Molecular Pathways of Protein Degradation in Muscular Dystrophies: Targets for Therapeutic Intervention

Muscular dystrophies, characterized by progressive muscle wasting and weakness, are the most common inherited muscle disorders. Twenty-five different muscular dystrophies have been characterized. Limb girdle muscular dystrophies (LGMD) are a group of heterogeneous disorders, prevalent worldwide and common in India, that predominantly affects upper and lower limb musculature. LGMD 2A, due to mutations in muscle specific cysteine protease calpain-3 gene, and LGMD 2B, due to mutations in the dysferlin gene, are major subtypes of LGMD and the focus of this thesis. Mechanisms of muscle wasting are not completely elucidated for any form of muscular dystrophy, which has prevented the development of specific treatment for these disorders. Compounds that inhibit pathogenic pathways of muscle wasting and induce muscle regeneration would be drugs of choice for treatment of muscular dystrophies. Muscle loss as a result of protein degradation through the ubiquitin-proteasomal pathway occurs in several muscle wasting conditions. Oxidant stress and activation of the transcription factor, NF-κB, initiate and mediate the ubiquitin pathway of protein degradation in cachexia. Their role in wasting of target muscles in LGMD 2A and dysferlinopathy has not been studied but would be helpful to examine in considering development of specific pharmacotherapy. If oxidant stress and activation of NF-κB lead to muscle wasting of LGMD, the use of polyphenolic curcumin, an inhibitor of these paths, could be explored. AIM OF THE STUDY: This study were to elucidate (1) Protein degrading pathways of LGMD 2A and dysferlinopathy, common but poorly studied dystrophies in Indian patients and (2) Target the pathways of muscle wasting with drugs that reduce protein degradation and stimulate muscle regeneration. METHODS: Protein content, oxidative and nitrosative stress, NADPH oxidase, NF-κBp65 and IKKβ activation, protein ubiquitinylation and muscle specific E3 ligases of the protein ubquitinylation system were determined in LGMD 2A and dysferlinopathic muscle biopsies and analyzed in comparison to normal muscle. All muscle biopsies were performed under standard conditions and obtained with informed consent from the patient or legal guardian. Further, rat myoblast cell lines and primary myoblast cultures were subject to H2O2 induced oxidative stress and examined for intracellular Ca2+ by live cell fluorescence imaging and for protein ubiquitinylation on immune blots. Myoblasts silenced for NF-κB or treated with curcumin and subject to oxidative stress were similarly studied. RESULTS: Reduced protein, increased ubiquitinylated proteins, oxidative and nitrosative stress and elevated NADPH oxidase activity occurred in LGMD muscle compared to normal. NF-κB was increased in both LGMD 2A and dysferlinopathic muscle. E3 ligases MAFbx and MURF 1 were activated in LGMD 2A but MAFbx not MURF 1 was activated in dysferlinopathic muscle. Myosin heavy chain, actin and antioxidant defense were reduced in wasted muscle but not in spared muscle compared to normal. Oxidative stress led to activation of NK-ƙB that induced protein ubiquitinylation, raised intracellular Ca2+ and led to cell death of rat myoblasts. NF-ƙB knockdown and curcumin prevented oxidative stress induced raised intracellular Ca2+, nitric oxide generation, protein ubiquitinylation and cell death. Curcumin also increased myoblast number. CCONCLUSIONS: The absence of calpain 3 or dysferlin induces oxidative stress in muscle that activates NF-ƙB signaling to induce protein degradation through the ubiquitin-proteasome pathway. NADPH oxidase contributes to oxidative stress of LGMD muscle. Loss of major myofibrillar proteins and failure of the antioxidant system may underlie selective loss of muscle in LGMD. Curcumin is effective in preventing oxidative stress induced myoblast death and stimulating myoblast division. IMPACT OF THE STUDY: There are no comprehensive studies from the Indian subcontinent on muscular dystrophies, especially LGMD and very few centers diagnose LGMD 2A and dysferlinopathy. This thesis describes Western blots suitable for the diagnosis of LGMD in the Indian population, which were used to determine the frequency of LGMD 2A and dysferlinopathy in a series of dystrophic muscles of patients from several parts of India. This study showed the efficacy of the nutraceutical, curcumin, to protect against muscle wasting of muscular dystrophies. Inclusion of curcumin in the therapeutic regimen of muscular dystrophies should be considered

Recurring Issues Encountered by Distance Educators in Developing and Emerging Nations

This article explores a number of challenges faced by e-learning or distance educators in developing and emerging countries, provides a context for many of the challenges, and outlines some measures devised to overcome them. These educators must determine a sound rationale for employing online learning, recognize that technology is only part of the educational transformation process, address the lack of infrastructure and the cost of Internet bandwidth and equipment, counter the cultural imperialism of courseware from Western nations, deal with limited educational resources, place a greater emphasis on quality assurance systems and change negative perceptions of distance education, respond to the needs and concerns of both students and faculty, access or develop up-to-date educational resources, and consider the implementation of mobile learning. The continued growth and success of distance education in developing and emerging nations will depend on the extent to which issues covered in this article are addressed as they bear on the quality of the learning experience provided to students

DETERMINATION OF EUCLIDEAN DISTANCES FOR SYMMETRY MOLECULES

Abstract This paper represents the geometric analysis of molecular surfaces of the molecules, indicates the blending operation of an atoms constitute to the small molecules. The decision which indicates advantages of Euclidean Voronoi diagram of an atom includes the blending surface among the atoms to make a fundamental study of docking, interactions with macromolecules. The algorithm which proposes the topological part of surfaces discussed through the Euclidean Voronoi Diagram of various accessibility procedures

The biopolymer produced by Rhizobium viscosum CECT 908 is a promising agent for application in Microbial Enhanced Oil Recovery

Polymer flooding is one of the most promising techniques used to increase the productivity of mature oil reservoirs. Polymers reduce the mobility ratio of the injected water relative to the crude oil, improving the displacement of the entrapped oil and consequently, increasing oil recovery. Biopolymers such as xanthan gum have emerged as environmentally friendly alternatives to the chemical polymers commonly employed by the oil industry. However, in order to seek more efficient biomolecules, alternative biopolymers must be studied. Here, the applicability of a biopolymer produced by Rhizobium viscosum CECT 908 in Microbial Enhanced Oil Recovery (MEOR) was evaluated. This biopolymer exhibited better rheological properties (including higher viscosity) when compared with xanthan gum. Its stability at high shear rates (up to 300 s-1), temperatures (up to 80?°C) and salinities (up to 200?g/L of NaCl) was also demonstrated. The biopolymer exhibited better performance than xanthan gum in oil recovery assays performed with a heavy crude oil, achieving 25.7?±?0.5% of additional recovery. Thus the R. viscosum CECT 908 biopolymer is a promising candidate for application in MEOR.This work was supported by PARTEX OIL AND GAS (Lisobon, Portugal). The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for financial support under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). The authors also acknowledge financial support from BioTecNorte operation (NORTE-01-0145FEDER-000004) and the project MultiBiorefinery (POCI-01-0145FEDER-016403) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Márcia R. Couto was supported by the doctoral Grant SFRH/BD/ 132998/2017 provided by FCT. Débora Ferreira is recipient of a fellowship (UMINHO/BD/21/2016) supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.E.J.Gudiñawassupported bythePost-Doctoral grant UMINHO/BPD/39/2015 from the project UID/BIO/04469/2013, funded by FCT.info:eu-repo/semantics/publishedVersio

Molecular Pathways of Protein Degradation in Muscular Dystrophies Targets for Therapeutic Intervention

This study shows that LGMD is common in the Indian population. Dysferlinopathy is more predominant than Calpainopathy (LGMD 2A) in India. Absence of calpain 3 or dysferlin induces oxidative and nitrosative stress in dystrophic muscle. The ubiquitin proteasomal pathway, the major pathway that governs protein degradation in DMD and other cachectic conditions, is also upregulated in LGMD 2A and dysferlinopathy. Ubiquitin E3 ligases MAFbx and MURF 1 underlie protein ubiquitinylation of LGMD 2A muscle. MAFbx but not MURF 1 plays a role in ubiquitinylation of dysferlinopahtic muscle. IKKβ mediated activation of NF - κBp65 appears critical in the pathology of LGMD 2A and dysferlinopathy (Figure 5.1). Loss of major myofibrillar proteins and failure of the antioxidant system may underlie selective loss of muscle in LGMD. Oxidative stress mediated activation of NF - κBp65 that causes protein ubiquitinylation and myoblast death indicates this as the the probable order of pathological events in LGMD muscle. Oxidative stress mediated intracellular calcium disturbance and myoblast death is related to NF-κBp65 signalling and could be effectively prevented by curcumin, an anti-oxidant and NF-κB inhibitor. Curcumin is effective in preventing basal and oxidative stress induced NO generation in myoblasts. Importantly curcumin induces myoblast division (Figure 5.1). All these properties of curcumin suggest it could be used as a therapeutic drug for muscular dystrophies especially LGMD 2A and dysferlinopathy. Further studies are needed to determine bio-delivery and therapeutic doses of curcumin. IMPACT OF THE STUDY: There are no comprehensive studies from the Indian subcontinent on muscular dystrophies, especially LGMD and very few centers diagnose LGMD 2A and dysferlinopathy. This thesis describes Western blots suitable for the diagnosis of LGMD in the Indian population, which were used to determine the frequency of LGMD 2A and dysferlinopathy in a series of dystrophic muscles of patients from several parts of India. This study showed the efficacy of the nutraceutical, curcumin, to protect against muscle wasting of muscular dystrophies. Inclusion of curcumin in the therapeutic regimen of muscular dystrophies should be considered

3D QSAR studies of synthetic compounds as potential inhibitors for Anti - hyperglycemic targets.

 Background: The identification of potential compounds for an anti-hyperglycemic makes real challenges in the pharmaceutical industry. Library ofcompounds have introduced so far, but identifying the specific target, which makes more sensation.Objective: In the present study, the quantitative structure-activity relationship (QSAR) studies have been analyzed from the compounds wereretrieved from online and literature survey.Methods: The compound, 6, 7, 8, 9-tetrahydro-2h-11-oxa-2, 4, 10-triaza-benzo [b] fluoren-1-one has taken as a potential target to perform QSARstudy based on the principle of the molecular docking analysis and pharmacophoric features. QSAR models were generated a target from the first 10potential targets in the training set.Results: The predictive ability of both models was determined using a randomly chosen test set gave predictive correlation coefficients of r2=0.9.Conclusion: This analysis shows the ADNRR shows very close to the interactions recorded in the active site of the ligand bound complex.Keywords: Quantitative structure-activity relationship, Pharmacophore Alignment and Scoring Engine, Dipeptidyl peptidase 4, Anti-hyperglycemictargets, Docking studies, Three dimensional quantitative structure-activity relationship

Recurring Issues Encountered by Distance Educators in Developing and Emerging Nations

This article explores a number of challenges faced by e-learning or distance educators in developing and emerging countries, provides a context for many of the challenges, and outlines some measures devised to overcome them. These educators must determine a sound rationale for employing online learning, recognize that technology is only part of the educational transformation process, address the lack of infrastructure and the cost of internet bandwidth and equipment, counter the cultural imperialism of courseware from Western nations, deal with limited educational resources, place a greater emphasis on quality assurance systems and change negative perceptions of distance education, respond to the needs and concerns of both students and faculty, access or develop up-to-date educational resources, and consider the implementation of mobile learning. The continued growth and success of distance education in developing and emerging nations will depend on the extent to which issues covered in this article are addressed as they bear on the quality of the learning experience provided to students