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GroEL and the GroEL-GroES Complex

Ishii, Noriyuki
Chaperonin is categorized as a molecular chaperone and mediates the formation of the native conformation of proteins by first preventing folding during synthesis or membrane translocation and subsequently by mediating the step-wise ATP-dependent release that result in proper folding. In the GroEL-GroES complex, a single heptameric GroEL ring binds one GroES ring in the presence of ATP/ADP, in this vein, the double ring GroEL tetradecamer is present in two distinct types of GroEL-GroES complexes: asymmetric 1:1 "bullet"-shaped GroEL:GroES and symmetric 1:2 "football" (American football)-shaped GroEL:GroES2. There have been debates as to which complex is critical to the productive protein folding mediated by the GroEL-GroES complex, and how GroES coordinates with GroEL in the chaperonin reaction cycle in association with regulation by adenine nucleotides and through the interplay of substrate proteins. A lot of knowledge on chaperonins has been accumulating as if expanding as ripples spread around the GroEL-GroES from Escherichia coli. In this article, an overview is presented on GroEL and the GroEL-GroES complex, with emphasis on their morphological variations, and some potential applications to the fabrication of nanocomposites using GroEL as a nano-block. In parallel, a guideline is presented that supports the recognition that the E. coli and its GroEL-GroES complex do not always receive in standard literature because the biochemical features of chaperonins derived from others special, such as mammals, are not always the same as those confirmed using GroEL-GroES derived from E. coli.
PMID: 28271487
ISSN: 0306-0225
CID: 3079732

A wild-type mouse-based model for the regression of inflammation in atherosclerosis

Peled, Michael; Nishi, Hitoo; Weinstock, Ada; Barrett, Tessa J; Zhou, Felix; Quezada, Alexandra; Fisher, Edward A
Atherosclerosis can be induced by the injection of a gain-of-function mutant of proprotein convertase subtilisin/kexin type 9 (PCSK9)-encoding adeno-associated viral vector (AAVmPCSK9), avoiding the need for knockout mice models, such as low-density lipoprotein receptor deficient mice. As regression of atherosclerosis is a crucial therapeutic goal, we aimed to establish a regression model based on AAVmPCSK9, which will eliminate the need for germ-line genetic modifications. C57BL6/J mice were injected with AAVmPCSK9 and were fed with Western diet for 16 weeks, followed by reversal of hyperlipidemia by a diet switch to chow and treatment with a microsomal triglyceride transfer protein inhibitor (MTPi). Sixteen weeks following AAVmPCSK9 injection, mice had advanced atherosclerotic lesions in the aortic root. Surprisingly, diet switch to chow alone reversed hyperlipidemia to near normal levels, and the addition of MTPi completely normalized hyperlipidemia. A six week reversal of hyperlipidemia, either by diet switch alone or by diet switch and MTPi treatment, was accompanied by regression of atherosclerosis as defined by a significant decrease of macrophages in the atherosclerotic plaques, compared to baseline. Thus, we have established an atherosclerosis regression model that is independent of the genetic background.
PMCID:5349694
PMID: 28291840
ISSN: 1932-6203
CID: 2488542

A Patient with Cystic Granuloma Trichophyticum who Required Surgical Resection [Case Report]

Kaneko, Takehiko; Kaneko, Michiyo
A 62-year-old male with numerous subcutaneous nodules in the lower extremities was referred to The University of Tokyo Hospital. The patient suffered from systemic lupus erythematosus (SLE), diabetes mellitus, and persisting hepatic dysfunction, and had been treated for SLE with oral prednisolone 20 mg/day and oral cyclosporine 3 mg/kg/day. The culture of scales collected from the patient's skin surface on Sabouraud's dextrose agar medium showed features of Trichophyton rubrum. Topically applied bifonazole cream was effective for tinea corporis, but oral griseofulvin 500 mg/day was discontinued after 2-month administration because of deteriorated liver function. All the nodules were resected surgically. Histologically, resected granulomas showed dermal abscesses that were tightly encapsulated by fibrous capsules. Grocott staining revealed numerous fungal elements within abscesses. The patient's condition indicated the need to perform histopathological examination of granuloma trichophyticum in order to determine whether it is tightly encapsulated. Namely, the presence of cystic granuloma trichophyticum with abscesses encapsulated by fibrous capsules suggested that the patient should be treated by surgical resection of the lesions.
PMID: 28250361
ISSN: 1882-0476
CID: 3079282

Could Circumcision of HIV-Positive Males Benefit Voluntary Medical Male Circumcision Programs in Africa? Mathematical Modeling Analysis

Awad, Susanne F; Sgaier, Sema K; Lau, Fiona K; Mohamoud, Yousra A; Tambatamba, Bushimbwa C; Kripke, Katharine E; Thomas, Anne G; Bock, Naomi; Reed, Jason B; Njeuhmeli, Emmanuel; Abu-Raddad, Laith J
BACKGROUND: The epidemiological and programmatic implications of inclusivity of HIV-positive males in voluntary medical male circumcision (VMMC) programs are uncertain. We modeled these implications using Zambia as an illustrative example. METHODS AND FINDINGS: We used the Age-Structured Mathematical (ASM) model to evaluate, over an intermediate horizon (2010-2025), the effectiveness (number of VMMCs needed to avert one HIV infection) of VMMC scale-up scenarios with varying proportions of HIV-positive males. The model was calibrated by fitting to HIV prevalence time trend data from 1990 to 2014. We assumed that inclusivity of HIV positive males may benefit VMMC programs by increasing VMMC uptake among higher risk males, or by circumcision reducing HIV male-to-female transmission risk. All analyses were generated assuming no further antiretroviral therapy (ART) scale-up. The number of VMMCs needed to avert one HIV infection was projected to increase from 12.2 VMMCs per HIV infection averted, in a program that circumcises only HIV-negative males, to 14.0, in a program that includes HIV-positive males. The proportion of HIV-positive males was based on their representation in the population (e.g. 12.6% of those circumcised in 2010 would be HIV-positive based on HIV prevalence among males of 12.6% in 2010). However, if a program that only reaches out to HIV-negative males is associated with 20% lower uptake among higher-risk males, the effectiveness would be 13.2 VMMCs per infection averted. If improved inclusivity of HIV-positive males is associated with 20% higher uptake among higher-risk males, the effectiveness would be 12.4. As the assumed VMMC efficacy against male-to-female HIV transmission was increased from 0% to 20% and 46%, the effectiveness of circumcising regardless of HIV status improved from 14.0 to 11.5 and 9.1, respectively. The reduction in the HIV incidence rate among females increased accordingly, from 24.7% to 34.8% and 50.4%, respectively. CONCLUSION: Improving inclusivity of males in VMMC programs regardless of HIV status increases VMMC effectiveness, if there is moderate increase in VMMC uptake among higher-risk males and/or if there is moderate efficacy for VMMC against male-to-female transmission. In these circumstances, VMMC programs can reduce the HIV incidence rate in males by nearly as much as expected by some ART programs, and additionally, females can benefit from the intervention nearly as much as males.
PMCID:5261810
PMID: 28118387
ISSN: 1932-6203
CID: 2439782

Deletion of neurotrophin signaling through the glucocorticoid receptor pathway causes tau neuropathology [Meeting Abstract]

Arango-Lievano, M; Peguet, C; Catteau, M; Parmentier, M L; Wu, S; Chao, M V; Ginsberg, S D; Freddy, J
Aims Glucocorticoid resistance is a risk factor for Alzheimer's disease (AD). Molecular and cellular mechanisms of glucocorticoid resistance in the brain have remained unknown and are potential therapeutic targets. Phosphorylation of glucocorticoid receptors (GR) by brain-derived neurotrophic factor (BDNF) signaling integrates both pathways for remodeling synaptic structure and plasticity. OBJECTIVES: To test (i) the role of the BDNF-dependent pathway on glucocorticoid signaling in a mouse model of glucocorticoid resistance, (ii) its influence on dendritic spine loss and tau phosphorylation as risk factors for AD, and (iii) its relevance for human pathology. Method We manipulated (1) BDNF signaling using a TrkB mutant that can be inactivated chemically, (2) glucocorticoid signaling using a BDNF insensitive GR mutant, and (3) the expression of DUSP1, the MAPK-phosphatase downstream of BDNF and GR pathways in a mouse model of glucocorticoid resistance featuring impaired cortisol awaking response. Synaptic defects and Tau phosphorylation were analyzed post-mortem. DUSP1 expression in human brain was analyzed in correlation to AD diagnosis and cognitive impairment in two independent American cohorts (10 controls + 15 AD and 17 controls + 29 AD). Results Deletion of GR phosphorylation at BDNF-responding sites and downstream signaling via DUSP1 triggers tau phosphorylation and dendritic spine atrophy in mouse cortex. In human cortex, DUSP1 protein expression correlates with tau phosphorylation, synaptic defects and cognitive decline in subjects diagnosed with AD. Conclusion Our findings provide evidence for a causal role of BDNF-dependent GR signaling on tau neuropathology and indicate that DUSP1 is potential target of therapeutics
EMBASE:615511017
ISSN: 1660-2862
CID: 2553662

Evolutionary Implications of Variability and Rates of Change in the Primate Lumbosacral Plexus [Meeting Abstract]

Shearer, Brian M.
ISI:000423063104130
ISSN: 0002-9483
CID: 4141142

New specimens of Stirtonia from the La Victoria Formation, La Venta, Colombia and the evolution of alouattin dental and mandibular form [Meeting Abstract]

Cooke, Siobhan B.; Felipe Vanegas, Andres; Link, Andres; Shearer, Brian M.; Stroik, Laura K.; Tallman, Melissa
ISI:000423063102186
ISSN: 0002-9483
CID: 4141132

The first case of recurrent ultra late onset group B streptococcal sepsis in a 3-year-old child

Hosoda, Ai; Gatayama, Ryohei; Moriyama, Shiori; Ishii, Noriyuki; Yamada, Kenichiro; Matsuzaki, Youhei; Shinjoh, Masayoshi
Group B streptococcus (GBS) is a commonly recognized cause of sepsis and meningitis in neonatal and young infants. Invasive GBS infection is classified into early onset GBS disease (EOD, day 0-6), late onset GBS disease (LOD, day 7-89) and ultra late onset GBS disease (ULOD, after 3 months of age). ULOD is uncommon and recurrence is especially rare. We present the first recurrent case of ULOD GBS sepsis in 3-year-old girl with a past medical history of hydrops fetalis and thoracic congenital lymphatic dysplasia. The first episode presented as sepsis at 2 years 8 months of age. The second episode occurred as sepsis with encephalopathy at 3 years 1 months of age. During each episode, the patient was treated using intravenous antimicrobials and her condition improved. Serotype examination was not performed in the first episode, but GBS type V was serotyped in the second episode. ULOD over 1 year of age is quite rare and may recur.
PMCID:5133645
PMID: 27920985
ISSN: 2214-2509
CID: 3094912

Correction: Voluntary Medical Male Circumcision for HIV Prevention in Malawi: Modeling the Impact and Cost of Focusing the Program by Client Age and Geography [Correction]

Kripke, Katharine; Chimbwandira, Frank; Mwandi, Zebedee; Matchere, Faustin; Schnure, Melissa; Reed, Jason; Castor, Delivette; Sgaier, Sema; Njeuhmeli, Emmanuel
[This corrects the article DOI: 10.1371/journal.pone.0156521.].
PMCID:5207517
PMID: 28046115
ISSN: 1932-6203
CID: 2439792

Multiple Mechanisms Linking Type 2 Diabetes and Alzheimer's Disease: Testosterone as a Modifier

Asih, Prita R; Tegg, Michelle L; Sohrabi, Hamid; Carruthers, Malcolm; Gandy, Samuel E; Saad, Farid; Verdile, Giuseppe; Ittner, Lars M; Martins, Ralph N
Evidence in support of links between type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has increased considerably in recent years. AD pathological hallmarks include the accumulation of extracellular amyloid-β (Aβ) and intracellular hyperphosphorylated tau in the brain, which are hypothesized to promote inflammation, oxidative stress, and neuronal loss. T2DM exhibits many AD pathological features, including reduced brain insulin uptake, lipid dysregulation, inflammation, oxidative stress, and depression; T2DM has also been shown to increase AD risk, and with increasing age, the prevalence of both conditions increases. In addition, amylin deposition in the pancreas is more common in AD than in normal aging, and although there is no significant increase in cerebral Aβ deposition in T2DM, the extent of Aβ accumulation in AD correlates with T2DM duration. Given these similarities and correlations, there may be common underlying mechanism(s) that predispose to both T2DM and AD. In other studies, an age-related gradual loss of testosterone and an increase in testosterone resistance has been shown in men; low testosterone levels can also occur in women. In this review, we focus on the evidence for low testosterone levels contributing to an increased risk of T2DM and AD, and the potential of testosterone treatment in reducing this risk in both men and women. However, such testosterone treatment may need to be long-term, and would need regular monitoring to maintain testosterone at physiological levels. It is possible that a combination of testosterone therapy together with a healthy lifestyle approach, including improved diet and exercise, may significantly reduce AD risk.
PMID: 28655134
ISSN: 1875-8908
CID: 3074142