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Neural progenitor cells (NPCs) are a promising cell source to repair damaged nervous tissue. However, expansion of therapeutically relevant numbers of NPCs and their efficient differentiation into desired mature cell types remains a challenge. Material‐based strategies, including culture within 3D hydrogels, have the potential to overcome these current limitations. An ideal material would enable both NPC expansion and subsequent differentiation within a single platform. It has recently been demonstrated that cell‐mediated remodeling of 3D hydrogels is necessary to maintain the stem cell phenotype of NPCs during expansion, but the role of matrix remodeling on NPC differentiation and maturation remains unknown. By culturing NPCs within engineered protein hydrogels susceptible to degradation by NPC‐secreted proteases, it is identified that a critical amount of remodeling is necessary to enable NPC differentiation, even in highly degradable gels. Chemical induction of differentiation after sufficient remodeling time results in differentiation into astrocytes and neurotransmitter‐responsive neurons. Matrix remodeling modulates expression of the transcriptional co‐activator Yes‐associated protein, which drives expression of NPC stemness factors and maintains NPC differentiation capacity, in a cadherin‐dependent manner. Thus, cell‐remodelable hydrogels are an attractive platform to enable expansion of NPCs followed by differentiation of the cells into mature phenotypes for therapeutic use. Matrix remodeling of engineered 3D hydrogels is required for efficient differentiation and maturation of neural progenitor cells (NPCs) into neurons and astrocytes. Provided sufficient remodeling time, NPCs degrade the surrounding hydrogel material, form cell–cell contacts, and activate β‐catenin signaling, which maintains expression of Yes‐associated protein and primes NPCs for differentiation.

Neural progenitor cell (NPC) culture within three-dimensional (3D) hydrogels is an attractive strategy for expanding a therapeutically relevant number of stem cells. However, relatively little is known about how 3D material properties such as stiffness and degradability affect the maintenance of NPC stemness in the absence of differentiation factors. Over a physiologically relevant range of stiffness from ∼0.5 to 50 kPa, stemness maintenance did not correlate with initial hydrogel stiffness. In contrast, hydrogel degradation was both correlated with, and necessary for, maintenance of NPC stemness. This requirement for degradation was independent of cytoskeletal tension generation and presentation of engineered adhesive ligands, instead relying on matrix remodelling to facilitate cadherin-mediated cell–cell contact and promote β-catenin signalling. In two additional hydrogel systems, permitting NPC-mediated matrix remodelling proved to be a generalizable strategy for stemness maintenance in 3D. Our findings have identified matrix remodelling, in the absence of cytoskeletal tension generation, as a previously unknown strategy to maintain stemness in 3D. The physical properties of biomaterials affect cell behaviour. Here, the authors investigate how stiffness and degradation of hydrogels affect signalling pathways that modulate the maintenance of stemness of neural progenitor cells.

Background Metabolic reprogramming is a key feature of malignant cells. While glucose is one of the primary substrates for malignant cells, cancer cells also display a remarkable metabolic flexibility. Depending on nutrient availability and requirements, cancer cells will utilize alternative fuel sources to maintain the TCA cycle for bioenergetic and biosynthetic requirements. Lactate was typically viewed as a passive byproduct of cancer cells. However, studies now show that lactate is an important substrate for the TCA cycle in breast, lung, and pancreatic cancer. Methods Metabolic analysis of colorectal cancer (CRC) cells was performed using a combination of bioenergetic analysis and 13 C stable isotope tracing. Results We show here that CRC cells use lactate to fuel the TCA cycle and promote growth especially under nutrient-deprived conditions. This was mediated in part by maintaining cellular bioenergetics. Therefore targeting the ability of cancer cells to utilize lactate via the TCA cycle would have a significant therapeutic benefit. Phosphoenolpyruvate carboxykinase (PEPCK) is an important cataplerotic enzyme that promotes TCA cycle activity in CRC cells. Treatment of CRC cells with low micromolar doses of a PEPCK inhibitor (PEPCKi) developed for diabetes decreased cell proliferation and utilization of lactate by the TCA cycle in vitro and in vivo. Mechanistically, we observed that the PEPCKi increased nutrient stress as determined by decreased cellular bioenergetics including decreased respiration, ATP levels, and increased AMPK activation. 13 C stable isotope tracing showed that the PEPCKi decreased the incorporation of lactate into the TCA cycle. Conclusions These studies highlight lactate as an important substrate for CRC and the use of PEPCKi as a therapeutic approach to target lactate utilization in CRC cells.

Pulmonary angiogenesis is a key driver of alveolarization. Our prior studies showed that NF-κB promotes pulmonary angiogenesis during early alveolarization. However, the mechanisms regulating temporal-specific NF-κB activation in the pulmonary vasculature are unknown. To identify mechanisms that activate proangiogenic NF-κB signaling in the developing pulmonary vasculature, proteomic analysis of the lung secretome was performed using two-dimensional difference gel electrophoresis. NF-κB activation and angiogenic function was assessed in primary pulmonary endothelial cells (PECs) and TGFBI (transforming growth factor-β–induced protein)–regulated genes identified using RNA sequencing. Alveolarization and pulmonary angiogenesis was assessed in wild-type and Tgfbi null mice exposed to normoxia or hyperoxia. Lung TGFBI expression was determined in premature lambs supported by invasive and noninvasive respiratory support. Secreted factors from the early alveolar, but not the late alveolar or adult lung, promoted proliferation and migration in quiescent, adult PECs. Proteomic analysis identified TGFBI as one protein highly expressed by the early alveolar lung that promoted PEC migration by activating NF-κB via αvβ3 integrins. RNA sequencing identified Csf3 as a TGFBI-regulated gene that enhances nitric oxide production in PECs. Loss of TGFBI in mice exaggerated the impaired pulmonary angiogenesis induced by chronic hyperoxia, and TGFBI expression was disrupted in premature lambs with impaired alveolarization. Our studies identify TGFBI as a developmentally regulated protein that promotes NF-κB–mediated angiogenesis during early alveolarization by enhancing nitric oxide production. We speculate that dysregulation of TGFBI expression may contribute to diseases marked by impaired alveolar and vascular growth.

Rationale: Pulmonary angiogenesis is a key driver of alveolarization. Our prior studies showed that nuclear factor kappa-B (NFlower case Greek kappaB) promotes pulmonary angiogenesis during early alveolarization. However, the mechanisms regulating temporal-specific NFlower case Greek kappaB activation in the pulmonary vasculature are unknown. Objectives: To identify mechanisms that activate pro-angiogenic NFlower case Greek kappaB signaling in the developing pulmonary vasculature. Methods: Proteomic analysis of the lung secretome was performed using 2D-DIGE. NFlower case Greek kappaB activation and angiogenic function was assessed in primary pulmonary endothelial cells (PEC) and TGFBI-regulated genes identified using RNA-sequencing. Alveolarization and pulmonary angiogenesis was assessed in WT and TGFBI null mice exposed to normoxia or hyperoxia. Lung TGFBI expression was determined in premature lambs supported by invasive and noninvasive respiratory support. Measurements and Main Results: Secreted factors from the early alveolar, but not the late alveolar or adult lung, promoted proliferation and migration in quiescent, adult PEC. Proteomic analysis identified transforming growth factor beta-induced protein (TGFBI) as a protein highly expressed by myofibroblasts in the early alveolar lung that promoted PEC migration by activating NFlower case Greek kappaB via lower case Greek alphavlower case Greek beta3 integrins. RNA-sequencing identified Csf3 as a TGFBI-regulated gene that enhances nitric oxide production in PEC. Loss of TGFBI in mice exaggerated the impaired pulmonary angiogenesis induced by chronic hyperoxia, and TGFBI expression was disrupted in premature lambs with impaired alveolarization. Conclusions: Our studies identify TGFBI as a developmentally-regulated protein that promotes NFkB-mediated angiogenesis during early alveolarization by enhancing nitric oxide production. We speculate that dysregulation of TGFBI expression may contribute to diseases marked by impaired alveolar and vascular growth. Competing Interest Statement The authors have declared no competing interest.

Robotic Roux-en-Y gastric bypass (RRYGB) is an innovative alternative to traditional laparoscopic approaches. Literature has been published investigating its safety/efficacy; however, the quality of reporting is uncertain. This systematic review used the Idea, Development, Exploration, Assessment and Long-term follow-up (IDEAL) framework to assess the reporting quality of available literature. A narrative summary was formulated, assessing how comprehensively governance/ethics, patient selection, demographics, surgeon expertise/training, technique description and outcomes were reported. Forty-seven studies published between 2005 and 2024 were included. There was incomplete/inconsistent reporting of governance/ethics, patient selection, surgeon expertise/training and technique description, with heterogenous outcome reporting. RRYGB reporting was poor and did not align with IDEAL guidance. Robust prospective studies reporting findings using IDEAL/other guidance are required to facilitate safe widespread adoption of RRYGB and other surgical innovations.

Robot-assisted anti-reflux surgery (RA-ARS) is increasingly being used to treat refractory gastro-oesophageal reflux disease. The IDEAL (Idea, Development, Exploration, Assessment, Long-term follow up) Collaboration’s framework aims to improve the evaluation of surgical innovation, but the extent to which the evolution of RA-ARS has followed this model is unclear. This study aims to evaluate the standard to which RA-ARS has been reported during its evolution, in relation to the IDEAL framework. A systematic review from inception to June 2020 was undertaken to identify all primary English language studies pertaining to RA-ARS. Studies of paraoesophageal or giant hernias were excluded. Data extraction was informed by IDEAL guidelines and summarised by narrative synthesis. Twenty-three studies were included: two case reports, five case series, ten cohort studies and six randomised controlled trials. The majority were single-centre studies comparing RA-ARS and laparoscopic Nissen fundoplication. Eleven (48%) studies reported patient selection criteria, with high variability between studies. Few studies reported conflicts of interest (30%), funding arrangements (26%), or surgeons’ prior robotic experience (13%). Outcome reporting was heterogeneous; 157 distinct outcomes were identified. No single outcome was reported in all studies.The under-reporting of important aspects of study design and high degree of outcome heterogeneity impedes the ability to draw meaningful conclusions from the body of evidence. There is a need for further well-designed prospective studies and randomised trials, alongside agreement about outcome selection, measurement and reporting for future RA-ARS studies.