Breaking News
October 22, 2018 - Overcoming bottlenecks in early drug discovery with the power of sound
October 22, 2018 - Scientists discover genes that contribute to ADHD development
October 22, 2018 - Incyte announces Phase 2 FIGHT-202 trial data in patients with cholangiocarcinoma
October 22, 2018 - FDA approves update to Rituxan label to include information on treatment of rare forms of vasculitis
October 22, 2018 - At-home biofeedback therapy effective in relieving difficult-to-treat constipation
October 22, 2018 - Merck presents KEYNOTE-057 trial results for patients with high-risk non-muscle invasive bladder cancer
October 22, 2018 - People with periodontal disease less likely to reach healthy blood pressure ranges
October 22, 2018 - Phase III LONSURF study shows progression-free survival in patients with refractory metastatic gastric cancer
October 22, 2018 - Primary care doctors ‘not doing enough’ to curb STDs
October 22, 2018 - Pfizer announces PALOMA-3 trial results in patients with HR+, HER2- metastatic breast cancer
October 22, 2018 - ImmunoGen announces study results of platinum-resistant ovarian cancer therapy at ESMO 2018 Congress
October 22, 2018 - Study findings could set new standard of care for advanced anal cancer
October 22, 2018 - Erlotinib improves progression-free survival in EGFR mutated NSCLC
October 22, 2018 - Pain, insomnia, and depression often drive osteoarthritis patients to seek medical care
October 22, 2018 - The International Society of Refractive Surgery honors Vivior Chairman with Casebeer Award
October 22, 2018 - Multi-strain probiotic helps reduce chemotherapy-induced diarrhea in cancer patients
October 22, 2018 - Study shows potential of avelumab plus axitinib as new treatment option for patients with advanced RCC
October 22, 2018 - Vertex gets European CHMP positive opinion for KALYDECO to treat patients with cystic fibrosis
October 22, 2018 - Phase III trial reports positive results with HDAC inhibitor in advanced breast cancer patients
October 22, 2018 - Prostate radiotherapy improves survival in men with low burden of metastatic disease
October 22, 2018 - Free phone app helps low-income obese patients to lose weight
October 22, 2018 - Immunotherapy with nivolumab and ipilimumab may improve survival in patients with MSI-high metastatic colorectal cancers
October 22, 2018 - FOTIVDA expected to be included in new ESMO guidelines for advanced renal cell carcinoma
October 22, 2018 - Compression Collar May Protect Brain of Female Soccer Players
October 22, 2018 - Technique visualizes neuron communication
October 22, 2018 - Advancement in medical imaging methods for health care
October 22, 2018 - Takeda presents vedolizumab phase 3 VISIBLE 1 trial results for treatment of moderately to severely active ulcerative colitis
October 22, 2018 - Immunotherapy increases survival in some patients with metastatic triple negative breast cancer
October 22, 2018 - Exelixis presents CABOSUN and METEOR trial results in patients with advanced renal cell carcinoma
October 22, 2018 - LYNPARZA Phase III SOLO-1 results show improved outcome for patients with advanced BRCA-mutated ovarian cancer
October 22, 2018 - Brainlab unveils ExacTrac Dynamic at ASTRO meeting in San Antonio, Texas
October 22, 2018 - Not exercising is worse than smoking, diabetes or heart disease finds study
October 22, 2018 - Shorter course of trastuzumab could be an option for women with HER2+ early breast cancer
October 22, 2018 - Map of Mouse Hippocampus Could Be Weapon Against Alzheimer’s
October 22, 2018 - Psychotropic polypharmacy is common in Alzheimer’s disease
October 22, 2018 - Texas A&M and UTA establish Texas Genomics Core Alliance
October 22, 2018 - Analyzing mouse’s potential as animal model of decision-making
October 22, 2018 - Radiotherapy can prolong survival in prostate cancer
October 22, 2018 - A genetic mutation involved in relapse
October 21, 2018 - Report reveals growing impact of cannabis on young people
October 21, 2018 - NSF awards $5 million grant to help scientists magnify societal impact of research
October 21, 2018 - Fertility Rates Down for Each Urbanization Level 2007 to 2017
October 21, 2018 - Genetically engineered 3-D human muscle transplant in a murine model
October 21, 2018 - Moms’ tight work schedules may affect their children’s sleep
October 21, 2018 - AHA: No Direct Link Between Preeclampsia and Cognitive Impairment, Study Finds
October 21, 2018 - Weight loss success linked with active self-control regions of the brain
October 21, 2018 - Scripps researchers successfully test potential new smoking-cessation treatment in rodents
October 21, 2018 - More accurate and less stressful way to measure a baby’s heartbeat
October 21, 2018 - Researchers show better cardiorespiratory fitness leads to longer life
October 21, 2018 - Healthy candies for diabetic patients
October 21, 2018 - Environment impact of microplastics remains unclear
October 21, 2018 - Antibiotics for appendicitis? Surgery often not needed
October 21, 2018 - AHA and AMA recognize more than 800 medical practices, health systems for blood pressure control
October 21, 2018 - Scientists obtain clearest ever image of Ebola virus protein
October 21, 2018 - Study reveals connection between two proteins known to be hyperactive in cancer
October 21, 2018 - Gabapentin Beats Pregabalin for Chronic Sciatica
October 21, 2018 - Cosmetic surgeons offering incomplete information for breast augmentation customers
October 21, 2018 - Chronic sleep disruption in early adult life accelerates AD-related tau pathology
October 21, 2018 - Take 10 for Mindfulness – Drugs.com MedNews
October 21, 2018 - Length of breathing disruption in OSA may be better predictor of mortality risk
October 21, 2018 - ApoE4 gene linked with chronic inflammation increases risk for Alzheimer’s disease
October 21, 2018 - Mother-daughter conflict associated with suicide risk in abused adolescent girls
October 21, 2018 - Scientists molding bacteria into unnatural shapes
October 21, 2018 - High diet quality associated with lower risk of death in colorectal cancer patients
October 21, 2018 - Discharged mental health patients ‘at greater risk of dying’
October 21, 2018 - Research provides insight into neurobiology of aggression and bullying
October 21, 2018 - As billions in tax dollars flow to private Medicaid plans, Who’s minding the store?
October 21, 2018 - Neuroscientists identify brain region that appears to be related to food preference decisions
October 21, 2018 - Deaths related to air pollution in the U.S. decreased by 47% between 1990 and 2010
October 21, 2018 - Study shows correlation between spatial memory and the sense of smell
October 21, 2018 - Increased cardiorespiratory fitness associated with reduced long-term mortality
October 21, 2018 - IU researchers receive $1.55 million from NIH to improve chronic-disease management
October 21, 2018 - Income and wealth affect the mental health of Australians, study shows
October 21, 2018 - Patients with hypertension and psoriasis more often require cardiovascular interventions
October 20, 2018 - Leading hip-hop videos depict use of tobacco and marijuana products, study finds
October 20, 2018 - Dose Range of IV Ketamine for Adjunct Tx of Depression Tested
October 20, 2018 - Infants can distinguish between leaders and bullies, study finds
October 20, 2018 - Mad Cow disease found on Aberdeenshire farm
October 20, 2018 - Study identifies factors associated with prescription opioid misuse among students
October 20, 2018 - Scientists uncover key regulator of mTORC1 in cancer growth
Silky webs of spiders may hold secrets to repairing our skeletons

Silky webs of spiders may hold secrets to repairing our skeletons

image_pdfDownload PDFimage_print

Some secrets to repairing our skeletons might be found in the silky webs of spiders, according to recent experiments guided by supercomputers. Scientists involved say their results will help understand the details of osteoregeneration, or how bones repair themselves.

The recently published study found that genes could be activated in human stem cells that initiate biomineralization, a key step in bone formation. Scientists achieved these results with engineered silk derived from the dragline of golden orb weaver spider webs, which they combined with silica. The study, published in September 2017 in the journal Advanced Functional Materials, was the result of a combined effort from three institutions: Tufts University, Massachusetts Institute of Technology, and Nottingham Trent University.

Study authors used the supercomputers Stampede at the Texas Advanced Supercomputing Center (TACC) at The University of Texas at Austin and Comet at the San Diego Supercomputer Center (SDSC) at the University of California San Diego through an allocation from XSEDE, the eXtreme Science and Engineering Discovery Environment that is funded by the National Science Foundation (NSF). The supercomputers helped scientists model how the cell membrane protein receptor called integrin folds and activates the intracellular pathways that lead to bone formation. The research will help larger efforts to treat bone growth diseases such as osteoporosis or calcific aortic valve disease.

“This work demonstrates a direct link between silk-silica-based biomaterials and intracellular pathways leading to osteogenesis,” said study co-author Zaira Martín-Moldes, a postdoctoral scholar at the Kaplan Lab at Tufts University who researches the development of new biomaterials based on silk. “The hybrid material promoted the differentiation of human mesenchymal stem cells, the progenitor cells from the bone marrow, to osteoblasts as an indicator of osteogenesis, or bone-like tissue formation.”

Silk has been shown to be a suitable scaffold for tissue regeneration, due to its outstanding mechanical properties, Martín-Moldes explained. It’s biodegradable. It’s biocompatible. And it’s fine-tunable through bioengineering modifications. The experimental team at Tufts University modified the genetic sequence of silk from golden orb weaver spiders (Nephila clavipes) and fused the silica-promoting peptide R5 derived from a gene of the diatom Cylindrotheca fusiformis silaffin.

The bone formation study targeted biomineralization, a critical process in materials biology. “We would love to generate a model that helps us predict and modulate these responses both in terms of preventing the mineralization and also to promote it,” Martín-Moldes said.

“High-performance supercomputing simulations are utilized along with experimental approaches to develop a model for the integrin activation, which is the first step in the bone formation process,” said study co-author Davoud Ebrahimi, a postdoctoral associate at the Laboratory for Atomistic and Molecular Mechanics of the Massachusetts Institute of Technology.

Integrin embeds itself in the cell membrane and mediates signals between the inside and the outside of cells. In its dormant state, the head unit sticking out of the membrane is bent over like a nodding sleeper. This inactive state prevents cellular adhesion. In its activated state, the head unit straightens out and is available for chemical binding at its exposed ligand region.

“Sampling different states of the conformation of integrins in contact with silicified or non-silicified surfaces could predict activation of the pathway,” said Ebrahimi. Sampling the folding of proteins remains a classically computationally expensive problem, despite recent and large efforts in developing new algorithms.

The derived silk–silica chimera they studied weighed in around a hefty 40 kilodaltons. “In this research, what we did in order to reduce the computational costs, we have only modeled the head piece of the protein, which is getting in contact with the surface that we’re modeling,” Ebrahimi said. “But again, it’s a big system to simulate and can’t be done on an ordinary system or ordinary computers.”

The computational team at MIT used the molecular dynamics package called Gromacs, a software for chemical simulation available on both the Stampede and Comet supercomputers. “We could perform those large simulations by having access to these XSEDE computational clusters,” said Ebrahimi.

Computation combined with experimentation helped advance work in developing a model of osteoregeneration. “We propose a mechanism in our work that starts with the silica-silk surface activating a specific cell membrane protein receptor, in this case integrin αVβ3,” said Martín-Moldes, adding that this activation triggers a cascade in the cell through three mitogen-activated protein kinsase (MAPK) pathways, the main one being the c-Jun N-terminal kinase (JNK) cascade.

Other factors are also involved in this process such as Runx2, the main transcription factor related to osteogenesis. According to the study, the control system did not show any response, and neither did the blockage of integrin using an antibody, confirming its involvement in this process. “Another important outcome was the correlation between the amount of silica deposited in the film and the level of induction of the genes that we analyzed,” said Martín-Moldes. “These factors also provide an important feature to control in future material design for bone-forming biomaterials.”

The researchers are building a pathway to generate biomaterials that could be used in the future, with the mineralization being a critical process. The final goal is to develop models that help design the biomaterials to optimize the bone regeneration process, when the bone is required to regenerate or to minimize it when we need to reduce the bone formation.

These results help advance the research and are useful in larger efforts to help cure and treat bone diseases. “We could help in curing disease related to bone formation, such as calcific aortic valve disease or osteoporosis, which we need to know the pathway to control the amount of bone formed, to either reduce or increase it,” Ebrahimi said.​

Tagged with:

About author

Related Articles