Physical activity in relation to metabolic health and obesity: The Feel4Diabetes study.

AIM: To examine physical activity levels in association with metabolic health and estimate the stability of metabolically healthy obese (MHO) phenotypes over a 2-year period. METHODS: In total, 2848 men and women from families at risk of the development of diabetes were recruited. Participants were classified as obese or non-obese and metabolic health was defined using five existing definitions. Physical activity was estimated with the International Physical Activity Questionnaire and pedometers. RESULTS: Prevalence of the MHO phenotype varied among definitions (0% to 20.2%). Overall, the MHO were more active than the metabolically unhealthy obese (MUO). Daily sitting hours (odds ratio [OR] = 1.055, 95% confidence interval [CI]: 1.009-1.104) and daily steps (per 500; OR = 0.934, 95% CI: 0.896-0.973) were remarkable predictors of metabolic health in individuals with obesity; and likewise, in individuals without obesity. After 2 years, 44.1% of baseline MHO adults transitioned to MUO, while 84.0% of the MUO at baseline remained at the same phenotype. Although physical activity was not a major determinant in phenotype transitioning, daily steps were associated with the maintenance of metabolic health over time in the non-obese group. CONCLUSION: A universally accepted definition for MHO is needed. Being physically active can contribute to a metabolically healthy profile even in the presence of obesity; still, MHO is a transient condition and physical activity alone may not be an adequate factor for its maintenance.

Long term culture promotes changes to growth, gene expression, and metabolism in CHO cells that are independent of production stability.

Phenotypic stability of Chinese hamster ovary (CHO) cells over long term culture (LTC) presents one of the most pressing challenges in the development of therapeutic protein manufacturing processess. However, our current understanding of the consequences of LTC on recombinant (r-) CHO cell lines is still limited, particularly as clonally-derived cell lines present distinct production stability phenotypes. This study evaluated changes of culture performance, global gene expression, and cell metabolism of two clonally-derived CHO cell lines with a stable or unstable phenotype during the LTC (early [EP] vs. late [LP] culture passages). Our findings indicated that LTC altered the behavior of CHO cells in culture, in terms of growth, overall gene expression, and cell metabolism. Regardless whether cells were categorized as stable or unstable in terms of r-protein production, CHO cells at LP presented an earlier decline in cell viability and loss of any observable stationary phase. These changes were parallelled by the upregulation of genes involved in cell proliferation and survival pathways (i.e., MAPK/ERK, PI3K-Akt). Stable and unstable CHO cell lines both showed increased consumption of glucose and amino acids at LP, with a parallel accumulation of greater amounts of lactate and TCA cycle intermediates. In terms of production stability, we found that decreased r-protein production in the unstable cell line directly correlated to the loss in r-gene copy number and r-mRNA expression. Our data revealed that LTC produced ubiquitious effects on CHO cell phenotypes, changes that were rooted in alterations in cell transcriptome and metabolome. Overall, we found that CHO cells adapted their cellular function to proliferation and survival during the LTC, some of these changes may well have limited effects on overall yield or specific productivity of the desired r-product, but they may be critical toward the capacity of cells to handle r-proteins with specific molecular features.

The essential anti-angiogenic strategies in cartilage engineering and osteoarthritic cartilage repair.

In the cartilage matrix, complex interactions occur between angiogenic and anti-angiogenic components, growth factors, and environmental stressors to maintain a proper cartilage phenotype that allows for effective load bearing and force distribution. However, as seen in both degenerative disease and tissue engineering, cartilage can lose its vascular resistance. This vascularization then leads to matrix breakdown, chondrocyte apoptosis, and ossification. Research has shown that articular cartilage inflammation leads to compromised joint function and decreased clinical potential for regeneration. Unfortunately, few articles comprehensively summarize what we have learned from previous investigations. In this review, we summarize our current understanding of the factors that stabilize chondrocytes to prevent terminal differentiation and applications of these factors to rescue the cartilage phenotype during cartilage engineering and osteoarthritis treatment. Inhibiting vascularization will allow for enhanced phenotypic stability so that we are able to develop more stable implants for cartilage repair and regeneration.

Synthetic symbiosis combining plasmid displacement enables rapid construction of phenotype-stable strains.

Plasmid-based microbial systems have been a major workhorse for chemical and pharmaceutical production. The biosafety issues and elevated industrial cost of antibiotic usage have led to the development of alternative strategies for plasmid selection and maintenance. Such strategies, including auxotrophy complementation, post-segregational killing, operator-repressor and RNA-based interactions often require extensive engineering of various elements and may result in extra metabolic burden in the cells. Herein, we report a design of synthetic symbiosis combining plasmid displacement to construct a phenotype-stable microbial system. By sequestrating an endogenous essential gene folP, cells obtained long-term plasmid maintenance with minimum cost. The phenotype performance was also inherited for up to 80 generations demonstrated by the production of salicylic acid in Escherichia coli. Meanwhile, the temperature-induced curing method of the intermediate plasmids enables rapid engineering. This design can lead to broad applications as a reliable and convenient plasmid-based expression system.

Maintaining the Phenotype Stability of Chondrocytes Derived from MSCs by C-Type Natriuretic Peptide.

Mesenchymal stem cells (MSCs) play a critical role in cartilage tissue engineering. However, MSCs-derived chondrocytes or cartilage tissues are not stable and easily lose the cellular and cartilage phenotype during long-term culture in vitro or implantation in vivo. As a result, chondrocytes phenotypic instability can contribute to accelerated ossification. Thus, it is a big challenge to maintain their correct phenotype for engineering hyaline cartilage. As one member of the natriuretic peptide family, C-type natriuretic peptide (CNP) is found to correlate with the development of the cartilage, affect the chondrocytes proliferation and differentiation. Besides, based on its biological effects on protection of extracellular matrix of cartilage and inhibition of mineralization, we hypothesize that CNP may contribute to the stability of chondrocyte phenotype of MSCs-derived chondrocytes.

The Changing Landscape of Renal Inflammation.

Kidney inflammation is a major contributor to progressive renal injury, leading to glomerulonephritis (GN) and chronic kidney disease. We review recent advances in our understanding of leukocyte accumulation in the kidney, emphasizing key chemokines involved in GN. We discuss features of renal inflammation such as the evolving concept of immune cell plasticity. We also describe certain aspects of organ-specific tissue microenvironments in shaping immune cell responses, as well as the current knowledge of how regulatory T lymphocytes impact on other immune effector cell populations to control inflammation. It is clear that present and future research in these areas may contribute to the development of novel targeted therapeutics, with the hope of alleviating the burden of end-stage renal disease (ESRD).

Phenotype Uniformity in Combined-Stress Environments has a Different Genetic Architecture than in Single-Stress Treatments.

For crop production it is desirable for the mapping between genotype and phenotype to be consistent, such that an optimized genotype produces uniform sets of individual plants. Uniformity is strongly selected in breeding programs, usually automatically, as harvest equipment eliminates severely non-uniform individuals. Uniformity is genetically controlled, is known to be increased by interplant competition, and is predicted to increase upon abiotic stress. We mapped maize loci controlling genotype by environment interaction in plant height uniformity. These loci are different than the loci controlling mean plant height. Uniformity decreases upon combining two abiotic stresses, with alleles conferring greater uniformity in a single stress showing little improvement in a combined stress treatment. The maize B73 and Mo17 inbreds do not provide segregating alleles for improvement in plant height uniformity, suggesting that the genetic network specifying plant height has a past history of selection for robustness.