Regeneration is the natural process of replacing or restoring cells that have been lost or damaged due to injury or disease. A few animals can regrow entire organs or other body parts, but most have limited abilities to regenerate.

Scientists in the field of regenerative medicine study how some animals are able to rebuild lost body parts. By better understanding these processes and learning how to control them, researchers hope to develop new methods to treat injuries and diseases in people.

Take this quiz to test what you know about regeneration and regenerative medicine. Then check out our Regeneration fact sheet and the regeneration issue of Pathways, a teaching resource produced in collaboration with Scholastic.

Michael Boyce, associate professor of biochemistry at Duke University in Durham, North Carolina. Credit: Michael Boyce.

Sugars aren't merely energy sources for our cells. They also play important signaling roles through a process called glycosylation, where they attach to proteins and lipids as tags. Although these sugar tags, called glycans, impact many cellular processes, they have long been understudied due to technical challenges. Now, advances in analytical tools like mass spectrometry are enabling scientists to examine the enormous complexity of glycans. Other advances also allow researchers to synthesize complex sugars, providing them with standards for analytical experiments.

Microbiota in the intestines. Credit: iStock.

Research on how diet impacts the gut microbiota has rapidly expanded in the last several years. Studies show that diets rich in red meat are linked to diseases such as colon cancer and heart disease. In both mice and humans, researchers have recently discovered differences in the gut microbiota of those who eat diets rich in red meat compared with those who don’t. This is likely because of a sugar molecule in the red meat, called N-glycolylneuraminic acid (Neu5Gc), that our bodies can't break down. Researchers believe the human immune system sees Neu5Gc as foreign. This triggers the immune system, causing inflammation in the body, and possibly leads to disease over time.

Vern Schramm, professor of biochemistry at Albert Einstein College of Medicine, Bronx, New York. Credit: Albert Einstein College of Medicine.

Enzymes drive life. Without them, we couldn’t properly digest food, make brain chemicals, move—or complete myriad other vital tasks. Unfortunately, in certain cases, enzymes also can trigger a host of health problems, including cancer, bacterial infections, and hypertension (high blood pressure).

Understanding how enzymes work has been the research focus of Vern Schramm for more than 4 decades.

“When we started our work, we were driven not by the desire to find drugs, but to understand the nature of enzymes, which are critical to human life,” Schramm says. But his research already led to one drug, and promises many more.

Happy Thanksgiving!

During this time of year, family and friends gather to enjoy rich foods and good company. Even if you typically follow a healthy diet, it can be hard to make wholesome food choices during occasions like these.

Our previous post, Five Fabulous Fats, highlighted essential fats made in our bodies. Here we discuss five important fats our bodies can't make on their own, the foods that contain them, and why you should include a healthy dose of each in your diet.

Geranial

Credit: iStock.

Geranial, a fat some people may not know about, is present in the oils of several citrus plants such as orange, lemon, and lime. Research suggests that its antibacterial and antimicrobial properties reduce inflammation in the body. So, think about adding some freshly squeezed lemonade to the menu.

Most of what we know comes from intensive study of research organisms—mice, fruit flies, worms, zebrafish, and a few others. But according to Alejandro Sánchez Alvarado, Ph.D., a researcher at the Stowers Institute for Medical Research in Kansas City and a Howard Hughes Medical Institute Investigator, these research organisms represent only a tiny fraction of all animal species on the planet. Under-studied organisms could reveal important biological phenomena that simply don’t occur in the handful of models typically studied, he says.

DNA, with its double-helix shape, is the stuff of genes. But genes themselves are only “recipes” for protein molecules, which are molecules that do the real heavy lifting (or do much of the work) inside cells.

Artist interpretation of RNAP grasping and unwinding a DNA double helix. Credit: Wei Lin and Richard H. Ebright.

Here’s how it works. A molecular machine called RNA polymerase (RNAP) travels along DNA to find a place where a gene begins. RNAP uses a crab-claw-like structure to grasp and unwind the DNA double helix at that spot. RNAP then copies (“transcribes”) the gene into messenger RNA (mRNA), a molecule similar to DNA.

The mRNA molecule travels to one of the cell’s many protein-making factories (ribosomes), which use the mRNA message as instructions for making a specific protein.

Credit: Zvonimir Dogic, Brandeis University.

Imagine an army of tiny soldiers stationed throughout your body, lining cells from your brain to every major organ system. Rather than standing at attention, this tiny force sweeps back and forth thousands of times a minute. Their synchronized action helps move debris along the ranks to the nearest opening. Other soldiers stand as sentries, detecting changes in your environment, relaying that information to your brain, and boosting your senses of taste, smell, sight, and hearing.

Your brain may be the commander in chief, but these rank-and-file soldiers are made up of microscopic cell structures called cilia (cilium in singular).

Here we describe these tiny but mighty cell structures in action.

Happy Fat Tuesday!

On this day, celebrated in many countries with lavish parties and high-fat foods, we're recognizing the importance of fats in the body.

You've probably heard about different types of fat, such as saturated, trans, monounsaturated, omega-3, and omega-6. But fats aren't just ingredients in food. Along with similar molecules, they fall under the broad term lipids and serve critical roles in the body. Lipids protect your vital organs. They help cells communicate. They launch chemical reactions needed for growth, immune function, and reproduction. They serve as the building blocks of your sex hormones (estrogen and testosterone).

Here we feature five of the hundreds of lipids that are essential to health.

• Can regrow a severed spinal cord?
• Is a culinary delicacy overseas but an invasive pest in the U.S.?
• Reveals insights about tissue regeneration, evolution, and cancer biology?