The research team, led by Ryan Wei Kwan Wong and Thibault Mayor of the Department of Biochemistry and Molecular Biology at the Michael Smith Laboratories, set out to characterize the proteomic changes that occur when Saccharomyces cerevisiae is pushed to produce a heterologous protein. Their model target was laccase, an enzyme that is not native to yeast and therefore places distinctive demands on the cell’s protein folding and secretion machinery. By tracking protein abundance over four days of batch cultivation, the researchers were able to separate the effects of ordinary growth and nutrient depletion from the specific burden imposed by recombinant protein expression.

The scale of the survey is significant. Using quantitative mass spectrometry, the team measured the abundance of thousands of proteins across the cultivation period, capturing the ebb and flow of the cellular machinery as the culture progressed. This time-resolved approach matters because recombinant production in batch culture is not a static process: cells pass through exponential growth, nutrient exhaustion, and stress phases, and each stage imposes its own demands. A single snapshot at the end of a fermentation run would miss much of the story.

One of the clearest results is that the bulk of proteomic change during batch cultivation is driven not by the recombinant protein itself but by the shifting nutritional environment. As nutrients are depleted, a substantial portion of the proteome shifts, with ribosomal and metabolic proteins among the categories that change most noticeably. This makes biological sense: as the growth rate slows, cells downsize their protein synthesis apparatus and rewire their metabolism to survive on whatever carbon and nitrogen sources remain. Distinguishing this background remodeling from the specific response to laccase production was a central analytical challenge of the study.

When the researchers isolated the signature of laccase expression, a striking pattern emerged: only a smaller subset of proteins was specifically affected by producing the foreign enzyme. In other words, the cell does not mount a wholesale, dramatic overhaul in response to a heterologous protein. Instead, the response is comparatively targeted, involving particular classes of proteins that help the cell cope with the added biosynthetic and folding load. This finding refines the common assumption that recombinant production is a broadly destabilizing stress for the host cell.

The most consequential part of the study came from a comparison across strains. Rather than working with a single laboratory isolate, the team examined S. cerevisiae strains of different origins and with different capacities to produce active laccase. What they found was that each strain displayed a distinct proteomic response to heterologous expression, and, notably, that this individuality persisted regardless of the origin of the laccase enzyme being produced. The strain, not the foreign protein, appeared to dictate the shape of the cellular response.

Concrete examples illustrate the point. The molecular chaperones Hsp26 and Kar2 were specifically elevated in a whey-derived strain upon laccase expression. Kar2, also known as BiP, is a key chaperone of the endoplasmic reticulum, the compartment where secreted proteins fold, while Hsp26 is a cytosolic chaperone associated with stress protection. Their selective induction in one strain but not others shows that different yeast lineages deploy different quality-control strategies when confronted with the same production task. The cellular environment each strain provides is genuinely unique.

Perhaps the most provocative conclusion is that the strains with a higher capacity to produce active recombinant laccase owe their advantage not to a stronger or better-coordinated response during production, but to small groups of proteins that are constitutively expressed at different levels even before the foreign gene is switched on. In other words, the winning strains start the race with an advantage already built in. Their baseline proteome, shaped by their evolutionary history and ecological origin, happens to provide a cellular milieu that is more favorable for folding, processing, or sustaining the recombinant product.

This has practical implications for the biotechnology industry. Recombinant protein production in yeast underpins the manufacture of biopharmaceuticals, industrial enzymes, and food ingredients, and yield improvement has traditionally focused on engineering the production strain: adding gene copies, overexpressing chaperones, or optimizing promoters and secretion signals. The new results suggest a complementary and potentially underexploited strategy: screening naturally occurring yeast diversity for strains whose native proteomes are already well suited to a given product. Rather than forcing a standard laboratory strain to adapt, producers could select a strain whose inherent biology does much of the work.

The study also carries a conceptual message for the field. Because each strain responds differently to the same recombinant protein, proteomic data gathered from one background may not generalize to another, a caveat for anyone using a single reference strain to model production behavior. At the same time, the identification of constitutively expressed protein groups associated with high yields provides concrete molecular leads for future work, whether in rational engineering or in breeding programs that combine favorable natural traits. As the authors note, this is the first look at the dynamic proteome remodeling that occurs during recombinant laccase expression, and it highlights the potential of exploiting naturally occurring yeast diversity rather than relying solely on strain engineering to improve recombinant protein yields. For an organism that has served biotechnology for decades, S. cerevisiae still has surprises hidden in its wild relatives and industrial isolates, and those hidden differences may be the key to the next generation of cell biofactories.

Subject of Research: Proteomic responses of Saccharomyces cerevisiae strains during recombinant laccase production

Article Title: Alterations of the Saccharomyces cerevisiae proteome by protein production are dependent on strain origins

Article References: Wong, R. W. K., Chandhok, S., Hui, E., & Mayor, T. (2026). Alterations of the Saccharomyces cerevisiae proteome by protein production are dependent on strain origins. Applied Microbiology and Biotechnology. https://doi.org/10.1007/s00253-026-14014-6

Image Credits: AI Generated

DOI: 10.1007/s00253-026-14014-6

Keywords: Saccharomyces cerevisiae, recombinant protein production, proteomics, laccase, yeast strain diversity, chaperones, mass spectrometry, cell biofactories, heterologous expression, biotechnology, Alterations, Saccharomyces

The immediate consequence of congenital diaphragmatic hernia is structural. A hole in the diaphragm, the muscular partition separating the chest from the abdomen, allows abdominal organs such as the stomach, liver, and intestines to migrate into the chest cavity during fetal development. The crowding effect is severe: the developing lungs are compressed at precisely the window of gestation when their airways and vascular trees should be branching and expanding. The result is pulmonary hypoplasia, lungs that are smaller, simpler in architecture, and less able to support gas exchange after birth. But the mechanical compression is only part of the story. Newborns with this condition frequently develop persistent pulmonary hypertension, in which the resistance of the pulmonary circulation is so high that the heart struggles to pump blood through the lungs, leading to critical oxygen deprivation that can be fatal even with aggressive intervention.

The pulmonary hypertension associated with the condition has always hinted at a vascular problem, and vascular problems invite scrutiny of the endothelium. Endothelial cells form the inner lining of every blood vessel, and in the pulmonary circulation they do far more than serve as a passive barrier. They regulate vascular tone by producing nitric oxide, a potent vasodilator; they orchestrate angiogenesis, the growth of new vessels; they modulate inflammation and blood clotting; and they communicate constantly with the smooth muscle cells that wrap around vessels and control their caliber. In pulmonary hypertension of any origin, endothelial dysfunction is a recurring theme, and congenital diaphragmatic hernia is no exception. Previous work has described abnormal vascular remodeling in the lungs of affected infants, including medial thickening of pulmonary arteries and aberrant extension of muscle into distal, normally non-muscularized vessels. What the new study adds is a specific mechanistic suspect: disturbed energy metabolism within the endothelial cells themselves.

Bioenergetics refers to the set of biochemical pathways by which a cell converts nutrients into usable chemical energy, chiefly in the form of adenosine triphosphate, or ATP. For most cells in the body, the mitochondria are the power plants, and their efficiency determines whether a cell thrives or struggles under stress. Endothelial cells are unusual in this respect. Unlike many other cell types, healthy endothelial cells generate the majority of their ATP through glycolysis, the anaerobic breakdown of glucose, even when oxygen is abundantly available. This glycolytic preference is not a quirk; it is functionally important. It spares oxygen for the surrounding tissue, positions the endothelium to survive in low-oxygen environments during vessel sprouting, and produces biosynthetic intermediates needed for the rapid proliferation of new vessel lining during angiogenesis. Any disruption to this finely tuned metabolic balance can therefore ripple outward, impairing nitric oxide production, promoting oxidative stress, and destabilizing the vessel wall.

It is against this background that the reported alterations in endothelial bioenergetics take on significance. The study investigated how endothelial cells in the setting of congenital diaphragmatic hernia differ in their energy-generating machinery, examining markers of mitochondrial function and respiratory activity. Cells under metabolic stress typically exhibit a recognizable signature: diminished mitochondrial respiratory capacity, altered balance between oxidative phosphorylation and glycolysis, elevated production of reactive oxygen species, and reduced ability to adapt when energy demands spike. Each of these changes can feed a vicious cycle relevant to pulmonary hypertension. Mitochondrial dysfunction impairs the enzymes that synthesize nitric oxide, and when the endothelial nitric oxide synthase enzyme becomes uncoupled, it can actually generate superoxide instead of the protective vasodilator molecule. The resulting oxidative burden damages proteins, lipids, and DNA inside the vessel wall, encouraging the very remodeling and vasoconstriction that define hypertensive lung circulation.

The clinical stakes of this line of investigation are considerable. Infants with congenital diaphragmatic hernia are among the most intensively supported patients in neonatal intensive care, often requiring high-frequency ventilation, inhaled nitric oxide therapy, and in severe cases extracorporeal membrane oxygenation, a heart-lung bypass machine that takes over gas exchange while the infant’s own circulation stabilizes. Despite these measures, mortality remains substantial, particularly in cases diagnosed early with severe lung involvement. One of the most difficult problems clinicians face is predicting which infants will deteriorate and tailoring the intensity of support accordingly. If endothelial bioenergetic status proves to correlate with disease severity, metabolic markers could eventually supplement current predictors of outcome, giving intensive care teams a biochemical window into the state of the pulmonary vasculature that imaging and blood gas measurements cannot fully provide.

There is also a therapeutic dimension to consider. Metabolism has moved to the center of vascular biology research over the past two decades, and drugs that modulate mitochondrial function or cellular energy pathways already exist for other conditions. The concept of a metabolically targeted therapy for pulmonary vascular disease is no longer speculative in principle; several metabolic modulators, including agents that influence fatty acid oxidation and mitochondrial dynamics, are under investigation for pulmonary hypertension more broadly. If the endothelial energy deficit identified in congenital diaphragmatic hernia can be corrected, or even partially compensated, it could complement existing treatments that work through entirely different mechanisms. Inhaled nitric oxide, for example, acts downstream to relax vessels, but it does nothing to repair the underlying endothelial dysfunction that limits natural nitric oxide production. A therapy aimed at restoring mitochondrial health would attack the problem at its cellular source.

Careful interpretation remains essential. The connection between altered endothelial bioenergetics and clinical outcomes in this disease is an association that must now be interrogated further. Key questions include whether the metabolic changes observed are a cause of the pulmonary vascular pathology or a consequence of it, whether they are present before birth or emerge postnatally under the stress of intensive care, and whether they can be detected reliably in accessible clinical samples such as blood or in cells grown from patient-derived material. Animal models of the condition, including the nitrofen-induced rodent model widely used in the field, will likely play an important role in establishing causality, since they allow researchers to examine lung vessels at defined developmental stages that are difficult or impossible to access in human fetuses. The heterogeneity of the disease, which ranges from mild cases detected incidentally to lethal ones diagnosed prenatally, adds another layer of complexity to any attempt at generalization.

For the broader research community, the study sits at the intersection of two fields that have been converging rapidly: developmental vascular biology and cellular metabolism. The same bioenergetic principles that govern tumor angiogenesis and wound healing apply to the construction of the fetal pulmonary circulation, and perturbations of those principles during gestation may leave lasting functional fingerprints. Congenital diaphragmatic hernia, precisely because its vascular pathology is so pronounced and its clinical course so well documented, offers a natural setting in which to test whether endothelial energetics shape developmental outcomes. As follow-up work refines these findings, the hope is that a condition whose treatment has long been defined by supportive care will begin to yield to targeted, mechanism-based interventions, giving newborns with this devastating diagnosis a better chance at healthy, unrestricted breathing from their very first days.

Subject of Research: Endothelial cell bioenergetic alterations in congenital diaphragmatic hernia

Article Title: Alterations of endothelial cell bioenergetics in congenital diaphragmatic hernia

Article References: Emrick, B. F., Zhevlakova, I., Novotny, M., Mavrakis, L., Mulya, A., Cass, D. L., Miyasaka, E., Byzova, T. V., Asosingh, K., Erzurum, S. C., & Robertson, J. O. (2026). Alterations of endothelial cell bioenergetics in congenital diaphragmatic hernia. Pediatric Research. https://doi.org/10.1038/s41390-026-05447-w

Image Credits: AI Generated

DOI: 10.1038/s41390-026-05447-w

Keywords: congenital diaphragmatic hernia, endothelial cells, bioenergetics, mitochondria, pulmonary hypertension, pulmonary hypoplasia, nitric oxide, neonatal care, vascular remodeling, pediatric research, Alterations, endothelial