Distress signal from fat cells prompts heart to shore up defenses against consequences of obesity

Medical XPress / UT Southwestern Medical Center / Cell Metabolism ^ | Aug. 20, 2021 | Clair Crewe et al

[ConservativeMind]

A stress signal received by the heart from fat could help protect against cardiac damage induced by obesity. The finding could explain the "obesity paradox," a phenomenon in which obese individuals have better short- and medium-term cardiovascular disease prognoses compared with those who are lean, but with ultimately worse long-term outcomes.

Study co-leader Clair Crewe, Ph.D., explained that the metabolic stress of obesity gradually makes fat tissue dysfunctional, causing its mitochondria—the cellular organelles that generate energy—to shrink and die. Eventually, this unhealthy fat loses the ability to store lipids generated by excess calories in food, poisoning other organs through an effect called lipotoxicity. Some organs, including the heart, appear to mount a preemptive defense to protect against lipotoxicity.

[The study] used a genetic technique to speed the loss of mitochondrial mass and function in mice. When these animals ate a high-fat diet and became obese, the researchers found that the rodents' fat cells began sending out extracellular vesicles filled with small pieces of dying mitochondria. Some of these mitochondrial snippets traveled through the bloodstream to the heart, triggering oxidative stress, a state in which cells generate harmful free radicals.

To counteract this stress, heart cells produce a flood of protective antioxidant molecules. This protective backlash was so strong that when the scientists injected mice with extracellular vesicles filled with mitochondrial snippets and later induced a heart attack, the animals had significantly less damage to their hearts compared with mice that didn't receive an injection.

Further research using fat tissue sampled from obese patients showed that these cells also release mitochondria-filled extracellular vesicles, Dr. Crewe said, suggesting that the effects in mice also take place in humans.

Eventually, she explained, the heart and other organs in obese individuals become overwhelmed by lipotoxic effects, leading to many of obesity's comorbidities.

[ConservativeMind]

The heart initially generates a strong response to the damage the fat cells’ damage to it, but we are left with dysfunctional fat cells that no longer work properly.

The stuff that is supposed to go into fat cells instead chooses to damage our organs.

As if I needed another reason to lose more weight…

[Eddie01]

AFGHANISTAN

[Red Badger]

Distress signal from fat cells?

Mine must be like a searchlight!................

[RushIsMyTeddyBear]

I was going to say that of myself. I could stand losing about 20. 😆

[fruser1]

The key to losing weight is not eating less, but crapping more.

[sauropod]

bkmk

[KeyLargo]

Fat ass IL Gov says, “I told you so.”