Publications by authors named "Bart J de Haan"

Understanding the impact of various culturing strategies on the secretome composition of adipose-derived stromal cells (ASC) enhances their therapeutic potential. This study investigated changes in the secretome of perirenal ASC (prASC) under different conditions: normoxia, cytokine exposure, high glucose, hypoxia, and hypoxia with high glucose. Using mass spectrometry and enrichment clustering analysis, we found that normoxia enriched pathways related to extracellular matrix (ECM) organization, platelet degranulation, and insulin-like growth factor (IGF) transport and uptake.

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Scope: Fructans are a group of dietary fibers which are known to have many beneficial effects including immune-modulating effects. A family of fructans are β-(2,6)-linked levan-type fructans that are known to serve as exopolysaccharides in the cell wall of many species of bacteria including commensal bacteria and probiotics. It is still largely unknown whether and how they can serve as immunomodulating molecules.

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Immunoisolation of pancreatic islets in alginate microcapsules allows for transplantation in the absence of immunosuppression but graft survival time is still limited. This limited graft survival is caused by a combination of tissue responses to the encapsulating biomaterial and islets. A significant loss of islet cells occurs in the immediate period after transplantation and is caused by a high susceptibility of islet cells to inflammatory stress during this period.

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Article Synopsis
  • Transplantation of microencapsulated pancreatic cells offers a new treatment for type 1 diabetes (T1DM) by protecting β-cells from immune response, reducing the need for continuous immunosuppression.
  • The article introduces a novel method to create semi-permeable, non-immunogenic polyethylene glycol-tyramine (PEG-TA) microgels that encapsulate β-cells, allowing them to form islet-sized structures and maintain function.
  • Results show that these microgels provide effective immunoprotection and allow β-cells to remain viable and responsive to glucose, successfully restoring normal blood sugar levels in diabetic mice after transplantation.
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Pectins support intestinal barrier function and have anti-diabetic effects, and can differ in the degree of methyl-esterification (DM) and the distribution of non-esterified galacturonic acid residues (DB). The mechanisms and effects of pectin type at different glucose levels are unknown. Pectins with different DM/DB on T84 cells were tested in the presence and absence of the barrier disruptor A23187 at 5 mM and 20 mM glucose.

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Immunoisolation of pancreatic-islets in alginate-microcapsules is applied to treat diabetes. However, long-term islet function is limited, which might be due to damaged and lack of contact with pancreatic extracellular matrix (ECM) components. Herein we investigated the impact of collagen IV combined with laminin sequences, either RGD, LRE, or PDSGR, on graft-survival of microencapsulated bioluminescent islets in vivo.

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Unlabelled: Islet transplantation is a promising treatment for type 1 diabetes. It has the potential to improve glycemic control, particularly in patients suffering from hypoglycemic unawareness and glycemic instability. As most islet grafts do not function permanently, efforts are needed to create an accessible and replaceable site, for islet grafts or for insulin-producing cells obtained from replenishable sources.

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Transplantation of pancreatic islets is a promising approach to controlling glucose levels in type 1 diabetes mellitus (T1DM), but islet survival is still limited. To overcome this, islet co-culture with mesenchymal stromal cells (MSCs) together with safe immunosuppressive agents like squalene-gusperimus nanoparticles (Sq-GusNPs) may be applied. This could support islet survival and engraftment.

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Galacto-oligosaccharides (GOS) and 2'-fucosyllactose (2'-FL) are non-digestible carbohydrates (NDCs) that are often added to infant formula to replace the functionalities of human milk oligosaccharides (HMOs). It is not known if combining GOS and 2'-FL will affect their fermentation kinetics and subsequent immune-modulatory effects such as AhR-receptor stimulation. Here, we used an set-up for the fermentation of 2'-FL and GOS, either individually or combined, by fecal microbiota of 8-week-old infants.

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Article Synopsis
  • Immunoisolation of pancreatic islets in alginate-based microcapsules offers a way to avoid immunosuppression, but inflammatory stress can damage islets due to extracellular matrix loss.
  • A combined strategy utilizing ECM components (collagen type IV/RGD) and a necroptosis inhibitor (Nec-1) was tested to enhance islet viability and function in an inflammatory environment.
  • The results show that the combination of collagen type IV/RGD and Nec-1 significantly protects islet cells from inflammatory damage, promoting their survival and potentially improving the success of islet transplants.
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This work investigated the effects of different chemical structures of human milk oligosaccharides (hMOs) and non-digestible carbohydrates (NDCs) on pathogen adhesion by serving as decoy receptors. Pre-exposure of pathogens to inulins and low degree of methylation (DM) pectin prevented binding to gut epithelial Caco2-cells, but effects were dependent on the molecules' chemistry, pathogen strain and growth phase. Pre-exposure to 3-fucosyllactose increased E.

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Gusperimus is an anti-inflammatory drug that has shown to be effective in managing autoimmunity and preventing graft rejection. This is unstable and easily broken down into cytotoxic components. We encapsulated gusperimus binding it covalently to squalene obtaining squalene-gusperimus nanoparticles (Sq-GusNPs).

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Cell-matrix interactions govern cell behavior and tissue function by facilitating transduction of biomechanical cues. Engineered tissues often incorporate these interactions by employing cell-adhesive materials. However, using constitutively active cell-adhesive materials impedes control over cell fate and elicits inflammatory responses upon implantation.

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: Non-digestible carbohydrates (NDCs) such as native chicory inulin and 2'-fucosyllactose (2'-FL) are added to infant formula to mimic some of the human milk oligosaccharide (HMO) functions. It is unknown whether combining inulin and 2'-FL influences their fermentation kinetics and whether the immune-modulatory effects of these NDCs are different under normal and inflammatory-prone Th2-polarizing conditions. : We investigated the fermentation of 2'-FL and native chicory inulin, fermented individually and combined, using fecal inocula of 8-week-old infants.

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Human milk oligosaccharides (hMOs) and non-digestible carbohydrates (NDCs) are known to inhibit the adhesion of pathogens to the gut epithelium, but the mechanisms involved are not well understood. Here, the effects of 2'-FL, 3-FL, DP3-DP10, DP10-DP60 and DP30-DP60 inulins and DM7, DM55 and DM69 pectins were studied on pathogen adhesion to Caco-2 cells. As the growth phase influences virulence, E.

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Scope: Intestinal mucositis is a common side effect of the chemotherapeutic agent doxorubicin, which is characterized by severe Toll-like receptor (TLR) 2-mediated inflammation. The dietary fiber pectin is shown to prevent this intestinal inflammation through direct inhibition of TLR2 in a microbiota-independent manner. Recent in vitro studies show that inhibition of TLR2 is determined by the number and distribution of methyl-esters of pectins.

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Scope: Next to galacto-oligosaccharides (GOS), starch-derived isomalto-oligosaccharide preparation (IMO) and isomalto/malto-polysaccharides (IMMP) could potentially be used as prebiotics in infant formulas. However, it remains largely unknown how the specific molecular structures of these non-digestible carbohydrates (NDCs) impact fermentability and immune responses in infants.

Methods And Results: In vitro fermentation of GOS, IMO and IMMP using infant fecal inoculum of 2- and 8-week-old infants shows that only GOS and IMO are fermented by infant fecal microbiota.

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Islet encapsulation in membrane-based devices could allow for transplantation of donor islet tissue in the absence of immunosuppression. To achieve long-term survival of islets, the device should allow rapid exchange of essential nutrients and be vascularized to guarantee continued support of islet function. Recently, we have proposed a membrane-based macroencapsulation device consisting of a microwell membrane for islet separation covered by a micropatterned membrane lid.

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Encapsulation of pancreatic islets in alginate-microcapsules is used to reduce or avoid the application of life-long immunosuppression in preventing rejection. Long-term graft function, however, is limited due to varying degrees of host tissue responses against the capsules. Major graft-longevity limiting responses include inflammatory responses provoked by biomaterials and islet-derived danger-associated molecular patterns (DAMPs).

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Immunosuppressive drugs are widely used for the treatment of autoimmune diseases and to prevent rejection in organ transplantation. Gusperimus is a relatively safe immunosuppressive drug with low cytotoxicity and reversible side effects. It is highly hydrophilic and unstable.

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Insufficient intake of dietary fibers in Western societies is considered a major contributing factor in the high incidence rates of diabetes. The dietary fiber pectin has been suggested to be beneficial for management of both Diabetes Type 1 and Type 2, but mechanisms and effects of pectin on insulin producing pancreatic β-cells are unknown. Our study aimed to determine the effects of lemon pectins with different degree of methyl-esterification (DM) on β-cells under oxidative (streptozotocin) and inflammatory (cytokine) stress and to elucidate the underlying rescuing mechanisms, including effects on galectin-3.

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Background: The intestinal epithelial cells, food molecules, and gut microbiota are continuously exposed to intestinal peristaltic shear force. Shear force may impact the crosstalk of human milk oligosaccharides (hMOs) with commensal bacteria and intestinal epithelial cells.

Objectives: We investigated how hMOs combined with intestinal peristaltic shear force impact intestinal epithelial cells and crosstalk with a commensal bacterium.

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: Non-digestible carbohydrates are added to infant formula to mimic the effects of human milk oligosaccharide by acting as prebiotics and stimulating the immune system. Although not yet used in infant formulas, β-glucans are known to have beneficial health effects, and are therefore of potential interest for supplementation. : We investigated the fermentation of native and endo-1,3(4)-β-glucanase-treated oat β-glucan using pooled fecal inocula of 2- and 8-week-old infants.

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Scope: Inulin-type fructans are commonly applied in infant formula to support development of gut microbiota and immunity. These inulin-type fructans are considered to be fermented by gut microbiota, but it is unknown how fermentation impacts immune modulating capacity and whether the process of fermentation is dependent on the infant's age.

Methods And Results: The in vitro fermentation of chicory fructo-oligosaccharides (FOS) and native inulin are investigated using pooled fecal inocula of two- and eight-week-old infants.

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With the increasing resistance of bacteria to current antibiotics, novel compounds are urgently needed to treat bacterial infections. Streptozotocin (STZ) is a natural product that has broad-spectrum antibiotic activity, albeit with limited use because of its toxicity to pancreatic β cells. In an attempt to derivatize STZ through structural modification at the C3 position, we performed the synthesis of three novel STZ analogues by making use of our recently developed regioselective oxidation protocol.

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