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American Journal of Physiology. Lung... Mar 2007We hypothesize that compensatory lung growth after unilateral pneumonectomy in a murine model is, in part, angiogenesis dependent and can be altered using angiogenic...
We hypothesize that compensatory lung growth after unilateral pneumonectomy in a murine model is, in part, angiogenesis dependent and can be altered using angiogenic agents, possibly through regulation of endothelial cell proliferation and apoptosis. Left pneumonectomy was performed in mice. Mice were then treated with proangiogenic factors [vascular endothelial growth factor (VEGF); basic fibroblast growth factor (bFGF)], VEGF receptor antibodies (MF-1, DC101), and VEGF receptor small molecule chemical inhibitors. Lung volume and mass were measured. The lungs were analyzed using immunohistochemistry by CD31 staining, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling, type II pneumocytes staining, and proliferating cell nuclear antigen. Compensatory lung growth was complete by postoperative day 10 and was associated with diffuse apoptosis of endothelial cells and pneumocytes. This process was accelerated by VEGF, such that growth was complete by postoperative day 4 with similar associated apoptosis. bFGF had no effect on lung growth. MF-1 and DC101 had no effect. The VEGF receptor small molecule chemical inhibitors also had no effect. VEGF, but not bFGF, accelerates growth. VEGF receptor inhibitors do not block growth, suggesting that other proangiogenic factors play a role or can compensate for VEGF receptor blockade. Diffuse apoptosis, endothelial cell and pneumocyte, occurs at cessation of both normal compensatory and VEGF-accelerated growth. Angiogenesis modulators may control growth via regulation of endothelial cell proliferation and apoptosis, although the exact relationship between endothelial cells and pneumocytes has yet to be determined. The fact that bFGF did not accelerate growth in our model when it did accelerate regeneration in the liver model suggests that angiogenesis during organ regeneration is regulated in an organ-specific manner.
Topics: Animals; Apoptosis; Blood Vessels; Cell Proliferation; Endothelial Growth Factors; Endothelium, Vascular; Fibroblast Growth Factor 2; Immunoenzyme Techniques; In Situ Nick-End Labeling; Lung; Male; Mice; Mice, Inbred C57BL; Neovascularization, Physiologic; Pneumonectomy; Regeneration; Vascular Endothelial Growth Factor A
PubMed: 17122356
DOI: 10.1152/ajplung.00064.2006 -
Nature Jan 2004Poor fetal growth is linked with long-term detrimental effects on health in adulthood. Here we investigate whether the lifespan of male mice is affected by their growth...
Poor fetal growth is linked with long-term detrimental effects on health in adulthood. Here we investigate whether the lifespan of male mice is affected by their growth rate when they were suckling and find that limiting growth during that period not only increases longevity but also protects against the life-shortening effect of an obesity-inducing diet later on. By contrast, we find that lifespan is considerably shortened if the postnatal period of growth is accelerated to make up for reduced growth in utero, and that, in addition, these mice are susceptible to the adverse effects on longevity of an obesity-inducing diet after weaning.
Topics: Animals; Animals, Newborn; Animals, Suckling; Diet; Growth; Longevity; Male; Mice; Nutritional Physiological Phenomena; Obesity; Prenatal Nutritional Physiological Phenomena
PubMed: 14749819
DOI: 10.1038/427411b -
Journal of Bacteriology Apr 2022Exploration is a recently discovered mode of growth and behavior exhibited by some species that is distinct from their classical sporulating life cycle. While much has...
Exploratory Growth in Streptomyces venezuelae Involves a Unique Transcriptional Program, Enhanced Oxidative Stress Response, and Profound Acceleration in Response to Glycerol.
Exploration is a recently discovered mode of growth and behavior exhibited by some species that is distinct from their classical sporulating life cycle. While much has been uncovered regarding initiating environmental conditions and phenotypic outcomes of exploratory growth, how this process is coordinated at a genetic level remains unclear. We used RNA sequencing to survey global changes in the transcriptional profile of exploring cultures over time in the model organism Streptomyces venezuelae. Transcriptomic analyses revealed widespread changes in gene expression impacting diverse cellular functions. Investigations into differentially expressed regulatory elements revealed specific groups of regulatory factors to be impacted, including the expression of several extracytoplasmic function (ECF) sigma factors, second messenger signaling pathways, and members of the -like () family of transcription factors. Dramatic changes were observed among primary metabolic pathways, especially among respiration-associated genes and the oxidative stress response; enzyme assays confirmed that exploring cultures exhibit an enhanced oxidative stress response compared with classically growing cultures. Changes in the expression of the glycerol catabolic genes in S. venezuelae led to the discovery that glycerol supplementation of the growth medium promotes a dramatic acceleration of exploration. This effect appears to be unique to glycerol as an alternative carbon source, and this response is broadly conserved across other exploration-competent species. Exploration represents an alternative growth strategy for bacteria and is initiated in response to other microbes or specific environmental conditions. Here, we show that entry into exploration involves comprehensive transcriptional reprogramming, with an emphasis on changes in primary metabolism and regulatory/signaling functions. Intriguingly, a number of transcription factor classes were downregulated upon entry into exploration. In contrast, respiration-associated genes were strongly induced, and this was accompanied by an enhanced oxidative stress response. Notably, our transcriptional analyses suggested that glycerol may play a role in exploration, and we found that glycerol supplementation dramatically enhanced the exploration response in many streptomycetes. This work sheds new light on the regulatory and metabolic cues that influence a fascinating new microbial behavior.
Topics: Acceleration; Bacterial Proteins; Gene Expression Regulation, Bacterial; Glycerol; Oxidative Stress; Streptomyces; Transcription Factors
PubMed: 35254103
DOI: 10.1128/jb.00623-21 -
The Journal of Experimental Biology Jul 2023The lifetime growth of almost all fishes follows a biphasic relationship - juvenile growth is rapid and adult growth subsequently decelerates. For a trend that is so...
The lifetime growth of almost all fishes follows a biphasic relationship - juvenile growth is rapid and adult growth subsequently decelerates. For a trend that is so ubiquitous, there is no general agreement as to the underlying mechanisms causing adult growth to decelerate. Ongoing theories argue that adult growth slows because either the gills fail to supply the body with surplus oxygen needed for continued somatic gain (i.e. oxygen limited), or sexual maturation induces a switch in energy allocation towards reproduction and away from growth (i.e. energy limited). Here, we empirically tested these notions by tracking the individual growth trajectories of ∼100 female Galaxias maculatus, ranging in size, during their first 3 months of adulthood. At a summer temperature of 20°C, we provided subsets of fish with additional energy (fed once versus twice a day), supplementary oxygen (normoxia versus hyperoxia), or a combination of the two, to assess whether we could change the trajectory of adult growth. We found that growth improved marginally with additional energy, yet remained unaffected by supplementary oxygen, thereby providing evidence for a role for energy reallocation in the deceleration of adult growth. Interestingly, additional dietary energy had a disproportionately larger effect on the growth of fish that matured at a greater size, revealing size-dependent variance in energy acquisition and/or allocation budgets at summer temperatures. Overall, these findings contribute towards understanding the mechanisms driving widespread declines in the body size of fish with climate warming.
Topics: Female; Animals; Oxygen; Deceleration; Fishes; Reproduction; Body Size; Temperature
PubMed: 37334714
DOI: 10.1242/jeb.246012 -
Microbiological Research Sep 2022Haematococcus lacustris is a chlamydomonadalean with high biotechnological interest owing to its capacity to produce astaxanthin, a valuable secondary carotenoid with...
Haematococcus lacustris is a chlamydomonadalean with high biotechnological interest owing to its capacity to produce astaxanthin, a valuable secondary carotenoid with extraordinary antioxidation properties. However, its prolonged growth has limited its utility commercially. Thus, rapid growth to attain high densities of H. lacustris cells optimally producing astaxanthin is an essential biotechnological target to facilitate profitable commercialisation. Our study focused on characterising the bacterial communities associated with the alga's phycosphere by metagenomics. Subsequently, we altered the bacterial consortia in combined co-culture with key beneficial bacteria to optimise the growth of H. lacustris. The algal biomass increased by up to 2.1-fold in co-cultures, leading to a 1.6-fold increase in the astaxanthin yield. This study attempted to significantly improve the H. lacustris growth rate and biomass yield via Next-Generation Sequencing analysis and phycosphere bacterial augmentation, highlighting the possibility to overcome the hurdles associated with astaxanthin production by H. lacustris at a commercial scale.
Topics: Acceleration; Bacteria; Biomass; Carotenoids; Chlorophyta; Microbiota
PubMed: 35751943
DOI: 10.1016/j.micres.2022.127097 -
Radiation Oncology (London, England) Aug 2012To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr) and the reduction of the effective doubling time (TD) during... (Review)
Review
PURPOSE
To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr) and the reduction of the effective doubling time (TD) during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT) is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC).
METHODS
A survey of the published papers comparing 3-years of local regional control rate (LCR) for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of TD were obtained by a model incorporating the overall time corrected biologically effective dose (BED) and a 3-year clinical LCR for high and low EGFr groups of patients (HEGFr and LEGFr), respectively. By obtaining the TD from the above analysis and the sub-sites' potential doubling time (Tpot) from flow cytometry and immunohistochemical methods, we were able to estimate the average TD for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (Dprolif), was estimated.
RESULTS
The averages of TD were 77 (27-90)95% days in LEGFr and 8.8 (7.3-11.0)95% days in HEGFr, if an onset of accelerated proliferation TK at day 21 was assumed. The correspondent HEGFr sub-sites' TD were 5.9 (6.6), 5.9 (6.6), 4.6 (6.1), 14.3 (12.9) days, with respect to literature immunohistochemical (flow cytometry) data of Tpot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The Dprolif for the HEGFr groups were 0.33 (0.29), 0.33 (0.29), 0.42 (0.31), 0.14 (0.15) Gy/day if α = 0.3 Gy-1 and α/β = 10 Gy were assumed.
CONCLUSIONS
A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced TD and Dprolif for each head and neck sub-site.
Topics: Acceleration; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Proliferation; Disease Progression; ErbB Receptors; Head and Neck Neoplasms; Humans; Immunohistochemistry; Prognosis; Radiotherapy Dosage; Squamous Cell Carcinoma of Head and Neck; Treatment Outcome
PubMed: 22920680
DOI: 10.1186/1748-717X-7-143 -
Proceedings of the National Academy of... Dec 2017Across mammals, prenatal maternal stress (PREMS) affects many aspects of offspring development, including offspring growth. However, how PREMS translates to offspring... (Meta-Analysis)
Meta-Analysis
Across mammals, prenatal maternal stress (PREMS) affects many aspects of offspring development, including offspring growth. However, how PREMS translates to offspring growth is inconsistent, even within species. To explain the full range of reported effects of prenatal adversity on offspring growth, we propose an integrative hypothesis: developmental constraints and a counteracting adaptive growth plasticity work in opposition to drive PREMS effects on growth. Mothers experiencing adversity reduce maternal investment leading to stunted growth (developmental constraints). Concomitantly, the pace of offspring life history is recalibrated to partly compensate for these developmental constraints (adaptive growth plasticity). Moreover, the relative importance of each process changes across ontogeny with increasing offspring independence. Thus, offspring exposed to PREMS may grow at the same rate as controls during gestation and lactation, but faster after weaning when direct maternal investment has ceased. We tested these predictions with a comparative analysis on the outcomes of 719 studies across 21 mammal species. First, the observed growth changes in response to PREMS varied across offspring developmental periods as predicted. We argue that the observed growth acceleration after weaning is not "catch-up growth," because offspring that were small for age grew slower. Second, only PREMS exposure early during gestation produced adaptive growth plasticity. Our results suggest that PREMS effects benefit the mother's future reproduction and at the same time accelerate offspring growth and possibly maturation and reproductive rate. In this sense, PREMS effects on offspring growth allow mother and offspring to make the best of a bad start.
Topics: Adaptation, Physiological; Animals; Body Size; Female; Mammals; Pregnancy; Prenatal Exposure Delayed Effects; Stress, Psychological
PubMed: 29180423
DOI: 10.1073/pnas.1707152114 -
Connective Tissue Research May 2022Pelvic organ prolapse (POP) is a common debilitating condition affecting approximately 30-40% of women. The FDA issued a warning about polypropylene mesh used for pelvic...
BACKGROUND
Pelvic organ prolapse (POP) is a common debilitating condition affecting approximately 30-40% of women. The FDA issued a warning about polypropylene mesh used for pelvic floor repair due to erosion, exposure and other complications and banned it in 2019. The application of stem cell therapy and growth factors has strongly promoted the development of pelvic tissue engineering.
PURPOSE
we intend to address the issues of direct application of growth factors, the side effects of long-term exogenous treatment, and the directional differentiation of stem cells. Methods: we evaluated the paracrine effects and directional differentiation of adipose mesenchymal stem cells through stable overexpression of basic fibroblast growth factor (bFGF).
RESULTS
we found that the modified stem cells could continuously and stably release bFGF in the initial stage and could spontaneously differentiate into fibroblasts with a high differentiation efficiency in the later stage.
CONCLUSION
following ADSCs are designed to continuously release controllable levels of growth factors during the control period of repair, taking advantage of the paracrine function of stem cells to accelerate cell growth and extracellular matrix (ECM) reconstruction during the early stage of stem cell implantation, and then stem cells are differentiated into target tissues-fibroblasts to accelerate the reconstruction of pelvic floor tissues, this study demonstrated the strong therapeutic potential of this approach for pelvic tissue engineering.
ABBREVIATIONS
POP: Pelvic organ prolapse; ADSCs: Adipose-derived stem cells; bFGF: Basic fibroblast growth factor; BMSCs: Bone marrow-derived mesenchymal stem cells; HUVECs: Human umbilical vein endothelial cells; EMSCs: Endometrial mesenchymal stem cells; VEGF: Vascular endothelial growth factor; PDGF: Platelet-derived growth factor ECM: Extracellular matrix; IGF: Insulin-like growth factor; HGF: Hepatocyte growth factor; EGF: Epidermal growth factor; BMP-2: Bone morphogenetic protein 2; FBR: Foreign body reaction.
Topics: Acceleration; Cell Differentiation; Cells, Cultured; Endothelial Cells; Female; Fibroblast Growth Factor 2; Humans; Stem Cells; Vascular Endothelial Growth Factor A
PubMed: 33627007
DOI: 10.1080/03008207.2021.1895130 -
Gravitational and Space Biology... Jun 2001The environment created on Earth within a clinostat or Rotating Wall Vessel (RWV) bioreactor is often referred to as "simulated microgravity". Both devices utilize...
The environment created on Earth within a clinostat or Rotating Wall Vessel (RWV) bioreactor is often referred to as "simulated microgravity". Both devices utilize constant reorientation to effectively nullify cumulative sedimentation of particles. Neither, however, can fully reproduce the concurrent lack of structural deformation, displacement of intercellular components and/or reduced mass transfer in the extracellular fluid that occur in actual weightlessness. Parameters including density, viscosity, and even container geometry must each be considered to determine the overall gravity-dependent effects produced by either a clinostat or the RWV bioreactor; in addition, the intended application of these two devices differs considerably. A state of particle "motionlessness" relative to the surrounding bulk fluid, which is nearly analogous to the extracellular environment encountered under weightless conditions, can theoretically be achieved through clinorotation. The RWV bioreactor, on the other hand, while similarly maintaining cells in suspension as they continually "fall" through the medium under 1 g conditions, can also purposefully induce a perfusion of nutrients to and waste from the culture. A clinostat, therefore, is typically used in an attempt to reproduce the quiescent, unstirred fluid conditions achievable on orbit; while the RWV bioreactor ideally creates a low shear, but necessarily mixed, fluid environment that is optimized for suspension culture and tissue growth. Other techniques for exploring altered inertial environments, such as freefall, neutral buoyancy and electromagnetic levitation, can also provide unique insight into how gravity affects biological systems. Ultimately, all underlying biophysical principles thought to give rise to gravity-dependent physiological responses must be identified and thoroughly examined in order to accurately interpret data from flight experiments or ground-based microgravity analogs.
Topics: Acceleration; Biophysical Phenomena; Biophysics; Bioreactors; Cell Culture Techniques; Cell Physiological Phenomena; Gravitation; Gravity, Altered; Rotation; Weightlessness Simulation
PubMed: 11865869
DOI: No ID Found -
Acta Paediatrica Scandinavica.... 1989The growth patterns of 158 infants with significant intrauterine growth retardation (IUGR) were studied for the first 2 years of life. Eighty-four infants were born...
The growth patterns of 158 infants with significant intrauterine growth retardation (IUGR) were studied for the first 2 years of life. Eighty-four infants were born after 36 completed weeks. All these full-term infants survived; complete follow-up data were obtained for 78. Acceleration of growth in weight began soon after birth and continued for an average of 6 months. Acceleration of linear growth began somewhat later, but was limited to the first 9 months. Twenty-three infants (29%) were still below the 5th centile for both weight and height by 2 years of age. There was a negative correlation between the neonatal ponderal index and length at 18 months for females only. Seventy-four infants were born prematurely, before 37 weeks' gestation. Mortality in this group was 18% and complete follow-up data were obtained for 49 of the 61 survivors. Birth weight was regained on average at 11 days; accelerated weight velocity began 4-6 weeks before the expected date of delivery (term date). The potential for catch-up growth lasted up to 9 months after the term date. By 18 months, however, 44% of these pre-term infants were still below the 5th centile for weight. Size at 18 months post-term was correlated with weight at the term date and length at 3 months post-term, but not with the degree of IUGR or with the ponderal index.
Topics: Body Height; Body Weight; Female; Fetal Growth Retardation; Follow-Up Studies; Humans; Infant, Newborn; Infant, Premature; Infant, Small for Gestational Age; Male; Pregnancy
PubMed: 2750529
DOI: 10.1111/j.1651-2227.1989.tb17164.x