Blocking glucagon improved sperm quality in male mice
A glucagon-receptor antibody raised sperm counts and motility in diabetic, aged, and healthy mice by restoring a lactate fuel line that glucagon had been throttling inside the testis.
Peptide research, regulation, discovery. Every story links to the peptide it’s about.
RSSA glucagon-receptor antibody raised sperm counts and motility in diabetic, aged, and healthy mice by restoring a lactate fuel line that glucagon had been throttling inside the testis.
Inspired by spider silk, a self-assembling peptide folded into nanofibers around glioma mitochondria and, under ultrasound, produced 3.7 times more of a cell-killing molecule than the loose peptide.
SS-31, a mitochondrial peptide already cleared for a rare heart disease, cut the share of irradiated heart-muscle cells showing an aging marker from 67 percent to 38 percent.
Most STING research tries to switch the innate-immune alarm on to fight cancer. A docking screen of 59,319 peptides went the other way and found one, Peptide-1, that binds STING at 0.15 micromolar and quiets cGAMP-driven inflammation in mouse macrophages. It is the mirror image of a peptide we covered last month.
MAX-7 degrades the cancer master-switch MYC through chaperone-mediated autophagy, bypassing the proteasome that most targeted degraders use, and shrank triple-negative breast tumors in mice.
In colorectal cancer cells and mice, the stapled peptide i7-01s-20 reactivated Beclin1 and degraded both EGFR and beta-catenin at once, and the effect vanished when Beclin1 was silenced.
Mephedrone built a place preference in rats only when dosed socially, not alone. Blocking that reward took opposite moves on two peptide receptors: turning the oxytocin receptor up (carbetocin) or the vasopressin V1A receptor down (SR49059). Peripheral vasopressin did nothing, so the switch is central.
Integrins share the same RGD binding address, so PET probes built on it cannot tell the subtypes apart. A Journal of Medicinal Chemistry study tuned the shape of cyclic RGD peptides instead of their sequence, building a 25-member ring library. Two of three lead probes imaged their target integrin in tumor-bearing mice; the third stayed selective in cells but failed in the animal.
GLP-1 drugs slow the stomach, and food left behind before an upper endoscopy can be inhaled under sedation. A retrospective study of 16,067 scopes found that keeping the drug on board raised the odds of retained stomach contents about tenfold, while a two-week hold brought them back near normal. Obese patients stayed high-risk even after holding.
A TriNetX records study published July 7 in the American Journal of Physical Medicine and Rehabilitation found that spinal cord injury patients started on a CGRP inhibitor were less likely to need a gabapentinoid within a month than those started on topiramate (odds ratio 0.62) or propranolol (0.75). CGRP is the pain-signaling peptide these migraine antibodies block, and it sprouts abnormally in the injured spinal cord, giving the repurposing idea a mechanism. It is an association, not a trial.
The full phase 3 TRANSCEND data published July 9 in the New England Journal of Medicine: setmelanotide dropped body-mass index 16.5 percent over a year in acquired hypothalamic obesity while placebo gained 3.3 percent. Read against Rhythm's EMANATE failure in partial-loss obesity two months ago, it draws a clean line: the MC4R agonist works only where the melanocortin satiety circuit is fully broken, whether a mutation silenced it or a tumor destroyed the tissue around it.
A single-center Japanese cohort of 34 adolescents aged 15 to 17 found CGRP monoclonal antibodies cut migraine impact by 9.4 HIT-6 points at 12 weeks, with about half of responders improving by weeks four to six and no serious side effects.
Tirzepatide activates the GIP receptor. MariTide blocks it. Both cause weight loss, and the field cannot say which is right. A new mouse study built a single peptide that does both in sequence, and the on-then-off design dropped body weight 21.6 percent, against 14.5 percent for a pure blocker.
A protein called CAP builds up in the gut of children with Hirschsprung disease and stalls the nerve cells that should colonize the colon. A fragment of that same protein, PDCAP, competes it off, and in two mouse models it let the missing nerves form.
Six phase 1 studies mapped orforglipron's drug interactions. A CYP3A4-blocking antibiotic raised the oral GLP-1 drug's levels, an epilepsy drug lowered them, and orforglipron barely touched other drugs. The injectable peptides carry no such map.