Publications
Here is a selection of publications where different laminin isoforms were used to create more authentic cell culture systems.
Structural and functional polarisation of human pancreatic beta cells in islets from organ donors with and without type 2 diabetes
Louise Cottle, Wan Jun Gan, Ian Gilroy, Jaswinder S. Samra, Anthony J. Gill, Thomas Loudovaris, Helen E. Thomas, Wayne J. Hawthorne, Melkam A. Kebede, and Peter Thorn. Diabetologia, 2021
Isolated human pancreatic beta cells were cultured on Biolaminin 511 -coated glass coverslips to study beta cells' structural and functional polarization. The study shows that human beta cells have a consistent orientation with respect to islet capillaries, surrounded by an extracellular matrix including laminin proteins. Live-cell imaging showed the distribution of insulin granule fusion around the cells. The study recognized beta cell polarity in the native human islet environment which plays a role in insulin secretion.
Culturing functional pancreatic islets on α5-laminins and curative transplantation to diabetic mice
Sigmundsson K., Ojala J.R.M., Öhman M.K. Österholm A-M., Moreno-Moral A., Domogatskaya A., Yen Chong L., Sun Y., Chai X., Steele J.A.M, George B., Patarroyo M., Nilsson A-S., Rodin S., Ghosh S., Stevens M.M., Petretto E., Tryggvason K. Matrix Biology, 2018
Here, the authors have developed a novel method to grow and maintain normoxic and functional islets which may significantly enhance the efficacy of islet transplantation treatment for diabetes. A key component of this method is the coating with biologically relevant laminins, found in the peri-islet capsule and BM of islet capillaries. Islets cultured in vitro on α5-laminins adhere and spread to form layers of 1-3 cells in thickness while maintaining cell-to-cell contacts. The cells remained normoxic and functional for at least 7 days in culture. In contrast, spherical islets kept in suspension developed hypoxia and central necrosis within 16 hours. Mouse islets plated on laminin-521 could be cultured in a serum-free mTeSR1 medium for an extended period of time. Approximately 20% of islet cells showed a co-expression of insulin and glucagon. The double-hormone expression was confirmed in histological analyses of mouse and monkey pancreata. The flattened islets start robust cell proliferation after a lag period of approximately two weeks in a serum-free mTeSR1 culture on laminin-521. Transplantation mouse islets cultured on α5-laminin-coated polydimethylsiloxane membranes for 3–7 days normalized blood glucose already within 3 days in mice with streptozotocin-induced diabetes.
Key matrix proteins within the pancreatic islet basement membrane are differentially digested during human islet isolation
Cross S.E., Vaughan R.H., Willcox A.J., McBride A.J., Abraham A.A., Han B., Johnson J.D., Maillard E., Bateman P.A., Ramracheya R.D., Rorsman P., Kadler K.E., Dunne M.J., Hughes S.J., Johnson P.R.V.Am J Transplant. 2016
Here the authors investigated the impact of islet isolation on basement membrane (BM) integrity in the human islet. Collagen IV, panlaminin, perlecan and laminin-α5 in the islet BM were significantly digested by enzyme treatment. Laminin-α5 (found in both layers of the duplex BM) and perlecan were lost entirely, with no restoration evident during culture. Islet function and survival decreased and islet cytotoxicity increased during culture. The islet basement membrane (BM) influences islet function and survival and an incomplete islet BM has implications for islet integrity and transplanted graft longevity.
Extracellular Matrix Protects Pancreatic Beta-Cells Against Apoptosis: Role of Short- and Long-Term Signaling Pathways
Hammar E., Parnaud G., Bosco D., Perriraz N., Maedler K., Donath M., Rouiller D.G., Halban P. A.Diabetes, 2004
Beta-cells cultured on laminin-332 rich surfaces improve their functions. This study provides evidence for the activation of signaling pathways and gene expression by laminin-332 leading to improved beta-cell survival. Laminin-332 protect sorted rat beta-cells against apoptosis under standard conditions (11.2 mmol/l glucose, 10% serum), after serum deprivation (1% serum), and in response to interleukin-1 (IL-1; 2 ng/ml), compared with the poly-L-lysine control. Caspase-8 activity was reduced in cells cultured on laminin-332, whereas FAK, Akt and ERK phosphorylation was augmented. Treatment with an anti-1 integrin antibody, with the ERK pathway inhibitor PD98059, and/or with the phosphatidylinositol 3-kinase inhibitor LY294002 augmented cell death on the laminin-332 rich matrix but not on pLL.
Unique basement membrane structure of human pancreatic islets: implications for b-cell growth and differentiation
Otonkoski T., Banerjee M., Korsgren O., Thornell L.-E., Virtanen I.Diabetes, Obesity and Metabolism, 2008
The authors showed that in the human islets, a double BM structure surrounding each blood vessel within the islet. In addition, a continuous peri-islet BM was surrounding the entire islet, invaginating into the islet tissue together with the arterioles. The capillaries are surrounded by a double BM both in fetal and adult tissues. The B-cells are facing a BM that is separate from the endothelia, unlike the situation in mouse where the B-cells interact directly with BMs of capillary endothelial cells. Here they show that (i) a1 is not expressed in the adult human pancreas; (ii) a2 is only expressed in the exocrine pancreas; (iii) a4 is expressed in the blood vessel BMs; (iv) a5 and b1 are expressed similarly, both in the endocrine and endothelial BMs in the islets. Taken together, this suggested that there is a double-layered BM organization around the vascular channels of human islets: the inner vascular leaflet of the duplex contains Lms-411/421 and -511/521 whereas the outer leaflet facing the parenchymal endocrine cells contains only Lm-511. In contrast to the adult pancreas, a laminin a1 chain could be found in the acinar BMs of the fetal pancreas and faintly also in the developing islets. Similarly, as in the adult pancreas, immunoreactivity for laminin a5 chain was distinctly surrounding the developing islets and also in BMs of intra-islet vessels. Strong expression of laminin B1 and g1 in the fetal pancreas. a3 and b1 integrin subunits were found both on the vascular channels and the endocrine cells. However, the integrin a6 subunit was clearly absent from the endocrine cells and only expressed in the endothelial cells. The islet cells facing this BM have a strong and polarized expression of Lutheran glycoprotein, which is a well-known receptor for the laminin a5 chain. Dispersed human islet cells adhere to purified human laminin-511 and the binding is equally effectively blocked by a soluble form of Lutheran as by antibody against integrin B1. The results reveal that the BM structure of human islets, different from rodents.
Extracellular Matrix and Integrins in Embryonic Stem Cell Differentiation
Wang H., Luo X. Leighton J.Biochemistry Insights, 2015
Here, the author summarizes the role of the ECM and integrins in the formation of three germ layer progenies. Various ECM–integrin interactions were found, facilitating differentiation toward definitive endoderm, hepatocyte-like cells, pancreatic beta cells, early mesodermal progenitors, cardiomyocytes, neuro-ectoderm lineages, and epidermal cells, such as keratinocytes and melanocytes.
Immunohistochemical Distribution of Laminin-5 γ 2 Chain and its Developmental Change in Human Embryonic and Foetal Tissues
Lu W., Miyazaki K., Mizushima H., Nemoto N.
Here, immunohistochemical distribution of laminin γ2 chain, a subunit of the basement membrane protein laminin 332, was examined in 19 cases of human embryos and foetuses ranging from 4 to 25 weeks of gestation. Laminin γ2 was first detected in the basement membranes underlying ectodermal epithelial tissues, such as the skin and tooth, as early as 5–6 weeks of gestation. Between 6–7 and 12–13 weeks, laminin γ2 was detected in the basement membranes of various endodermal epithelial tissues, such as the bronchus, oesophagus, stomach, intestines, urinary bladder, gallbladder, and hepatopancreatic duct. The deposition of laminin γ2 in the basement membrane was associated with the process of morphogenesis. In the small intestine, laminin γ2 first appeared in the basement membrane of the primitive short villi, and its level gradually increased in the villus region but decreased in the cryptic region during the maturation of the organ. In addition, non-basement membrane immunoreactivity for laminin γ2 was detected in some mesoderm-derived tissues, such as the cartilage and skeletal and smooth muscle fibers. These results suggest a common role of laminin 332 and some specific roles of its γ2 chain in the morphogenesis of human tissues.
Immunohistochemical Distribution of Laminin-5 γ 2 Chain and its Developmental Change in Human Embryonic and Foetal Tissues
Lu W., Miyazaki K., Mizushima H., Nemoto N.The Histochemical Journal, 2001
Here, immunohistochemical distribution of laminin γ2 chain, a subunit of the basement membrane protein laminin 332, was examined in 19 cases of human embryos and fetuses ranging from 4 to 25 weeks of gestation. Laminin γ2 was first detected in the basement membranes underlying ectodermal epithelial tissues, such as the skin and tooth, as early as 5–6 weeks of gestation. Between 6–7 and 12–13 weeks, laminin γ2 was detected in the basement membranes of various endodermal epithelial tissues, such as the bronchus, oesophagus, stomach, intestines, urinary bladder, gallbladder, and hepatopancreatic duct. The deposition of laminin γ2 in the basement membrane was associated with the process of morphogenesis. In the small intestine, laminin γ2 first appeared in the basement membrane of the primitive short villi, and its level gradually increased in the villus region but decreased in the cryptic region during the maturation of the organ. In addition, non-basement membrane immunoreactivity for laminin γ2 was detected in some mesoderm-derived tissues, such as the cartilage and skeletal and smooth muscle fibers. These results suggest a common role of laminin 332 and some specific roles of its γ2 chain in the morphogenesis of human tissues.
Extracellular matrix microarrays to study inductive signaling for endoderm specification
Braga Malta D.F., Reticker-Flynn N.E., da Silva C.L., Cabral J.M.S, Fleming H.E., Zaret K.S., Bhatia S.N., Underhill G.H. Acta Biomaterialia, 2016
The authors implemented an extracellular matrix (ECM) array platform that facilitates the study of 741 distinct combinations of 38 different ECM components in a systematic, unbiased and high throughput manner. Seeded definitive endoderm (DE) cells onto the arrays and evaluated cell adhesion and hepatic and pancreatic differentiation. When comparing the ECM conditions that best supported hepatic and pancreatic differentiation, we noted that two combinations (fibronectin + merosin (laminin α2) and laminin (α1) + superfibronectin) are among the most robust domains for both hepatic and pancreatic differentiation.
The Vascular Basement Membrane: A Niche for Insulin Gene Expression and B Cell Proliferation
Nikolova G., Jabs N., Konstantinova I., Domogatskaya A., Tryggvason K., Sorokin L., Fässler R., Gu G., Gerber H-P., Ferrara N., Melton D.A., Lammert E.Developmental Cell, 2006
Mouse pancreatic islets intimately interact with endothelial cells and differentiation and delamination of insulin-producing b cells from pancreatic epithelium strictly require endothelial cells. Doug Melton and colleagues show that BMs within islets are formed and found exclusively around capillaries but not islet cells. Islet endothelial cells express laminin a4 and a5. Laminins promote insulin gene expression and proliferation in B-cells and B1-integrin is required for this laminin response. Laminin-411 and -511 worked well but also laminin-111 which shows that the applied laminin does not necessarily have to be endothelial cell-derived. Research on islet transplantation has shown that it takes about 1–2 weeks for transplanted islets to become revascularized in the host and the authors suggest that treating islets with these laminins prior to transplantation will help maintain insulin production until new capillaries are formed in transplanted islets.