Osteoarthritis is a chronic disease characterized by cartilage degeneration and chondrocyte apoptosis. Mitogen-activated protein kinase (MAPK) signaling pathway plays a key role in regulating OA process. Autophagy has an important effect on the OA process, and it is believed to be regulated by MAPKs. To reveal the mechanism and the effect of JNK and p38 MAPKs on matrix metalloproteinase 3 (MMP3) and autophagy in OA, the study established OA model in rabbits, used the measurement of the Osteoarthritis Research Society International scoring system to evaluate OA model, and conducted general observation, histological observation, and Western blotting of JNK, phosphorylate-JNK (P-JNK), p38, phosphorylate-p38 (Pp38), MMP3, and light-chain 3 (LC3)-II/LC3-I to explore the variation of JNK, p38 MAPKs, and autophagy at the early stage of OA. With OA progressing at the early stage, MMP3, P-p38, and P-JNK were gradually upregulated from the baseline to the peak in study groups when compared with the control group; JNK and p38 variated of turbulence without statistical difference; and LC3-II/LC3-I had a decreasing tendency from the 0-to 15-day group. This study identifies that compromised autophagy may be related to the OA progress and that JNK and p38 MAPKs have positive regulation on MMP3 and negative regulation on autophagy. It also implicates a new therapeutic strategy for OA and other degenerate diseases based on selective MAPK inhibitors, reduction of MMP3, and autophagy. V C 2016 IUBMB Life, 68(4): [293][294][295][296][297][298][299][300][301][302] 2016

Blood clotting at the vascular injury site is a complex process that involves platelet adhesion and clot stiffening/contraction in the milieu of fluid flow. An integrated understanding of the hemodynamics and tissue mechanics regulating this process is currently lacking due to the absence of an experimental system that can simultaneously model clot formation and measure clot mechanics under shear flow. Here we develop a microfluidic-integrated microclot-array-elastometry system (clotMAT) that recapitulates dynamic changes in clot mechanics under physiological shear. Treatments with procoagulants and platelet antagonists and studies with diseased patient plasma demonstrate the ability of the system to assay clot biomechanics associated with common antiplatelet treatments and bleeding disorders. The changes of clot mechanics under biochemical treatments and shear flow demonstrate independent yet equally strong effects of these two stimulants on clot stiffening. This microtissue force sensing system may have future research and diagnostic potential for various bleeding disorders.

Objective To estimate the prevalence of disability and anxiety in Covid-19 survivors at discharge from hospital and analyze relative risk by exposures. Design Multi-center retrospective cohort study. Setting Twenty-eight hospitals located in eight provinces of China. Methods A total of 432 survivors with laboratory-confirmed SARS CoV-2 infection participated in this study. At discharge, we assessed instrumental activities of daily living (IADL) with Lawton’s IADL scale, dependence in activities of daily living (ADL) with the Barthel Index, and anxiety with Zung’s self-reported anxiety scale. Exposures included comorbidity, smoking, setting (Hubei vs. others), disease severity, symptoms, and length of hospital stay. Other risk factors considered were age, gender, and ethnicity (Han vs. Tibetan). Results Prevalence of at least one IADL problem was 36.81% (95% CI: 32.39–41.46). ADL dependence was present in 16.44% (95% CI: 13.23–20.23) and 28.70% (95% CI: 24.63–33.15) were screened positive for clinical anxiety. Adjusted risk ratio (RR) of IADL limitations (RR 2.48, 95% CI: 1.80–3.40), ADL dependence (RR 2.07, 95% CI 1.15–3.76), and probable clinical anxiety (RR 2.53, 95% CI 1.69–3.79) were consistently elevated in survivors with severe Covid-19. Age was an additional independent risk factor for IADL limitations and ADL dependence; and setting (Hubei) for IADL limitations and anxiety. Tibetan ethnicity was a protective factor for anxiety but a risk factor for IADL limitations. Conclusion A significant proportion of Covid-19 survivors had disability and anxiety at discharge from hospital. Health systems need to be prepared for an additional burden resulting from rehabilitation needs of Covid-19 survivors.

Due to the importance of fluid flow during thrombotic episodes, it is quite appropriate to study clotting and bleeding processes in devices that have well-defined fluid shear environments. Two common devices for applying these defined shear stresses include the cone-and-plate viscometer and parallel-plate flow chamber. While such tools have many salient features, they require large amounts of blood or other protein components. With growth in the area of microfluidics over the last two decades, it has become feasible to miniaturize such flow devices. Such miniaturization not only enables saving of precious samples but also increases the throughput of fluid shear devices, thus, enabling the design of combinatorial experiments and making the technique more accessible to the larger scientific community. In addition to simple flows that are common in traditional flow apparatus, more complex geometries that mimic stenosed arteries and the human microvasculature can also be generated. The composition of the microfluidics cell substrate can also be varied for diverse basic science investigations, and clinical investigations that aim to assay either individual patient coagulopathy or response to anti-coagulation treatment. This review summarizes the current state of the art for such microfluidic devices and their applications in the field of thrombosis and hemostasis.

BackgroundVon Willebrand Factor (VWF) A1‐domain binding to platelet receptor GpIbα is an important fluid‐shear dependent interaction that regulates both soluble VWF binding to platelets, and platelet tethering onto immobilized VWF. We evaluated the roles of different structural elements at the N‐terminus of the A1‐domain in regulating shear dependent platelet binding. Specifically, the focus was on the VWF D′D3‐domain, A1‐domain N‐terminal flanking peptide (NFP), and O‐glycans on this peptide.Methods and ResultsFull‐length dimeric VWF (ΔPro‐VWF), dimeric VWF lacking the D′D3 domain (ΔD′D3‐VWF), and ΔD′D3‐VWF variants lacking either the NFP (ΔD′D3NFP─‐VWF) or just O‐glycans on this peptide (ΔD′D3OG─‐VWF) were expressed. Monomeric VWF‐A1 and D′D3‐A1 were also produced. In ELISA, the apparent dissociation constant (KD) of soluble ΔPro‐VWF binding to immobilized GpIbα (KD≈100 nmol/L) was 50‐ to 100‐fold higher than other proteins lacking the D′D3 domain (KD~0.7 to 2.5 nmol/L). Additionally, in surface plasmon resonance studies, the on‐rate of D′D3‐A1 binding to immobilized GpIbα (kon=1.8±0.4×104 (mol/L)−1·s−1; KD=1.7 μmol/L) was reduced compared with the single VWF‐A1 domain (kon=5.1±0.4×104 (mol/L)−1·s−1; KD=1.2 μmol/L). Thus, VWF‐D′D3 primarily controls soluble VWF binding to GpIbα. In contrast, upon VWF immobilization, all molecular features regulated A1‐GpIbα binding. Here, in ELISA, the number of apparent A1‐domain sites available for binding GpIbα on ΔPro‐VWF was ≈50% that of the ΔD′D3‐VWF variants. In microfluidics based platelet adhesion measurements on immobilized VWF and thrombus formation assays on collagen, human platelet recruitment varied as ΔPro‐VWF<ΔD′D3‐VWF<ΔD′D3NFP─‐VWF<ΔD′D3OG─‐VWF.ConclusionsWhereas VWF‐D′D3 is the major regulator of soluble VWF binding to platelet GpIbα, both the D′D3‐domain and N‐terminal peptide regulate platelet translocation and thrombus formation.

Continuous exposure to human activity has led to considerable behavioural changes in some wildlife populations. Animals are more likely to survive in a changing environment by adjusting their behaviour to repeatedly occurring but harmless stimulations. During the COVID-19 pandemic, starting in late 2019, face masks were recommended to the public to prevent the spread of pathogens. In this context, we compared the flight initiation distance (FID) of the Eurasian tree sparrow ( Passer montanus ), a commonly seen bird across China, in Yibin and Dazhou, Sichuan, in response to people with or without face masks. After continuous exposure to people wearing face masks for nearly six months, sparrows evidently became adapted to people wearing face masks, and correspondingly showed shorter FIDs in response to people wearing masks. To our knowledge, this is the first study showing that birds show reduced fear responses to people wearing face masks during the COVID-19 pandemic. Our results suggest a novel aspect of short-term adaptation of wildlife to human behaviour, and that the learning ability of sparrows allows them to adjust their behaviours to adapt to such subtle changes in the environment.

MicroRNAs (miRs) are a class of small non-coding RNAs of 18–25 nucleotides in length that serve as key regulators in the development and progression of human cancers. Recently, miR-30b-5p, as a member of the miR-30 family, has been reported to act as a tumor suppressor in gastric cancer. However, the expression and function of miR-30a-5p in gastric cancer, as well as the corresponding underlying mechanism, remain unknown. In the present study, it was demonstrated that the expression of miR-30a-5p was significantly reduced in gastric cancer tissues (n=43) compared with normal gastric tissues (n=10; P<0.01). Similarly, miR-30a-5p was significantly downregulated in the gastric cancer cell lines AGS, HGC27, BGC823 and SGC7901, when compared with the normal gastric mucosa epithelial cell line GES-1 (P<0.01). In addition, overexpression of miR-30a-5p significantly inhibited the proliferation and invasion of AGS cells (P<0.01). Insulin-like growth factor 1 receptor (IGF-1R) was identified as a novel target of miR-30a-5p, and the protein expression of IGF-1R was negatively regulated by miR-30a-5p in AGS cells (P<0.01). Furthermore, overexpression of IGF-1R significantly reversed the inhibitory effect of miR-30a-5p on the proliferation and invasion of AGS cells (P<0.01), indicating that IGF-1R was involved in miR-30a-5p-mediated proliferation and invasion of AGS cells. It was also observed that the expression of IGF-1R mRNA was upregulated in gastric cancer tissues compared with normal gastric tissues (P<0.01), and its levels of expression were reversely correlated with that of miR-30a-5p in gastric cancer tissues (R2=0.3892; P<0.01). Collectively, these data suggest that miR-30a-5p inhibits the growth and metastasis of gastric cancer by directly targeting IGF-1R. Therefore, the miR-30a-5p/IGF-1R axis may be a potential therapeutic target in the treatment of gastric cancer.

von Willebrand factor (VWF) self-association results in the homotypic binding of VWF upon exposure to fluid shear. The molecular mechanism of this process is not established. In this study, we demonstrate that the shear-dependent unfolding of the VWF A2 domain in the multimeric protein is a major regulator of protein self-association. This mechanism controls self-association on the platelet glycoprotein Ibα receptor, on collagen substrates, and during thrombus growth ex vivo. In support of this, A2-domain mutations that prevent domain unfolding due to disulfide bridging of N- and C-terminal residues (“Lock-VWF”) reduce self-association and platelet activation under various experimental conditions. In contrast, reducing assay calcium concentrations, and 2 mutations that destabilize VWF-A2 conformation by preventing coordination with calcium (D1498A and R1597W VWD type 2A mutation), enhance self-association. Studies using a panel of recombinant proteins that lack the A1 domain (“ΔA1 proteins”) suggest that besides pure homotypic A2 interactions, VWF-A2 may also engage other protein domains to control self-association. Addition of purified high-density lipoprotein and apolipoprotein-A1 partially blocked VWF self-association. Overall, similar conditions facilitate VWF self-association and ADAMTS13-mediated proteolysis, with low calcium and A2 disease mutations enhancing both processes, and locking-A2 blocking them simultaneously. Thus, VWF appears to have evolved 2 balancing molecular functions in a single A2 functional domain to dynamically regulate protein size in circulation: ADAMTS13-mediated proteolysis and VWF self-association. Modulating self-association rates by targeting VWF-A2 may provide novel methods to regulate the rates of thrombosis and hemostasis.