As midlife crises go, you could do a lot worse than Fox’s “BH90210,” a clever and intentionally cheesy reunion of the original cast of the 1990s high school drama “Beverly Hills, 90210.” They’ve engineered it in a way that lessens the burden of full commitment — theirs or ours.

Managing to be both light and cynical, “BH90210” (a six-episode miniseries, premiering Wednesday) brings back Jennie Garth, Tori Spelling, Shannen Doherty, Gabrielle Carteris, Brian Austin Green, Jason Priestley and Ian Ziering (everyone but Luke Perry, who died five months ago) to play exaggerated versions of themselves — which is to say, actors who happened to hit it big on an enjoyably mediocre TV series three decades ago and have had to cope with that fact ever since.

The show opens on the slightly pathetic scene of a “90210” fan convention in Las Vegas, where six of the actors have been lured to appear on a panel Q&A, each quietly dealing with a fresh personal setback: Jennie is working on her third divorce; Tori, once a reality-show queen, has run out of reality that’s worth showing; Jason just lost a gig directing a superhero TV show because he punched its mouthy young star; Brian is a slightly bored stay-at-home dad married to a superstar pop singer; Gabrielle, head of the actors union, just became a grandmother but is rather belatedly realizing she might be a lesbian; Ian and his trophy wife are in a constant state of entrepreneurial self-promotion, hawking a workout guide with little success.

Shannen, still the cast member no one else likes, beams into the convention hall Q&A via an Instagram stream from India, where she is selflessly rescuing baby Bengal tigers and generally saving the planet. She gets a standing ovation from the audience; her former co-stars can only roll their eyes.

None of the above tongue-in-cheekiness is exactly true, but it does give the actors — who now range in age from 46 to 58 — a playful chance to riff on their celebrity personas and post-“90210” epilogues.

The first episode, in fact, verges on one of the smartest portrayals of midlife ennui we’re likely to see this year, save for FX’s “Better Things” and the belatedly satisfying final season of HBO’s “Divorce.” Even if none of the “90210” actors spend their nights on a park bench (fictionally or otherwise), a viewer can at least take a moment to appreciate that their career trajectories aren’t quite what they once imagined.

“How the hell did we end up here?” Jennie asks Jason, just before they sneak off together for some throwback nookie. “Did you ever wonder what our lives would be like if we hadn’t done that show?”

“Every single day,” he sighs.

Perry’s death, at 52, is somewhat nominally acknowledged — a group toast here, a heavy sigh there — but it’s a chill wind that nevertheless blows across the occasion. “We’re not all going to be here forever,” a drunk Tori declares. “But we made something that will be.”

“BH90210” easily locates a tone of self-mockery; if it could somehow remain in the slightly dour, don’t-remind-me mood of this first episode, it might get to a deeper, more profound place than it ever intended: a meta-commentary on fame, age and nostalgia. Instead, shenanigans break out, the dialogue heads for the ham (to go with the cheese), and the gang winds up spending a night in jail.

The ensuing media attention gives Tori the bright idea to approach Fox with a can’t-miss pitch for a reboot of “Beverly Hills, 90210”; the network enthusiastically agrees, if and only if the rest of the cast — including the elusive Shannen — will come aboard. The road back to the Peach Pit, it turns out, is a long one.

Enlisting a dubious Jennie to her cause, Tori discovers that her co-stars have their own demands — more creative than financial. They each want a chance to color outside the lines, reshaping the tropes that once defined their characters and pigeonholed the actors’ careers. (Except in the case of “Sharknado” star Ziering, who merely wants opportunities for product placement.) The conceit of “BH90210,” then, is to keep viewers guessing whether this project will come together or not.

“What is it that one guy said, ‘You can’t go home again?’ ” Jennie asks Tori.

“What guy?” Tori asks.

“I don’t know,” Jennie says. “I only went to a fake high school.”

BH90210 (one hour) premieres Wednesday at 9 p.m. on Fox.