Aug
12
Mon
2013
Invited Talk: Osteoarthritis: diagnosis, treatment and challenges @ Acharya Hall
Aug 12 @ 11:42 am – 12:07 pm

hideakiHideaki Nagase, Ph.D.
Kennedy Institute of Rheumatology-Centre for Degenerative Diseases, University of Oxford, UK


Osteoarthritis: diagnosis, treatment and challenges

Hideaki Nagase1, Ngee Han Lim1, George Bou-Gharios1, Ernst Meinjohanns2  and Morten Meldal3

  1. Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, London, W6 8LH  UK
  2. Carlsberg Laboratory, Copenhagen, Denmark,
  3. Nano-Science Center, Department of Chemistry, University of Copenhagen, Denmark

Osteoarthritis (OA) is the most prevalent age-related degenerative joint disease. With the expanding ageing population, it imposes a major socio-economic burden on society.  A key feature of OA is a gradual loss of articular cartilage and deformation of bone, resulting in the impairment of joint function. Currently, there is no effective disease-modifying treatment except joint replacement surgery. There are many possible causes of cartilage loss (e.g. mechanical load, injury, reactive oxygen species, aging, etc.) and etiological factors (obesity, genetics), but the degradation of cartilage is primarily caused by elevated levels of active metalloproteinases.  It is therefore attractive to consider proteinase inhibitors as potential therapeutics. However, there are several hurdles to overcome, namely early diagnosis and continuous monitoring of the efficacy of inhibitor therapeutics. We are therefore aiming at developing non-invasive probes to detect cartilage degrading metalloproteinase activities.

We have designed in vivo imaging probes to detect MMP-13 (collagenase 3) activity that participates in OA by degrade cartilage collagen II and MMP-12 (macrophage elastase) activity involved in inflammatory arthritis. These activity-based probes consist of a peptide that is selectively cleaved by the target proteinase, a near-infrared fluorophore and a quencher. The probe’s signal multiplies upon proteolysis.  They were first used to follow the respective enzyme activity in vivo in the mouse model of collagen-induced arthritis and we found MMP-12 activity probe (MMP12AP) activation peaked at 5 days after onset of the disease, whereas MMP13AP activation was observed at 10-15 days. The in vivo activation of these probes was inhibited by specific low molecule inhibitors.  We proceeded to test both probes in the mouse model of OA induced by the surgical destabilization of medial meniscus of the knee joints.  In this model, degradation of knee cartilage is first detected histologically 6 weeks after surgery with significant erosion detectable at 8 weeks. Little activation of MMP12AP was detected, which was expected, as macrophage migration is not obvious in OA. MMP13AP, on the other hand, was significantly activated in the operated knee at 6 weeks compared with the non-operated contralateral knee, but there were no significant differences between the operated and sham-operated knees.  At 8 weeks, however, the signals in the operated knees were significantly higher than both the contralateral and sham-operated controls. Activation of aggrecanases and MMP-13 are observed before structural changes of cartilage. We are therefore currently improving the MMP-13 probe for earlier detection by attaching it to polymers that are retained in  cartilage.

 

Aug
13
Tue
2013
Delegate Talk: PC based heart sound monitoring system @ Amriteshwari Hall
Aug 13 @ 3:29 pm – 3:53 pm
Delegate Talk: PC based heart sound monitoring system @ Amriteshwari Hall | Vallikavu | Kerala | India

Arathy R and Binoy B Nair


PC based heart sound monitoring system

Heart diseases caused by disorders of the heart and blood vessels, are world’s largest killers. Early detection and monitoring of heart abnormalities is essential for diagnosis and effective treatment of heart diseases. Severalmethodologies are used for screening and diagnosing heart diseases. They are auscultation, electrocardiogram (ECG), echo-cardiogram, ultrasound etc. The effectiveness and applicability of all these diagnostic methods are highly dependent on the equipment cost and size as well as skill of the physician. This paper presents the design and development of a low cost portable wireless/tubeless digital stethoscope which can be used by the physician for monitoring the patient from a distance. The stethoscope system interfaces to a PC and is also capable of analyzing the heart sounds and identifying abnormalities in the heart sound and its classification. Storage of heart sound for later analysis is also possible.This advanced functionality increases the physician’s diagnostic capability, and such a PCG is not still available in most hospitals. Acoustic stethoscope can be changed into a digital stethoscope by inserting an electric capacity microphone into its diaphragm (Wang, Chen and Samjin, 2009).

Aug
14
Wed
2013
Plenary Talk: Combined Crystallography and SAXS Methods for Studying Macromolecular Complexes @ Amriteshwari Hall
Aug 14 @ 9:38 am – 10:19 am

JeffPerryJeff Perry, Ph.D.
Assistant Professor, University of California, Riverside


Combined Crystallography and SAXS Methods for Studying Macromolecular Complexes

Recent developments in small angle X-ray scattering (SAXS) are rapidly providing new insights into protein interactions, complexes and conformational states in solution, allowing for detailed biophysical quantification of samples of interest1. Initial analyses provide a judgment of sample quality, revealing the potential presence of aggregation, the overall extent of folding or disorder, the radius of gyration, maximum particle dimensions and oligomerization state. Structural characterizations may include ab initio approaches from SAXS data alone, or enhance structural solutions when combined with previously determined crystal/NMR domains. This combination can provide definitions of architectures, spatial organizations of the protein domains within a complex, including those not yet determined by crystallography or NMR, as well as defining key conformational states. Advantageously, SAXS is not generally constrained by macromolecule size, and rapid collection of data in a 96-well plate format provides methods to screen sample conditions. Such screens include co-factors, substrates, differing protein or nucleotide partners or small molecule inhibitors, to more fully characterize the variations within assembly states and key conformational changes. These analyses are also useful for screening constructs and conditions that are most likely to promote crystal growth. Moreover, these high throughput structural determinations can be leveraged to define how polymorphisms affect assembly formations and activities. Also, SAXS-based technologies may be potentially used for novel structure-based screening, for compounds inducing shape changes or associations/diassociations. This is addition to defining architectural characterizations of complexes and interactions for systems biology-based research, and distinctions in assemblies and interactions in comparative genomics. Thus, SAXS combined with crystallography/NMR and computation provides a unique set of tools that should be considered as being part of one’s repertoire of biophysical analyses, when conducting characterizations of protein and other macromolecular interactions.

1 Perry JJ & Tainer JA. Developing advanced X-ray scattering methods combined with crystallography and computation. Methods. 2013 Mar;59(3):363-71.

Jeff (1)