RESUMO
The number of new cases world-wide for the COVID-19 disease is increasing dramatically, while efforts to contain Severe Acute Respiratory Syndrome Coronavirus 2 is producing varied results in different countries. There are three key SARS-CoV-2 enzymes potentially targetable with antivirals: papain-like protease (PLpro), main protease (Mpro), and RNA-dependent RNA polymerase. Of these, PLpro is an especially attractive target because it plays an essential role in several viral replication processes, including cleavage and maturation of viral polyproteins, assembly of the replicase-transcriptase complex (RTC), and disruption of host viral response machinery to facilitate viral proliferation and replication. Moreover, this enzyme is conserved across different coronaviruses and promising inhibitors have already been discovered for its SARS-CoV variant. Here we report a substantive body of structural, biochemical, and virus replication studies that identify several inhibitors of the enzyme from SARS-CoV-2 in both wild-type and mutant forms. These efforts include the first structures of wild-type PLpro, the active site C111S mutant, and their complexes with inhibitors, determined at 1.60-2.70 Angstroms. This collection of structures provides fundamental molecular and mechanistic insight to PLpro, and critically, illustrates details for inhibitors recognition and interactions. All presented compounds inhibit the peptidase activity of PLpro in vitro, and some molecules block SARS-CoV-2 replication in cell culture assays. These collated findings will accelerate further structure-based drug design efforts targeting PLpro, with the ultimate goal of identifying high-affinity inhibitors of clinical value for SARS-CoV-2.
RESUMO
The correlations between the clinicopathological features and the long-term outcomes of renal amyloidosis (RA) were analyzed with a view to develop strategies for improving diagnosis and prognosis of RA. We retrospectively reviewed the clinicopathological characteristics of 47 patients diagnosed with RA between 2004 and 2014 at the Wuhan Union Hospital. The data on the renal histology, clinical manifestations, and prognosis of RA patients were retrieved from the hospital records and characteristic patterns were identified. The histological changes in the kidneys were correlated with the clinical manifestations of RA. Additionally, most RA patients in this study had decreased serum levels of κ light chain and increased urine levels of κ and λ light chains as well as presence of M-protein in the urine and serum. Patients with early RA showed no specific pathognomonic symptoms. Bleeding associated with diagnostic renal biopsy was rare. We recommend that the routine work-up of patients aged over 40 years and presenting with non-diabetic nephropathy includes the non-invasive tests for the measurement of serum and urine levels of κ and λ light chains as well as protein electrophoresis tests for the presence of urinary and serum M-protein. Additionally, such patients should undergo renal biopsy screening with Cong-red staining to ensure early diagnosis of RA and improve their survival, since the risk of hemorrhage related to renal biopsy screening is low at early stages of RA.
RESUMO
The correlations between the clinicopathological features and the long-term outcomes of renal amyloidosis (RA) were analyzed with a view to develop strategies for improving diagnosis and prognosis of RA. We retrospectively reviewed the clinicopathological characteristics of 47 patients diagnosed with RA between 2004 and 2014 at the Wuhan Union Hospital. The data on the renal histology, clinical manifestations, and prognosis of RA patients were retrieved from the hospital records and characteristic patterns were identified. The histological changes in the kidneys were correlated with the clinical manifestations of RA. Additionally, most RA patients in this study had decreased serum levels of κ light chain and increased urine levels of κ and λ light chains as well as presence of M-protein in the urine and serum. Patients with early RA showed no specific pathognomonic symptoms. Bleeding associated with diagnostic renal biopsy was rare. We recommend that the routine work-up of patients aged over 40 years and presenting with non-diabetic nephropathy includes the non-invasive tests for the measurement of serum and urine levels of κ and λ light chains as well as protein electrophoresis tests for the presence of urinary and serum M-protein. Additionally, such patients should undergo renal biopsy screening with Cong-red staining to ensure early diagnosis of RA and improve their survival, since the risk of hemorrhage related to renal biopsy screening is low at early stages of RA.
Assuntos
Humanos , Amiloidose , Diagnóstico , Patologia , Biópsia , Imunoglobulinas , Sangue , Urina , Nefropatias , Diagnóstico , Patologia , PrognósticoRESUMO
To clear the structural specificity of calmodulin (CaM) on the specific 125I-omega-CTX binding to crude membranes from whole chick brain, the following experiments were investigated in this study: (i) the attenuating effect of semisynthetic tetrahydroisoquinoline derivatives on the inhibitory effect of Ca2+/CaM, (ii) the effects of chimeras of yeast and chicken Ca2+/CaM, and (iii) the effects of Ca2+-binding proteins (such as troponin c, S 100 a and b, and annexin I, III-V). The inhibitory effect of Ca2+/CaM was attenuated by isoquinoline derivatives (PX 28, 34, 216, 224, and CPU57) and a CaM antagonist W-7. PX 34, a typical synthesized isoquinoline derivative, showed the attenuating effect in a dose-dependent manner. The ED50 value for the attenuating effect of PX 34 was about 20 microM, which is similar to that of W-7 reported previously. Some chimeric CaMs such as YC 51-53 (which are close to the properties of vertebrate CaM) showed a significant inhibitory effect on the specific 125I-omega-CTX binding, but YC 129 and 130 (which retain the properties of yeast CaM), troponin c, S100 a, b, and annexin I, III-V had no effect on the specific 125I-omega-CTX binding. These results suggest that the characteristic structure containing the EF-hand structure of CaM itself is needed to cause the inhibitory effect on the specific 125I-omega-CTX binding.
