@article {1178, title = {Serotonin is essential for eye regeneration in planaria Schmidtea~mediterranea [Mass Spectrometry (Metabolomics) and Central Imaging \& Flow Cytometry Facilities (INT)]}, journal = {FEBS Lett}, year = {2019}, month = {2019 Sep 17}, abstract = {

Planaria is an ideal system to study factors involved in regeneration and tissue homeostasis. Little is known about the role of metabolites and small molecules in stem cell maintenance and lineage specification in planarians. Using liquid chromatography and mass spectrometry (LC-MS)-based quantitative metabolomics, we determined the relative levels of metabolites in stem cells, progenitors, and differentiated cells of the planarian Schmidtea\ mediterranea. Tryptophan and its metabolic product serotonin are significantly enriched in stem cells and progenitor population. Serotonin biosynthesis in these cells is brought about by a noncanonical enzyme, phenylalanine hydroxylase. Knockdown of Smed-pah leads to complete disappearance of eyes in regenerating planaria, while exogenous supply of serotonin and its precursor rescues the eyeless phenotype. Our results demonstrate a key role for serotonin in eye regeneration.

}, issn = {1873-3468}, doi = {10.1002/1873-3468.13607}, author = {Sarkar, Arunabha and Mukundan, Namita and Sowndarya, Sai and Dubey, Vinay Kumar and Babu, Rosana and Lakshmanan, Vairavan and Rangiah, Kannan and Panicker, Mitradas M and Palakodeti, Dasaradhi and Subramanian, Sabarinath Peruvemba and Subramanian, Ramaswamy} } @article {815, title = {Quantification of Neurotransmitters from Intact and Regenerating Planarians Using UHPLC-MS/SRM Method. [Mass Spectrometry - Metabolomics Facility (INT)]}, journal = {Methods Mol Biol}, volume = {1774}, year = {2018}, month = {2018}, pages = {555-570}, abstract = {

Freshwater planarian species S. mediterranea is an emerging stem cell model because of its capability of regenerating large portions of missing body parts. It is one of the best model systems available to address the basic biological mechanisms in the regeneration processes. Absolute quantification of metabolites from planarians is imperative to understand their role in the regeneration processes. Here we describe a stable isotope dilution ultrahigh performance liquid chromatography/mass spectrometry/selected reaction monitoring (UHPLC-MS/SRM) assay for a sensitive and quantitative assessment of neurotransmitters (NTs) in planaria. We used this method for the simultaneous quantification of 16 NTs from both intact and regenerating planarians.

}, issn = {1940-6029}, doi = {10.1007/978-1-4939-7802-1_25}, author = {Rangiah, Kannan and Palakodeti, Dasaradhi} } @article {540, title = {A method for comparative metabolomics in urine using high resolution mass spectrometry.}, journal = {J Chromatogr A}, volume = {1443}, year = {2016}, month = {2016 Apr 22}, pages = {83-92}, abstract = {

Developing a workflow for metabolite profiling from biological fluids using mass spectrometry is imperative to extract accurate information. In this study, urine samples from smokers (n=10) and nonsmokers (n=10) were analyzed using an ultrahigh performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) system. For the analysis, two different chromatographic methods [Reversed phase chromatography (RPC) and Hydrophilic interaction liquid chromatography (HILIC)], in two ionization modes (positive and negative) were used. Spiked reserpine (positive ion mode) or taurocholate (negative ion mode) were used for data extraction and normalization. Quality controls (QCs), prepared by pooling urine samples from both smokers and non-smokers (each n=10), were used to assess the reproducibility of the method. The final data output from SIEVE 2.2 after applying a cut-off for QC coefficient of variation (CV) \<20\% and p-value \<0.05 showed 165, 83, 177 and 100 unique components in RP positive/negative, HILIC positive/negative modes, respectively. Statistical analysis showed clustering of the two groups and the QCs, while the variable importance in projection (VIP) scores for the top fifteen metabolites in each of the four modes indicated the metabolites most responsible for the differences. Application of the developed workflow for comparative metabolomic analysis of urine in different diseased models will be of great use in the field of clinical metabolomics.

}, keywords = {Chromatography, Liquid, Chromatography, Reverse-Phase, Hydrophobic and Hydrophilic Interactions, Mass Spectrometry, Metabolomics, Reproducibility of Results, Urinalysis}, issn = {1873-3778}, doi = {10.1016/j.chroma.2016.02.080}, author = {Ramakrishnan, Padma and Nair, Sreenath and Rangiah, Kannan} } @article {499, title = {Comprehensive analyses of genomes, transcriptomes and metabolites of neem tree. [Mass spectrometry - Metabolomics]}, journal = {PeerJ}, volume = {3}, year = {2015}, month = {2015}, pages = {e1066}, abstract = {

Neem (Azadirachta indica A. Juss) is one of the most versatile tropical evergreen tree species known in India since the Vedic period (1500 BC-600 BC). Neem tree is a rich source of limonoids, having a wide spectrum of activity against insect pests and microbial pathogens. Complex tetranortriterpenoids such as azadirachtin, salanin and nimbin are the major active principles isolated from neem seed. Absolutely nothing is known about the biochemical pathways of these metabolites in neem tree. To identify genes and pathways in neem, we sequenced neem genomes and transcriptomes using next generation sequencing technologies. Assembly of Illumina and 454 sequencing reads resulted in 267 Mb, which accounts for 70\% of estimated size of neem genome. We predicted 44,495 genes in the neem genome, of which 32,278 genes were expressed in neem tissues. Neem genome consists about 32.5\% (87 Mb) of repetitive DNA elements. Neem tree is phylogenetically related to citrus, Citrus sinensis. Comparative analysis anchored 62\% (161 Mb) of assembled neem genomic contigs onto citrus chromomes. Ultrahigh performance liquid chromatography-mass spectrometry-selected reaction monitoring (UHPLC-MS/SRM) method was used to quantify azadirachtin, nimbin, and salanin from neem tissues. Weighted Correlation Network Analysis (WCGNA) of expressed genes and metabolites resulted in identification of possible candidate genes involved in azadirachtin biosynthesis pathway. This study provides genomic, transcriptomic and quantity of top three neem metabolites resource, which will accelerate basic research in neem to understand biochemical pathways.

}, doi = {10.7717/peerj.1066}, author = {Kuravadi, Nagesh A and Yenagi, Vijay and Rangiah, Kannan and Mahesh, H B and Rajamani, Anantharamanan and Shirke, Meghana D and Russiachand, Heikham and Loganathan, Ramya Malarini and Shankara Lingu, Chandana and Siddappa, Shilpa and Ramamurthy, Aishwarya and Sathyanarayana, B N and Gowda, Malali} } @article {501, title = {A quantitative metabolomics peek into planarian regeneration. [Mass spectrometry - Metabolomics]}, journal = {Analyst}, volume = {140}, year = {2015}, month = {2015 May 21}, pages = {3445-64}, abstract = {

The fresh water planarian species Schmidtea mediterranea is an emerging stem cell model because of its capability to regenerate a whole animal from a small piece of tissue. It is one of the best model systems to address the basic mechanisms essential for regeneration. Here, we are interested in studying the roles of various amines, thiols and nucleotides in planarian regeneration, stem cell function and growth. We developed mass spectrometry based quantitative methods and validated the differential enrichment of 35 amines, 7 thiol metabolites and 4 nucleotides from both intact and regenerating planarians. Among the amines, alanine in sexual and asparagine in asexual are the highest (\>1000 ng/mg) in the intact planarians. The levels of thiols such as cysteine and GSH are 651 and 1107 ng mg(-1) in planarians. Among the nucleotides, the level of cGMP is the lowest (0.03 ng mg(-1)) and the level of AMP is the highest (187 ng mg(-1)) in both of the planarian strains. We also noticed increasing levels of amines in both anterior and posterior regenerating planarians. The blastema from day 3 regenerating planarians also showed higher amounts of many amines. Interestingly, the thiol (cysteine and GSH) levels are well maintained during planarian regeneration. This suggests an inherent and effective mechanism to control induced oxidative stress because of the robust regeneration and stem cell proliferation. Like in intact planarians, the level of cGMP is also very low in regenerating planarians. Surprisingly, the levels of amines and thiols in head regenerating blastemas are \~{}3 times higher compared to those for tail regenerating blastemas. Thus our results strongly indicate the potential roles of amines, thiols and nucleotides in planarian regeneration.

}, keywords = {Animals, Calibration, Chromatography, High Pressure Liquid, Limit of Detection, Metabolomics, Planarians, Reference Standards, Regeneration, Reproduction, Asexual, Species Specificity, Tandem Mass Spectrometry}, issn = {1364-5528}, doi = {10.1039/c4an02037e}, author = {Natarajan, Nivedita and Ramakrishnan, Padma and Lakshmanan, Vairavan and Palakodeti, Dasaradhi and Rangiah, Kannan} } @article {502, title = {Sensitive UHPLC-MS/SRM method for quantifying olanzapine metabolites and degradation products from sera}, journal = {Anal. Methods}, volume = {6}, year = {2014}, pages = {5250-5257}, abstract = {

In recent years{,} the use of antipsychotics like olanzapine has increased leading to potentially serious adverse metabolic effects. A sensitive method to quantify olanzapine and its metabolites is therefore highly needed. A stable isotope dilution ultrahigh performance liquid chromatography-mass spectrometry/selected reaction monitoring based quantitative assay has been developed for the simultaneous estimation of olanzapine and its metabolites. This method includes the parent drug olanzapine{,} its metabolites (desmethyl olanzapine and olanzapine-N-oxide) and degradation derived piperazinium chloride{,} lactam and cyclic amine impurities. All analytes were well resolved and showed a linear relationship across a large dynamic range (0.017-1.25 ng mL-1) for all olanzapine metabolites except the lactam{,} in which the linear relationship was demonstrated at concentrations five times higher (0.085-6.25 ng mL-1). All analytes had regression coefficients higher than 0.998{,} accuracies between 92-113\% and low coefficients of variation (0.94 to 9.3\%). The recovery for all of the analytes from the sera matrix was 80 to 115\%. This validated method is suitable for quantifying olanzapine and its metabolites from small volumes of sera samples with great sensitivity.

}, doi = {10.1039/C4AY00450G}, url = {http://dx.doi.org/10.1039/C4AY00450G}, author = {Rangiah, Kannan} } @article {503, title = {Comprehensive analysis of neurotransmitters from regenerating planarian extract using an ultrahigh-performance liquid chromatography/mass spectrometry/selected reaction monitoring method.}, journal = {Rapid Commun Mass Spectrom}, volume = {27}, year = {2013}, month = {2013 Nov 15}, pages = {2439-52}, abstract = {

RATIONALE: Absolute quantification of neurotransmitters (NTs) from biological systems is imperative to track how changes in concentration of active neurochemicals may affect biological behavior. A sensitive method for the absolute quantification of multiple NTs in a single method is highly needed.

METHODS: A stable-isotope dilution ultrahigh-performance liquid chromatography/mass spectrometry/selected reaction monitoring (UHPLC/MS/SRM) assay has been developed for a sensitive and quantitative assessment of NTs in planaria. We used this method for the simultaneous quantification of 16 NTs. All analytes showed a linear relationship between concentrations (0.78-50 ng/mL), regression coefficients higher than 0.97, accuracy (91-109\%) and low coefficients of variation (CVs). The inter-day CVs for the lowest quality controls (1.56 ng/mL) were in the range between 2-11\%.

RESULTS: The levels of most of the NTs were similar in both sexual and asexual planarians except for glutamic acid, which was about two-fold higher in asexual compared to sexual planarians. We identified high levels of serotonin and failed to detect tryptamine suggesting that the pathway essential for the conversion of tryptophan into tryptamine is absent in planarians. Interestingly, we also found high levels of dopamine and L-DOPA in regenerating planarians suggesting their possible role in regeneration.

CONCLUSIONS: For the first time, we developed novel methodology based on UHPLC/MS/SRM and quantified 16 NTs with high sensitivity and specificity from sexual and asexual strains of planarian Schmidtea mediterranea. This method will also have great application in quantifying various NTs with great precision in different model systems.

}, keywords = {Animals, Chromatography, High Pressure Liquid, Glutamic Acid, Limit of Detection, Neurotransmitter Agents, Planarians, Reproduction, Reproduction, Asexual, Serotonin, Spectrometry, Mass, Electrospray Ionization, Tryptamines}, issn = {1097-0231}, doi = {10.1002/rcm.6706}, author = {Rangiah, Kannan and Palakodeti, Dasaradhi} }