Mehta S

References (4)

Title : Insights into ultra-low affinity lipase-antibody noncovalent complex binding mechanisms - Hecht_2022_MAbs_14_2135183
Author(s) : Hecht ES , Mehta S , Wecksler AT , Aguilar B , Swanson N , Phung W , Dubey Kelsoe A , Benner WH , Tesar D , Kelley RF , Sandoval W , Sreedhara A
Ref : MAbs , 14 :2135183 , 2022
Abstract : Detection of host cell protein (HCP) impurities is critical to ensuring that recombinant drug products, including monoclonal antibodies (mAbs), are safe. Mechanistic characterization as to how HCPs persist in drug products is important to refining downstream processing. It has been hypothesized that weak lipase-mAb interactions enable HCP lipases to evade drug purification processes. Here, we apply state-of-the-art methods to establish lipase-mAb binding mechanisms. First, the mass spectrometry (MS) approach of fast photochemical oxidation of proteins was used to elucidate putative binding regions. The CH1 domain was identified as a conserved interaction site for IgG1 and IgG4 mAbs against the HCPs phospholipase B-like protein (PLBL2) and lysosomal phospholipase A2 (LPLA2). Rationally designed mutations in the CH1 domain of the IgG4 mAb caused a 3- to 70-fold K(D) reduction against PLBL2 by surface plasmon resonance (SPR). LPLA2-IgG4 mutant complexes, undetected by SPR and studied using native MS collisional dissociation experiments, also showed significant complex disruption, from 16% to 100%. Native MS and ion mobility (IM) determined complex stoichiometries for four lipase-IgG4 complexes and directly interrogated the enrichment of specific lipase glycoforms. Confirmed with time-course and exoglycosidase experiments, deglycosylated lipases prevented binding, and low-molecular-weight glycoforms promoted binding, to mAbs. This work demonstrates the value of integrated biophysical approaches to characterize micromolar affinity complexes. It is the first in-depth structural report of lipase-mAb binding, finding roles for the CH1 domain and lipase glycosylation in mediating binding. The structural insights gained offer new approaches for the bioengineering of cells or mAbs to reduce HCP impurity levels.Abbreviations: CAN, Acetonitrile; AMAC, Ammonium acetate; BFGS, Broyden-Fletcher-Goldfarb-Shanno; CHO, Chinese Hamster Ovary; K(D), Dissociation constant; DTT, Dithiothreitol; ELISA, Enzyme-linked immunosorbent assay; FPOP, Fast photochemical oxidation of proteins; FA, Formic acid; F(ab'), Fragment antibodies; HCP, Host cell protein; IgG, Immunoglobulin; IM, Ion mobility; LOD, Lower limit of detection; LPLA2, Lysosomal phospholipase A2; Man, Mannose; MS, Mass spectrometry; MeOH, Methanol; MST, Microscale thermophoresis; mAbs, Monoclonal antibodies; PPT1, Palmitoyl protein thioesterase; ppm, Parts per million; PLBL2, Phospholipase B-like protein; PLD3, Phospholipase D3; PS-20, Polysorbate-20; SP, Sphingomyelin phosphodiesterase; SPR, Surface plasmon resonance; TFA, Trifluoroacetic acid.
ESTHER : Hecht_2022_MAbs_14_2135183
PubMedSearch : Hecht_2022_MAbs_14_2135183
PubMedID: 36284469

Title : Pharmacological interventions for the treatment of delirium in critically ill adults - Burry_2019_Cochrane.Database.Syst.Rev_9_CD011749
Author(s) : Burry L , Hutton B , Williamson DR , Mehta S , Adhikari NK , Cheng W , Ely EW , Egerod I , Fergusson DA , Rose L
Ref : Cochrane Database Syst Rev , 9 :CD011749 , 2019
Abstract : BACKGROUND: Although delirium is typically an acute reversible cognitive impairment, its presence is associated with devastating impact on both short-term and long-term outcomes for critically ill patients. Advances in our understanding of the negative impact of delirium on patient outcomes have prompted trials evaluating multiple pharmacological interventions. However, considerable uncertainty surrounds the relative benefits and safety of available pharmacological interventions for this population. OBJECTIVES: Primary objective1. To assess the effects of pharmacological interventions for treatment of delirium on duration of delirium in critically ill adults with confirmed or documented high risk of deliriumSecondary objectivesTo assess the following:1. effects of pharmacological interventions on delirium-free and coma-free days; days with coma; delirium relapse; duration of mechanical ventilation; intensive care unit (ICU) and hospital length of stay; mortality; and long-term outcomes (e.g. cognitive; discharge disposition; health-related quality of life); and2. the safety of such treatments for critically ill adult patients. SEARCH METHODS: We searched the following databases from their inception date to 21 March 2019: Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Embase Classic+Embase, and PsycINFO using the Ovid platform. We also searched the Cochrane Library on Wiley, the International Prospective Register of Systematic Reviews (PROSPERO) (, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science. We performed a grey literature search of relevant databases and websites using the resources listed in Grey Matters developed by the Canadian Agency for Drugs and Technologies in Health (CADTH). We also searched trial registries and abstracts from annual scientific critical care and delirium society meetings. SELECTION CRITERIA: We sought randomized controlled trials (RCTs), including quasi-RCTs, of any pharmacological (drug) for treatment of delirium in critically ill adults. The drug intervention was to be compared to another active drug treatment, placebo, or a non-pharmacological intervention (e.g. mobilization). We did not apply any restrictions in terms of drug class, dose, route of administration, or duration of delirium or drug exposure. We defined critically ill patients as those treated in an ICU of any specialty (e.g. burn, cardiac, medical, surgical, trauma) or high-dependency unit. DATA COLLECTION AND ANALYSIS: Two review authors independently identified studies from the search results; four review authors (in pairs) performed data extraction and assessed risk of bias independently. We performed data synthesis through pairwise meta-analysis and network meta-analysis (NMA). Our hypothetical network structure was designed to be analysed at the drug class level and illustrated a network diagram of 'nodes' (i.e. drug classes) and 'edges' (i.e. comparisons between different drug classes from existing trials), thus describing a treatment network of all possible comparisons between drug classes. We assessed the quality of the body of evidence according to GRADE, as very low, low, moderate, or high. MAIN RESULTS: We screened 7674 citations, from which 14 trials with 1844 participants met our inclusion criteria. Ten RCTs were placebo-controlled, and four reported comparisons of different drugs. Drugs examined in these trials were the following: antipsychotics (n = 10), alpha2 agonists (n = 3; all dexmedetomidine), statins (n = 2), opioids (n = 1; morphine), serotonin antagonists (n = 1; ondansetron), and cholinesterase (CHE) inhibitors (n = 1; rivastigmine). Only one of these trials consistently used non-pharmacological interventions that are known to improve patient outcomes in both intervention and control groups.Eleven studies (n = 1153 participants) contributed to analysis of the primary outcome. Results of the NMA showed that the intervention with the smallest ratio of means (RoM) (i.e. most preferred) compared with placebo was the alpha2 agonist dexmedetomidine (0.58; 95% credible interval (CrI) 0.26 to 1.27; surface under the cumulative ranking curve (SUCRA) 0.895; moderate-quality evidence). In order of descending SUCRA values (best to worst), the next best interventions were atypical antipsychotics (RoM 0.80, 95% CrI 0.50 to 1.11; SUCRA 0.738; moderate-quality evidence), opioids (RoM 0.88, 95% CrI 0.37 to 2.01; SUCRA 0.578; very-low quality evidence), and typical antipsychotics (RoM 0.96, 95% CrI 0.64 to1.36; SUCRA 0.468; high-quality evidence).The NMAs of multiple secondary outcomes revealed that only the alpha2 agonist dexmedetomidine was associated with a shorter duration of mechanical ventilation (RoM 0.55, 95% CrI 0.34 to 0.89; moderate-quality evidence), and the CHE inhibitor rivastigmine was associated with a longer ICU stay (RoM 2.19, 95% CrI 1.47 to 3.27; moderate-quality evidence). Adverse events often were not reported in these trials or, when reported, were rare; pair-wise analysis of QTc prolongation in seven studies did not show significant differences between antipsychotics, ondansetron, dexmedetomidine, and placebo. AUTHORS' CONCLUSIONS: We identified trials of varying quality that examined six different drug classes for treatment of delirium in critically ill adults. We found evidence that the alpha2 agonist dexmedetomidine may shorten delirium duration, although this small effect (compared with placebo) was seen in pairwise analyses based on a single study and was not seen in the NMA results. Alpha2 agonists also ranked best for duration of mechanical ventilation and length of ICU stay, whereas the CHE inhibitor rivastigmine was associated with longer ICU stay. We found no evidence of a difference between placebo and any drug in terms of delirium-free and coma-free days, days with coma, physical restraint use, length of stay, long-term cognitive outcomes, or mortality. No studies reported delirium relapse, resolution of symptoms, or quality of life. The ten ongoing studies and the six studies awaiting classification that we identified, once published and assessed, may alter the conclusions of the review.
ESTHER : Burry_2019_Cochrane.Database.Syst.Rev_9_CD011749
PubMedSearch : Burry_2019_Cochrane.Database.Syst.Rev_9_CD011749
PubMedID: 31479532

Title : A comparison of whole-genome shotgun-derived mouse chromosome 16 and the human genome - Mural_2002_Science_296_1661
Author(s) : Mural RJ , Adams MD , Myers EW , Smith HO , Miklos GL , Wides R , Halpern A , Li PW , Sutton GG , Nadeau J , Salzberg SL , Holt RA , Kodira CD , Lu F , Chen L , Deng Z , Evangelista CC , Gan W , Heiman TJ , Li J , Li Z , Merkulov GV , Milshina NV , Naik AK , Qi R , Shue BC , Wang A , Wang J , Wang X , Yan X , Ye J , Yooseph S , Zhao Q , Zheng L , Zhu SC , Biddick K , Bolanos R , Delcher AL , Dew IM , Fasulo D , Flanigan MJ , Huson DH , Kravitz SA , Miller JR , Mobarry CM , Reinert K , Remington KA , Zhang Q , Zheng XH , Nusskern DR , Lai Z , Lei Y , Zhong W , Yao A , Guan P , Ji RR , Gu Z , Wang ZY , Zhong F , Xiao C , Chiang CC , Yandell M , Wortman JR , Amanatides PG , Hladun SL , Pratts EC , Johnson JE , Dodson KL , Woodford KJ , Evans CA , Gropman B , Rusch DB , Venter E , Wang M , Smith TJ , Houck JT , Tompkins DE , Haynes C , Jacob D , Chin SH , Allen DR , Dahlke CE , Sanders R , Li K , Liu X , Levitsky AA , Majoros WH , Chen Q , Xia AC , Lopez JR , Donnelly MT , Newman MH , Glodek A , Kraft CL , Nodell M , Ali F , An HJ , Baldwin-Pitts D , Beeson KY , Cai S , Carnes M , Carver A , Caulk PM , Center A , Chen YH , Cheng ML , Coyne MD , Crowder M , Danaher S , Davenport LB , Desilets R , Dietz SM , Doup L , Dullaghan P , Ferriera S , Fosler CR , Gire HC , Gluecksmann A , Gocayne JD , Gray J , Hart B , Haynes J , Hoover J , Howland T , Ibegwam C , Jalali M , Johns D , Kline L , Ma DS , MacCawley S , Magoon A , Mann F , May D , McIntosh TC , Mehta S , Moy L , Moy MC , Murphy BJ , Murphy SD , Nelson KA , Nuri Z , Parker KA , Prudhomme AC , Puri VN , Qureshi H , Raley JC , Reardon MS , Regier MA , Rogers YH , Romblad DL , Schutz J , Scott JL , Scott R , Sitter CD , Smallwood M , Sprague AC , Stewart E , Strong RV , Suh E , Sylvester K , Thomas R , Tint NN , Tsonis C , Wang G , Williams MS , Williams SM , Windsor SM , Wolfe K , Wu MM , Zaveri J , Chaturvedi K , Gabrielian AE , Ke Z , Sun J , Subramanian G , Venter JC , Pfannkoch CM , Barnstead M , Stephenson LD
Ref : Science , 296 :1661 , 2002
Abstract : The high degree of similarity between the mouse and human genomes is demonstrated through analysis of the sequence of mouse chromosome 16 (Mmu 16), which was obtained as part of a whole-genome shotgun assembly of the mouse genome. The mouse genome is about 10% smaller than the human genome, owing to a lower repetitive DNA content. Comparison of the structure and protein-coding potential of Mmu 16 with that of the homologous segments of the human genome identifies regions of conserved synteny with human chromosomes (Hsa) 3, 8, 12, 16, 21, and 22. Gene content and order are highly conserved between Mmu 16 and the syntenic blocks of the human genome. Of the 731 predicted genes on Mmu 16, 509 align with orthologs on the corresponding portions of the human genome, 44 are likely paralogous to these genes, and 164 genes have homologs elsewhere in the human genome; there are 14 genes for which we could find no human counterpart.
ESTHER : Mural_2002_Science_296_1661
PubMedSearch : Mural_2002_Science_296_1661
PubMedID: 12040188
Gene_locus related to this paper: mouse-ABH15 , mouse-Ces3b , mouse-Ces4a , mouse-dpp4 , mouse-FAP , mouse-Lipg , mouse-Q8C1A9 , mouse-rbbp9 , mouse-SERHL , mouse-SPG21 , mouse-w4vsp6

Title : Distribution of ten laminin chains in dystrophic and regenerating muscles - Patton_1999_Neuromuscul.Disord_9_423
Author(s) : Patton BL , Connoll AM , Martin PT , Cunningham JM , Mehta S , Pestronk A , Miner JH , Sanes JR
Ref : Neuromuscular Disorders , 9 :423 , 1999
Abstract : Using immunohistochemical methods, we assessed the distribution of all 10 known laminin chains (alpha1-5, beta1-3, gamma1 and gamma2) in skeletal muscles from patients with Duchenne, congenital, limb girdle, or Emery-Dreifuss muscular dystrophies. The alpha2, beta1 and gamma1 chains were abundant in the basal lamina surrounding muscle fibers in normal controls; alpha1, alpha3-alpha5, beta3, and gamma2 were undetectable; and beta2 was present at a low level. Compared to controls, levels of the alpha5 chain were increased in muscles from many dystrophic patients; levels of beta1 were reduced and/or levels of beta2 were increased in a minority. However, these changes were neither specific for, nor consistent within, diagnostic categories. In contrast, levels of alpha4 were increased in muscles from all patients with alpha2 laminin (merosin)-deficient congenital muscular dystrophy. Loss of alpha2 laminin in congenital dystrophy is disease-specific but some other changes in laminin isoform expression in dystrophic muscles could be secondary consequences of myopathy, denervation, regeneration or immaturity. To distinguish among these possibilities, we compared the laminins of embryonic, denervated, regenerating, and mutant mouse muscles with those in normal adult muscle. Embryonic muscle basal lamina contained alpha4 and alpha5 along with alpha2, and regenerating muscle re-expressed alpha5 but not alpha4. Levels of alpha5 but not alpha4 were increased in dystrophin (mdx) mutants and in dystrophin/utrophin double mutants (mdx:utrn -/-), models for Duchenne dystrophy. In contrast, laminin alpha4 was upregulated more than alpha5 in muscles of laminin alpha2 mutant mice (dy/dy; a model for alpha2-deficient congenital dystrophy). Based on these results, we hypothesize that the expression of alpha5 in many dystrophies reflects the regenerative process, whereas the selective expression of alpha4 in alpha2-deficient muscle is a specific compensatory response to loss of alpha2.
ESTHER : Patton_1999_Neuromuscul.Disord_9_423
PubMedSearch : Patton_1999_Neuromuscul.Disord_9_423
PubMedID: 10545049