Involvement of progranulin (PGRN) in the pathogenesis and prognosis of breast cancer

RIPK1: A Promising Target for Intervention Neuroinflammation

Necroptosis is a novel mode of cell death that differs from traditional apoptosis, characterized by distinct molecular mechanisms and physiopathological features. Recent research has increasingly underscored the pivotal role of necroptosis in various neurological diseases, including stroke, Alzheimer's disease and multiple sclerosis. A defining hallmark of these conditions is neuroinflammation, a complex inflammatory response that critically influences neuronal survival. This review provides a comprehensive analysis of the mechanistic underpinnings of necroptosis and its intricate interplay with neuroinflammation, exploring the interrelationship between the two processes and their impact on neurological disorders. In addition, we discuss potential therapeutic strategies that target the intervention of necroptosis and neuroinflammation, offering novel avenues for intervention. By deepening our understanding of these interconnected processes, the development of more effective treatments approaches holds significant promise for improving patient outcomes in neurological disorders.

Molecular mechanisms and targeted therapy of progranulin in metabolic diseases

Progranulin (PGRN) is a secreted glycoprotein with cytokine-like properties, exerting tripartite mechanisms of inflammation suppression, tissue repair promotion, and metabolic regulation. This multifaceted functionality positions PGRN as a potential "multi-effect therapeutic strategy" for metabolic disorders characterised by cartilage degradation and imbalanced bone remodelling, potentially establishing it as a novel therapeutic target for such conditions. Osteoarthritis, rheumatoid arthritis, intervertebral disc degeneration, osteoporosis, periodontitis, and diabetes-related complications-representing the most prevalent metabolic diseases-currently lack effective treatments due to incomplete understanding of their precise pathogenic mechanisms. Recent studies have revealed that PGRN expression levels are closely associated with the onset and progression of these metabolic disorders. However, the exact regulatory role of PGRN in these diseases remains elusive, partly owing to its tissue-specific actions and context-dependent dual roles (anti-inflammatory vs. pro-inflammatory). In this review, we summarise the structure and functions of PGRN, explore its involvement in neurological disorders, immune-inflammatory diseases, and metabolic conditions, and specifically focus on its molecular mechanisms in metabolic diseases. Furthermore, we consolidate advances in targeting PGRN and the application of its engineered derivative, Atsttrin, in metabolic bone disorders. We also discuss potential unexplored mechanisms through which PGRN may exert influence within this field or other therapeutic domains. Collectively, this work aims to provide a new framework for elucidating PGRN's role in disease pathogenesis and advancing strategies for the prevention and treatment of metabolic disorders.

The role of circRNAs and miRNAs in drug resistance and targeted therapy responses in breast cancer

MicroRNAs (miRNAs) are small non-coding RNAs comprising 19-24 nucleotides that indirectly control gene expression. In contrast to other non-coding RNAs (ncRNAs), circular RNAs (circRNAs) are defined by their covalently closed loops, forming covalent bonds between the 3' and 5' ends. circRNAs regulate gene expression by interacting with miRNAs at transcriptional or post-transcriptional levels. Accordingly, circRNAs and miRNAs control many biological events related to cancer, including cell proliferation, metabolism, cell cycle, and apoptosis. Both circRNAs and miRNAs are involved in the pathogenesis of diseases, such as breast cancer. This review focuses on the latest discoveries on dysregulated circRNAs and miRNAs related to breast cancer, highlighting their potential as biomarkers for clinical diagnosis, prognosis, and chemotherapy response.

Progranulin inhibits autophagy to facilitate intracellular colonization of Helicobacter pylori through the PGRN/mTOR/DCN axis in gastric epithelial cells

Helicobacter pylori (H. pylori) infection is the primary risk factor for the progress of gastric diseases. The persistent stomach colonization of H. pylori is closely associated with the development of gastritis and malignancies. Although the involvement of progranulin (PGRN) in various cancer types has been well-documented, its functional role and underlying mechanisms in gastric cancer (GC) associated with H. pylori infection remain largely unknown. This report demonstrated that PGRN was up-regulated in GC and associated with poor prognosis, as determined through local and public database analysis. Additionally, H. pylori induced the up-regulation of PGRN in gastric epithelial cells both in vitro and in vivo. Functional studies have shown that PGRN promoted the intracellular colonization of H. pylori. Mechanistically, H. pylori infection induced autophagy, while PGRN inhibited autophagy to promote the intracellular colonization of H. pylori. Furthermore, PGRN suppressed H. pylori-induced autophagy by down-regulating decorin (DCN) through the mTOR pathway. In general, PGRN inhibited autophagy to facilitate intracellular colonization of H. pylori via the PGRN/mTOR/DCN axis. This study provides new insights into the molecular mechanisms underlying the progression of gastric diseases, suggesting PGRN as a potential therapeutic target and prognostic predictor for these disorders.

PGRN inhibits CD8+T cell recruitment and promotes breast cancer progression by up-regulating ICAM-1 on TAM

BACKGROUND

Tumor microenvironment actually reduces antitumor effect against the immune attack by exclusion of CD8+T cells. Progranulin (PGRN) is a multifunctional growth factor with significant pathological effects in multiple tumors; however, its role in immunity evasion of breast cancer (BCa) is not completely understood.

METHODS

We depleted GRN (PGRN gene) genetically in mice or specifically in PY8119 murine BCa cell line, and mouse models of orthotopic or subcutaneous transplantation were used. Chimeric mice-deficient of PGRN (Grn-/-) in bone marrow (BM) compartment was also generated. Association of PGRN expression with chemokine production or BCa development was investigated by histological and immunological assays.

RESULTS

We found PGRN was involved in exhaustion of cytotoxic CD8+T cell in BCa with the increasing expressions of M2 markers and intercellular cell adhesion molecule-1 (ICAM-1) on macrophages. Specifically, ablation of PGRN in PY8119 cells reduced tumor burden, accompanied by the infiltrating of cytotoxic CD8+T cells into tumor nests. Moreover, our result revealed that blockade of PD-1 in PGRN-depleted tumors exhibited better antitumor effect in vivo and significantly decreased tumor burden.

CONCLUSION

These findings suggest that inhibition of PGRN may act as a potential immune-therapeutic strategy by recovering infiltration of CD8+T cell in BCa tissue and thereby enhancing the response to anti-PD-1 therapy.

Progranulin and GPNMB: interactions in endo-lysosome function and inflammation in neurodegenerative disease

BACKGROUND

Alterations in progranulin (PGRN) expression are associated with multiple neurodegenerative diseases (NDs), including frontotemporal dementia (FTD), Alzheimer's disease (AD), Parkinson's disease (PD), and lysosomal storage disorders (LSDs). Recently, the loss of PGRN was shown to result in endo-lysosomal system dysfunction and an age-dependent increase in the expression of another protein associated with NDs, glycoprotein non-metastatic B (GPNMB).

MAIN BODY

It is unclear what role GPNMB plays in the context of PGRN insufficiency and how they interact and contribute to the development or progression of NDs. This review focuses on the interplay between these two critical proteins within the context of endo-lysosomal health, immune function, and inflammation in their contribution to NDs.

SHORT CONCLUSION

PGRN and GPNMB are interrelated proteins that regulate disease-relevant processes and may have value as therapeutic targets to delay disease progression or extend therapeutic windows.

Serum progranulin as a potential biomarker for frailty in Chinese older adults

BACKGROUND

Frailty can increase adverse health outcomes in older adults. Progranulin is a secreted glycoprotein involved in regulating various biological processes. Different perspectives exist on the relationship between progranulin and frailty.

AIMS

We aimed to evaluate the association of progranulin with frailty in older Chinese adults.

METHODS

We included 265 older in-patients who were divided into the robust (n = 31), pre-frail (n = 116) and frail (n = 118) groups according to the FRAIL scale. Serum IL-6, CXCL-10, progranulin, and CRP levels were assayed. Spearman's correlation and logistic regression models were used to analyze the association of serum biomarkers with frailty, and ROC was used to evaluate the diagnostic progranulin value for frailty.

RESULTS

The frail group was older and had lower BMI, higher prevalence of coronary heart disease, worse grip strength and walking speed, and higher IL-6, CXCL-10, progranulin, and CRP serum levels than the robust and pre-frail groups. Progranulin levels were negatively correlated with grip strength (r = - 0.152, p = 0.016) and positively correlated with IL-6 (r = 0.207, p = 0.001) and CXCL-10 (r = 0.160, p = 0.009) after adjusting for age and sex. Furthermore, progranulin remained associated with frailty after adjusting for age, sex, BMI, smoking, chronic diseases, and pro-inflammatory cytokines (OR = 1.003, 95% CI 1.001-1.006, p = 0.022). The AUC of serum progranulin levels for diagnostic frailty was 0.927 (95% CI 0.896-0.958, p < 0.001).

CONCLUSION

High serum progranulin levels were observed in frail older adults and were associated with worse physical function and increased chronic inflammation. Progranulin may be a potential biomarker for frailty.

Can serum progranulin level be used as a prognostic biomarker in non-small cell lung cancer?

Progranulin has been considered to be a poor prognostic biomarker for some types of malignancies. However, the clinical significance of serum progranulin level and the prognostic value are still not explored in advanced stages of lung cancer.  The current study investigates the prognostic significance of progranulin serum levels in advanced-stage non-small cell lung cancer (NSCLC) patients. This study involved 94 subjects (70 advanced-stage NSCLC patients and 24 healthy controls). Serum progranulin level was measured by enzyme-linked immunosorbent assay (ELISA) and was correlated with patient outcome. The association between circulating progranulin level and clinicopathological parameters was detected. Serum progranulin cut-off level predicting six-month survival was determined. Serum progranulin level was found significantly elevated in NSCLC patients than in the control group (p<0.001). We did not determine a significant difference between stage IIIB and stage IV NSCLC patients for serum progranulin levels (p=0.166). When we evaluated the laboratory parameters, only serum LDH level was found significantly correlated with serum progranulin level (p=0.043), also bone and liver metastasis showed a significant correlation with progranulin level (p=0.008 and p = 0.024, respectively). The cut-off level of serum progranulin in predicting six months of survival was determined as 16.03 ng/ml (AUC = 0.973, 95%Cl: 0.903-0.997, p<0.001) with 97.06% sensitivity and 88.89% specificity. Overall survival was determined shorter in patients with progranulin level ≥16 ng/ml than those with <16 ng/ml (p<0.001). Also, in the multivariate analysis using the Cox regression model serum progranulin level was found as an independent prognostic factor for NSCLC (p=0.001). Serum progranulin level may be a useful biomarker for predicting poor survival in advanced-stage NSCLC patients.