Anti-arthritic effects of combined treatment with histone deacetylase inhibitor and low-intensity ultrasound in the presence of microbubbles in human rheumatoid synovial cells.
OBJECTIVE
The therapeutic effects of histone deacetylase (HDAC) inhibitor combined with ultrasound (US) (1 MHz, 10% duty factor, 0.1 or 0.2 W/cm(2)) in RA synovial fibroblasts (RASFs) were examined.


METHODS
RASFs were isolated from rheumatoid synovial tissues obtained from patients with RA during total knee arthroplasty. RASFs were treated with an HDAC inhibitor, trichostatin A (TSA), with or without US. Cell viability was estimated using the Trypan blue dye exclusion test and cell cycle was examined by flow cytometry using propidium iodide (PI) staining. Gene expression of cell cycle-related genes cyclin D, cyclin A, cyclin B and p21(WAF1/Cip1) was analysed by semi-quantitative RT-PCR. Detection of apoptosis was examined by flow cytometry using annexin V-FITC and PI staining. Microarray analysis was carried out to profile gene expression of inflammation-related genes.


RESULTS
Dose-dependent decreases in cell viability, cell cycle arrest and apoptosis in RASFs due to TSA were observed. US treatment in the presence of microbubbles increased cellular uptake, but did not induce cell cycle arrest or apoptosis. The combination of TSA and US modulated cell cycle-related gene expression and significantly decreased S phase cells and increased G(2)-M phase cells. US also further enhanced TSA-induced RASF apoptosis and regulated expression of inflammation-related genes.


CONCLUSIONS
HDAC inhibitor in combination with US effectively reduces cell viability and induces apoptosis in RASFs. The combination therapy could be useful to control synovial proliferation and inflammation, since US can be easily applied to targeted joints as local physiotherapy.
Nakamura
C
C
Department of Orthopaedic Surgery, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan.
Matsushita
I
I
Kosaka
E
E
Kondo
T
T
Kimura
T
T
D017209:Apoptosis / Q000187:drug effects; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D018816:Genes, cdc; D056572:Histone Deacetylase Inhibitors; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D045423:Microbubbles; D020411:Oligonucleotide Array Sequence Analysis; D011134:Polysaccharides / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013583:Synovial Membrane / Q000187:drug effects* / Q000473:pathology; D014464:Ultrasonic Therapy
D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D011134:Polysaccharides; C059891:SHU 508; C012589:trichostatin A