Yavuz. Ersin E; Sağır. Melih S MS; Ercan. Alp A; Erginer. Merve M; Barlas. Fırat B...
A new nerve tube made from a plant stem and a gel was tested in rats with a small sciatic nerve gap. It slowly released the peptide IGF‑1 LR3, which helped nerves grow back as well as the current gold‑standard nerve graft, and it didn’t cause any obvious side effects.
Boes. Mary M; Dake. Brian L BL; Booth. Barbara A BA; Sandra. Alexander A; Bateman. Mathew M; Knudtso...
The study shows that in rat hearts, IGF‑1 gets into the tissue through two routes: directly binding to its own sites and via complexes with the carrier protein IGFBP‑3. Blocking IGF‑1’s own sites cuts uptake a lot, while using IGF‑1 bound to IGFBP‑3 still allows a decent amount to get in. This hints that the way IGF‑1 is delivered (free vs. bound) matters for how much reaches heart tissue.
White. Alicia A; Stremming. Jane J; Boehmer. Brit H BH; Chang. Eileen I EI; Jonker. Sonnet S SS; Wes...
A week‑long infusion of the IGF‑1 analog IGF‑1 LR3 in late‑pregnancy sheep lowered the babies' blood insulin and glucose levels and made their pancreas cells release less insulin, even when the cells were studied outside the body. This suggests that high IGF‑1 exposure can directly impair the cells that make insulin.
The study shows that IGF‑1 and its long‑acting version LR3‑IGF‑1 are naturally present in the small intestine and can increase the number of cells lining the gut, but they don’t make the gut bigger or longer. IGF‑II can grow gut tissue in adult rats and changes some digestive enzymes. Overall, the findings confirm modest gut‑lining effects of IGF‑1/LR3‑IGF‑1 but give little guidance for dosing or clear performance benefits.
The study shows that an IGF‑1 LR3‑like molecule can boost the growth and hormone output of ovarian cells in sheep, helping follicles develop and increasing estrogen and androgen levels. Other factors like TGF‑alpha and EGF also affect these cells but tend to suppress hormone production, while inhibin A has mixed effects. These results confirm IGF‑1’s role in promoting cell proliferation and hormone synthesis, but they’re specific to the ovary and were done in animals, not humans.
The study shows that cells need proper N‑glycosylation to make enough IGF‑1 receptors on their surface, and without it, the IGF‑1 LR3 hormone can’t trigger the downstream ERK signaling as well. This suggests that the effectiveness of IGF‑1 LR3 depends on the cell’s glycosylation machinery, not just the dose of the peptide.
Tomas. F M FM; Chandler. C S CS; Coyle. P P; Bourgeois. C S CS; Burgoyne. J L JL; Rofe. A M AM
In rats with tumors, giving IGF‑1 LR3 (a stronger IGF‑1) cut food intake, lowered insulin and glucose, and actually sped up tumor growth while hurting muscle protein balance. Adding insulin boosted food intake, reduced tumor size, and increased muscle and fat mass, but IGF‑1 LR3 didn’t help muscle growth even with insulin. The study suggests IGF‑1 LR3 can worsen metabolic problems in a disease state and may need insulin to offset the effects.
Oliver. William T WT; Rosenberger. Judy J; Lopez. Rusmely R; Gomez. Adam A; Cummings. Kathleen K KK;...
In mice that make extra IGF‑I in their muscles, muscle size grew about 20% and stayed larger, but the levels of proteins that normally bind IGF (IGFBPs) didn’t change because of the extra IGF‑I. Instead, IGFBP levels shifted with age and sex. A modified IGF‑I called LR3‑IGF‑I turned on the IGF‑1 receptor more strongly than regular IGF‑I, no matter the mouse’s age, sex, or genetics.
Tomas. F M FM; Knowles. S E SE; Owens. P C PC; Chandler. C S CS; Francis. G L GL; Ballard. F J FJ
In diabetic rats, the IGF‑1 variants LR3‑IGF‑1 and des(1‑3)IGF‑1 grew the animals about three times faster than regular IGF‑1, adding mostly lean tissue, while insulin made them gain more fat. However, none of the IGF‑1 peptides lowered blood sugar or reduced muscle protein breakdown like insulin did. This shows the variants are strong anabolic agents but don’t act like insulin for glucose control.
Martin. Janet L JL; Lin. Mike Z MZ; McGowan. Eileen M EM; Baxter. Robert C RC
The study shows that IGF‑binding protein‑3 (IGFBP‑3) can boost the activity of IGF‑1 LR3 and EGF in breast cells, but it needs an enzyme called sphingosine kinase‑1 (SphK1) and specific S1P receptors to do this. This means IGFBP‑3 isn’t just a passive carrier; it actively enhances growth‑factor signals through a lipid‑signaling pathway.
Scientists figured out a way to make lots of IGF‑1 and its longer‑acting version LR3 IGF‑1 using a yeast system called Pichia pastoris, by attaching a xylanase protein that boosts production. The resulting proteins work just as well as regular IGF‑1 in lab cell tests, and they can be produced at relatively high amounts, which could make them cheaper and more accessible for research or self‑experimentation.
The study shows that regular IGF‑I and the analog Des[1‑3] cause breakdown of IGFBP‑4, a protein that normally holds IGF in check, and this breakdown needs IGFBP‑3. The LR3 analog, however, does not trigger this breakdown because it doesn’t bind IGFBP‑3. This means LR3 may keep IGF‑1 activity more stable without prompting the body’s own protein‑cleaving response, at least in skin cells in a dish.
Robertson. J G JG; Belford. D A DA; Ballard. F J FJ
In rats, the study showed that the modified growth factor LR3‑IGF‑I disappears from wound fluid faster than regular IGF‑I because it doesn't stick to the body's IGF‑binding proteins. This faster clearance leads to more of the peptide ending up in the blood and urine, while regular IGF‑I stays longer at the wound site.
Jonker. Sonnet S SS; Giraud. George D GD; Chang. Eileen I EI; Elman. Miriam R MR; Louey. Samantha S
In a study on near‑term fetal sheep, giving the IGF‑1 LR3 peptide boosted heart muscle cell growth and overall heart size, and the heart’s blood vessels grew proportionally so blood flow per gram of tissue stayed the same. The ways the vessels dilated (using adenosine and nitric oxide) were unchanged compared with untreated animals.
Stremming. J J; White. A A; Donthi. A A; Batt. D G DG; Hetrick. B B; Chang. E I EI; Wesolowski. S R...
A sheep‑specific version of IGF‑1 (oIGF‑1) was given to unborn sheep and it made certain organs like the heart and kidneys grow bigger and increased muscle‑cell activity, but it didn’t make the overall muscle bigger or speed up protein building in the muscle. The hormone behaved similarly to the human version in terms of not changing the body’s natural IGF‑binding proteins.
Dunshea. Frank R FR; Chung. Chung S CS; Owens. Phil C PC; Ballard. John F JF; Walton. Paul E PE
In baby pigs that were fed milk, giving them extra IGF‑1 or a stronger version called LR3‑IGF‑1 didn’t change growth when food was limited, but both increased how much milk they drank. In the second half of the study, the LR3 version helped the pigs gain weight faster than the regular IGF‑1. Blood levels of a binding protein (IGFBP‑3) were linked to how quickly they grew.
Hadsell. Darryl L DL; Parlow. Albert F AF; Torres. Daniel D; George. Jessy J; Olea. Walter W
In mice, giving the IGF‑1 variant LR3 under the skin slightly boosted signals in the breast that are linked to milk production and gave a small increase in how much milk the pups gained, but it was less effective than growth hormone. The study shows LR3 can affect mammary pathways, but the effect on actual milk output is modest.
Thomas. Fiona H FH; Campbell. Bruce K BK; Armstrong. David G DG; Telfer. Evelyn E EE
The study shows that adding IGF‑1 (including the LR3 version) to cow egg follicles in a dish makes them grow bigger, but too much IGF‑1 can lead to poorer egg quality and more cell death. Natural proteins that bind IGF‑1 are present and seem to keep its effects balanced, meaning that uncontrolled high doses aren’t beneficial.
White. Alicia A; Stremming. Jane J; Brown. Laura D LD; Rozance. Paul J PJ
A short, 90‑minute infusion of the IGF‑1 LR3 peptide in fetal sheep quickly drops the amount of insulin the animals release, but once the pancreas cells are taken out and tested, they can still make normal amounts of insulin. This means the drop in insulin is temporary and not due to permanent damage to the insulin‑producing cells.
Engel. Matthew G MG; Narayan. Sushma S; Cui. Min-Hui MH; Branch. Craig A CA; Zhang. Xusheng X; Gandy...
Giving mice a nasal spray of a strong IGF‑1 version (LR3‑IGF‑1) changed the shape of Alzheimer‑related plaques in the brain and made the mice a bit leaner, but it didn’t help them think better or remember things. The drug helped break down harmful small amyloid pieces and made plaques look more inert, yet memory stayed the same.