Structural-functional diversity of CD47 proteoforms

Red blood cells-derived components as biomimetic functional materials: Matching versatile delivery strategies based on structure and function

Red blood cells (RBCs), often referred to as "intelligent delivery systems", can serve as biological or hybrid drug carriers due to their inherent advantages and characteristics. This innovative approach has the potential to enhance biocompatibility, pharmacokinetics, and provide targeting properties for drugs. By leveraging the unique structure and contents of RBCs, drug-loading pathways can be meticulously designed to align with these distinctive features. This review article primarily discusses the drug delivery strategies and their applications that are informed by the structural and functional properties of the main components of RBCs, including living RBCs, membranes, hollow RBCs, and hemoglobin. Overall, this review article would assist efforts to make better decisions on optimization and rational utilization of RBCs derivatives-based drug delivery strategies for the future direction in clinical translation.

Nano-chameleons: A review on cluster of differentiation-driven immune cell-engineered nanoarchitectonics for non-small cell lung cancer

Cancer, being one of the most outrageous diseases, contributed to 48 % of the mortality in 2022, with lung cancer leading the race with a 12.4 % incidence rate. Conventional treatment modalities like radio-, chemo-, photo-, and immunotherapy employing nanocarriers often face several setbacks, such as non-specific delivery, off-site toxicity, rapid opsonization via the host immune system, and greater tumor recurrence rates. Moreover, the heterogeneous variability in the tumor microenvironment is responsible for existing therapy failure. With the advent of biomimetic nanoparticles as a novel and intriguing platform, researchers have exploited the inherent functionalities of the Cluster of Differentiation proteins (CD) as cell surface biomarkers and imparted the nanocarriers with enhanced homologous tumor targetability, immune evasion capability, and stealth properties, paving the way for improved therapy and diagnosis. This article explores pathogenesis and the multifaceted role of immune cells in non-small cell lung cancer. Moreover, the agenda of this article is to shed light on biomimetic nanoarchitectonics with respect to their fabrication, evaluation, and applications unraveling their synergistic effect with conventional therapies. Further discussion mentions the hurdles in clinical translation with viable solutions. The regulatory bottlenecks underscore the need for a regulatory roadmap with respect to commercialization. We believe that biomimetic nanoarchitectonics will be a beacon of hope in warfare against lung cancer.

Elevated CD47 Expression Impairs Elimination of Photoaged Fibroblasts by Macrophages and Serves as a Potential Biomarker for Photoaging

BACKGROUND

CD47 could negatively regulate macrophage-mediated phagocytosis and contribute to senescent cells accumulation in aging. However, it remains unknown whether CD47 is overexpressed in photoaged skin and involved in photoaging pathogenesis.

AIMS

To investigate the expression, clinical significance, and mechanism of CD47 in photoaging.

METHODS

Sun-exposed (n = 10) and sun-protected (n = 10) skin samples were collected from elderly subjects and stained for CD47, and its association with collagen and elastin content and p16 expression was subsequently analyzed. A cellular photoaging model was then established to examine CD47 expression in photoaged fibroblasts. Furthermore, the influence of photoaged fibroblasts on macrophage-mediated phagocytosis and elimination was assessed by constructing a co-culture system. SiRNA was applied to block the CD47/SIRPα axis to determine its role in this process. Finally, the activation of the CD47/SIRPα axis was evaluated in skin samples.

RESULTS

We showed the increased dermal CD47 expression in sun-exposed aged skin, which was closely correlated with the reduced collagen content and enhanced elastin accumulation and dermal p16 expression. Next, elevated CD47 was detected in both sun-exposed aged skin-derived fibroblasts and photoaged ones. We discovered that photoaged fibroblasts impaired the phagocytotic function of co-cultured macrophages via CD47/SIRPα axis, and blocking the CD47/SIRPα axis could improve their elimination. Moreover, the CD47/SIRPα axis was found to be activated in the sun-exposed aged skin.

CONCLUSIONS

The present study demonstrated for the first time that CD47 was highly expressed and involved in mediating photoaged fibroblasts accumulation, providing important evidence for CD47 as a potential biomarker and therapeutic target for photoaging.

CD47 Contributes to the Proliferation of Breast Cancer

BACKGROUND

The CD47 molecule (CD47) performs a novel role in regulating immunoreactions by binding to signal-regulatory protein alpha (SIRPα), resulting in the tumorigenesis of multiple malignant neoplasms. However, its effects and mechanisms in breast cancer (BC) remain unknown.

METHODS

To explore the molecular mechanisms and explicit impacts of CD47, we screened two databases for CD47-associated signaling pathways and cellular functions. BC samples and patients' basic information were collected to identify the statistical significance of CD47 expression. We also constructed experiments to validate the regulatory role of CD47 in BC cell proliferation.

RESULTS

Analysis of the TCGA-BRCA, GSE42568, and GSE15852 datasets demonstrated an elevated level of CD47 in BC tissues. A Venn diagram revealed 11,194 co-expressed genes, and pathway analysis linked elevated CD47 levels to critical signaling pathways, such as cytokine-receptor interactions and Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling, which are integral to cell proliferation and invasiveness. Clinical data from 108 BC specimens showed that CD47 localization was primarily membranous, with higher levels correlating with proliferation marker Ki-67 (Ki-67) expression (p < 0.0001) and advanced tumor/node/metastasis (TNM) stage (p < 0.0001). Additionally, functional assays demonstrated that CD47 depletion reduced cell viability (p < 0.01), migration (p < 0.001), and invasion (p < 0.05 in 4T1 cells; p < 0.001 in MDA-MB-231 cells) in vitro and led to smaller tumor volumes (p < 0.0001) in vivo.

CONCLUSION

CD47 is a key regulator of BC cell proliferation and invasiveness and serves as a potential marker for assessing tumor aggressiveness and guiding therapeutic strategies.

Progress in cancer research on the regulator of phagocytosis CD47, which determines the fate of tumor cells (Review)

Cluster of differentiation 47 (CD47) is a transmembrane protein that is widely and moderately expressed on the surface of various cells and can have an essential role in mediating cell proliferation, migration, phagocytosis, apoptosis, immune homeostasis and other related responses by binding to its ligands, integrins, thrombospondin-1 and signal regulatory protein α. The poor prognosis of cancer patients is closely associated with high expression of CD47 in glioblastoma, ovarian cancer, breast cancer, bladder cancer, colon cancer and hepatocellular carcinoma. Upregulation of CD47 expression facilitates the growth of numerous types of tumor cells, while downregulation of its expression promotes phagocytosis of tumor cells by macrophages, thereby limiting tumor growth. In addition, blocking CD47 activates the cyclic GMP-AMP (cGAMP) synthase/cGAMP/interferon gene stimulating factor signaling pathway and initiates an adaptive immune response that kills tumor cells. The present review describes the structure, function and interactions of CD47 with its ligands, as well as its regulation of phagocytosis and tumor cell fate. It summarizes the therapeutics, mechanisms of action, research advances and challenges of targeting CD47. In addition, this paper provides an overview of the latest therapeutic options for targeting CD47, such as chimeric antigen receptor (CAR) T-cells, CAR macrophages and nanotechnology-based delivery systems, which are essential for future clinical research on targeting CD47.