| 1. |
- Kaucka, Marketa, et al.
(författare)
-
Analysis of neural crest-derived clones reveals novel aspects of facial development
- 2016
-
Ingår i: Science Advances. - : American Association for the Advancement of Science. - 2375-2548. ; 2:8
-
Tidskriftsartikel (refereegranskat)abstract
- Cranial neural crest cells populate the future facial region and produce ectomesenchyme-derived tissues, such as cartilage, bone, dermis, smooth muscle, adipocytes, and many others. However, the contribution of individual neural crest cells to certain facial locations and the general spatial clonal organization of the ectomesenchyme have not been determined. We investigated how neural crest cells give rise to clonally organized ectomesenchyme and how this early ectomesenchyme behaves during the developmental processes that shape the face. Using a combination of mouse and zebrafish models, we analyzed individual migration, cell crowd movement, oriented cell division, clonal spatial overlapping, and multilineage differentiation. The early face appears to be built from multiple spatially defined overlapping ectomesenchymal clones. During early face development, these clones remain oligopotent and generate various tissues in a given location. By combining clonal analysis, computer simulations, mouse mutants, and live imaging, we show that facial shaping results from an array of local cellular activities in the ectomesenchyme. These activities mostly involve oriented divisions and crowd movements of cells during morphogenetic events. Cellular behavior that can be recognized as individual cell migration is very limited and short-ranged and likely results from cellular mixing due to the proliferation activity of the tissue. These cellular mechanisms resemble the strategy behind limb bud morphogenesis, suggesting the possibility of common principles and deep homology between facial and limb outgrowth.
|
|
| 2. |
- Kaukua, Nina, et al.
(författare)
-
Glial origin of mesenchymal stem cells in a tooth model system
- 2014
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 513:7519, s. 551-554
-
Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal stem cells occupy niches in stromal tissues where they provide sources of cells for specialized mesenchymal derivatives during growth and repair(1). The origins of mesenchymal stem cells have been the subject of considerable discussion, and current consensus holds that perivascular cells form mesenchymal stem cells in most tissues. The continuously growing mouse incisor tooth offers an excellent model to address the origin of mesenchymal stem cells. These stem cells dwell in a niche at the tooth apex where they produce a variety of differentiated derivatives. Cells constituting the tooth are mostly derived from two embryonic sources: neural crest ectomesenchyme and ectodermal epithelium(2). It has been thought for decades that the dental mesenchymal stem cells(3) giving rise to pulp cells and odontoblasts derive from neural crest cells after their migration in the early head and formation of ectomesenchymal tissue(4,5). Here we show that a significant population of mesenchymal stem cells during development, self-renewal and repair of a tooth are derived from peripheral nerve-associated glia. Glial cells generate multipotent mesenchymal stem cells that produce pulp cells and odontoblasts. By combining a clonal colour-coding technique(6) with tracing of peripheral glia, we provide new insights into the dynamics of tooth organogenesis and growth.
|
|
| 3. |
- Stenudd, Moa, et al.
(författare)
-
Identification of a discrete subpopulation of spinal cord ependymal cells with neural stem cell properties
- 2022
-
Ingår i: Cell Reports. - : CELL PRESS. - 2211-1247. ; 38:9
-
Tidskriftsartikel (refereegranskat)abstract
- Spinal cord ependymal cells display neural stem cell properties in vitro and generate scar-forming astrocytes and remyelinating oligodendrocytes after injury. We report that ependymal cells are functionally heterogeneous and identify a small subpopulation (8% of ependymal cells and 0.1% of all cells in a spinal cord segment), which we denote ependymal A (EpA) cells, that accounts for the in vitro stem cell potential in the adult spinal cord. After spinal cord injury, EpA cells undergo self-renewing cell division as they give rise to differentiated progeny. Single-cell transcriptome analysis revealed a loss of ependymal cell gene expression programs as EpA cells gained signaling entropy and dedifferentiated to a stem-cell-like transcriptional state after an injury. We conclude that EpA cells are highly differentiated cells that can revert to a stem cell state and constitute a therapeutic target for spinal cord repair.
|
|
| 4. |
- Ahluwalia, Bani, et al.
(författare)
-
A Distinct Faecal Microbiota and Metabolite Profile Linked to Bowel Habits in Patients with Irritable Bowel Syndrome
- 2021
-
Ingår i: Cells. - : MDPI AG. - 2073-4409. ; 10:6
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with irritable bowel syndrome (IBS) are suggested to have an altered intestinal microenvironment. We therefore aimed to determine the intestinal microenvironment profile, based on faecal microbiota and metabolites, and the potential link to symptoms in IBS patients. The faecal microbiota was evaluated by the GA-map(TM) dysbiosis test, and tandem mass spectrometry (GC-MS/MS) was used for faecal metabolomic profiling in patients with IBS and healthy subjects. Symptom severity was assessed using the IBS Severity Scoring System and anxiety and depression were assessed using the Hospital Anxiety and Depression Scale. A principal component analysis based on faecal microbiota (n = 54) and metabolites (n = 155) showed a clear separation between IBS patients (n = 40) and healthy subjects (n = 18). Metabolites were the main driver of this separation. Additionally, the intestinal microenvironment profile differed between IBS patients with constipation (n = 15) and diarrhoea (n = 11), while no clustering was detected in subgroups of patients according to symptom severity or anxiety. Furthermore, ingenuity pathway analysis predicted amino acid metabolism and several cellular and molecular functions to be altered in IBS patients. Patients with IBS have a distinct faecal microbiota and metabolite profile linked to bowel habits. Intestinal microenvironment profiling, based on faecal microbiota and metabolites, may be considered as a future non-invasive diagnostic tool, alongside providing valuable insights into the pathophysiology of IBS.
|
|
| 5. |
- Algera, Joost, 1993, et al.
(författare)
-
Associations between postprandial symptoms, hydrogen and methane production, and transit time in irritable bowel syndrome
- 2023
-
Ingår i: Neurogastroenterology and Motility. - : Wiley. - 1350-1925 .- 1365-2982. ; 35:2
-
Tidskriftsartikel (refereegranskat)abstract
- Background Abnormal oroanal transit time (OATT) and visceral hypersensitivity are key pathophysiological factors in irritable bowel syndrome (IBS). The lactulose nutrient challenge test (LNCT) has been developed to assess the postprandial symptoms and gut microbial fermentation. We aimed to investigate associations between OATT, rectal sensitivity, and LNCT in IBS patients. Methods We included 263 IBS patients from two study cohorts, where the link between pathophysiology and symptoms was investigated. During the LNCT, severity of postprandial symptoms was graded, and breath hydrogen/methane concentrations were measured after ingestion of a combined lactulose nutrient drink every 15 min for 4 h. The patients underwent rectal sensitivity (rectal barostat) and OATT (radiopaque markers) investigations. Comorbid conditions (functional dyspepsia, anxiety, depression, and somatization) were assessed with questionnaires. Key Results After controlling for comorbid conditions, rectal sensitivity was associated with abdominal pain (p < 0.05), and more rapid OATT was associated with higher severity of abdominal discomfort, rumbling, nausea, and urgency (p < 0.05 for all) both pre- and post-prandially. Postprandial nausea, urgency, and abdominal pain changed differently over time depending on OATT (p < 0.05 for all). OATT, but not rectal sensitivity, was associated with hydrogen and methane concentrations (p = 0.002 for both). Trajectories over time of postprandial symptoms and exhaled hydrogen/methane concentrations were correlated with different correlations depending on OATT. Conclusion and Inferences This study highlights the importance of oroanal transit and hydrogen and methane production in the pathophysiology of IBS and increases our understanding of pathophysiological factors involved in postprandial symptom generation. Treatments targeting oroanal transit and hydrogen and methane production may improve specific postprandial symptoms.
|
|
| 6. |
- Bianco, Paolo, et al.
(författare)
-
Regulation of stem cell therapies under attack in Europe: for whom the bell tolls
- 2013
-
Ingår i: EMBO Journal. - : Wiley. - 1460-2075 .- 0261-4189. ; 32:11, s. 1489-1495
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- At the time of writing, the Italian Parliament is debating a new law that would make it legal to practice an unproven stem cell treatment in public hospitals. The treatment, offered by a private non-medical organization, may not be safe, lacks a rationale, and violates current national laws and European regulations. This case raises multiple concerns, most prominently the urgent need to protect patients who are severely ill, exposed to significant risks, and vulnerable to exploitation. The scientific community must consider the context-social, financial, medical, legal-in which stem cell science is currently situated and the need for stringent regulation. Additional concerns are emerging. These emanate from the novel climate, created within science itself, and stem cell science in particular, by the currently prevailing model of 'translational medicine'. Only rigorous science and rigorous regulation can ensure translation of science into effective therapies rather than into ineffective market products, and mark, at the same time, the sharp distinction between the striving for new therapies and the deceit of patients.
|
|
| 7. |
- Boj, Sylvia F, et al.
(författare)
-
Organoid models of human and mouse ductal pancreatic cancer
- 2015
-
Ingår i: Cell. - : Cell press. - 0092-8674 .- 1097-4172. ; 160:1-2, s. 324-338
-
Tidskriftsartikel (refereegranskat)abstract
- Pancreatic cancer is one of the most lethal malignancies due to its late diagnosis and limited response to treatment. Tractable methods to identify and interrogate pathways involved in pancreatic tumorigenesis are urgently needed. We established organoid models from normal and neoplastic murine and human pancreas tissues. Pancreatic organoids can be rapidly generated from resected tumors and biopsies, survive cryopreservation, and exhibit ductal- and disease-stage-specific characteristics. Orthotopically transplanted neoplastic organoids recapitulate the full spectrum of tumor development by forming early-grade neoplasms that progress to locally invasive and metastatic carcinomas. Due to their ability to be genetically manipulated, organoids are a platform to probe genetic cooperation. Comprehensive transcriptional and proteomic analyses of murine pancreatic organoids revealed genes and pathways altered during disease progression. The confirmation of many of these protein changes in human tissues demonstrates that organoids are a facile model system to discover characteristics of this deadly malignancy.
|
|
| 8. |
- Cammareri, Patrizia, et al.
(författare)
-
Inactivation of TGFβ receptors in stem cells drives cutaneous squamous cell carcinoma
- 2016
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Melanoma patients treated with oncogenic BRAF inhibitors can develop cutaneous squamous cell carcinoma (cSCC) within weeks of treatment, driven by paradoxical RAS/RAF/MAPK pathway activation. Here we identify frequent TGFBR1 and TGFBR2 mutations in human vemurafenib-induced skin lesions and in sporadic cSCC. Functional analysis reveals these mutations ablate canonical TGFβ Smad signalling, which is localized to bulge stem cells in both normal human and murine skin. MAPK pathway hyperactivation (through Braf V600E or Kras G12D knockin) and TGFβ signalling ablation (through Tgfbr1 deletion) in LGR5 +ve stem cells enables rapid cSCC development in the mouse. Mutation of Tp53 (which is commonly mutated in sporadic cSCC) coupled with Tgfbr1 deletion in LGR5 +ve cells also results in cSCC development. These findings indicate that LGR5 +ve stem cells may act as cells of origin for cSCC, and that RAS/RAF/MAPK pathway hyperactivation or Tp53 mutation, coupled with loss of TGFβ signalling, are driving events of skin tumorigenesis.
|
|
| 9. |
- Clevers, Egbert, et al.
(författare)
-
Adherence to diet low in fermentable carbohydrates and traditional diet for irritable bowel syndrome
- 2020
-
Ingår i: Nutrition. - : Elsevier BV. - 0899-9007. ; 73
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Dietary interventions in irritable bowel syndrome (IBS) include a traditional IBS diet following the guidelines from the National Institute for Health and Clinical Excellence and a diet low in fermentable oligo-, di-, monosaccharides and polyols (FODMAPs). The aim of this study was to evaluate the adherence to these diets, food groups difficult to replace, and dietary determinants of symptom improvement. Methods: Sixty-six patients with IBS were randomized to a 4-wk low FODMAP or traditional IBS diet. Participants completed 4-d diet diaries before and during the intervention and reported symptoms on the IBS severity scoring system. We described adherence to the diets on the food group and product level and investigated the association between adherence and symptom improvement. Results: Adherence to the low FODMAP diet was good and consistent: All participants had a comparable shift in the diet's principal components compatible with the guidelines. Most high FODMAP products were well replaced with low FODMAP equivalents. However, total energy intake fell by 25%, mainly owing to a 69% decreased intake of snacks (P < 0.001). The traditional IBS diet did not shift the diet's principal components, and despite the guidelines, consumption of coffee and alcoholic beverages remained rather high (>50% of baseline). Total energy intake fell by 11% (P = 0.15). For both diets, there was a trend toward an association between adherence and symptom improvement (P < 0.10). Conclusion: In both the low FODMAP and traditional IBS diet, certain food groups were difficult to replace. Because adherence may predict symptom improvement, close dietary guidance might enhance the efficacy of both diets. © 2020 Elsevier Inc.
|
|
| 10. |
- Clevers, Egbert, et al.
(författare)
-
Development of Irritable Bowel Syndrome Features Over a 5-year Period
- 2018
-
Ingår i: Clinical Gastroenterology and Hepatology. - : Elsevier BV. - 1542-3565. ; 16:8, s. 1244-
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: There are few data from longitudinal studies of the gastrointestinal and psychologic features of irritable bowel syndrome (IBS). We studied within-person correlations among features of IBS, along with progression of gastrointestinal (GI) symptoms and quality of life, and factors associated with changes over time. METHODS: We performed a longitudinal study of 276 patients with IBS in Sweden (70% female; ages, 19-76 years) who completed questionnaires, each year for 5 years, about their GI symptom severity, quality of life, GI-specific anxiety, general anxiety, depression, and coping resources. We performed within-person correlation analyses, latent class growth analysis, and random-intercept cross-lagged panel analysis. RESULTS: Within-person correlations with GI symptom severity were strongest for quality of life (r = -0.56) and GI-specific anxiety (r = 0.47). Progression of GI symptom severity was defined based on 3 classes; the class with the highest mean levels of GI, depression, and (GI-specific) anxiety symptoms at baseline did not improve over the 5-year period, contrary to the other classes. GI-specific anxiety was associated with an increase in GI symptom severity and decrease in quality of life 1 year later (P < .05) but other features of IBS were not. CONCLUSIONS: In a 5-year study of patients with IBS in Sweden, we found 3 classes of GI symptom development. We found levels of GI-specific anxiety to associate with GI symptom severity and quality of life 1 year later. Clinicians should be aware of GI-specific anxiety in patients with IBS, to identify patients at risk for lack of long-term symptom improvement with standard medical treatment.
|
|
