Gastrin-Cck2r signaling drives a regenerative burst in the gastric corpus
A gastrin-rich milieu rapidly expanded Cck2r+ isthmus progenitors in the gastric corpus, while low gastrin sharply reduced that compartment. In a mouse system built to trace corpus progenitors across homeostasis and injury, the gastrin-Cck2r axis emerged as a central regulator of mucosal repair rather than a passive marker of epithelial turnover. The biological logic is straightforward: gastrin does more than stimulate acid secretion. By engaging Cck2r-positive progenitors, it appears to mobilize the epithelial reserve needed to rebuild damaged mucosa after ulceration or chronic inflammatory stress.
The model used Cck2r-CreERT2; Gastrin-DTR-p2A-TdTomato; Rosa26-ZsGreen mice, allowing lineage tracing during both gastrin deficiency and excess. That design matters because the corpus is not a uniform sheet of cells; it contains distinct populations with different regenerative potential, and the isthmus progenitor niche sits at the center of that repair machinery. When gastrin levels rose, those progenitors expanded. When gastrin fell, they contracted. The direction of travel was consistent across the experimental conditions described here.
Ulcer injury triggered endogenous gastrin release and epithelial repair
Acute gastric ulceration produced a twofold increase in plasma gastrin by day 14, alongside expansion of antral G cells. Complete ulcer healing followed by day 28. The sequence suggests a compensatory endocrine response to injury: mucosal damage triggers hypergastrinemia, which then feeds back on the corpus epithelium to accelerate restitution and restore the barrier. In practical terms, the stomach appears to recruit its own hormonal repair signal in response to injury, and that signal is tightly linked to the Cck2r progenitor pool.
Two interventions intensified that response. Gastrin infusion and proton pump inhibitor treatment each drove gastrin higher and were associated with complete ulcer healing by day 14. The speed of that recovery is clinically striking. In this model, heightened gastrin signaling did not simply accompany healing; it shortened the time needed for the ulcer to close. Proton pump inhibition likely achieved this by suppressing acid output and removing the inhibitory feedback on gastrin secretion, while exogenous gastrin supplied the same regenerative cue directly. The result in both settings was a more rapid repair program centered on corpus progenitor expansion.
G-cell ablation removed the healing advantage of proton pump inhibition
Ablating G cells lowered gastrin, impaired healing, and erased the benefit of proton pump inhibitor treatment. This is the clearest demonstration in the study that gastrin is not an incidental biomarker of acid suppression. It is part of the mechanism. Without gastrin, the regenerative response weakened, even when acid suppression would otherwise be expected to aid mucosal recovery. The corpus progenitor compartment lost the proliferative push it needed, and ulcer closure slowed.
That finding has direct biological implications. Acid reduction alone does not fully explain mucosal restitution. The endocrine response to hypochlorhydria appears to contribute a second layer of benefit by activating Cck2r+ progenitors in the corpus. For ulcer repair, the combination of a less hostile luminal environment and a stronger gastrin signal seems to be more effective than either component in isolation.
Hypergastrinemia also altered chronic injury and neoplastic risk markers
The study extended beyond acute ulceration into chronic H. pylori gastritis and N-Nitroso-N-Methylurea exposure, both of which model longer-term injury and dysplastic pressure. Within those settings, gastrin signaling again shaped epithelial behavior. Hypergastrinemia expanded Cck2r+ isthmus progenitors, while hypogastrinemia reduced them, linking the hormone to progenitor pool size under conditions where repeated injury and abnormal regeneration can create a platform for dysplasia.
This dual effect is clinically important because the same proliferative machinery that closes an ulcer can, if misdirected or chronically amplified, participate in precancerous remodeling. The study’s title captures that tension accurately: gastrin-dependent expansion accelerated ulcer healing and inhibited gastric dysplasia. The data place gastrin in a narrow but consequential range of epithelial control, where the outcome depends on context, timing, and the nature of the injury signal. In acute damage, the response is reparative. In chronic injury, the same pathway may help preserve orderly regeneration and limit the drift toward dysplasia.
The corpus progenitor niche is the key target of the gastrin signal
The work focuses attention on the corpus isthmus as a biologically privileged zone for gastric renewal. Cck2r expression in corpus isthmus progenitors, enterochromaffin-like cells, and parietal cells has long suggested that gastrin influences both secretory physiology and epithelial turnover. What this study adds is direct evidence that the progenitor arm of that network responds dynamically to gastrin during injury and regeneration. The stomach does not simply secrete acid and wait for passive recovery. It deploys a hormone-driven regenerative circuit that expands the very cells capable of restoring mucosal integrity.
For translational medicine, the message is not that gastrin should be raised indiscriminately. Chronic hypergastrinemia has long-standing associations with epithelial proliferation, and any therapeutic strategy that manipulates this axis would need careful context. But the data clarify a mechanistic gap that has limited gastric biology for years: gastrin has a regenerative role in the corpus, and that role runs through Cck2r+ progenitors.
Regeneration and dysplasia share the same hormonal control point
The most useful insight from these experiments is the same one that makes them clinically delicate. Gastrin can accelerate repair while also shaping the epithelial population from which dysplastic change may emerge during chronic injury. The study shows that the balance can tilt toward healing when the signal is coordinated with acute ulcer repair, and away from dysplasia when the corpus progenitor compartment is supported in an orderly fashion rather than left to repeated inflammatory injury.
What remains unresolved in this mouse work is how directly these findings translate to human ulcer disease, chronic H. pylori infection, or gastric premalignancy. The experiments establish causality in a controlled preclinical system, but the therapeutic window for leveraging gastrin biology in patients is still undefined. Even so, the pathway now looks far more actionable than before: gastrin is not just a secretagogue. In the gastric corpus, it is a lineage-controlling signal that governs how fast the mucosa heals and how safely it does so.