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Katelas DA, Cruz-Miron R, Arroyo-Olarte RD, Brouwers JF, Srivastav RK, Gupta N. Phosphatidylserine Synthase in the Endoplasmic Reticulum of Toxoplasma is Essential for its Lytic Cycle in Human Cells. J Lipid Res 2024:100535. [PMID: 38522751 DOI: 10.1016/j.jlr.2024.100535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 03/04/2024] [Accepted: 03/18/2024] [Indexed: 03/26/2024] Open
Abstract
Glycerophospholipids have emerged as a significant contributor to the intracellular growth of pathogenic protist Toxoplasma gondii. Phosphatidylserine (PtdSer) is one such lipid, attributed to the locomotion and motility-dependent invasion and egress events in its acutely-infectious tachyzoite stage. However, the de novo synthesis of PtdSer and the importance of the pathway in tachyzoites remain poorly understood. We show that a base-exchange-type PtdSer synthase (PSS) in the parasite's endoplasmic reticulum produces PtdSer, which is rapidly converted to phosphatidylethanolamine (PtdEtn) by PtdSer decarboxylase (PSD). The PSS-PSD pathway enables the synthesis of several species, including PtdSer (16:0/18:1) and PtdEtn (18:2/20:4, 18:1/18:2 and 18:2/22:5). The PSS-depleted strain exhibited a lower abundance of the major ester-linked PtdEtn species and concurrent accrual of host-derived ether-PtdEtn species. Most phosphatidylthreonine (PtdThr) species- an exclusive natural analog of PtdSer made in the endoplasmic reticulum- were repressed, while PtdSer species remained largely unaltered, likely driven by the serine-exchange reaction of PtdThr synthase in favor of PtdSer upon PSS depletion. Not least, the loss of PSS abrogated the lytic cycle of tachyzoites due to impairment of cell division, motility, and egress. In a nutshell, our data demonstrate the critical role of PSS in the biogenesis of PtdSer and PtdEtn species and its physiologically-essential repurposing for the asexual reproduction of a clinically-relevant intracellular pathogen.
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Affiliation(s)
- Dimitrios Alexandros Katelas
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Intracellular Parasite Education and Research Labs (iPEARL), Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-Pilani), Hyderabad, India
| | - Rosalba Cruz-Miron
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Intracellular Parasite Education and Research Labs (iPEARL), Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-Pilani), Hyderabad, India
| | - Ruben D Arroyo-Olarte
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Carrera de Médico Cirujano y Unidad de Biomedicina (UBIMED), FES-Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Jos F Brouwers
- Analysis Techniques in the Life Sciences, Centre of Expertise Perspective in Health, Avans University of Applied Sciences, Breda, The Netherlands
| | - Ratnesh Kumar Srivastav
- Intracellular Parasite Education and Research Labs (iPEARL), Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-Pilani), Hyderabad, India
| | - Nishith Gupta
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany; Intracellular Parasite Education and Research Labs (iPEARL), Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-Pilani), Hyderabad, India.
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2
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Wang C, Liu L, Wang T, Liu X, Peng W, Srivastav RK, Zhu XQ, Gupta N, Gasser RB, Hu M. H11-induced immunoprotection is predominantly linked to N-glycan moieties during Haemonchus contortus infection. Front Immunol 2022; 13:1034820. [PMID: 36405717 PMCID: PMC9667387 DOI: 10.3389/fimmu.2022.1034820] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/10/2022] [Indexed: 11/23/2022] Open
Abstract
Nematodes are one of the largest groups of animals on the planet. Many of them are major pathogens of humans, animals and plants, and cause destructive diseases and socioeconomic losses worldwide. Despite their adverse impacts on human health and agriculture, nematodes can be challenging to control, because anthelmintic treatments do not prevent re-infection, and excessive treatment has led to widespread drug resistance in nematode populations. Indeed, many nematode species of livestock animals have become resistant to almost all classes of anthelmintics used. Most efforts to develop commercial anti-nematode vaccines (native or recombinant) for use in animals and humans have not succeeded, although one effective (dead) vaccine (Barbervax) has been developed to protect animals against one of the most pathogenic parasites of livestock animals – Haemonchus contortus (the barber’s pole worm). This vaccine contains native molecules, called H11 and H-Gal-GP, derived from the intestine of this blood-feeding worm. In its native form, H11 alone consistently induces high levels (75-95%) of immunoprotection in animals against disease (haemonchosis), but recombinant forms thereof do not. Here, to test the hypothesis that post-translational modification (glycosylation) of H11 plays a crucial role in achieving such high immunoprotection, we explored the N-glycoproteome and N-glycome of H11 using the high-resolution mass spectrometry and assessed the roles of N-glycosylation in protective immunity against H. contortus. Our results showed conclusively that N-glycan moieties on H11 are the dominant immunogens, which induce high IgG serum antibody levels in immunised animals, and that anti-H11 IgG antibodies can confer specific, passive immunity in naïve animals. This work provides the first detailed account of the relevance and role of protein glycosylation in protective immunity against a parasitic nematode, with important implications for the design of vaccines against metazoan parasites.
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Affiliation(s)
- Chunqun Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Lu Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Tianjiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Xin Liu
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Wenjie Peng
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ratnesh Kumar Srivastav
- Department of Biological Sciences, Birla Institute of Technology and Science – Pilani (BITS-P), Hyderabad, India
| | - Xing-Quan Zhu
- College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, China
| | - Nishith Gupta
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Department of Biological Sciences, Birla Institute of Technology and Science – Pilani (BITS-P), Hyderabad, India
- Department of Molecular Parasitology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Robin B. Gasser
- Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
- *Correspondence: Robin B. Gasser, ; Min Hu,
| | - Min Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- *Correspondence: Robin B. Gasser, ; Min Hu,
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Mileshkin LR, Yoong J, Eggins R, Philip J, Brown C, Wright GM, Tognela A, Blinman P, Poon P, Nowak AK, Oar A, Pavlakis N, Walker M, Chong J, Jurkovic H, Srivastav RK, Abdi EA, Mersiades A, Thomas R, Stockler MR. PEARL: A randomised phase 3 trial of palliative care early in advanced lung cancers (ALTG/TOGA 13/008). J Clin Oncol 2022. [DOI: 10.1200/jco.2022.40.16_suppl.12020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
12020 Background: Early referral to palliative care was associated with improved health-related quality of life (HRQL) and overall survival (OS) in a US phase 3 trial in lung cancer patients (pts). International studies in mixed cancer types have reported conflicting results. PEARL aimed to determine whether early referral to palliative care would improve HRQL, OS, and resource use in Australian pts with recently diagnosed, advanced thoracic cancers. Methods: Eligible participants (pts) in this unblinded, multi-centre, randomised, phase 3 trial had advanced thoracic cancers diagnosed within 60 days, and the ability to complete patient-rated outcome measures (PROMS). Pts were randomly allocated to early referral to palliative care (ER) or referral at clinician’s discretion (DR). All pts received standard oncological care. PROMS were completed at baseline, every 3-4 weeks for 6 months, then 6-8 weekly. The primary objective was to determine the frequency of sustained, substantial improvements in HRQL, defined as a 5-point improvement in the FACT-L Trial Outcome Index (TOI) maintained for at least 2 consecutive assessments. Secondary outcomes included OS, documentation of advanced care plan (ACP), PROM scores at 12 weeks, anxiety/depression (PROMIS-ED), lung cancer symptoms (FACT-L), global HRQL (ICECAP-SCM), carer-satisfaction and burden, and understanding of illness and prognosis. The accrual target of 200 gave 80% power (alpha 0.05) to detect an absolute improvement of 20% in the proportion of pts achieving the primary endpoint. Results: 113 pts and 78 carers were recruited when the trial closed for slow accrual. Pt characteristics were well balanced: 88 (75%) had NSCLC, 18 (16%) small cell and 7 (6%) mesothelioma. Median age was 69 (IQR 62-74), 63 (56%) were male; systemic anti-cancer therapy ongoing or planned in 88 (78%). Median follow-up was 30 months. First consultations with a palliative care specialist within 60 days of diagnosis occurred in more pts assigned ER vs DR (57% vs 3.5%). Sustained substantial improvements in FACT-L TOI were reported by similar numbers of pts assigned ER vs DR: 33% vs 32%, p = 0.9. OS was similar among those assigned ER versus DR (median 12 vs 18.4 months, p = 0.11). A similar % had a written advanced care plan at death: 15/40 (39%) vs 15/33 (47%). We found no important differences between arms in global HRQL (ICECAP-SCM), depression/anxiety (PROMIS-ED), lung cancer symptoms (FACT-L), carer satisfaction (FAMCARE-2), carer burden (CRA), or understanding of illness by carers or pts. Conclusions: Early referral to palliative care, compared with discretionary referral, did not improve important outcomes for Australian thoracic cancer pts or carers. Our findings suggest that the palliative care needs of such pts were addressed equally well by delayed referral when clinically indicated, resulting in reduced burden for resource-limited specialist palliative services. Clinical trial information: ACTRN12617000166370.
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Affiliation(s)
- Linda R. Mileshkin
- Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia
| | | | - Renee Eggins
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
| | | | - Chris Brown
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
| | | | | | - Prunella Blinman
- Concord Cancer Centre, Concord Repatriation General Hospital, Concord, NSW, Australia
| | - Peter Poon
- Supportive and Palliative Care Unit, Monash Health, Clayton, VIC, Australia
| | - Anna K. Nowak
- Medical School, University of Western Australia, Perth, Western Australia, Australia
| | - Andrew Oar
- Icon Cancer Centre, Gold Coast University Hospital, Southport, QLD, Australia
| | - Nick Pavlakis
- Royal North Shore Hospital, St. Leonards, NSW, Australia
| | - Mariya Walker
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
| | - Jennifer Chong
- NHMRC Clinical Trials Centre, Camperdown, NSW, Australia
| | - Hannora Jurkovic
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
| | | | - Ehtesham A. Abdi
- The Tweed Hospital, Griffith University Gold Coast, Tweed Heads, NSW, Australia
| | - Antony Mersiades
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
| | - Rajesh Thomas
- Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Martin R. Stockler
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
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4
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Nigam K, Srivastav RK. Notch signaling in oral pre-cancer and oral cancer. Med Oncol 2021; 38:139. [PMID: 34633549 DOI: 10.1007/s12032-021-01593-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/29/2021] [Indexed: 10/20/2022]
Abstract
Notch signaling involves cell to cell contact. It is an ancient signaling mechanism that is conserved throughout the animal kingdom. The basic function of Notch signaling is to decide cell fate and execute asymmetrical division. Notch signaling is indispensable for embryo growth. Aberrant Notch signaling involves in cancer progression by altering cell proliferation rate, tumor micro-environment, stem cell activities. The role of Notch signaling in cancer progression is context-dependent. In breast cancer and T cell lymphoma Notch signaling is highly active, whereas in squamous cell carcinoma (SCC) as oral and skin cancer, the signaling is suppressed. It is believed that in SCC, Notch-mediated tumor growth is due to the cell non-autonomous function. Oral cancer is the 6th most risky cancer worldwide. In many patients, oral cancer is preceded by pre-cancer conditions. In this review, we have summarized the research knowledge related to the role of Notch signaling in oral cancer and pre-cancer conditions and the therapeutic options available targeting different components of Notch pathways.
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Affiliation(s)
- Kumud Nigam
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow, 226028, Uttar Pradesh, India
| | - Ratnesh Kumar Srivastav
- Department of Oral Pathology & Microbiology, King George's Medical University, Lucknow, Uttar Pradesh, 226003, India.
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5
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Nigam K, Gupta S, Gupta OP, Srivastav RK, Singh SP, Sanyal S. Alteration of the risk of pre-oral cancer and cancer in North Indian population by NAT1 and NAT2 polymorphisms genotypes and haplotypes. Eur Arch Otorhinolaryngol 2021; 278:4081-4089. [PMID: 33813602 DOI: 10.1007/s00405-021-06774-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/20/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE The risk of oral cancer is strongly related to consumption of tobacco, smoking and drinking alcohol. N-acetyl transferases 1,2 are phase II metabolic enzymes, metabolize aryl and heterocyclic amines which are present in tobacco. NAT2 slows acetylator phenotype and the genotype is related to reduced ability to detoxify these xenobiotic that are carcinogenic to tissues. The aim of our study to determine the risk of oral cancer as well as oral precancerous lesions in North Indian population with polymorphisms in these two N-acetyl transferases 1,2 genes. MATERIALS AND METHODS A total of 250 patients with pre oral cancer, oral cancer and 250 healthy volunteers were genotypes for the NAT1 and NAT2 gene polymorphisms. Genotypes were identified by PCR and RFLP. Genotype frequencies were evaluated by Chi-square test and risk of disease was estimated by Odds ratio (OR) with 95% confidence interval. RESULT Our results showed that individuals with CT and TT genotypes of NAT1 C > T polymorphism were significantly lower risk of oral diseases (p value = 0.02, OR = 0.60 and p value = 0.04, OR = 0.58, respectively). For NAT2 C > T polymorphism, the TT genotype significantly increased the risk of OSMF (Oral Sub mucous Fibrosis) and Leukoplakia (p value = 0.001, OR = 4.16; p value = 0.002, OR = 4.38, respectively). In contrary, the CC genotype for NAT2 T > C polymorphism increased the risk of OSMF (p value = 0.01, OR = 3.00, 95% CI = 1.31-6.86). CONCLUSION Our study concludes that the NAT1 polymorphism shows protective association with oral diseases and NAT2 polymorphism and haplotypes also influence the susceptibility to oral diseases in North Indian population subjects.
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Affiliation(s)
- Kumud Nigam
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow, Uttar Pradesh, 226028, India.,Department of Oral Pathology & Microbiology, King George's Medical University, Lucknow, Uttar Pradesh, 226 003, India
| | - Shalini Gupta
- Department of Oral Pathology & Microbiology, King George's Medical University, Lucknow, Uttar Pradesh, 226 003, India.
| | | | - Ratnesh Kumar Srivastav
- Department of Oral Pathology & Microbiology, King George's Medical University, Lucknow, Uttar Pradesh, 226 003, India
| | - Saurabh Pratap Singh
- Department of Oral Pathology & Microbiology, King George's Medical University, Lucknow, Uttar Pradesh, 226 003, India
| | - Somali Sanyal
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Lucknow, Uttar Pradesh, 226028, India.
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6
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Coutandin D, Osterburg C, Srivastav RK, Sumyk M, Kehrloesser S, Gebel J, Tuppi M, Hannewald J, Schäfer B, Salah E, Mathea S, Müller-Kuller U, Doutch J, Grez M, Knapp S, Dötsch V. Quality control in oocytes by p63 is based on a spring-loaded activation mechanism on the molecular and cellular level. eLife 2016; 5. [PMID: 27021569 PMCID: PMC4876613 DOI: 10.7554/elife.13909] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/28/2016] [Indexed: 01/07/2023] Open
Abstract
Mammalian oocytes are arrested in the dictyate stage of meiotic prophase I for long
periods of time, during which the high concentration of the p53 family member TAp63α
sensitizes them to DNA damage-induced apoptosis. TAp63α is kept in an inactive and
exclusively dimeric state but undergoes rapid phosphorylation-induced tetramerization
and concomitant activation upon detection of DNA damage. Here we show that the TAp63α
dimer is a kinetically trapped state. Activation follows a spring-loaded mechanism
not requiring further translation of other cellular factors in oocytes and is
associated with unfolding of the inhibitory structure that blocks the tetramerization
interface. Using a combination of biophysical methods as well as cell and ovary
culture experiments we explain how TAp63α is kept inactive in the absence of DNA
damage but causes rapid oocyte elimination in response to a few DNA double strand
breaks thereby acting as the key quality control factor in maternal reproduction. DOI:http://dx.doi.org/10.7554/eLife.13909.001 The irradiation and chemotherapy drugs that are used to destroy cancer cells also
damage healthy cells. Germ cells – from which egg cells and sperm cells develop – are
particularly vulnerable as they contain sensitive quality control mechanisms that
kill any cell that contain damaged DNA. Consequently, after surviving cancer many
patients are confronted with infertility. A protein called p63, which is closely related to another protein that suppresses the
formation of tumors, plays an essential role in detecting and responding to DNA
damage. In immature egg cells (also known as oocytes), p63 mostly exists in an
inactive form. The protein then switches to an active form when DNA damage is
detected to trigger the process of cell self-destruction. Now, Coutandin, Osterburg et al. have performed a range of biochemical, biophysical
and cell culture experiments to study how p63 is kept in its inactive form in the
oocytes of mice. The experiments showed that in the inactive form, the two ends of
the protein form a sheet that closes a key site on the protein and prevents it from
changing into its active form. However, this closed form can be thought of as being
like a spring-loaded trap – it doesn’t take much energy to spring the trap and open
the protein into its active form. Once this change has occurred, it is
irreversible. Coutandin, Osterburg et al. also found that the oocytes of mice already contain all
the proteins necessary to activate p63. This means that once the switch to the active
form is triggered there is no delay waiting for other proteins to be made, which
makes oocytes extremely sensitive to DNA damage. Further work is now needed to
investigate the exact molecular mechanisms behind the activation of p63. DOI:http://dx.doi.org/10.7554/eLife.13909.002
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Affiliation(s)
- Daniel Coutandin
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
| | - Christian Osterburg
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
| | - Ratnesh Kumar Srivastav
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
| | - Manuela Sumyk
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
| | - Sebastian Kehrloesser
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
| | - Jakob Gebel
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
| | - Marcel Tuppi
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
| | - Jens Hannewald
- MS-DTB-C Protein Purification, Merck KGaA, Darmstadt, Germany
| | - Birgit Schäfer
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
| | - Eidarus Salah
- Nuffield Department of Medicine, Structural Genomics Consortium, University of Oxford, Oxford, United Kingdom
| | - Sebastian Mathea
- Nuffield Department of Medicine, Structural Genomics Consortium, University of Oxford, Oxford, United Kingdom
| | | | - James Doutch
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot, United Kingdom
| | | | - Stefan Knapp
- Nuffield Department of Medicine, Structural Genomics Consortium, University of Oxford, Oxford, United Kingdom.,Institute for Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany.,Buchmann Institute for Molecular Life Science, Goethe University, Frankfurt, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt, Germany
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7
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Nölle A, Zeug A, van Bergeijk J, Tönges L, Gerhard R, Brinkmann H, Al Rayes S, Hensel N, Schill Y, Apkhazava D, Jablonka S, O'mer J, Srivastav RK, Baasner A, Lingor P, Wirth B, Ponimaskin E, Niedenthal R, Grothe C, Claus P. The spinal muscular atrophy disease protein SMN is linked to the Rho-kinase pathway via profilin. Hum Mol Genet 2011; 20:4865-78. [PMID: 21920940 DOI: 10.1093/hmg/ddr425] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Spinal muscular atrophy (SMA), a frequent neurodegenerative disease, is caused by reduced levels of functional survival of motoneuron (SMN) protein. SMN is involved in multiple pathways, including RNA metabolism and splicing as well as motoneuron development and function. Here we provide evidence for a major contribution of the Rho-kinase (ROCK) pathway in SMA pathogenesis. Using an in vivo protein interaction system based on SUMOylation of proteins, we found that SMN is directly interacting with profilin2a. Profilin2a binds to a stretch of proline residues in SMN, which is heavily impaired by a novel SMN2 missense mutation (S230L) derived from a SMA patient. In different SMA models, we identified differential phosphorylation of the ROCK-downstream targets cofilin, myosin-light chain phosphatase and profilin2a. We suggest that hyper-phosphorylation of profilin2a is the molecular link between SMN and the ROCK pathway repressing neurite outgrowth in neuronal cells. Finally, we found a neuron-specific increase in the F-/G-actin ratio that further support the role of actin dynamics in SMA pathogenesis.
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Affiliation(s)
- Anna Nölle
- Institute for Neuroanatomy, Hannover Medical School, Hannover 30623, Germany
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8
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Shrimali V, Anand RS, Kumar V, Srivastav RK. Medical feature based evaluation of structuring elements for morphological enhancement of ultrasonic images. J Med Eng Technol 2009; 33:158-69. [PMID: 19205994 DOI: 10.1080/03091900802133939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This paper investigates the use of morphology-based nonlinear filters, and performs deterministic and statistical analysis of the linear combinations of the filters for the image quality enhancement of B-mode ultrasound images. The fact that the structuring element shape greatly influences the output of the filter, is one of the most important features of mathematical morphology. The present reported work comparatively evaluates the structuring elements for morphological liver image enhancement and verifies the hypothesis that the speckles visible in US images are short, slightly 'banana-shaped' white lines. Initially, five different liver images were morphologically filtered using 10 different structuring elements and then the filtered images were assessed quantitatively. Image quality parameters such as peak signal-to-noise ratio, mean square error and correlation coefficient have been used to evaluate the performance of the morphological filters with different structuring elements. To endorse the observation of the quantitative analysis, the filtered images were then evaluated qualitatively, based on the image features looked into by the medical fraternity. The evaluation parameters have been taken on the basis of the suggestions made by a group of radiologists. The results of the processed images were then evaluated by a different group of radiologists. A multi-point rank order method has been used to identify small differences or trends in observation. The subjective analysis by radiologists indicates that morphological filter using line shaped structuring element with length 2 performs better than the other structuring elements. These observations were found to be in line with the observations of quantitative analysis.
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Affiliation(s)
- V Shrimali
- Department of Electrical Engineering, Indian Institute of Technology, Roorkee, Uttarakhand, India.
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9
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Goel D, Mittal M, Bansal KK, Srivastav RK, Singhal A. Sleep seizures versus wake seizures: A comparative hospital study on clinical, electroencephalographic and radiological profile. Neurol India 2008; 56:151-5. [DOI: 10.4103/0028-3886.41992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Goel D, Bansal KK, Gupta C, Kishor S, Srivastav RK, Raghuvanshi S, Behari S. Why we missed an early diagnosis of cerebral aspergilloma: Lesson from a case. Ann Indian Acad Neurol 2007. [DOI: 10.4103/0972-2327.37821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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11
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Karmodiya K, Srivastav RK, Surolia N. Production and purification of refolded recombinant Plasmodium falciparum β-ketoacyl-ACP reductase from inclusion bodies. Protein Expr Purif 2005; 42:131-6. [PMID: 15939298 DOI: 10.1016/j.pep.2005.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 02/11/2005] [Accepted: 02/11/2005] [Indexed: 11/21/2022]
Abstract
A recombinant form of Plasmodium falciparum beta-ketoacyl-ACP reductase (PfFabG) was overexpressed in Escherichia coli BL-21 codon plus (DE3). The resulting insoluble inclusion bodies were separated from cellular debris by extensive washing with buffer containing 0.05% Tween 20 and solubilized by homogenization with 8 M urea. Attempts to refold PfFabG from solubilized inclusion bodies employing Rotofor (separation based on different pIs of proteins in a mixture) followed by Ni(2+) or cation exchange chromatography were not successful either by bringing down the urea concentration instantaneously, stepwise, or by dialysis. Denatured PfFabG was therefore initially purified by cation exchange chromatography and was then correctly refolded at a final concentration of 100-200 microg/ml in a 20 mM Na-acetate buffer, pH 5.3, with 300 mM NaCl, 10% glycerol, and 0.05% Tween 20. The protein was found to be properly folded only in the presence of the cofactor NADPH and salt at a concentration 300 mM by drop dilution method at 2-8 degrees C for 12 h. The purified final product was >98% pure by denaturing gel electrophoresis. The purified protein was biologically active in a standard enzymatic assay using acetoacetyl-CoA as a substrate. The enzyme was found to be stable up to fourth day of purification and glycerol was found to stabilize enzyme activity for several weeks, during storage. This effort paves the way for elucidation of the structure-function correlations for PfFabG as well as exploration of the enzyme for developing inhibitors against it for combating malaria.
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Affiliation(s)
- Krishanpal Karmodiya
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India
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Saxena AK, Singh KP, Nagle SL, Gupta BN, Ray PK, Srivastav RK, Tewari SP, Singh R. Effect of exposure to toxic gas on the population of Bhopal: Part IV--Immunological and chromosomal studies. Indian J Exp Biol 1988; 26:173-6. [PMID: 3397120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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