Production of plasminogen activator inhibitor by cultured keratinocytes

Production of plasminogen activator inhibitor by cultured keratinocytes

122 A-51 ELEVATION OF IN SKIN Kazuhiko Mizuno. RABBIT Ichikawa, Dept. of TISSUE PLASMIN ACTIVITY FOLLOWING CULTURED Akira Takashima, Shos...

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122 A-51

ELEVATION

OF

IN

SKIN

Kazuhiko Mizuno.

RABBIT

Ichikawa, Dept. of

TISSUE

PLASMIN

ACTIVITY

FOLLOWING

CULTURED

Akira Takashima, Shoshl Dermatology. Nagoya City

Yasuda Univ.,

and Nabuyukl Nagoya, Japan

K. Hshlmoto.

Plasmmogen

PRODUCTION

BY MOUSE KERATINOCYTE

Akira Takashima, Kazuhiko Ichikawa, Shoshi M1Z”“O. Dept. of Dermatology, Nagoya City

Yasuda Univ.,

Matsumoto.

aztivator

PA1 - 1 (endothebal )and

present

study,

protease

autoradiography immunaprecipitated

specifically

and Nobuyuki Nagoya, Japan

M. Higashiyama.

They

of

canditnned

a band wtb

immunoprecwtated

Universitv

BY

Y. Kobayashi

plays important

roles I” activator,

InhIbItor ). PA1 -2 (placental

cultured

keratmocytes

were

medium

by “ar,ous

type

cells.

produce

labeled by 135S]

was followed

In the these

methmnme.

by SDS-PAGE

ard

anti - PA I - 1 antiserum specd~cally Mr

46KD

a band with

keratinccytes

and

anti -PA

Mr 58KD.

synthesized

I- 2 antwrum

These

.

School of Medicine

for plasminogen

are produced

keratinccytes

We found that

whxh

itibibltors

cell type

nexin.

Cultured

that cultured

INHIBITOR

Y. Nlshida.

Osaka

proteinase

specifx

we studied whether

or not.

ACTIVATOR

of Dermatology.

is a ser,ne

inh,bitor

Immunopreclpitatmn

I

,

PLASMINOGEN

Depatment

namely

,nh,b,tors

CELL

We report in the accompanying paper that in “l”o UVB xrradlation induced elevated plasmln(PL) activity 1” whole skw extract. The purpose of this study was to assess whether keratlnocyte(KC) might be actively involved I” this effect. Mouse KC-derived cell line, Pam 212, were cultured in the presence of 10% FCS, and culture media assayed for PL activity using a synthetic fluoragenic peptlde substrate. Boc-“al-Leu-Lvs-MCA. Sinnlflcantlv higher PL activity was detected I” the condItioned media than fresh media, and this effect was dependent on culture period and the presence of cells and FCS* When cells were pretreated with sublethal doses o,f ““B (100-330 J/m 1, the subsequent PL production was clearly enhanced 1” a dose-dependent fashion. Maximal enhancement (250%) was seen with 330 J/m and this dose was found to induce 50% supp~‘esslon of cell proliferation without affecting cell viability. In contrast, lethal UVB doses suppressed PL production. Time course experiment demonstrated the initial enhancement to occur within 24 hours after irradiation. These results indicate that UVB exposure may Induce PL production by epidermal KC in situ.

OF

KERATINOCYTES

skin. Recent advances identlfled

lndlcated

““8 ENHANCES PLASMIN LINE IN VITRO

K.

K. Yoshlkawa,

We examined whether UVB exposure may Induce tissue plasmin (tPL) activation in the skin. The tPL activity in homogenate of UVB-irradiated rabbit back skxn was assayed as cleavage of a synthetic fluarosenic peptlde substrate, Boc-“al-La-Lys-MCA. Erythema was measured by calorimeter and swelling was determIned by skin thickness. As a result, maxlmal3elev~tion of tPL activity was detected in the skin receiving 1.5~10 J/m of UVB, equivalent to 2 MED. With hwher UVB fluence. the elevation of tPL activity was not observed. Time course experiment showed that tPL activlt; began to rise 5 hours after irradiation and reached a plateau after 24 hours with gradual increase. This progress corresponded with the degree of skin swelling rather than that of erythema. These results indicated that appropriate doses of UVB enhance tPL production of skin and that tPL might be an unportant chemical substance mediating swelling of the sunburn reaction.

A-55

PRODUCTION

A-56

‘JVB EXPOSURE

results

bath PA1 - 1 and PAI-

2.