Raman Spectroscopic Studies on Screening of Myopathies

Myopathies are among the major causes of mortality in the world. There is no complete cure for this heterogeneous group of diseases, but a sensitive, specific, and fast diagnostic tool may improve therapy effectiveness. In this study, Raman spectroscopy is applied to discriminate between muscle mutants in Drosophila on the basis of associated changes at the molecular level. Raman spectra were collected from indirect flight muscles of mutants, <i>upheld¹</i> (<i>up¹</i>), <i>heldup²</i> (<i>hdp²</i>), <i>myosin heavy chain⁷</i> (<i>Mhc⁷</i>), <i>actin88F^KM88</i> (<i>Act88F^KM88</i>), <i>upheld¹⁰¹</i> (<i>up¹⁰¹</i>), and <i>Canton-S</i> (<i>CS</i>) control group, for both 2 and 12 days old flies. Difference spectra (mutant minus control) of all the mutants showed an increase in nucleic acid and β-sheet and/or random coil protein content along with a decrease in α-helix protein. Interestingly, the 12th day samples of <i>up¹</i> and <i> Act88F^KM88</i> showed significantly higher levels of glycogen and carotenoids than <i>CS</i>. A principal components based linear discriminant analysis classification model was developed based on multidimensional Raman spectra, which classified the mutants according to their pathophysiology and yielded an overall accuracy of 97% and 93% for 2 and 12 days old flies, respectively. The <i>up¹</i> and <i>Act88F^KM88</i> (nemaline-myopathy) mutants form a group that is clearly separated in a linear discriminant plane from <i>up¹⁰¹</i> and <i>hdp²</i> (cardiomyopathy) mutants. Notably, Raman spectra from a human sample with nemaline-myopathy formed a cluster with the corresponding Drosophila mutant (<i>up¹</i>). In conclusion, this is the first demonstration in which myopathies, despite their heterogeneity, were screened on the basis of biochemical differences using Raman spectroscopy

Additional file 1: of MLPA identification of dystrophin mutations and in silico evaluation of the predicted protein in dystrophinopathy cases from India

Listing of mutations found in our samples. (XLSX 16 kb

Western blot analysis of telethonin protein in muscle biopsies of control and telethoninopathy patients.

<p><b>A</b>. Telethonin western Blot: Lane C corresponds to non-dystrophic positive control which shows telethonin band at 19 kDa. Lanes 1–7 corresponding to the Telethoninopathy patient samples, shows complete absence of the telethonin band. <b>B</b>. Coomassie stained SDS PAGE (15%) profile of total muscle extract from the samples.</p

MRI staging of the individual muscles of lower limb for presence of fatty infiltration and myoedema.

<p>MRI staging of the individual muscles of lower limb for presence of fatty infiltration and myoedema.</p

Transversely cut skeletal muscle tissue stained for Haematoxylin and eosin (HE) shows variation in fiber diameter clusters of basophilic regenerating fibers and myophagocytosis.

<p>Immunolabeling to antibodies against dystrophin (dys1,dys2,dys3) sarcoglycans (alpha-A, beta-B, delta-D, gamma-G, merosin, dysferlin (DYSF), caveolin, beta dystroglycan (B-DG), alpha dystroglycan (A-DG) shows uniform labeling along the sarcolemma and positive sarcoplasmic labeling to titin. X400</p

Mutational analysis of TCAP gene.

<p>A&B. Pedigree of F50 & F97 families respectively and the arrow indicates the proband; C. Electrophorogram representing heterozygous, homozygous and wild type c.32C>A mutation from family F50; Arrow indicates the polymorphic site; D. IB representing absence of telethonin band in F50-1 and F97-1; (E). Represents myosin bands of F50-1 and F97-1; (F). Electrophorogram representing homozygous, heterozygous and wild type c.26_33dupAGGTGTCG mutation in family F97.</p

Description of genetic analysis of <i>TCAP</i> gene.

<p>*Novel mutation.</p

Muscle MRI of patient F97-1.

<p><b>A</b>. T1W image showing global atrophy of muscles of anterior compartment, medial compartment and posterior compartment of thigh. Biceps femoris long head shows stage 3 fatty infiltration. Short head of biceps femoris, sartorius and gracilis are hypertrophied; <b>B</b>. shows severely atrophied vastus intermedius muscle, Mercurie stage 2b infiltration of vastus medialis muscle. Short head of biceps femoris, sartorius and gracilis are hypertrophied; <b>C</b>. Tibilialis anterior, extensor hallucis longus and extensor digitorum longus are atrophied (right more than left). On right side the medial head of gastrocnemius is hypertrophied and lateral head is atrophied. Left soleus is atrophied. Mild fatty infiltration of soleus muscle is noted in left side. Striking asymmetry is present; <b>D</b>. STIR image of thigh shows asymmetrical myoedema pattern. On the right side there is stage 3a myoedema and on the left side it is stage 2a. There is stage 2b myodema noted in the posterior compartment on left side; <b>E</b>. Myoedema mainly seen in gastrocnemius and soleus muscle. Stage 2b on right side and stage 2a on left side.</p

Clinical features and Muscle Histopathology findings of patients with LGMD-2G.

<p>Yrs-Years; F-Female; M-Male; KA-Karnataka; TN-Tamilnadu; AP-Andhra Pradesh; EDB-Extensor digitorumbrevis; TA-Tibialis anterior; CK-Creatine kinase; MDFRS-Muscular dystrophy functional rating scale; Note: Biopsy was not done for patient F111-2 (sibling of patient F111-1).</p

Clinical phenotype of patient F97-1.

<p>A. Slender habitus, B. Generalised poor muscle mass, global wasting of thigh muscles, C. moderate scapular winging, D. mild clf hypertrophy with minimal ankle contracture.</p