PDE5A Suppresses Proteasome Activity Leading to Insulin Resistance in C2C12 Myotubes

<div>Effects of PDE5 inhibitor icariin (Ica) on proteasome activity in PDE5A-overexpressed C2C12 myotubes. (a) Representative western blots showing the effects of icariin on the GFPu protein levels; (b) quantification of the GFPu protein levels in (a); (c) effects of icariin on the chymotrypsin-like activity of proteasome. <span class="nowrap"><svg height="8.8423pt" id="M15" style="vertical-align:-0.2064009pt" version="1.1" viewbox="-0.0498162 -8.6359 32.2343 8.8423" width="32.2343pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M822 650H589L583 622C660 617 677 607 674 561C672 534 664 481 647 390L600 137H596L273 650H126L120 622C176 620 194 615 207 594C221 571 225 557 214 504L161 257C141 166 129 112 121 85C108 42 83 30 29 28L23 0H260L266 28C193 33 173 42 176 89C178 122 186 172 202 255L256 527H259L583 -8H612L690 390C708 481 720 535 728 558C744 603 756 619 816 622L822 650Z"></path></g><g transform="matrix(.013,0,0,-0.013,14.542,0)"><path d="M535 323V373H52V323H535ZM535 138V188H52V138H535Z"></path></g><g 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d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z"></path></g></svg> vs. the control group; <span class="nowrap"><svg height="9.2729pt" id="M17" style="vertical-align:-0.6370001pt" version="1.1" viewbox="-0.0498162 -8.6359 51.1027 9.2729" width="51.1027pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M448 453H361L394 608H355L322 453H214L248 608H210L176 453H79L70 395H163L134 259H35L24 201H120L82 27H120L158 201H266L229 27H267L305 201H395L404 259H318L348 395H439L448 453ZM310 395L280 259H173L202 395H310Z"></path></g><g transform="matrix(.013,0,0,-0.013,6.24,0)"><path d="M600 480C600 590 528 650 384 650H143L137 622C222 614 225 607 210 531L130 127C113 41 106 36 23 28L17 0H294L300 28C204 36 195 42 212 127L243 284L314 263C327 263 339 263 352 264C465 271 600 337 600 480ZM508 481C508 351 402 304 329 304C289 304 265 311 250 317L295 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395H439L448 453ZM310 395L280 259H173L202 395H310Z"></path></g><g transform="matrix(.013,0,0,-0.013,12.48,0)"><path d="M600 480C600 590 528 650 384 650H143L137 622C222 614 225 607 210 531L130 127C113 41 106 36 23 28L17 0H294L300 28C204 36 195 42 212 127L243 284L314 263C327 263 339 263 352 264C465 271 600 337 600 480ZM508 481C508 351 402 304 329 304C289 304 265 311 250 317L295 559C302 594 310 606 323 611C335 616 350 619 367 619C455 619 508 573 508 481Z"></path></g><g transform="matrix(.013,0,0,-0.013,24.138,0)"><path d="M512 -3V55L134 254V256L512 456V514L75 281V230L512 -3Z"></path></g><g transform="matrix(.013,0,0,-0.013,35.401,0)"><path d="M241 635C89 635 35 457 35 312C35 153 89 -12 240 -12C390 -12 443 166 443 312C443 466 390 635 241 635ZM238 602C329 602 354 454 354 312C354 172 330 22 240 22C152 22 124 173 124 313S148 602 238 602Z"></path></g><g transform="matrix(.013,0,0,-0.013,41.641,0)"><path d="M113 -12C146 -12 170 11 170 46C170 78 146 103 114 103S58 78 58 46C58 11 82 -12 113 -12Z"></path></g><g transform="matrix(.013,0,0,-0.013,44.605,0)"><path d="M241 635C89 635 35 457 35 312C35 153 89 -12 240 -12C390 -12 443 166 443 312C443 466 390 635 241 635ZM238 602C329 602 354 454 354 312C354 172 330 22 240 22C152 22 124 173 124 313S148 602 238 602Z"></path></g><g transform="matrix(.013,0,0,-0.013,50.845,0)"><path d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z"></path></g></svg> vs. the PDE5A-overexpression (OE) group.</div>

International Journal of Endocrinology

fig5

Figure 5

Figure 5: PDE5A Suppresses Proteasome Activity Leading to Insulin Resistance in C2C12 Myotubes 