@article {2423, title = {Lysate-based pipeline to characterize microtubule-associated proteins uncovers unique microtubule behaviours.}, journal = {Nat Cell Biol}, volume = {24}, year = {2022}, month = {2022 Feb}, pages = {253-267}, abstract = {

The microtubule cytoskeleton forms complex macromolecular assemblies with a range of microtubule-associated proteins (MAPs) that have fundamental roles in cell architecture, division and motility. Determining how an individual MAP modulates microtubule behaviour is an important step in understanding the physiological roles of various microtubule assemblies. To characterize how MAPs control microtubule properties and functions, we developed an approach allowing for medium-throughput analyses of MAPs in cell-free conditions using lysates of mammalian cells. Our pipeline allows for quantitative as well as ultrastructural analyses of microtubule-MAP assemblies. Analysing 45 bona fide and potential mammalian MAPs, we uncovered previously unknown activities that lead to distinct and unique microtubule behaviours such as microtubule coiling or hook formation, or liquid-liquid phase separation along the microtubule lattice that initiates microtubule branching. We have thus established a powerful tool for a thorough characterization of a wide range of MAPs and MAP variants, thus opening avenues for the determination of mechanisms underlying their physiological roles and pathological implications.

}, issn = {1476-4679}, doi = {10.1038/s41556-021-00825-4}, author = {Jijumon, A S and Bodakuntla, Satish and Genova, Mariya and Bangera, Mamata and Sackett, Violet and Besse, Laetitia and Maksut, Fatlinda and Henriot, Veronique and Magiera, Maria M and Sirajuddin, Minhajuddin and Janke, Carsten} } @article {2068, title = {Lithium response in bipolar disorder correlates with improved cell viability of patient derived cell lines.}, journal = {Sci Rep}, volume = {10}, year = {2020}, month = {2020 May 04}, pages = {7428}, abstract = {

Lithium is an effective, well-established treatment for bipolar disorder (BD). However, the mechanisms of its action, and reasons for variations in clinical response, are unclear. We used neural precursor cells (NPCs) and lymphoblastoid cell lines (LCLs), from BD patients characterized for clinical response to lithium (using the "Alda scale" and "NIMH Retrospective Life chart method"), to interrogate cellular phenotypes related to both disease and clinical lithium response. NPCs from two biologically related BD patients who differed in their clinical response to lithium were compared with healthy controls. RNA-Seq and analysis, mitochondrial membrane potential (MMP), cell viability, and cell proliferation parameters were assessed, with and without in vitro lithium. These parameters were also examined in LCLs from 25 BD patients (16 lithium responders and 9 non-responders), and 12 controls. MMP was lower in both NPCs and LCLs from BD; but it was reversed with in vitro lithium only in LCLs, and this was unrelated to clinical lithium response. The higher cell proliferation observed in BD was unaffected by in vitro lithium. Cell death was greater in BD. However, LCLs from clinical lithium responders could be rescued by addition of in vitro lithium. In vitro lithium also enhanced BCL2 and GSK3B expression in these cells. Our findings indicate cellular phenotypes related to the disease (MMP, cell proliferation) in both NPCs and LCLs; and those related to clinical lithium response (cell viability, BCL2/GSK3B expression) in LCLs.

}, issn = {2045-2322}, doi = {10.1038/s41598-020-64202-1}, author = {Paul, Pradip and Iyer, Shruti and Nadella, Ravi Kumar and Nayak, Rashmitha and Chellappa, Anirudh S and Ambardar, Sheetal and Sud, Reeteka and Sukumaran, Salil K and Purushottam, Meera and Jain, Sanjeev and Viswanath, Biju} } @article {1154, title = {Life as an early career researcher: interview with Minhaj Sirajuddin.}, journal = {Future Sci OA}, volume = {4}, year = {2018}, month = {2018 Feb}, pages = {FSO258}, abstract = {

Minhaj Sirajuddin is currently an Assistant Investigator at the Institute for Stem Cell Biology and Regenerative Medicine (InStem), Bangalore, India. His lab works on understanding biological motility mediated by cytoskeleton elements using biophysics and cell biology. Previously his tenures were at UCSF (CA, USA) for his postdoctoral work and the Max Planck Institute (Dortmund, Germany) for his PhD. Minhaj is a recipient of Wellcome Trust - DBT India Alliance Intermediate Fellowship and the EMBO Young Investigator Award. He was also a finalist in the inaugural Future Science Early Career Research Award.

}, issn = {2056-5623}, doi = {10.4155/fsoa-2017-0106}, author = {Sirajuddin, Minhaj} } @article {1189, title = {Local injections of tacrolimus-loaded hydrogel reduce systemic immunosuppression-related toxicity in vascularized composite allotransplantation.}, journal = {Transplantation}, year = {2018}, month = {2018 May 23}, abstract = {

BACKGROUND: Routine application of vascularized composite allotransplantation (VCA) is hampered by immunosuppression-related health comorbidities. To mitigate these we developed an inflammation-responsive hydrogel for local immunosuppression. Here we report on its long-term effect on graft survival, immunological and toxicological impact.

METHODS: Brown Norway-to-Lewis rat hind limb transplantations were treated either systemically with daily injections of 1 mg/kg tacrolimus or with subcutaneous intragraft injections of hydrogel containing 7 mg tacrolimus, every 70 days. Animals were monitored for rejection or other pathology for 280 days. Systemic and graft tacrolimus levels, regulatory T cells, and donor cell chimerism were measured periodically. At endpoint, markers for kidney, liver and metabolic state were compared to na{\"\i}ve age-matched rats.

RESULTS: Both daily systemic tacrolimus and subcutaneous intragraft tacrolimus hydrogel at 70 day intervals were able to sustain graft survival for \>280 days in 5 out of 6 recipients. In the hydrogel group, 1 graft progressed to grade 3 rejection at postoperative day (POD) 149. In systemic tacrolimus group, 1 animal was euthanized due to lymphoma on POD 275. Hydrogel treatment provided stable graft- and reduced systemic tacrolimus levels, and a 4 times smaller total tacrolimus dose compared with systemic immunosuppression. Hydrogel-treated animals showed preserved kidney function, absence of malignancies or opportunistic infections and increased hematopoietic chimerism compared to systemic immunosuppression.

CONCLUSIONS: Our findings demonstrate that localized immunosuppression with tacrolimus hydrogel is a long-term safe and reliable treatment. It may reduce the burden of systemic immunosuppression in VCA, potentially boosting the clinical application of this surgical intervention.

}, issn = {1534-6080}, doi = {10.1097/TP.0000000000002283}, author = {Dzhonova, Dzhuliya V and Olariu, Radu and Leckenby, Jonathan and Banz, Yara and Prost, Jean-Christophe and Dhayani, Ashish and Vemula, Praveen K and Voegelin, Esther and Taddeo, Adriano and Rieben, Robert} } @article {1592, title = {Local release of tacrolimus from hydrogel-based drug delivery system is controlled by inflammatory enzymes in vivo and can be monitored non-invasively using in vivo imaging.}, journal = {PLoS One}, volume = {13}, year = {2018}, month = {2018}, pages = {e0203409}, abstract = {

BACKGROUND: Local drug delivery systems that adjust the release of immunosuppressive drug in response to the nature and intensity of inflammation represent a promising approach to reduce systemic immunosuppression and its side effects in allotransplantation. Here we aimed to demonstrate that release of tacrolimus from triglycerol monostearate hydrogel is inflammation-dependent in vivo. We further report that by loading the hydrogel with a near-infrared dye, it is possible to monitor drug release non-invasively in an in vivo model of vascularized composite allotransplantation.

MATERIALS AND METHODS: Inflammation was induced by local challenge with lipopolysaccharides in na{\"\i}ve rats 7 days after injection of tacrolimus-loaded hydrogel in the hind limb. Tacrolimus levels in blood and tissues were measured at selected time points. A near-infrared dye was encapsulated in the hydrogel together with tacrolimus in order to monitor hydrogel deposits and drug release in vitro and in vivo in a model of vascularized composite allotransplantation.

RESULTS: Injection of lipopolysaccharides led to increased blood and skin tacrolimus levels (p = 0.0076, day 7 vs. day 12 in blood, and p = 0.0007 in treated limbs, 48 h after injection compared to controls). Moreover, lipopolysaccharides-injected animals had higher tacrolimus levels in treated limbs compared to contralateral limbs (p = 0.0003 for skin and p = 0.0053 for muscle). Imaging of hydrogel deposits and tacrolimus release was achieved by encapsulating near-infrared dye in the hydrogel for 160 days. The correlation of tacrolimus and near-infrared dye release from hydrogel was R2 = 0.6297 and R2 = 0.5619 in blood and grafts of transplanted animals respectively and R2 = 0.6066 in vitro.

CONCLUSIONS: Here we demonstrate the inflammation-responsiveness of a tacrolimus-loaded hydrogel in vivo. Moreover, we show that encapsulating a near-infrared dye in the hydrogel provides a reliable correlation of tacrolimus and dye release from the hydrogel, and an accessible non-invasive method for monitoring drug release from hydrogel deposits.

}, keywords = {Animals, Drug Delivery Systems, Humans, Hydrogels, Immunosuppressive Agents, Inflammation, Male, Rats, Rats, Inbred BN, Rats, Inbred Lew, Tacrolimus}, issn = {1932-6203}, doi = {10.1371/journal.pone.0203409}, author = {Dzhonova, Dzhuliya and Olariu, Radu and Leckenby, Jonathan and Dhayani, Ashish and Vemula, Praveen Kumar and Prost, Jean-Christophe and Banz, Yara and Taddeo, Adriano and Rieben, Robert} } @article {1172, title = {Low Oxygen Tension Enhances Expression of Myogenic Genes When Human Myoblasts Are Activated from G0 Arrest.}, journal = {PLoS One}, volume = {11}, year = {2016}, month = {2016}, pages = {e0158860}, abstract = {

OBJECTIVES: Most cell culture studies have been performed at atmospheric oxygen tension of 21\%, however the physiological oxygen tension is much lower and is a factor that may affect skeletal muscle myoblasts. In this study we have compared activation of G0 arrested myoblasts in 21\% O2 and in 1\% O2 in order to see how oxygen tension affects activation and proliferation of human myoblasts.

MATERIALS AND METHODS: Human myoblasts were isolated from skeletal muscle tissue and G0 arrested in vitro followed by reactivation at 21\% O2 and 1\% O2. The effect was assesses by Real-time RT-PCR, immunocytochemistry and western blot.

RESULTS AND CONCLUSIONS: We found an increase in proliferation rate of myoblasts when activated at a low oxygen tension (1\% O2) compared to 21\% O2. In addition, the gene expression studies showed up regulation of the myogenesis related genes PAX3, PAX7, MYOD, MYOG (myogenin), MET, NCAM, DES (desmin), MEF2A, MEF2C and CDH15 (M-cadherin), however, the fraction of DES and MYOD positive cells was not increased by low oxygen tension, indicating that 1\% O2 may not have a functional effect on the myogenic response. Furthermore, the expression of genes involved in the TGFβ, Notch and Wnt signaling pathways were also up regulated in low oxygen tension. The differences in gene expression were most pronounced at day one after activation from G0-arrest, thus the initial activation of myoblasts seemed most sensitive to changes in oxygen tension. Protein expression of HES1 and β-catenin indicated that notch signaling may be induced in 21\% O2, while the canonical Wnt signaling may be induced in 1\% O2 during activation and proliferation of myoblasts.

}, keywords = {Adolescent, Cell Cycle Checkpoints, Cell Hypoxia, Cell Proliferation, Cell Separation, Cells, Cultured, Down-Regulation, Female, Gene Expression Regulation, Humans, Ki-67 Antigen, Male, Muscle Development, Muscle Proteins, Myoblasts, Oxygen, Receptors, Notch, Resting Phase, Cell Cycle, Transforming Growth Factor beta, Wnt Signaling Pathway, Young Adult}, issn = {1932-6203}, doi = {10.1371/journal.pone.0158860}, author = {Sellathurai, Jeeva and Nielsen, Joachim and Hejb{\o}l, Eva Kildall and J{\o}rgensen, Louise Helskov and Dhawan, Jyotsna and Nielsen, Michael Friberg Bruun and Schr{\o}der, Henrik Daa} }