Exosomal tumor necrosis factor‐α from hepatocellular cancer cells (Huh‐7) promote osteoclast differentiation

Abstract

Bone is the common extra-hepatic site for cancer metastasis. Hepatic cancer is associated with a higher incidence of pathological fracture. However, this important regulatory mechanism remains unexplored. Thus, exosomemediated cell-cell communication between hepatocellular cancer and bone might be key to osteolytic bone destruction. Huh-7 exosomes were characterized for size and exosome marker expressions (CD63, Alix). Exosome mediated osteoclast differentiation in the RAW 264.7 cells was monitored from day 1 to 6 and multinucleated osteoclast formation and bone resorption activity were analyzed. The osteoclastogenic factor expressions in the exosomes and osteoclast differentiation markers such as tumor necrosis factor receptor 6 (TRAF6), nuclear factor κB (NF-κB), nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), and cathepsin K (CTSK) were analyzed using western blot. Exosomes released by liver cancer cells (Huh-7) promoted osteoclast differentiation in RAW 264.7 cells. Analysis of osteoclastogenic factors in the exosomes showed that exosomes were specifically enriched with tumor necrosis factor α (TNF-α). Huh-7 exosomes promoted osteoclast differentiation by significantly increasing the number of TRAP-positive multi nucleated osteoclasts and resorption pits. Importantly, exosomes upregulated osteoclast markers TRAF6, NF-κB, and CTSK expressions. Further, neutralizing exosomal TNF-α reverted exosome-mediated osteoclast differentiation in RAW 264.7 cells. Collectively, our findings show that cellular communication of exosomal TNF-α from hepatocellular cancer cells (Huh-7) regulates osteoclast differentiation through NF-κB/CTSK/TRAP expressions. Thus, exosomal TNFα might act as an important therapeutic target to prevent hepatocellular cancer mediated pathological bone disease.

Periodontal ligament cells-derived exosomes promote osteoclast differentiation via modulating macrophage polarization

“…Exos are involved in intercellular signaling and regulation, making them a hot research topic in biomedical fields 33 . Previous studies have shown that Exos play a crucial role in bone immunology and remodeling 33 , 34 . Although extensive research has been conducted on the effect of Exos on bone remodeling 35 , studies on bone immunology and osteoclast differentiation remain limited.…”

The systemic-level repercussions of cancer-associated inflammation mediators produced in the tumor microenvironment

“…During this phenomenon, the TNF-a stored in the exosomes produced by hepatocellular Huh-7 cells caused the expression of osteoclast-associated differentiation markers when added to murine macrophage/ monocyte cell lines through the activation of the NF-kB/ cathepsin K/triiodothyronine receptor auxiliary protein axis. These findings explain the tendency of hepatocellular cancer cells to generate bone metastases (179).…”

TGF-β-Containing Small Extracellular Vesicles From PM2.5-Activated Macrophages Induces Cardiotoxicity

“…Meanwhile, the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α induced the transcription of IL-10, PDGF, or TGF-β to promote the fibrotic macrophage (M2c) phenotype (29). The growing evidences reflected that sEV transferred the cytokines to modulate the functions of recipient cells (30)(31)(32). According to previous studies, PM 2.5 increased the levels of TGF-β1 in mice lung tissue and bronchoalveolar lavage fluid, suggesting that PM 2.5 exposure may increase TGF-β1 and cause myocardial fibrosis (33).…”