Roxithromycin inhibits transforming growth factor-beta production by cultured human mesangial cells.
BACKGROUND
Transforming growth factor-beta (TGF-beta) plays an important role in progression of renal injury. However, few materials which inhibit TGF-beta have been known. Roxithromycin (ROX), macrolide antibiotics, is known to have anti-inflammatory, immunomodulatory and tissue reparative effects besides its bacteriostatic activity, although the exact mechanism of its anti-inflammatory and immunomodulatory effects was not defined. We examined the effect of ROX on production of TGF-beta and type IV collagen by cultured human mesangial cells (HMC).


METHODS
Human mesangial cells were incubated with several concentrations of ROX and TGF-beta and type IV collagen levels in the culture supernatants were measured by enzyme-linked immunoassay. Amount of TGF-beta mRNA was also quantified by using a colourimetric mRNA quantification kit and semiquantitative reverse transcriptase polymerase chain reaction. We also examined the effect of ROX on tyrosine kinase, MAP kinase and NF-kappaB stimulated by thrombin.


RESULTS
Roxithromycin (0.1-10.0 microg/mL) inhibited TGF-beta production by HMC in a dose- and time-dependent manner without inducing cell injury. ROX (10.0 microg/mL) also inhibited mRNA expression of TGF-beta in HMC. Thrombin (5 U/mL) stimulated TGF-beta production by HMC and ROX significantly inhibited the stimulating effect of thrombin on TGF-beta production. ROX also inhibited the increment of type IV collagen production stimulated by thrombin. ROX (10.0 microg/mL) suppressed the thrombin-induced NF-kappaB activation, although ROX did not inhibit the activation of tyrosine kinase and MAP kinase by thrombin.


CONCLUSIONS
Roxithromycin has an inhibitory effect on TGF-beta production by HMC possibly via inhibition of NF-kappaB. ROX may be a potential agent for the treatment of glomerulosclerosis.
Yamabe
Hideaki
H
The Second Department of Internal Medicine, Hirosaki University School of Medicine, Hirosaki, Japan. yamabe@cc.hirosaki-u.ac.jp
Shimada
Michiko
M
Kaizuka
Mitsuaki
M
Nakamura
Masayuki
M
Kumasaka
Ryuichiro
R
Murakami
Rei-Ichi
R
Fujita
Takeshi
T
Nakamura
Norio
N
Osawa
Hiroshi
H
Okumura
Ken
K
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D024141:Collagen Type IV / Q000235:genetics / Q000378:metabolism; D004347:Drug Interactions; D004789:Enzyme Activation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006490:Hemostatics / Q000494:pharmacology; D006801:Humans; D050527:Mesangial Cells / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015575:Roxithromycin / Q000494:pharmacology*; D013917:Thrombin / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism
D000900:Anti-Bacterial Agents; D024141:Collagen Type IV; D006490:Hemostatics; D016328:NF-kappa B; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D015575:Roxithromycin; D011505:Protein-Tyrosine Kinases; D020928:Mitogen-Activated Protein Kinases; D013917:Thrombin