Cell motility and migration play pivotal roles in numerous physiological and pathophysiological processes including development and tissue repair. Cell migration is regulated through external stimuli such as platelet-derived growth factor-AA (PDGF-AA), a key regulator in directional cell migration during embryonic development and a chemoattractant during postnatal migratory responses including wound healing. We previously showed that PDGFRα signaling is coordinated by the primary cilium in quiescent cells. However, little is known about the function of the primary cilium in cell migration. Here we used micropipette analysis to show that a normal chemosensory response to PDGF-AA in fibroblasts requires the primary cilium. In vitro and in vivo wound healing assays revealed that in ORPK mouse (IFT88^Tg737Rpw) fibroblasts, where ciliary assembly is defective, chemotaxis towards PDGF-AA is absent, leading to unregulated high speed and uncontrolled directional cell displacement during wound closure, with subsequent defects in wound healing. These data suggest that in coordination with cytoskeletal reorganization, the fibroblast primary cilium functions via ciliary PDGFRα signaling to monitor directional movement during wound healing.

Objective: This study was performed to investigate the dose-response effects of supplementation with Bifidobacterium animalis subsp lactis (BB-12) and Lactobacillus paracasei subsp paracasei (CRL-431) on blood lipids, recovery from feces and bowel habits. Changes of the fecal microflora was analyzed in the 10 10 CFU/day probiotic and placebo group. Design: The study was designed as a randomized, placebo-controlled, double-blinded, parallel dose-response study. Subjects: Healthy young adults (18-40 years) were recruited by advertising in local newspapers. Of the 75 persons enrolled, 71 (46 women, 25 men, mean age 25.6 years (range 18-40 years)) completed the study. Intervention: The volunteers were randomly assigned into five groups receiving either placebo or a mixture of the two probiotics in the concentration of 10 8 , 10 9 , 10 10 or 10 11 CFU/day in 2 weeks run-in period, 3 weeks intervention and 2 weeks wash-out. Diary reporting bowel habits and well being (abdominal bloating, flatulence and headache) was kept for all 7 weeks and blood lipids, fecal recovery of BB-12 and CRL-431, as well as fecal microflora was tested before, immediately and 2 weeks after intervention. Results: The fecal recovery of BB-12 increased significantly (Po0.001) with increasing dose. In the group receiving 10 11 CFU/ day BB-12 was recovered from 13 out of 15 volunteers. CRL-431 was not recovered in any of the fecal samples. Supplementation with probiotics did not change the fecal bacterial composition. A significant linear increase in fecal consistency (looser stool) with increasing probiotic dose (P ¼ 0.018) was observed. No overall dose-response effect was found on the blood lipids. High doses of probiotics were well tolerated. Conclusion: A dose-related recovery of BB-12 from feces was observed. Sponsorship: The study was sponsored by Chr. Hansen A/S, Hoersholm, Denmark. Keywords: dose-response study; probiotics; cholesterol; recovery from feces; constipation European Journal of Clinical Nutrition IntroductionIt is generally accepted that the composition of the intestinal microflora influences the health and well being of humans. With the many publications showing beneficial effects of probiotic bacteria, there has been an increasing interest in the mechanism behind. Most clinical studies have tested only one dose of probiotics, ranging from 4 Â 10 8 CFU/day for determination of gastrointestinal colonization and immune modulation (Valeur et al., 2004) Contributors: DCE, CNL and KFM wrote the protocol. DCE performed the study. CNL did the microbiological analysis of fecal samples and study product. EB performed the fluorescent whole cell hybridization of BB-12 like colonies. MB performed the PFGE of CRL-431 like colonies. PK performed the statistical analysis. CNL and SN wrote the first draft of the paper and all contributors participated in the revision and final approval of the paper.

Because beta(1)-integrin is involved in sensing of fluid flow rate in endothelial cells, a function that in Madin-Darby canine kidney (MDCK) cells is confined to the primary cilium, we hypothesized beta(1)-integrin to be an important part of the primary ciliary mechanosensory apparatus in MDCK cells. We observed that beta(1)-integrin, alpha(3)-integrin, and perhaps alpha(5)-integrin were localized to the primary cilium of MDCK cells by combining lectin and immunofluorescence confocal microscopy. beta(1)-Integrin was also colocalized with tubulin to the primary cilia of the rat renal collecting ducts, as well as to the cilia of proximal tubules and thick ascending limbs. Immunogold-electron microscopy confirmed the presence of beta(1)-integrin on primary cilia of MDCK cells and rat collecting ducts. Intracellular Ca(2+) levels, monitored by fluorescence microscopy on fluo 4-loaded MDCK cells, significantly increased on addition of fibronectin, a beta(1)-integrin ligand, to mature MDCK cells with an IC(50) of 0.02 mg/l. In immature, nonciliated cells or in deciliated mature cells, the IC(50) was 0.40 mg/l. Blocking the fibronectin-binding sites of beta(1)-integrin with RGD peptide prevented the Ca(2+) signal. Cross-linking of beta(1)-integrins by Sambucus nigra agglutinin produced a Ca(2+) response similar to the addition of fibronectin. Furthermore, the fibronectin-induced response was not dependent on flow or a flow-induced Ca(2+) response. Finally, the flow-induced Ca(2+) response was not prevented by the fibronectin-induced signal. Although beta(1)-integrin on the primary cilium greatly potentiates the fibronectin-induced Ca(2+) signaling in MDCK cells, the flow-dependent Ca(2+) signal is not mediated through activation of beta(1)-integrin.

Hedgehog (Hh) signaling controls pancreatic development and homeostasis; aberrant Hh signaling is associated with several pancreatic diseases. Here we investigated the link between Hh signaling and primary cilia in the human developing pancreatic ducts and in cultures of human pancreatic duct adenocarcinoma cell lines, PANC-1 and CFPAC-1. We show that the onset of Hh signaling from human embryogenesis to fetal development is associated with accumulation of Hh signaling components Smo and Gli2 in duct primary cilia and a reduction of Gli3 in the duct epithelium. Smo, Ptc, and Gli2 localized to primary cilia of PANC-1 and CFPAC-1 cells, which may maintain high levels of nonstimulated Hh pathway activity. These findings indicate that primary cilia are involved in pancreatic development and postnatal tissue homeostasis.

Microorganisms in the environment do not exist as the often-studied pure cultures but as members of complex microbial communities. Characterizing the interactions within microbial communities is essential to understand their function in both natural and engineered environments. In this study, we investigated how the presence of a nitrite-oxidizing bacterium (NOB) and heterotrophic bacteria affect the growth and proteome of the chemolithoautotrophic ammonia-oxidizing bacterium (AOB) Nitrosomonas sp. strain Is79. We investigated Nitrosomonas sp. Is79 in co-culture with Nitrobacter winogradskyi, in co-cultures with selected heterotrophic bacteria, and as a member of the nitrifying enrichment culture G5-7. In batch culture, N. winogradskyi and heterotrophic bacteria had positive effects on the growth of Nitrosomonas sp. Is79. An isobaric tag for relative and absolute quantification (iTRAQ) liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach was used to investigate the effect of N. winogradskyi and the co-cultured heterotrophic bacteria from G5-7 on the proteome of Nitrosomonas sp. Is79. In co-culture with N. winogradskyi, several Nitrosomonas sp. Is79 oxidative stress response proteins changed in abundance, with periplasmic proteins increasing and cytoplasmic proteins decreasing in abundance. In the presence of heterotrophic bacteria, the abundance of proteins directly related to the ammonia oxidation pathway increased, while the abundance of proteins related to amino acid synthesis and metabolism decreased. In summary, the proteome of Nitrosomonas sp. Is79 was differentially influenced by the presence of either N. winogradskyi or heterotrophic bacteria. Together, N. winogradskyi and heterotrophic bacteria reduced the oxidative stress for Nitrosomonas sp. Is79, which resulted in more efficient metabolism. IMPORTANCEAerobic ammonia-oxidizing microorganisms play an important role in the global nitrogen cycle, converting ammonia to nitrite. In their natural environment, they coexist and interact with nitrite oxidizers, which convert nitrite to nitrate, and with heterotrophic microorganisms. The presence of nitrite oxidizers and heterotrophic bacteria has a positive influence on the growth of the ammonia oxidizers. Here, we present a study investigating the effect of nitrite oxidizers and heterotrophic bacteria on the proteome of a selected ammonia oxidizer in a defined culture to elucidate how these two groups improve the performance of the ammonia oxidizer. The results show that the presence of a nitrite oxidizer and heterotrophic bacteria reduced the stress for the ammonia oxidizer and resulted in more efficient energy generation. This study contributes to our understanding of microbemicrobe interactions, in particular between ammonia oxidizers and their neighboring microbial community.