123 research outputs found
Broad Efficacy of a Computationally Designed ACE2 Decoy Against SARS-CoV-2 Omicron Variants and Related Viruses In Vitro and In Vivo
Background: The SARS-CoV-2 omicron variant (B.1.1.529) and its sublineages are currently the dominant variants in the United States accounting for 100% of COVID-19 cases. Problem: The S protein receptor-binding domain (RBD), located in the S1 subunit of the S protein, binds the human angiotensin-converting enzyme 2 (hACE2) leading to S1 shedding and proteolytic processing of S2 that is important for membrane fusion and release of viral RNA. Various neutralizing therapeutics including protein minibinders, peptides, monoclonal antibodies, and nanobodies have been developed to block the critical interaction between the RBD and hACE2. However, these therapeutics are often developed against the S protein of wildtype or a specific variant of SARSCoV- 2, making them highly susceptible to mutational escape.1 Solution: A strategy employed by our group includes using sACE2 (soluble dimeric ACE2 that contains both the protease and dimerization domains) with enhanced S RBD affinity to outcompete native ACE2 expressed on host cells, acting as a ‘decoy’ to block the interaction between the RBD and hACE2 (Figure 1). sACE2 has moderate affinity for the S protein (~20 nM)2. Therefore, sACE2 must be engineered (by introducing affinity enhancing mutations) to bind with tighter affinity to outcompete membrane bound ACE2-S interaction and rival the potency of mAbs. These sACE2 derivatives maintain close similarity to the native ACE2 receptor making them extremely resistant to virus escape. Any mutation in the RBD that limits binding to the sACE2 derivative will likely have reduced binding towards native ACE2 receptors potentially making the virus unfit to propagate.https://jdc.jefferson.edu/aoa_research_symposium_posters/1000/thumbnail.jp
A novel superior factor widely controlling the rice grain quality
Synthesis of storage starch and protein accumulation is the main action of endosperm organogenesis in term of the economic importance of rice. This event is strongly disturbed by abiotic stresses such as high temperature; thus, the upcoming global warming will cause a crisis with a great impact on food production^1,2^. The enzymes for the protein storage and starch synthesis pathway should work in concert to carry out the organogenesis of rice endosperm^3-5^, but the regulatory mechanism is largely unknown. Here we show that a novel regulatory factor, named OsCEO1, acts as the conductor of endosperm organogenesis during the rice grain filling stage. The physiological properties of _floury-endosperm-2_ (_flo2_) mutants showed many similarities to symptoms of grains developed under high-temperature conditions, suggesting important roles of the responsible gene in sensitivity to high-temperature stress. Our map-based cloning identified the responsible gene for the _flo2_ mutant, _OsCEO1_, which has no homology to any genes of known function. The _OsCEO1_ belongs to a novel conserved gene family and encodes a protein composed of 1,720 amino acid residues containing a TPR (tetratricopeptide repeat) motif, which is considered to mediate a protein-protein interaction. The yeast two-hybrid analysis raised an unknown protein showing homology to a late embryogenesis abundant protein and a putative basic helix-loop-helix protein as candidates for the direct interactor for _OsCEO1_, whereas no enzyme genes for the synthesis of storage substances were detected. The _flo2_ mutant exhibited reduced expression of several genes for putative regulatory proteins as well as many enzymes involved in storage starch and proteins. These results suggest that _OsCEO1_ is a superior conductor of the novel regulatory cascade of endosperm organogenesis and may have important roles in the response to high-temperature stress
Pulmonary Artery Leiomyosarcoma Diagnosed without Delay
A 63-year-old female presented with abnormal lung shadows but had, apart from this, few symptoms. Computed tomography (CT) revealed multiple nodules and blockage of the pulmonary artery. She was immediately diagnosed with pulmonary artery sarcoma based on a careful differential diagnosis and underwent surgery. Her tumor was pathologically diagnosed as leiomyosarcoma (i.e. intimal sarcoma). Pulmonary artery sarcoma can be easily confounded with thromboembolism in a clinical setting and some cases are diagnosed post mortem only. In our case, clinical prediction scores (Wells score, Geneva score, and revised Geneva score) for the pulmonary embolism showed low probability. Moreover, chest CT showed uncommon findings for pulmonary thromboembolism, as the nodules were too big for thrombi. Because surgical resection can provide the only hope of long-term survival in cases of pulmonary artery sarcoma, clinicians should consider this possibility in the differential diagnosis of pulmonary embolism. Clinical prediction scores and CT findings might help to reach the correct diagnosis of pulmonary artery sarcoma
Pterosin B prevents chondrocyte hypertrophy and osteoarthritis in mice by inhibiting Sik3.
植物由来成分であるプテロシンBはSIK3を阻害し変形性関節症の治療薬開発のリード化合物となる. 京都大学プレスリリース. 2016-03-31.Yahara, Y., Takemori, H., Okada, M. et al. Correction: Corrigendum: Pterosin B prevents chondrocyte hypertrophy and osteoarthritis in mice by inhibiting Sik3. Nat Commun 7, 12117 (2016).Osteoarthritis is a common debilitating joint disorder. Risk factors for osteoarthritis include age, which is associated with thinning of articular cartilage. Here we generate chondrocyte-specific salt-inducible kinase 3 (Sik3) conditional knockout mice that are resistant to osteoarthritis with thickened articular cartilage owing to a larger chondrocyte population. We also identify an edible Pteridium aquilinum compound, pterosin B, as a Sik3 pathway inhibitor. We show that either Sik3 deletion or intraarticular injection of mice with pterosin B inhibits chondrocyte hypertrophy and protects cartilage from osteoarthritis. Collectively, our results suggest Sik3 regulates the homeostasis of articular cartilage and is a target for the treatment of osteoarthritis, with pterosin B as a candidate therapeutic
A Computationally Designed ACE2 Decoy Has Broad Efficacy Against SARS-CoV-2 Omicron Variants and Related Viruses in Vitro and in Vivo
SARS-CoV-2, especially B.1.1.529/omicron and its sublineages, continues to mutate to evade monoclonal antibodies and antibodies elicited by vaccination. Affinity-enhanced soluble ACE2 (sACE2) is an alternative strategy that works by binding the SARS-CoV-2 S protein, acting as a \u27decoy\u27 to block the interaction between the S and human ACE2. Using a computational design strategy, we designed an affinity-enhanced ACE2 decoy, FLIF, that exhibited tight binding to SARS-CoV-2 delta and omicron variants. Our computationally calculated absolute binding free energies (ABFE) between sACE2:SARS-CoV-2 S proteins and their variants showed excellent agreement to binding experiments. FLIF displayed robust therapeutic utility against a broad range of SARS-CoV-2 variants and sarbecoviruses, and neutralized omicron BA.5 in vitro and in vivo. Furthermore, we directly compared the in vivo therapeutic efficacy of wild-type ACE2 (non-affinity enhanced ACE2) against FLIF. A few wild-type sACE2 decoys have shown to be effective against early circulating variants such as Wuhan in vivo. Our data suggest that moving forward, affinity-enhanced ACE2 decoys like FLIF may be required to combat evolving SARS-CoV-2 variants. The approach described herein emphasizes how computational methods have become sufficiently accurate for the design of therapeutics against viral protein targets. Affinity-enhanced ACE2 decoys remain highly effective at neutralizing omicron subvariants
Histological Remission during Corticosteroid Therapy of Overlapping Nonalcoholic Steatohepatitis and Autoimmune Hepatitis: Case Report and Literature Review
Concurrence of nonalcoholic steatohepatitis (NASH) with autoimmune hepatitis (AIH) is a rare condition that is challenging to diagnosis, due to the relatively high prevalence of autoantibodies in NASH. It is also difficult to determine the most effective treatment as corticosteroids are likely to worsen NASH despite being effective in the treatment of AIH. In this case report, we present a female diagnosed with NASH-AIH overlap with accompanying diabetes mellitus, who successfully achieved normalization of serum alanine aminotransferase levels following prednisolone therapy and weight loss. A follow-up liver biopsy performed 40 months after the initial diagnosis showed only minimal inflammatory infiltrates in the portal area without any NASH histology. Resolution of NASH, in conjunction with a reduction in hepatic fibrosis, might suggest that prednisolone itself does not aggravate steatohepatitis, but rather prevents disease progression. Appropriate immunosuppressive treatment may therefore be an important component of the optimum therapy for NASH-AIH overlap
A novel transgenic chimaeric mouse system for the rapid functional evaluation of genes encoding secreted proteins
A major challenge of the post-genomic era is the functional characterization of anonymous open reading frames (ORFs) identified by the Human Genome Project. In this context, there is a strong requirement for the development of technologies that enhance our ability to analyze gene functions at the level of the whole organism. Here, we describe a rapid and efficient procedure to generate transgenic chimaeric mice that continuously secrete a foreign protein into the systemic circulation. The transgene units were inserted into the genomic site adjacent to the endogenous immunoglobulin (Ig) κ locus by homologous recombination, using a modified mouse embryonic stem (ES) cell line that exhibits a high frequency of homologous recombination at the Igκ region. The resultant ES clones were injected into embryos derived from a B-cell-deficient host strain, thus producing chimaerism-independent, B-cell-specific transgene expression. This feature of the system eliminates the time-consuming breeding typically implemented in standard transgenic strategies and allows for evaluating the effect of ectopic transgene expression directly in the resulting chimaeric mice. To demonstrate the utility of this system we showed high-level protein expression in the sera and severe phenotypes in human EPO (hEPO) and murine thrombopoietin (mTPO) transgenic chimaeras
Prevention of hypoglycemia by intermittent-scanning continuous glucose monitoring device combined with structured education in patients with type 1 diabetes mellitus : A randomized, crossover trial
Aims: We conducted a randomized, crossover trial to compare intermittent-scanning continuous glucose monitoring (isCGM) device with structured education (Intervention) to self-monitoring of blood glucose (SMBG) (Control) in the reduction of time below range.
Methods: This crossover trial involved 104 adults with type 1 diabetes mellitus (T1DM) using multiple daily injections. Participants were randomly allocated to either sequence Intervention/Control or sequence Control/Intervention. During the Intervention period which lasted 84 days, participants used the first-generation FreeStyle Libre (Abbott Diabetes Care, Alameda, CA, USA) and received structured education on how to prevent hypoglycemia based on the trend arrow and by frequent sensor scanning (≥10 times a day). Confirmatory SMBG was conducted before dosing insulin. The Control period lasted 84 days. The primary endpoint was the decrease in the time below range (TBR; <70 mg/dL).
Results: The time below range was significantly reduced in the Intervention arm compared to the Control arm (2.42 ± 1.68 h/day [10.1 %±7.0 %] vs 3.10 ± 2.28 h/day [12.9 %±9.5 %], P = 0.012). The ratio of high-risk participants with low blood glucose index >5 was significantly reduced (8.6 % vs 23.7 %, P < 0.001).
Conclusions: The use of isCGM combined with structured education significantly reduced the time below range in patients with T1DM
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