) recipients , we observed augmented frequencies of senescent cells in draining lymph nodes, adipose tissue, livers, and hindlimb muscles 30 days after transplantation. These observations went along with compromised physical performance and impaired spatial learning and memory abilities. Systemic levels of the senescence-associated secretory phenotype factors, including mitochondrial DNA (mt-DNA), were elevated in recipients. Of mechanistic relevance, injections of mt-DNA phenocopied effects of age-mismatched organ transplantation on accelerating aging. Single treatment of old donor animals with senolytics prior to transplantation attenuated mt-DNA release and improved physical capacities in young recipients. Collectively, we show that transplanting older organs induces senescence in transplant recipients, resulting in compromised physical and cognitive capacities. Depleting senescent cells with senolytics, in turn, represents a promising approach to improve outcomes of older organs.

Activation of MAP Kinase Pathway by Polyisoprenylated Cysteinyl Amide Inhibitors Causes Apoptosis and Disrupts Breast Cancer Cell Invasion

Prognoses for TNBC remain poor due to its aggressive nature and the lack of therapies that target its "drivers". RASA1, a RAS-GAP or GTPase-activating protein whose activity inhibits RAS signaling, is downregulated in up to 77% of TNBC cases. As such, RAS proteins become hyperactive and similar in effect to mutant hyperactive RAS proteins with impaired GTPase activities. PCAIs are a novel class of agents designed to target and disrupt the activities of KRAS and other G-proteins that are hyperactive in various cancers. This study shows the anticancer mechanisms of the PCAIs in two breast cancer cell lines, MDA-MB-468 and MDA-MB-231. PCAIs (NSL-YHJ-2-27) treatment increased BRAF phosphorylation, whereas CRAF phosphorylation significantly decreased in both cell lines. Moreover, the PCAIs also stimulated the phosphorylation of MEK, ERK, and p90RSK by 116, 340, and 240% in MDA-MB-468 cells, respectively. However, in MDA-MB-231 cells, a significant increase of 105% was observed only in p90RSK phosphorylation. Opposing effects were observed for AKT phosphorylation, whereby an increase was detected in MDA-MB-468 cells and a decrease in MDA-MB-231 cells. The PCAIs also induced apoptosis, as observed in the increased pro-apoptotic protein BAK1, by 51%, after treatment. The proportion of live cells in PCAIs-treated spheroids decreased by 42 and 34% in MDA-MB-468 and MDA-MB-231 cells, respectively, which further explains the PCAIs-induced apoptosis. The movement of the cells through the Matrigel was also inhibited by 74% after PCAIs exposure, which could have been due to the depleted levels of F-actin and vinculin punctate, resulting in the shrinkage of the cells by 76%, thereby impeding cell movement. These results show promise for PCAIs as potential therapies for TNBC as they significantly inhibit the hallmark processes and pathways that promote cell proliferation, migration, and invasion, which result in poor prognoses for breast cancer patients.

Gastrointestinal Malignancy: Genetic Implications to Clinical Applications

Advances in molecular genetics have revolutionized our understanding of the pathogenesis, progression, and therapeutic options for treating gastrointestinal (GI) cancers. This chapter provides a comprehensive overview of the molecular landscape of GI cancers, focusing on key genetic alterations implicated in tumorigenesis across various anatomical sites including GIST, colon and rectum, and pancreas. Emphasis is placed on critical oncogenic pathways, such as mutations in tumor suppressor genes, oncogenes, chromosomal instability, microsatellite instability, and epigenetic modifications. The role of molecular biomarkers in predicting prognosis, guiding treatment decisions, and monitoring therapeutic response is discussed, highlighting the integration of genomic profiling into clinical practice. Finally, we address the evolving landscape of precision oncology in GI cancers, considering targeted therapies and immunotherapies.

Differential Gene Expression and Tumorigenicity Analysis of Cultured Melanocyte Comparing Melanoma

This study aimed to identify the optimal growth media for culturing human skin melanocytes for clinical applications and to assess their tumorigenic potential both in vitro and in vivo. Various growth media were tested to determine the most effective and safest for melanocyte culture, avoiding harmful growth factors such as TPA and colorant toxins. The study evaluated changes in RAF and NRAS gene expression through real-time PCR and gene sequencing of BRAF V600E and NRAS in exons 1 and 2, comparing these with melanoma. Melanocytes were subcutaneously injected into BALB/c nude mice to assess tumorigenic risk. Results indicated that a mixture of MGM-M2 supplemented with melanocyte growth factors provided the best outcomes in terms of cell proliferation and melanocyte count. Gene expression analysis revealed that HRAS and BRAF expressions in melanocytes at passage 6 showed less than 2-fold increases, whereas these genes were up-regulated by more than 3 and 8 folds, respectively, in melanoma cell lines. NRAS expression in melanocytes at passage 6 increased by 5-fold but remained lower than in melanoma cell lines. Gene sequencing of BRAF V600E and NRAS in exons 1 and 2 showed no mutations, and melanocytes injected into BALB/c nude mice exhibited no tumor formation risk. Furthermore, gene sequencing of BRAF and NRAS in the injected melanocytes 16 weeks' post-transplantation revealed no mutations. These findings suggest that while standard growth media protocols may elevate specific proto-oncogene expressions, they do not induce tumorigenic mutations in melanocytes, both in vitro and in vivo.

Dabrafenib protects from cisplatin-induced hearing loss in a clinically relevant mouse model

The widely used chemotherapy cisplatin causes permanent hearing loss in 40%-60% of patients with cancer. One drug, sodium thiosulfate, is approved by the FDA for use in pediatric patients with localized solid tumors for preventing cisplatin-induced hearing loss, but more drugs are desperately needed. Here, we tested dabrafenib, an FDA-approved BRAF kinase inhibitor and anticancer drug, in a clinically relevant multidose cisplatin mouse model. The protective effects of dabrafenib, given orally twice daily with cisplatin, were determined by functional hearing tests and cochlear outer hair cell counts. Toxicity of the drug cotreatment was evaluated, and levels of phosphorylated ERK were measured. A dabrafenib dose of 3 mg/kg BW, twice daily, in mice, was determined to be the minimum effective dose, and it is equivalent to one-tenth of the daily FDA-approved dose for human cancer treatment. The levels of hearing protection acquired, 20-25 dB at the 3 frequencies tested, in both female and male mice, persisted for 4 months after completion of treatments. Moreover, dabrafenib exhibited a good in vivo therapeutic index (> 25), protected hearing in 2 mouse strains, and diminished cisplatin-induced weight loss. This study demonstrates that dabrafenib is a promising candidate drug for protection from cisplatin-induced hearing loss.

[Tumor-immune cell interaction and senescence-associated molecules in colorectal carcinoma]

BACKGROUND

Cellular senescence permanently arrests the cell cycle of premalignant cells following protumorigenic stimuli, counteracting tumor progression. Senescence induction leads to phenotypic and metabolic changes and alters the interaction with the cells' microenvironment. This mediates tumor immunosurveillance but bears promalignant potential and may contribute to disease progression.

OBJECTIVES

Our study aims to investigate the prognostic potential of senescence markers in colorectal carcinoma (CRC) and to understand the interaction of senescent tumor cells and immune cells.

MATERIALS AND METHODS

Immunohistochemical markers were studied on a tissue microarray (TMA) containing tumor tissue of n = 598 CRC patients and were evaluated using digital image analysis. Results were correlated with disease-specific survival (DSS) and progression-free survival (PFS). Consecutive TMA sections were stained for senescence markers and immune cell markers to analyze the spatial relation of those cell populations. Senescence was induced in CRC cell lines in vitro and co-cultures with various immune cell lines were established to study the interactions.

RESULTS

Expression of different senescent-associated markers is associated with increased or decreased DSS and PFS. Close proximity of p21+ senescent tumor cells and CD8+ immune cells correlates with increased DSS and PFS. In vitro, senescent cells were dose-dependently eliminated by immune cells, which is facilitated via direct cell-cell contact and induction of apoptosis.

CONCLUSIONS

Depicting the initiation of this important anti-tumor mechanism, markers of cellular senescence are of significant prognostic relevance in CRC. Moreover, our results show the pleiotropic effect of senescence in vivo. Absence as well as exceeding expression of senescence markers are associated with a negative prognosis in CRC. The impact of cellular senescence depends on the tumor microenvironment and the immunosurveillance of senescent cells. Proximity analyses of senescent cells and tumor-infiltrating immune cells have significant prognostic relevance and reflect this.

YBX1 Regulates Satellite II RNA Loading into Small Extracellular Vesicles and Promotes the Senescent Phenotype

Senescent cells secrete inflammatory proteins and small extracellular vesicles (sEVs), collectively termed senescence-associated secretory phenotype (SASP), and promote age-related diseases. Epigenetic alteration in senescent cells induces the expression of satellite II (SATII) RNA, non-coding RNA transcribed from pericentromeric repetitive sequences in the genome, leading to the expression of inflammatory SASP genes. SATII RNA is contained in sEVs and functions as an SASP factor in recipient cells. However, the molecular mechanism of SATII RNA loading into sEVs is unclear. In this study, we identified Y-box binding protein 1 (YBX1) as a carrier of SATII RNA via mass spectrometry analysis after RNA pull-down. sEVs containing SATII RNA induced cellular senescence and promoted the expression of inflammatory SASP genes in recipient cells. YBX1 knockdown significantly reduced SATII RNA levels in sEVs and inhibited the propagation of SASP in recipient cells. The analysis of the clinical dataset revealed that YBX1 expression is higher in cancer stroma than in normal stroma of breast and ovarian cancer tissues. Furthermore, high YBX1 expression was correlated with poor prognosis in breast and ovarian cancers. This study demonstrated that SATII RNA loading into sEVs is regulated via YBX1 and that YBX1 is a promising target in novel cancer therapy.

Senescence-associated inflammation and inhibition of adipogenesis in subcutaneous fat in Werner syndrome

Werner syndrome (WS) is a hereditary premature aging disorder characterized by visceral fat accumulation and subcutaneous lipoatrophy, resulting in severe insulin resistance. However, its underlying mechanism remains unclear. In this study, we show that senescence-associated inflammation and suppressed adipogenesis play a role in subcutaneous adipose tissue reduction and dysfunction in WS. Clinical data from four Japanese patients with WS revealed significant associations between the decrease of areas of subcutaneous fat and increased insulin resistance measured by the glucose clamp. Adipose-derived stem cells from the stromal vascular fraction derived from WS subcutaneous adipose tissues (WSVF) showed early replicative senescence and a significant increase in the expression of senescence-associated secretory phenotype (SASP) markers. Additionally, adipogenesis and insulin signaling were suppressed in WSVF, and the expression of adipogenesis suppressor genes and SASP-related genes was increased. Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), alleviated premature cellular senescence, rescued the decrease in insulin signaling, and extended the lifespan of WS model of C. elegans. To the best of our knowledge, this study is the first to reveal the critical role of cellular senescence in subcutaneous lipoatrophy and severe insulin resistance in WS, highlighting the therapeutic potential of rapamycin for this disease.

Panic at the Bile Duct: How Intrahepatic Cholangiocytes Respond to Stress and Injury

In the liver, biliary epithelial cells (BECs) line intrahepatic bile ducts (IHBDs) and are primarily responsible for modifying and transporting hepatocyte-produced bile to the digestive tract. BECs comprise only 3% to 5% of the liver by cell number but are critical for maintaining choleresis through homeostasis and disease. To this end, BECs drive an extensive morphologic remodeling of the IHBD network termed ductular reaction (DR) in response to direct injury or injury to the hepatic parenchyma. BECs are also the target of a broad and heterogenous class of diseases termed cholangiopathies, which can present with phenotypes ranging from defective IHBD development in pediatric patients to progressive periductal fibrosis and cancer. DR is observed in many cholangiopathies, highlighting overlapping similarities between cell- and tissue-level responses by BECs across a spectrum of injury and disease. The following core set of cell biological BEC responses to stress and injury may moderate, initiate, or exacerbate liver pathophysiology in a context-dependent manner: cell death, proliferation, transdifferentiation, senescence, and acquisition of neuroendocrine phenotype. By reviewing how IHBDs respond to stress, this review seeks to highlight fundamental processes with potentially adaptive or maladaptive consequences. A deeper understanding of how these common responses contribute to DR and cholangiopathies may identify novel therapeutic targets in liver disease.

Dynamics of redox signaling in aging via autophagy, inflammation, and senescence

Review paper attempts to explain the dynamic aspects of redox signaling in aging through autophagy, inflammation, and senescence. It begins with ROS source in the cell, then states redox signaling in autophagy, and regulation of autophagy in aging. Next, we discuss inflammation and redox signaling with various pathways involved: NOX pathway, ROS production via TNF-α, IL-1β, xanthine oxidase pathway, COX pathway, and myeloperoxidase pathway. Also, we emphasize oxidative damage as an aging marker and the contribution of pathophysiological factors to aging. In senescence-associated secretory phenotypes, we link ROS with senescence, aging disorders. Relevant crosstalk between autophagy, inflammation, and senescence using a balanced ROS level might reduce age-related disorders. Transducing the context-dependent signal communication among these three processes at high spatiotemporal resolution demands other tools like multi-omics aging biomarkers, artificial intelligence, machine learning, and deep learning. The bewildering advancement of technology in the above areas might progress age-related disorders diagnostics with precision and accuracy.

Single-cell RNA sequencing of a poorly metastatic melanoma cell line and its subclones with high lung and brain metastasis potential reveals gene expression signature of metastasis with prognostic implication

The molecular mechanisms underlying melanoma metastasis remain poorly understood. In this study, we aimed to delineate the mechanisms underlying gene expression alterations during metastatic potential acquisition and characterize the metastatic subclones within primary cell lines. We performed single-cell RNA sequencing of a poorly metastatic melanoma cell line (WM239A) and its subclones with high metastatic potential to the lung (113/6-4L) and the brain (131/4-5B1 and 131/4-5B2). Unsupervised clustering of 8173 melanoma cells identified three distinct clusters according to cell type ('Primary', 'Lung' and 'Brain' clusters) with differential expression of MITF and AXL pathways and putative cancer and cell cycle drivers, with the lung cluster expressing intermediate but distinct gene profiles between primary and brain clusters. Principal component (PC) analysis revealed that PC2 (the second PC), which was positively associated with MITF expression and negatively with AXL pathways, primarily segregated cell types, in addition to PC1 of the cell cycle pathway. Pseudotime trajectory and RNA velocity analyses suggested the existence of cellular subsets with metastatic potential in the Primary cluster and an association between PC2 signature alteration and metastasis potential acquisition. Analysis of The Cancer Genome Atlas melanoma samples by clustering into PC2-high and -low clusters by quartiles of PC2 signature expression revealed that the PC2-high cluster was an independent significant factor for poor prognosis (p-value = 0.003) with distinct genomic and transcriptomic characteristics, compared to the PC2-low cluster. In conclusion, we identified signatures of melanoma metastasis with prognostic significance and putative pro-metastatic subclones within a primary cell line.

Senescent Cells: Dual Implications on the Retinal Vascular System

Cellular senescence, a state of permanent cell cycle arrest in response to endogenous and exogenous stimuli, triggers a series of gradual alterations in structure, metabolism, and function, as well as inflammatory gene expression that nurtures a low-grade proinflammatory milieu in human tissue. A growing body of evidence indicates an accumulation of senescent neurons and blood vessels in response to stress and aging in the retina. Prolonged accumulation of senescent cells and long-term activation of stress signaling responses may lead to multiple chronic diseases, tissue dysfunction, and age-related pathologies by exposing neighboring cells to the heightened pathological senescence-associated secretory phenotype (SASP). However, the ultimate impacts of cellular senescence on the retinal vasculopathies and retinal vascular development remain ill-defined. In this review, we first summarize the molecular players and fundamental mechanisms driving cellular senescence, as well as the beneficial implications of senescent cells in driving vital physiological processes such as embryogenesis, wound healing, and tissue regeneration. Then, the dual implications of senescent cells on the growth, hemostasis, and remodeling of retinal blood vessels are described to document how senescent cells contribute to both retinal vascular development and the severity of proliferative retinopathies. Finally, we discuss the two main senotherapeutic strategies-senolytics and senomorphics-that are being considered to safely interfere with the detrimental effects of cellular senescence.

Angiogenesis modulated by CD93 and its natural ligands IGFBP7 and MMRN2: a new target to facilitate solid tumor therapy by vasculature normalization

The tumor vasculature was different from the normal vasculature in both function and morphology, which caused hypoxia in the tumor microenvironment (TME). Previous anti-angiogenesis therapy had led to a modest improvement in cancer immunotherapy. However, antiangiogenic therapy only benefitted a few patients and caused many side effects. Therefore, there was still a need to develop a new approach to affect tumor vasculature formation. The CD93 receptor expressed on the surface of vascular endothelial cells (ECs) and its natural ligands, MMRN2 and IGFBP7, were now considered potential targets in the antiangiogenic treatment because recent studies had reported that anti-CD93 could normalize the tumor vasculature without impacting normal blood vessels. Here, we reviewed recent studies on the role of CD93, IGFBP7, and MMRN2 in angiogenesis. We focused on revealing the interaction between IGFBP7-CD93 and MMRN2-CD93 and the signaling cascaded impacted by CD93, IGFBP7, and MMRN2 during the angiogenesis process. We also reviewed retrospective studies on CD93, IGFBP7, and MMRN2 expression and their relationship with clinical factors. In conclusion, CD93 was a promising target for normalizing the tumor vasculature.

Selective Clearance of Senescent Chondrocytes in Osteoarthritis by Targeting Excitatory Amino Acid Transporter Protein 1 to Induce Ferroptosis

Aims: This study aimed at exploring the mechanism of ferroptosis (an iron-dependent form of nonapoptotic cell death) resistance in senescent chondrocytes (SenChos). Results: In this study, by utilizing metabolomics and single-cell RNA sequencing, we found that hyperactivation of ferroptosis metabolism was one of the most prominent metabolic features in SenChos. Interestingly, however, SenChos were able to survive in this state and were resistant to ferroptosis-induced cell death. Next, we elucidated that this survival mechanism of SenChos could be primarily attributed to overexpression of the membrane protein excitatory amino acid transporter protein 1 (EAAT1), which can increase intracellular glutamate (Glu) levels and activate the glutathione system to counteract ferroptosis. In addition, 2-amino-5,6,7,8-tetrahydro-4-(4-methoxyphenyl)-7-(naphthalen-1-yl)-5-oxo-4H-chromene-3-carbonitrile (UCPH-101) (a specific inhibitor of EAAT1) and siRNA-EAAT1 were able to substantially increase the sensitivity of SenChos to ferroptosis and to induce cell death, with no apparent effects on the normal cells. Administration of an intraarticular injection of UCPH-101 caused inhibition of EAAT1 selectively, cleared SenChos from cartilage, improved the cartilage homeostasis, and significantly delayed the progression of osteoarthritis (OA). Innovation: This work supports a relevant role for EAAT1 in ferroptosis resistance mechanism for SenChos, revealing a potential therapeutic target of OA. Conclusions: EAAT1-Glu-glutathione peroxidase 4 anti-ferroptosis axis is a key survival mechanism for SenChos, and EAAT1 is an effective and specific target for anti-senescence therapy in OA. Antioxid. Redox Signal. 39, 262-277.

The NephroCheck bedside system for detecting stage 3 acute kidney injury after open thoracoabdominal aortic repair

Acute kidney injury (AKI) is a common complication after complex aortic procedures and it is associated with relevant mortality and morbidity. Biomarkers for early and specific AKI detection are lacking. The aim of this work is to investigate the reliability of the NephroCheck bedside system for diagnosing stage 3 AKI following open aortic surgery. In this prospective, multicenter, observational study,- https://clinicaltrials.gov/ct2/show/NCT04087161 -we included 45 patients undergoing open thoracoabdominal aortic repair. AKI risk (AKIRisk-Index) was calculated from urine samples at 5 timepoints: baseline, immediately postoperatively and at 12, 24, 48, and 72 h post-surgery. AKIs were classified according to the KDIGO criteria. Contributing factors were identified in univariable and multivariable logistic regression. Predictive ability was assessed with the area under the receiver operator curve (ROCAUC). Among 31 patients (68.8%) that developed AKIs, 21 (44.9%) developed stage-3 AKIs, which required dialysis. AKIs were correlated with increased in-hospital mortality (p = .006), respiratory complications (p < .001), sepsis (p < .001), and multi-organ dysfunction syndrome (p < .001). The AKIRisk-Index showed reliable diagnostic accuracy starting at 24 h post-surgery (ROCAUC: .8056, p = .001). In conclusion, starting at 24 h after open aortic repair, the NephroCheck system showed adequate diagnostic accuracy for detecting the patients at risk for stage 3 AKIs.

Connecting the dots: Neuronal senescence, stress granules, and neurodegeneration

Cellular senescence increases with aging. While senescence is associated with an exit of the cell cycle, there is ample evidence that post-mitotic cells including neurons can undergo senescence as the brain ages, and that senescence likely contributes significantly to the progression of neurodegenerative diseases (ND) such as Alzheimer's Disease (AD) and Amyotrophic Lateral Sclerosis (ALS). Stress granules (SGs) are stress-induced cytoplasmic biomolecular condensates of RNA and proteins, which have been linked to the development of AD and ALS. The SG seeding hypothesis of NDs proposes that chronic stress in aging neurons results in static SGs that progress into pathological aggregates Alterations in SG dynamics have also been linked to senescence, though studies that link SGs and senescence in the context of NDs and the aging brain have not yet been performed. In this Review, we summarize the literature on senescence, and explore the contribution of senescence to the aging brain. We describe senescence phenotypes in aging neurons and glia, and their links to neuroinflammation and the development of AD and ALS. We further examine the relationships of SGs to senescence and to ND. We propose a new hypothesis that neuronal senescence may contribute to the mechanism of SG seeding in ND by altering SG dynamics in aged cells, thereby providing additional aggregation opportunities within aged neurons.

Reshaping of the tumor microenvironment by cellular senescence: An opportunity for senotherapies

Cellular senescence is a stress response associated with aging and disease, including cancer. Senescent cells undergo a stable cell cycle arrest, undergo a change in morphology and metabolic reprogramming, and produce a bioactive secretome termed the senescence-associated secretory phenotype (SASP). In cancer, senescence is an important barrier to tumor progression. Induction of senescence in preneoplastic cells limits cancer initiation, and many cancer therapies act in part by inducing senescence in cancer cells. Paradoxically, senescent cells lingering in the tumor microenvironment (TME) can contribute to tumor progression, metastasis, and therapy resistance. In this review, we discuss the different types of senescent cells present in the TME and how these senescent cells and their SASP reshape the TME, affect immune responses, and influence cancer progression. Furthermore, we will highlight the importance of senotherapies, including senolytic drugs that eliminate senescent cells and impede tumor progression and metastasis by restoring anti-tumor immune responses and influencing the TME.

Unraveling Heterogeneity in the Aging Hematopoietic Stem Cell Compartment: An Insight From Single-cell Approaches

Specific cell types and, therefore, organs respond differently during aging. This is also true for the hematopoietic system, where it has been demonstrated that hematopoietic stem cells alter a variety of features, such as their metabolism, and accumulate DNA damage, which can lead to clonal outgrowth over time. In addition, profound changes in the bone marrow microenvironment upon aging lead to senescence in certain cell types such as mesenchymal stem cells and result in increased inflammation. This heterogeneity makes it difficult to pinpoint the molecular drivers of organismal aging gained from bulk approaches, such as RNA sequencing. A better understanding of the heterogeneity underlying the aging process in the hematopoietic compartment is, therefore, needed. With the advances of single-cell technologies in recent years, it is now possible to address fundamental questions of aging. In this review, we discuss how single-cell approaches can and indeed are already being used to understand changes observed during aging in the hematopoietic compartment. We will touch on established and novel methods for flow cytometric detection, single-cell culture approaches, and single-cell omics.

Autophagy inhibition signals through senescence to promote tumor suppression

Macroautophagy/autophagy, a stress-responsive cellular survival mechanism, plays important and context-dependent roles in cancer, and its inhibition has been implicated as a promising cancer therapeutic approach. The detailed mechanisms underlying the function of autophagy in cancer have not been fully understood. In this study, we show that autophagy inhibition promotes both the efficacy of chemotherapy for the treatment of glioblastoma (GBM) and therapy-induced senescence of GBM cells. As a specific cell fate characterized by permanent cell cycle arrest, senescence is also associated with the expression of a panel of specific secreted protein factors known as senescence-associated secretory phenotype (SASP). Intriguingly, we found that autophagy inhibition not only quantitatively enhanced GBM cell senescence but also qualitatively altered the spectrum of SASP. The altered SASP had increased potent activity to induce paracrine senescence of neighboring GBM cells, to skew macrophage polarization toward the anti-tumor M1 state, and to block the recruitment of pro-tumor neutrophils to GBM tumor tissues. Taken together, this study reveals novel functional communication between autophagy and senescence and suggests cancer therapeutic approaches harnessing autophagy blockage in inducing senescence-mediated antitumor immunity.

IGFBP-7 secreted by adipose-derived stem cells inhibits keloid formation via the BRAF/MEK/ERK signaling pathway

BACKGROUND

Adipose tissue-derived stem cells (ASCs) have important clinical significance as regulators of skin scar tissue regeneration. ASCs inhibit keloid formation and increase insulin-like growth factor-binding protein-7 (IGFBP-7) expression. However, whether ASCs inhibit keloid formation through IGFBP-7 remains unclear.

OBJECTIVE

We aimed to assess the roles of IGFBP-7 in keloid formation.

METHODS

We analyzed the proliferation, migration, and apoptosis of keloid fibroblasts (KFs) treated with recombinant IGFBP-7 (rIGFBP-7) or by co-culture with ASCs using CCK8 assays, transwell assays, and flow cytometry, respectively. In addition, immunohistochemical staining, quantitative polymerase chain reaction, human umbilical vein endothelial cell tube formation, and western blotting experiments were used to assess keloid formation.

RESULTS

IGFBP-7 expression was significantly lower in keloid tissues than that in normal skin tissues. Stimulation of KFs with rIGFBP-7 at different concentrations or by co-culture with ASCs resulted in decreased KF proliferation. Additionally, KF stimulation with rIGFBP-7 resulted in increased apoptosis of KFs. IGFBP-7 also reduced angiogenesis in a concentration-dependent manner, and stimulation with different rIGFBP-7 concentrations or co-culture of KFs with ASCs inhibited the expression of transforming growth factor-β1, vascular endothelial growth factor, collagen I, interleukin (IL)-6, IL-8, B-raf proto-oncogene (BRAF), mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK) in KFs.

CONCLUSION

Collectively, our findings suggested that ASC-derived IGFBP-7 prevented keloid formation by inhibiting the BRAF/MEK/ERK signaling pathway.

Senescence induces fundamental changes in the secretome of mesenchymal stromal cells (MSCs): implications for the therapeutic use of MSCs and their derivates

Mesenchymal stromal cells (MSCs) are a heterogeneous population containing multipotent adult stem cells with a multi-lineage differentiation capacity, which differentiated into mesodermal derivatives. MSCs are employed for therapeutic purposes and several investigations have demonstrated that the positive effects of MSC transplants are due to the capacity of MSCs to modulate tissue homeostasis and repair via the activity of their secretome. Indeed, the MSC-derived secretomes are now an alternative strategy to cell transplantation due to their anti-inflammatory, anti-apoptotic, and regenerative effects. The cellular senescence is a dynamic process that leads to permanent cell cycle arrest, loss of healthy cells' physiological functions and acquiring new activities, which are mainly accrued through the release of many factors, indicated as senescence-associated secretory phenotype (SASP). The senescence occurring in stem cells, such as those present in MSCs, may have detrimental effects on health since it can undermine tissue homeostasis and repair. The analysis of MSC secretome is important either for the MSC transplants and for the therapeutic use of secretome. Indeed, the secretome of MSCs, which is the main mechanism of their therapeutic activity, loses its beneficial functions and acquire negative pro-inflammatory and pro-aging activities when MSCs become senescent. When MSCs or their derivatives are planned to be used for therapeutic purposes, great attention must be paid to these changes. In this review, we analyzed changes occurring in MSC secretome following the switch from healthy to senescence status.

Circulating exosomes from Alzheimer's disease suppress VE-cadherin expression and induce barrier dysfunction in recipient brain microvascular endothelial cell

Background

Blood-brain barrier (BBB) breakdown is a component of the progression and pathology of Alzheimer's disease (AD). BBB dysfunction is primarily caused by reduced or disorganized tight junction or adherens junction proteins of brain microvascular endothelial cell (BMEC). While there is growing evidence of tight junction disruption in BMECs in AD, the functional role of adherens junctions during BBB dysfunction in AD remains unknown. Exosomes secreted from senescent cells have unique characteristics and contribute to modulating the phenotype of recipient cells. However, it remains unknown if and how these exosomes cause BMEC dysfunction in AD.

Objectives

This study aimed to investigate the potential roles of AD circulating exosomes and their RNA cargos in brain endothelial dysfunction in AD.

Methods

We isolated exosomes from sera of five cases of AD compared with age- and sex-matched cognitively normal controls using size-exclusion chromatography technology. We validated the qualities and particle sizes of isolated exosomes with nanoparticle tracking analysis and atomic force microscopy. We measured the biomechanical natures of the endothelial barrier of BMECs, the lateral binding forces between live BMECs, using fluidic force miscopy. We visualized the paracellular expressions of the key adherens junction protein VE-cadherin in BMEC cultures and a 3D BBB model that employs primary human BMECs and pericytes with immunostaining and evaluated them using confocal microscopy. We also examined the VE-cadherin signal in brain tissues from five cases of AD and five age- and sex-matched cognitively normal controls.

Results

We found that circulating exosomes from AD patients suppress the paracellular expression levels of VE-cadherin and impair the barrier function of recipient BMECs. Immunostaining analysis showed that AD circulating exosomes damage VE-cadherin integrity in a 3D model of microvascular tubule formation. We found that circulating exosomes in AD weaken the BBB depending on the RNA cargos. In parallel, we observed that microvascular VE-cadherin expression is diminished in AD brains compared to normal controls.

Conclusion

Using in vitro and ex vivo models, our study illustrates that circulating exosomes from AD patients play a significant role in mediating the damage effect on adherens junction of recipient BMEC of the BBB in an exosomal RNA-dependent manner. This suggests a novel mechanism of peripheral senescent exosomes for AD risk.

Auto- and paracrine rewiring of NIX-mediated mitophagy by insulin-like growth factor-binding protein 7 in septic AKI escalates inflammation-coupling tubular damage

AIMS

Inflammation-coupling tubular damage (ICTD) contributes to pathogenesis of septic acute kidney injury (AKI), in which insulin-like growth factor-binding protein 7 (IGFBP-7) serves as a biomarker for risk stratification. The current study aims to discern how IGFBP-7 signalling influences ICTD, the mechanisms that underlie this process and whether blockade of the IGFBP-7-dependent ICTD might have therapeutic value for septic AKI.

MATERIALS AND METHODS

In vivo characterization was carried out in B6/JGpt-Igfbp7^em1Cd1165/Gpt mice subjected to cecal ligation and puncture (CLP). Transmission electron microscopy, immunofluorescence, flow cytometry, immunoblotting, ELISA, RT-qPCR and dual-luciferase reporter assays were used to determine mitochondrial functions, cell apoptosis, cytokine secretion and gene transcription.

KEY FINDINGS

ICTD augments the transcriptional activity and protein secretion of tubular IGFBP-7, which enables an auto- and paracrine signalling via deactivation of IGF-1 receptor (IGF-1R). Genetic knockout (KO) of IGFBP-7 provides renal protection, improves survival and resolves inflammation in murine models of cecal ligation and puncture (CLP), while administering recombinant IGFBP-7 aggravates ICTD and inflammatory invasion. IGFBP-7 perpetuates ICTD in a NIX/BNIP3-indispensable fashion through dampening mitophagy that restricts redox robustness and preserves mitochondrial clearance programs. Adeno-associated viral vector 9 (AAV9)-NIX short hairpin RNA (shRNA) delivery ameliorates the anti-septic AKI phenotypes of IGFBP-7 KO. Activation of BNIP3-mediated mitophagy by mitochonic acid-5 (MA-5) effectively attenuates the IGFBP-7-dependent ICTD and septic AKI in CLP mice.

SIGNIFICANCE

Our findings identify IGFBP-7 is an auto- and paracrine manipulator of NIX-mediated mitophagy for ICTD escalation and propose that targeting the IGFBP-7-dependent ICTD represents a novel therapeutic strategy against septic AKI.

cGAS-STING signalling in cancer: striking a balance with chromosomal instability

Chromosomal instability (CIN) is a hallmark of cancer that drives tumour evolution. It is now recognised that CIN in cancer leads to the constitutive production of misplaced DNA in the form of micronuclei and chromatin bridges. These structures are detected by the nucleic acid sensor cGAS, leading to the production of the second messenger 2'3'-cGAMP and activation of the critical hub of innate immune signalling STING. Activation of this immune pathway should instigate the influx and activation of immune cells, resulting in the eradication of cancer cells. That this does not universally occur in the context of CIN remains an unanswered paradox in cancer. Instead, CIN-high cancers are notably adept at immune evasion and are highly metastatic with typically poor outcomes. In this review, we discuss the diverse facets of the cGAS-STING signalling pathway, including emerging roles in homeostatic processes and their intersection with genome stability regulation, its role as a driver of chronic pro-tumour inflammation, and crosstalk with the tumour microenvironment, which may collectively underlie its apparent maintenance in cancers. A better understanding of the mechanisms whereby this immune surveillance pathway is commandeered by chromosomally unstable cancers is critical to the identification of new vulnerabilities for therapeutic exploitation.

Biology and genetics of acquired and congenital melanocytic naevi

Acquired and congenital melanocytic naevi are common benign neoplasms. Understanding their biology and genetics will help clinicians and pathologists correctly diagnose melanocytic tumours, and generate insights into naevus aetiology and melanomagenesis. Genomic data from published studies analysing acquired and congenital melanocytic naevi, including oncogenic driver mutations, common melanoma associated mutations, copy number aberrations, somatic mutation signature patterns, methylation profile, and single nucleotide polymorphisms, were reviewed. Correlation of genomic changes to dermoscopic features, particular anatomic sites and total body naevus counts, was also performed. This review also highlights current scientific theories and evidence concerning naevi growth arrest. Acquired and congenital melanocytic naevi show simple genomes, typically characterised by mutually exclusive single oncogenic driver mutations in either BRAF or NRAS genes. Genomic differences exist between acquired and congenital naevi, common and dysplastic naevi, and by dermoscopic features. Acquired naevi show a higher rate of BRAF hotspot mutations and a lower rate of NRAS hotspot mutations compared to congenital naevi. Dysplastic naevi show upregulation of follicular keratinocyte-related genes compared to common naevi. Anatomical locations and DNA signatures of naevi implicates ultraviolet radiation and non-ultraviolet radiation pathways in naevogenesis. DNA driver point mutations in acquired and congenital melanocytic naevi have been well characterised. Future research is required to better understand transcriptional and epigenetic changes in naevi, as well as those regulating naevus growth arrest and cell environment signalling.