The Role of Ames Dwarfism and Calorie Restriction on Gut Microbiota.


  • 影响因子:4.54
  • DOI:10.1093/gerona/glz236
  • 作者列表:"Wiesenborn DS","Gálvez EJC","Spinel L","Victoria B","Allen B","Schneider A","Gesing A","Al-Regaiey KA","Strowig T","Schäfer KH","Masternak MM
  • 发表时间:2020-06-18

:The gut microbiome (GM) represents a large and very complex ecosystem of different microorganisms. There is an extensive interest in the potential role of the GM in different diseases including cancer, diabetes, cardiovascular diseases, and aging. The GM changes over the lifespan and is strongly associated with various age-related diseases. Ames dwarf (df/df) mice are characterized by an extended life- and healthspan, and although these mice are protected from many age-related diseases, their microbiome has not been studied. To determine the role of microbiota on longevity animal models, we investigated the changes in the GM of df/df and normal control (N) mice, by comparing parents before mating and littermate mice at three distinct time points during early life. Furthermore, we studied the effects of a 6-month calorie restriction (CR), the most powerful intervention extending the lifespan. Our data revealed significant changes of the GM composition during early life development, and we detected differences in the abundance of some bacteria between df/df and N mice, already in early life. Overall, the variability of the microbiota by genotype, time-point, and breeding pair showed significant differences. In addition, CR caused significant changes in microbiome according to gastrointestinal (GI) location (distal colon, ileum, and cecum), genotype, and diet. However, the overall impact of the genotype was more prominent than that of the CR. In conclusion, our findings suggest that the gut microbiota plays an important role during postnatal development in long-living df/df mice and CR dietary regimen can significantly modulate the GM.


: 肠道微生物组 (GM) 代表了一个由不同微生物组成的庞大而复杂的生态系统。人们对转基因在包括癌症、糖尿病、心血管疾病和衰老在内的不同疾病中的潜在作用有着广泛的兴趣。转基因在寿命周期内发生变化,并与各种年龄相关疾病密切相关。Ames dwarf (df/df) 小鼠的特点是寿命和健康时间延长,尽管这些小鼠受到许多与年龄相关的疾病的保护,但它们的微生物组尚未被研究。为了确定微生物群在长寿动物模型中的作用,我们研究了 df/df 和正常对照 (N) 小鼠的 GM 的变化,通过比较交配前的父母和早期生命中三个不同时间点的同窝小鼠。此外,我们研究了 6 个月热量限制 (CR) 的影响,这是延长寿命的最有力的干预措施。我们的数据揭示了生命早期发育过程中 GM 组成的显著变化,我们检测到 df/df 和 N 小鼠之间一些细菌的丰度存在差异,这些细菌已经在生命早期。总体而言,基因型、时间点和繁殖对的微生物群变异性表现出显著差异。此外,根据胃肠道 (GI) 位置 (远端结肠、回肠和盲肠) 、基因型和饮食,CR 引起微生物组的显著变化。然而,基因型的总体影响比 CR 更突出。总之,我们的研究结果表明,肠道菌群在长寿 df/df 小鼠的出生后发育中起着重要作用,CR 饮食方案可以显著调节 GM。



作者列表:["Galm, Brandon P.","Buckless, Colleen","Swearingen, Brooke","Torriani, Martin","Klibanski, Anne","Bredella, Miriam A.","Tritos, Nicholas A."]

METHODS:Purpose Given the paucity of reliable predictors of tumor recurrence, progression, or response to somatostatin receptor ligand (SRL) therapy in acromegaly, we attempted to determine whether preoperative MR image texture was predictive of these clinical outcomes. We also determined whether image texture could differentiate somatotroph adenomas from non-functioning pituitary adenomas (NFPAs). Methods We performed a retrospective study of patients with acromegaly due to a macroadenoma who underwent transsphenoidal surgery at our institution between 2007 and 2015. Clinical data were extracted from electronic medical records. MRI texture analysis was performed on preoperative non-enhanced T1-weighted images using ImageJ (NIH). Logistic and Cox models were used to determine if image texture parameters predicted outcomes. Results Eighty-nine patients had texture parameters measured, which were compared to that of NFPAs, while 64 of these patients had follow-up and were included in the remainder of analyses. Minimum pixel intensity, skewness, and kurtosis were significantly different in somatotroph adenomas versus NFPAs (area under the receiver operating characteristic curve, 0.7771, for kurtosis). Furthermore, those with a maximum pixel intensity above the median had an increased odds of IGF-I normalization on SRL therapy (OR 5.96, 95% CI 1.33–26.66), which persisted after adjusting for several potential predictors of response. Image texture did not predict tumor recurrence or progression. Conclusion Our data suggest that MRI texture analysis can distinguish NFPAs from somatotroph macroadenomas with good diagnostic accuracy and can predict normalization of IGF-I with SRL therapy.

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作者列表:["Xiong Y","Tang Y","Fan F","Zeng Y","Li C","Zhou G","Hu Z","Zhang L","Liu Z"]

METHODS::Growth hormone-secreting pituitary adenoma (GHPA), a benign endocrine tumor located in the base of the skull, results in acromegaly. In addition to the mass effect of the tumor itself in the sellar region, GHPA can lead to the overgrowth of almost every organ. Previous findings indicated that the processes underlying acromegaly were partly attributable to hyperactivity of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis. However, the mechanisms driving this syndrome remains largely unknown. Additionally, the roles of GHPA-derived exosomes, which contain functional microRNAs and proteins that manipulate target cell proliferation and differentiation in distal extremities, are also unknown. In this study, we demonstrated that GHPA exosomes promote bone formation in vitro and trabecula number in vivo. The mechanism of increased trabecula formation may be attributable to GHPA exosome-induced osteoblast proliferation via increased cell viability and DNA replication. We further discovered that exosomal hsa-miR-21-5p plays a distinct role from the GH/IGF-1 axis in these processes. Accordingly, the results of this study provide a novel mechanism whereby GHPA influences distal extremities and a new perspective for treating GHPA.

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作者列表:["Arlien-Søborg MC","Grøndahl C","Bæk A","Dal J","Madsen M","Høgild ML","Pedersen SB","Bjerre M","Jørgensen JOL"]

METHODS:BACKGROUND:Fibroblast growth factor 21 (FGF21) is a circulating hormone with pleiotropic metabolic effects, which is inactivated by fibroblast activation protein (FAP). Data regarding interaction between FGF21, FAP, and growth hormone (GH) are limited, but it is noteworthy that collagens are also FAP substrates, since GH potently stimulates collagen turnover. AIM:To measure circulating FGF21 components, including FAP, in patients with acromegaly before and after disease control. METHODS:Eighteen patients with active acromegaly were studied at the time of diagnosis and ≥ 6 months after disease control by either surgery or medical treatment. Serum levels of total and active FGF21, β-klotho, FAP, and collagen turnover markers were measured by immunoassays. Expression of putative FGF21-dependent genes were measured in adipose tissue by reverse transcriptase-polymerase chain reaction, body composition assessed by dual-energy x-ray absorptiometry scan, and insulin sensitivity estimated with homeostatic model assessment of insulin resistance (HOMA-IR). RESULTS:Total FGF21, active FGF21 and β-klotho remained unchanged. Insulin sensitivity and body fat mass increased after disease control but neither correlated with active FGF21. Expression of FGF21-dependent genes did not change after treatment. FAP levels (µg/L) were markedly reduced after treatment [105.6 ± 29.4 vs 62.2 ± 32.4, P < 0.000]. Collagen turnover markers also declined significantly after treatment and ΔFAP correlated positively with ΔProcollagen Type I (P < 0.000) and Type III (P < 0.000). CONCLUSION:1) Circulating FGF21 and β-klotho do not change in response to acromegaly treatment, 2) FAP concentrations in serum decrease after disease control and correlate positively with collagen turnover markers, and 3) FAP is a hitherto unrecognized GH target linked to collagen turnover. CLINICAL TRIALS REGISTRATION:NCT00647179.