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PurposePatients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) frequently develop arterial hyperoxaemia, which may be harmful. However, lower oxygen saturation targets may also lead to harmful episodes of hypoxaemia.MethodsIn this registry-embedded, multicentre trial, we randomly assigned adult patients receiving VA-ECMO in an intensive care unit (ICU) to either a conservative (target SaO2 92–96%) or to a liberal oxygen strategy (target SaO2 97–100%) through controlled oxygen administration via the ventilator and ECMO gas blender. The primary outcome was the number of ICU-free days to day 28. Secondary outcomes included ICU-free days to day 60, mortality, ECMO and ventilation duration, ICU and hospital lengths of stay, and functional outcomes at 6 months.ResultsFrom September 2019 through June 2023, 934 patients who received VA-ECMO were reported to the EXCEL registry, of whom 300 (192 cardiogenic shock, 108 refractory cardiac arrest) were recruited. We randomised 149 to a conservative and 151 to a liberal oxygen strategy. The median number of ICU-free days to day 28 was similar in both groups (conservative: 0 days [interquartile range (IQR) 0–13.7] versus liberal: 0 days [IQR 0–13.3], median treatment effect: 0 days [95% confidence interval (CI) – 3.1 to 3.1]). Mortality at day 28 (59/149 [39.6%] vs 59/151 [39.1%]) and at day 60 (64/149 [43%] vs 62/151 [41.1%] were similar in conservative and liberal groups, as were all other secondary outcomes and adverse events. The conservative group experienced 44 (29.5%) major protocol deviations compared to 2 (1.3%) in the liberal oxygen group (P < 0.001).ConclusionsIn adults receiving VA-ECMO in ICU, a conservative compared to a liberal oxygen strategy, did not affect the number of ICU-free days to day 28.

Background The optimal transfusion threshold for patients undergoing venoarterial extracorporeal membrane oxygenation (VA-ECMO) remains uncertain. Methods We used data from OBLEX (ClinicalTrials.gov: NCT03714048), an international, prospective, observational study conducted across 12 centres in Australia, Europe, and North America between 2019 and 2022. The study collected information on patient demographics, bleeding risk factors, transfusion practices during the first seven days of ECMO, and in-hospital mortality. Using these data, we emulated a target trial comparing the effects of liberal transfusion practice (transfusion initiated at Hb ≥ 90 g/L) and restrictive transfusion practice (transfusion initiated at Hb ≤ 70 g/L) on hospital mortality within seven days of ECMO initiation. Sequential trials approach was used to estimate the causal contrast. Results A total of 534 patients were included, with 46% dying during hospitalisation. After accounting for potential confounders, the liberal transfusion practice demonstrated a modest survival benefit within the first two days of ECMO, with differences in survival probabilities of 12% (95% CI 3% to 21%) at day 2 and 13% (95% CI 2% to 25%) at day 3, corresponding to the number needed to treat (NNT) of 8 and 7 respectively. No differences in survival benefit were found after day 3. These results were consistent across sensitivity and exploratory analyses. Conclusion This target trial emulation study suggests that a liberal transfusion threshold may provide a modest survival benefit during the early course of VA-ECMO, but no benefit afterwards. Prospective studies are needed to confirm these findings, assess clinical adoption, and investigate underlying mechanism.

The mTORC1 complex has been implicated in tumorigenesis owing partially to its ability to increase protein translation; now, mTORC1 activity in the mouse intestine is shown not to be required for normal homeostasis but to be necessary for the triggering of tumorigenesis by APC mutations, suggesting that it could be a good target for the prevention of colorectal cancer in high-risk patients. How mTORC sustains tumour growth The mTORC1 complex, a protein kinase complex found in all eukaryotic cells, has been implicated in tumorigenesis because it is known to stimulate protein translation. The main effector pathway downstream of mTORC1 is thought to be 4EBP1, which promotes initiation of translation. William Faller et al . now show that in the mouse intestine, mTORC1 activity is not required for normal homeostasis, but is absolutely required for intestinal tumour formation triggered by APC tumour suppressor gene mutations. The authors identify increased translational elongation downstream of S6 kinase via the elongation factor eEF2 as a requirement for proliferation in APC-deficient but not normal cells. This suggests that translational elongation, rather than initiation, is limiting to cancer cell proliferation in vivo . These findings raise the possibility that targeting mTORC1 signalling may be beneficial in prevention of colorectal cancers in high-risk patients. Inactivation of APC is a strongly predisposing event in the development of colorectal cancer 1 , 2 , prompting the search for vulnerabilities specific to cells that have lost APC function. Signalling through the mTOR pathway is known to be required for epithelial cell proliferation and tumour growth 3 , 4 , 5 , and the current paradigm suggests that a critical function of mTOR activity is to upregulate translational initiation through phosphorylation of 4EBP1 (refs 6 , 7 ). This model predicts that the mTOR inhibitor rapamycin, which does not efficiently inhibit 4EBP1 (ref. 8 ), would be ineffective in limiting cancer progression in APC-deficient lesions. Here we show in mice that mTOR complex 1 (mTORC1) activity is absolutely required for the proliferation of Apc -deficient (but not wild-type) enterocytes, revealing an unexpected opportunity for therapeutic intervention. Although APC-deficient cells show the expected increases in protein synthesis, our study reveals that it is translation elongation, and not initiation, which is the rate-limiting component. Mechanistically, mTORC1-mediated inhibition of eEF2 kinase is required for the proliferation of APC-deficient cells. Importantly, treatment of established APC-deficient adenomas with rapamycin (which can target eEF2 through the mTORC1–S6K–eEF2K axis) causes tumour cells to undergo growth arrest and differentiation. Taken together, our data suggest that inhibition of translation elongation using existing, clinically approved drugs, such as the rapalogs, would provide clear therapeutic benefit for patients at high risk of developing colorectal cancer.

Cancer development is associated with dysregulation of the translatome, and targeting canonical eukaryotic initiation and elongation factors can offer treatment avenues for various neoplasms. Emerging evidence indicates that dysregulated mRNA elongation, involving alterations in eEF2 activity and eIF5A expression, also contributes to tumour cell growth. In this study, we investigate whether targeting eIF5A with the inhibitor GC7 is a viable strategy to curtail aberrant cell growth. Our findings demonstrate that inhibiting elongation by reducing eIF5A activity induces feedback inhibition of initiation through eIF2α phosphorylation, decreasing ternary complex formation and shutting down bulk protein synthesis. Employing dynamic SILAC, we identify proteins impacted by reduced eIF5A activity, and show their decreased translation results from feedback inhibition to initiation or other processes downstream of eIF5A. Decreased eIF5A activity impairs mitochondrial function, which activates signalling through HRI to eIF2α phosphorylation, reducing cancer cell proliferation. These effects are reversed by treatment with the integrated stress response inhibitor, implying that the impact of GC7 on cancer cell proliferation is mediated via translation initiation rather than elongation inhibition. These data suggest that eIF5A inhibition could be used to target cancer cells that depend on mitochondrial function for their proliferation and survival. Translation initiation and elongation factors can be targets for cancer treatment. Here, the authors show that inhibiting translation elongation through eIF5A impairs mitochondrial function, slowing the proliferation of tumour cells.

The concept of regulatory T cell (Treg)-based immunotherapy has enormous potential for facilitating tolerance in autoimmunity and transplantation. Clinical translation of Treg cell therapy requires production processes that satisfy the rigors of Good Manufacturing Practice (GMP) standards. In this regard, we report our findings on the implementation of a robust GMP compliant process for the expansion of clinical grade Tregs, demonstrating the feasibility of this developed process for the manufacture of a final product for clinical application. This Treg isolation procedure ensured the selection of a pure Treg population that underwent a 300-fold expansion after 36 days of culture, while maintaining a purity of more than 75% CD4 CD25 FOXP3 cells and a suppressive function of above 80%. Furthermore, we report the successful cryopreservation of the final product, demonstrating the maintenance of phenotype and function. The process outlined in this manuscript has been implemented in the ONE study, a multicenter phase I/IIa clinical trial in which cellular therapy is investigated in renal transplantation.

Oncogenic KRAS mutations and inactivation of the APC tumor suppressor co-occur in colorectal cancer (CRC). Despite efforts to target mutant KRAS directly, most therapeutic approaches focus on downstream pathways, albeit with limited efficacy. Moreover, mutant KRAS alters the basal metabolism of cancer cells, increasing glutamine utilization to support proliferation. We show that concomitant mutation of Apc and Kras in the mouse intestinal epithelium profoundly rewires metabolism, increasing glutamine consumption. Furthermore, SLC7A5, a glutamine antiporter, is critical for colorectal tumorigenesis in models of both early- and late-stage metastatic disease. Mechanistically, SLC7A5 maintains intracellular amino acid levels following KRAS activation through transcriptional and metabolic reprogramming. This supports the increased demand for bulk protein synthesis that underpins the enhanced proliferation of KRAS-mutant cells. Moreover, targeting protein synthesis, via inhibition of the mTORC1 regulator, together with Slc7a5 deletion abrogates the growth of established Kras -mutant tumors. Together, these data suggest SLC7A5 as an attractive target for therapy-resistant KRAS-mutant CRC. Colorectal tumors with mutated KRAS and APC require the amino acid transporter SLC7A5 to drive tumorigenesis. Mechanistically, SLC7A5 drives transcriptional and metabolic reprogramming by maintaining intracellular amino acid levels, leading to enhanced protein synthesis.

The International Mouse Phenotyping Consortium reports the generation of new mouse mutant strains for more than 5,000 genes, including 2,850 novel null, 2,987 novel conditional-ready and 4,433 novel reporter alleles.

The rodent parasite Plasmodium chabaudi is an important in vivo model of malaria. The ability to produce chronic infections makes it particularly useful for investigating the development of anti- Plasmodium immunity, as well as features associated with parasite virulence during both the acute and chronic phases of infection. P. chabaudi also undergoes asexual maturation (schizogony) and erythrocyte invasion in culture, so offers an experimentally-amenable in vivo to in vitro model for studying gene function and drug activity during parasite replication. To extend the usefulness of this model, we have further optimised transfection protocols and plasmids for P. chabaudi and generated stable, fluorescent lines that are free from drug-selectable marker genes. These mother-lines show the same infection dynamics as wild-type parasites throughout the lifecycle in mice and mosquitoes; furthermore, their virulence can be increased by serial blood passage and reset by mosquito transmission. We have also adapted the large-insert, linear Plasmo GEM vectors that have revolutionised the scale of experimental genetics in another rodent malaria parasite and used these to generate barcoded P. chabaudi gene-deletion and –tagging vectors for transfection in our fluorescent P. chabaudi mother-lines. This produces a tool-kit of P. chabaudi lines, vectors and transfection approaches that will be of broad utility to the research community.

The rodent parasite Plasmodium chabaudi is an important in vivo model of malaria. The ability to produce chronic infections makes it particularly useful for investigating the development of anti- Plasmodium immunity, as well as features associated with parasite virulence during both the acute and chronic phases of infection. P. chabaudi also undergoes asexual maturation (schizogony) and erythrocyte invasion in culture, so offers an experimentally-amenable in vivo to in vitro model for studying gene function and drug activity during parasite replication. To extend the usefulness of this model, we have further optimised transfection protocols and plasmids for P. chabaudi and generated stable, fluorescent lines that are free from drug-selectable marker genes. These mother-lines show the same infection dynamics as wild-type parasites throughout the lifecycle in mice and mosquitoes; furthermore, their virulence can be increased by serial blood passage and reset by mosquito transmission. We have also adapted the large-insert, linear Plasmo GEM vectors that have revolutionised the scale of experimental genetics in another rodent malaria parasite and used these to generate barcoded P. chabaudi gene-deletion and –tagging vectors for transfection in our fluorescent P. chabaudi mother-lines. This produces a tool-kit of P. chabaudi lines, vectors and transfection approaches that will be of broad utility to the research community.