Cartilage‐Specific Autophagy Deficiency Promotes ER Stress and Impairs Chondrogenesis in PERK‐ATF4‐CHOP–Dependent Manner

Autophagy is activated during nutritionally depleted or hypoxic conditions to facilitate cell survival. Because growth plate is an avascular and hypoxic tissue, autophagy may have a crucial role during chondrogenesis; however, the functional role and underlying mechanism of autophagy in regulation of growth plate remains elusive. In this study, we generated ^TamCartAtg7^–/– (Atg7cKO) mice to explore the role of autophagy during endochondral ossification. Atg7cKO mice exhibited growth retardation associated with reduced chondrocyte proliferation and differentiation, and increased chondrocyte apoptosis. Meanwhile, we observed that Atg7 ablation mainly induced the PERK‐ATF4‐CHOP axis of the endoplasmic reticulum (ER) stress response in growth plate chondrocytes. Although Atg7 ablation induced ER stress in growth plate chondrocytes, the addition of phenylbutyric acid (PBA), a chemical chaperone known to attenuate ER stress, partly neutralized such effects of Atg7 ablation on longitudinal bone growth, indicating the causative interaction between autophagy and ER stress in growth plate. Consistent with these findings in vivo, we also observed that Atg7 ablation in cultured chondrocytes resulted in defective autophagy, elevated ER stress, decreased chondrocytes proliferation, impaired expression of col10a1, MMP­13, and VEGFA for chondrocyte differentiation, and increased chondrocyte apoptosis, while such effects were partly nullified by reduction of ER stress with PBA. In addition, Atg7 ablation‐mediated impaired chondrocyte function (chondrocyte proliferation, differentiation, and apoptosis) was partly reversed in CHOP^–/– cells, indicating the causative role of the PERK‐ATF4‐CHOP axis of the ER stress response in the action of autophagy deficiency in chondrocytes. In conclusion, our findings indicate that autophagy deficiency may trigger ER stress in growth plate chondrocytes and contribute to growth retardation, thus implicating autophagy as an important regulator during chondrogenesis and providing new insights into the clinical potential of autophagy in cartilage homeostasis. © 2017 American Society for Bone and Mineral Research.     

Therapeutic Effects of FGF23 c‐tail Fc in a Murine Preclinical Model of X‐Linked Hypophosphatemia Via the Selective Modulation of Phosphate Reabsorption

Fibroblast growth factor 23 (FGF23) is the causative factor of X‐linked hypophosphatemia (XLH), a genetic disorder effecting 1:20,000 that is characterized by excessive phosphate excretion, elevated FGF23 levels and a rickets/osteomalacia phenotype. FGF23 inhibits phosphate reabsorption and suppresses 1α,25‐dihydroxyvitamin D (1,25D) biosynthesis, analytes that differentially contribute to bone integrity and deleterious soft‐tissue mineralization. As inhibition of ligand broadly modulates downstream targets, balancing efficacy and unwanted toxicity is difficult when targeting the FGF23 pathway. We demonstrate that a FGF23 c‐tail‐Fc fusion molecule selectively modulates the phosphate pathway in vivo by competitive antagonism of FGF23 binding to the FGFR/α klotho receptor complex. Repeated injection of FGF23 c‐tail Fc in Hyp mice, a preclinical model of XLH, increases cell surface abundance of kidney NaPi transporters, normalizes phosphate excretion, and significantly improves bone architecture in the absence of soft‐tissue mineralization. Repeated injection does not modulate either 1,25D or calcium in a physiologically relevant manner in either a wild‐type or disease setting. These data suggest that bone integrity can be improved in models of XLH via the exclusive modulation of phosphate. We posit that the selective modulation of the phosphate pathway will increase the window between efficacy and safety risks, allowing increased efficacy to be achieved in the treatment of this chronic disease. © 2017 American Society for Bone and Mineral Research.     

Vascular Endothelial Growth Factor (VEGF) in Crohn's Disease Increased Production by Peripheral Blood Mononuclear Cells and Decreased VEGF165 Labeling of Peripheral CD14+ Monocytes

Recently, increased serum levels of vascularendothelial growth factor (VEGF) have been shown inpatients with inflammatory bowel disease. The origins ofthe circulating VEGF are still not described. Monocytes play an important role in the inflammatoryprocess. VEGF binding to monocytes mediates monocyterecruitment and activation. The present studyinvestigates the VEGF production of peripheral bloodmononuclear cells and the ability of peripheral monocytesto bind VEGF₁₆₅ in patients with Crohn'sdisease. Nineteen patients with Crohn's disease and 10healthy volunteers were studied. VEGF₁₆₅labeling of CD14⁺ monocytes was measured using two-color flow cytometry.Density of VEGF labeling was expressed as the meanfluorescence intensity (MFI). Furthermore, VEGF levelswere determined in culture supernatants of unstimulated peripheral blood mononuclear cells. VEGF inculture supernatants was measured using a solid-phaseenzyme-linked immunosorbent assay. There was asignificantly decreased VEGF₁₆₅ labeling ofmonocytes of patients with active Crohn's disease (MFI:369.9 ± 121.6, N = 7, P < 0.002) compared topatients with inactive disease (MFI: 457.7 ±74.5, N = 6) and healthy controls (MFI: 542.9 ±96.2, N = 10). Unstimulated peripheral blood mononuclear cellsof patients with active Crohn's disease producedsignificantly higher amounts of VEGF (1142.6 ±483.9 pg/ml, N = 12, P < 0.001) compared withperipheral blood mononuclear cells of healthy volunteers(113.4 ± 101.8 pg/ml, N = 10). VEGF production byperipheral blood mononuclear cells of patients withactive disease was significantly increased compared to patients with quiescent disease (261.6± 254.8 pg/ml, N = 7, P < 0.001). Inconclusion, our data describe peripheral bloodmononuclear cells as one of the origins of the elevatedVEGF serum levels in patients with active Crohn's disease.Furthermore, a decrease in VEGF₁₆₅ bindingsites on peripheral monocytes of patients with activeCrohn's disease has been shown. The study underlines theimportant role of VEGF in Crohn's disease.     

表皮生长因子防治急性胰腺炎大鼠肠粘膜屏障损害

目的 探讨表皮生长因子（ＥＧＦ）对急性胰腺炎（ＡＰ）大鼠肠粘膜屏障的保护作用。方法 ＳＤ大鼠３２只,建立ＡＰ模型后随机分为对照组（ｎ＝１６）和治疗组（ｎ＝１６）。对照组给予全肠外营养的支持;治疗组给予全肠外营养支持和ＥＧＦ皮下注射。于成模后１．５d 死,检测大鼠肠道通透性、空肠粘膜湿重、微绒毛高度和面积、双糖酶活性及髓 过氧化酶活性。结果 在成模后５d,治疗组动物空肠粘膜湿重、微绒毛高度及面积、双糖     

胃癌血管内皮生长因子的表达与微血管密度的关系及其临床意义

目的探讨胃癌组织中血管内皮生长因子（VEGF）的表达和微血管密度（MVD）的关系,以及这两项指标与临床病理特征和预后之间的关系。方法观察分析116例胃癌组织中VEGF的表达和计算微血管密度(MVD),分析VEGF的表达与MVD间的关系及它们与临床病理因素和预后的关系。结果116例胃癌组织中,VEGF的阳性率为60.34%。VEGF阳性组中的MVD值明显高于VEGF阴性组（分别为26.16±8.50和19.22±8.20,P<0.01)。在淋巴结转移组中VEGF表达的阳性率明显高于无淋巴结转移组(P<0.05)。在肿瘤分期晚的病人中,其VEGF表达的阳性率也明显高于分期早的(P<0.05)。MVD与胃癌的淋巴结转移及腹腔内转移有关(P均<0.01),且随TNM分期而增加(P<0.01)。VEGF表达阴性组和低MVD组(MVD<23)的5年生存率均明显高于VEGF表达阳性组和高MVD组(MVD≥23)(均P<0.01)。多因素分析表明,MVD和VEGF的表达均是独立的预后因素。结论胃癌组织中VEGF的表达和MVD能反映胃癌的恶性程度,是判断预后和指导辅助治疗的有效指标。     

通痹灵对胶原诱导性关节炎大鼠滑膜组织血管内皮生长因子表达水平的影响

目的 观察通痹灵对胶原诱导性关节炎（CIA）大鼠关节滑膜组织炎症和血管内皮生长因子（VEGF）表达水平的影响，以探讨通痹灵治疗类风湿性关节炎（RA）的作用机理。方法 大鼠尾根部皮下注射Ⅱ型胶原蛋白建立CIA模型，分组给药治疗，给药37d后处死动物，对动物膝关节滑膜病理切片后分别常规HE染色和免疫组化染色。对HE染色切片用显微镜观察炎症细胞浸润，巨噬细胞增生和纤维增生情况，对免疫组化染色切片观察血管内皮生长因子（VEGF）阳性细胞情况以了解各组动物关节滑膜VEGF的表达水平。结果 HE染色切片显示通痹灵高剂量组滑膜炎症细胞浸润，巨噬样A型细胞增生和纤维组织增生的程度均比模型组低（P＜0．05或P＜0．01），并与正常组相仿（P＞0．05）。免疫组化染色切片显示通通痹灵和雷公藤高剂量组均能降低滑膜VEGF表达水平（P＜0．05）。结论 通痹灵有改善大鼠关节滑膜炎症，抑制滑膜VEGF表达作用，这可能是通痹灵治疗关节炎取得临床疗效的机理之一。     

Worry: A Cognitive Phenomenon Intimately Linked to Affective, Physiological, and Interpersonal Behavioral Processes

Research on worry during the past 15 years hasrevealed a remarkable amount of knowledge about thispervasive human phenomenon. Worry involves apredominance of verbal thought activity, functions as atype of cognitive avoidance, and inhibits emotionalprocessing. Worry also produces not only anxiousexperience but depressive affect as well. Recentevidence suggests that the very private experience ofworry is developmentally connected to enmeshedchildhood relationships with the primary caregiver andis currently associated with significant interpersonalproblems, especially those involving tendency to be overly nurturing to others. At thephysiological level, worry is characterized peripherallyby parasympathetic deficiency and autonomic rigidity andcentrally by left-frontal activation.     

Relative Skeletal Maturation and Population Ancestry in Nonobese Children and Adolescents

More rapid skeletal maturation in African‐American (AA) children is recognized and generally attributed to an increased prevalence of obesity. The objective of the present study was to evaluate the effects of population ancestry on relative skeletal maturation in healthy, non‐obese children and adolescents, accounting for body composition and sexual maturation. To do this, we leveraged a multiethnic, mixed‐longitudinal study with annual assessments for up to 7 years (The Bone Mineral Density in Childhood Study and its ancillary cohort) conducted at five US clinical centers. Participants included 1592 children, skeletally immature (45% females, 19% AA) who were aged 5 to 17 years at study entry. The primary outcome measure was relative skeletal maturation as assessed by hand‐wrist radiograph. Additional covariates measured included anthropometrics, body composition by dual‐energy X‐ray absorptiometry (DXA), and Tanner stage of sexual maturation. Using mixed effects longitudinal models, without covariates, advancement in relative skeletal maturation was noted in self‐reported AA girls (～0.33 years, p < 0.001) and boys (～0.43 years, p < 0.001). Boys and girls of all ancestry groups showed independent positive associations of height, lean mass, fat mass, and puberty with relative skeletal maturation. The effect of ancestry was attenuated but persistent after accounting for covariates: for girls, 0.19 years (ancestry by self‐report, p = 0.02) or 0.29 years (ancestry by admixture, p = 0.004); and for boys, 0.20 years (ancestry by self‐report, p = 0.004), or 0.29 years (ancestry by admixture, p = 0.004). In summary, we conclude that advancement in relative skeletal maturation was associated with AA ancestry in healthy, non‐obese children, independent of growth, body composition, and puberty. Further research into the mechanisms underlying this observation may provide insights into the regulation of skeletal maturation. © 2016 American Society for Bone and Mineral Research.