Effects of serum and compressive loading on the cartilage matrix synthesis and spatiotemporal deposition around chondrocytes in 3D culture

The aim of this study was to investigate the effects of serum and compressive dynamic loading on the cartilaginous matrix spatiotemporal distribution around chondrocytes in vitro. Murine chondrocytes suspended in agarose were cultured in serum-free media or in varying concentrations of serum with or without compressive dynamic loading. Gene expression was assayed by quantitative polymerase chain reaction. Immunohistochemistry was performed for type II collagen and type VI collagen, aggrecan, or cartilage oligomeric matrix protein (COMP) to study the effect of serum and dynamic loading on the spatiotemporal distribution of cartilage matrix components. Chondrocytes in serum-free culture exhibited negligible differences in type II collagen, aggrecan, and COMP mRNA expression levels over 15 days of cultivation. However, higher serum concentrations decreased matrix gene expression. Expression of the matrix metalloproteinases (MMP)-3 and MMP-13 mRNA increased over time in serum-free or reduced serum levels, but was significantly suppressed in 10% fetal bovine serum (FBS). Compressive loading significantly stimulated MMP-3 expression on days 7 and 15. Immunohistochemical analysis demonstrated that maximum pericellular matrix deposition was achieved in 10% FBS culture in the absence of compressive loading. The pericellular distribution of type II and VI collagens, aggrecan, and COMP proteins tended to be more co-localized in the pericellular region from day 9 to day 21; compressive loading helped promote this co-localization of matrix proteins. The results of this study suggest that the quantity, quality, and spatial distribution of cartilaginous matrix can be altered by serum concentrations and compressive loading

Resistin stimulates expression of chemokine genes in chondrocytes via combinatorial regulation of C/EBPβ and NF-κB

To further investigate the regulation role of two chemokine genes CCL3 and CCL4 in chondrocytes in response to resistin, human primary chondrocytes and T/C-28a2 cells were cultured. The function of resistin on the chemokine genes, and the expression of C/EBPβ, NF-κB isoforms were tested using qPCR. The methods used to investigate timed co-regulation of C/EBPβ and NF-κB were NF-κB inhibitor (IKK-NBD) and C/EBPβ inhibitor (SB303580) treatments, and subcellular localization, with or without resistin stimulation. Results showed that resistin could increase the up-regulation of chemokine genes independently. Resistin increased the expression of C/EBPβ and NF-κB isoforms. C/EBPβ regulated basal activity and steadily increased over time up to 24h with resistin. NF-κB was up-regulated upon induction with resistin, peaking at 4 h. C/EBPβ and NF-κB co-enhanced the chemokines expression; inhibition of their activity was additive. The timing of activation in chondrocytes was confirmed by subcellular localization of C/EBPβ and c-rel. Chondrocytes react to resistin in a non-restricted cell-specific manner, utilizing C/EBPβ and NF-κB in a combinatorial regulation of chemokine gene expression. The activity of C/EBPβ is augmented by a transient increase in activity of NF-κB, and both transcription factors act independently on the chemokine genes, CCL3 and CCL4. Thus, resistin stimulates CCL3 and CCL4 through combinatorial regulation of C/EBPβ and NF-κB in chondrocytes

CDK6 and miR-320c Co-Regulate Chondrocyte Catabolism Through NF-κB Signaling Pathways

Background/Aims: Cyclin-dependent kinase 6 (CDK6) regulates inflammatory response and cell differentiation. This study sought to determine whether CDK6 and miR-320c co-regulate chondrogenesis and inflammation. Methods: Utilizing quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC), CDK6 and miR-320c expression were assessed in a micromass culture of human bone mesenchymal stem cells that underwent chondrogenesis in vitro as well as in chondrocytes from E16.5 mouse forelimbs. Normal chondrocytes were transfected with miR-320c mimic, miR-320c inhibitor, or CDK6-siRNA. Luciferase reporter assay results confirmed that miR-320c directly targets CDK6 by interacting with the 3′-untranslated region (3′-UTR) of its mRNA. qRT-PCR, Western blotting, and Cell Counting Kit-8 were subsequently used to evaluate the effects of miR-320c overexpression and CDK6 inhibition on inflammatory factor expression, as well as to investigate the effects of NF-kB and MAPK signaling pathway activation on IL-1β-induced chondrocyte inflammation. Results: Our results show that miR-320c expression increased during the middle stage and decreased during the late stage of hBMSC chondrogenic differentiation. In contrast, CDK6 expression decreased during the middle stage and increased during the late stage of hBMSC chondrogenic differentiation. Moreover, CDK6 expression increased in severe OA cartilage and in hypertrophic chondrocytes of mouse forelimbs at E16.5. Results of the luciferase reporter assay showed that miR-320c modulated CDK6 expression by binding to the 3′-UTR of its mRNA. miR-320c overexpression and CDK6 inhibition repressed IL-1β-induced expression of inflammatory factors and regulated the NF-kB signaling pathway. Conclusion: CDK6 and miR-320c co-regulate hBMSC chondrogenesis and IL-1β-induced chondrocyte inflammation through the NF-kB signaling pathway, suggesting that miR-320c and CDK6 inhibitors can be used to repress catabolism in human chondrocytes

Epidemiologic, Clinical, and Laboratory Findings of the COVID-19 in the current pandemic.

BACKGROUND: The COVID-19 caused the pandemic affected the world deeply, with more than 3,000,000 people infected and nearly 200,000 deaths. This article aimed to summarize the epidemiologic traits, clinical spectrum, CT results and laboratory findings of COVID-19 pandemic. METHODS: We scoped for relevant literatures published during 1st Dec 2019 to 23rd Apr 2020 based on four databases by using English and Chinese. The evidence was synthesized narratively. RESULTS: The COVID-19 pandemic was found to have a higher transmission rate compared to SARS and MERS, and involved 4 stages of evolution. The basic reproduction number (R0) is 3.32 (95% CI:3.24-3.39) and the incubation period was 5.24 days (95% CI:3.97-6.50, 5 studies) on average, and the average time for symptoms onset varied by countries. Common clinical spectrums identified included fever (38.1-39.0°C), cough and fatigue, with Acute Respiratory Distress Syndrome (ARDS) being the most common complication reported. Body temperatures above 39.0 °C, dyspnea, and anorexia were more common symptoms in severe patients. Aged over 60 years old, having co-morbidities, and developing complications were the commonest high-risk factors associated with severe conditions. Leucopenia and lymphopenia were the most common signs of infection while liver and kidney damage were rare but may cause bad outcomes for patients. The bilateral, multifocal Ground-Glass Opacification (GGO) on peripheral, and the consolidative pulmonary opacity were the most frequent CT results and the tendency of mortality rates differed by region. CONCLUSIONS: We provided a bird's-eye view of the COVID-19 during the current pandemic, which will help better understanding the key traits of the disease. The findings could be used for disease's future research, control and prevention

Epidemiologic, clinical, and laboratory findings of the COVID-19 in the current pandemic: systematic review and meta-analysis.

BACKGROUND: The COVID-19 pandemic has affected the world deeply, with more than 14,000,000 people infected and nearly 600,000 deaths. This review aimed to summarize the epidemiologic traits, clinical spectrum, CT results and laboratory findings of the COVID-19 pandemic. METHODS: We scoped for relevant literatures published during 1st December 2019 to 16th July 2020 based on three databases using English and Chinese languages. We reviewed and analyzed the relevant outcomes. RESULTS: The COVID-19 pandemic was found to have a higher transmission rate compared to SARS and MERS and involved 4 stages of evolution. The basic reproduction number (R0) is 3.32 (95% CI:3.24-3.39), the incubation period was 5.24 days (95% CI:3.97-6.50, 5 studies) on average, and the average time for symptoms onset varied by countries. Common clinical spectrums identified included fever (38.1-39.0 °C), cough and fatigue, with Acute Respiratory Distress Syndrome (ARDS) being the most common complication reported. Body temperatures above 39.0 °C, dyspnea, and anorexia were more common symptoms in severe patients. Aged over 65 years old, having co-morbidities, and developing complications were the commonest high-risk factors associated with severe conditions. Leucopenia and lymphopenia were the most common signs of infection while liver and kidney damage were rare but may cause bad outcomes for patients. The bilateral, multifocal Ground-Glass Opacification (GGO) on peripheral, and the consolidative pulmonary opacity were the most frequent CT results and the tendency of mortality rates differed by region. CONCLUSIONS: We provided a bird's-eye view of the COVID-19 during the current pandemic, which will help better understanding the key traits of the disease. The findings could be used for disease's future research, control and prevention

The Changing Patterns of Coronavirus Disease 2019 (COVID-19) in China: A Tempogeographic Analysis of the Severe Acute Respiratory Syndrome Coronavirus 2 Epidemic.

BACKGROUND: Evaluating whether an infectious disease has reached a turning point is important for planning additional intervention efforts. This study aimed to analyze the changing patterns and the tempogeographic features of the coronavirus disease 2019 (COVID-19) epidemic in China, to provide further evidence for real-time responses. METHODS: Daily data on COVID-19 cases between 31 December 2019 and 26 February 2020 were collected and analyzed for Hubei and non-Hubei regions in China. Observed trends for new and cumulative cases were analyzed through joinpoint regression analysis. Spatial analysis was applied to show the geographic distribution and changing patterns of the epidemic. RESULTS: By 26 February 2020, 78 630 confirmed COVID-19 cases had been reported in China. In Hubei, an increasing trend (slope = 221) was observed for new cases between 24 January and 7 February 2020, after which a decline commenced (slope = -868). However, as the diagnosis criteria changed, a sudden increase (slope = 5530) was observed on 12 February, which sharply decreased afterward (slope = -4898). In non-Hubei regions, the number of new cases increased from 20 January to 3 February and started to decline afterward (slope = -53). The spatial analysis identified Chongqing, Guangzhou, Shenzhen, Changsha, Nanchang, Wenzhou, Shanghai, Xinyang, Jining, and Beijing as the hotspots outside of Hubei Province in China. CONCLUSIONS: The joinpoint regression analysis indicated that the epidemic might be under control in China, especially for regions outside of Hubei Province. Further improvement in the response strategies based on these new patterns is needed

A differentiated digital intervention to improve antiretroviral therapy adherence among men who have sex with men living with HIV in China: a randomized controlled trial.

BACKGROUND: Antiretroviral therapy (ART) adherence is still suboptimal among some key populations, highlighting the need for innovative tailored strategies. This randomized controlled trial (RCT) aimed to evaluate the effect of a differentiated digital intervention on ART adherence among men who have sex with men (MSM) living with HIV in China. METHODS: The two-armed parallel RCT was conducted at one HIV clinic in Jinan of China from October 19, 2020, to June 31, 2021. Men were referred by health providers to join the study and then choose one of three digital strategies-text message, only instant message, or instant message plus social media. They were assigned in a 1:1 ratio to the intervention arm or control arm using block randomization, and inside each arm, there were three groups depending on the type of delivering the message. The groups were divided according to participants' preferred digital strategies. The intervention arm received ART medication messages, medication reminders, peer education, and involved in online discussion. The control arm received messages on health behavior and nutrition. The primary outcome was self-reported optimal ART adherence, defined as not missing any doses and not having any delayed doses within a one-month period. Secondary outcomes included CD4 T cell counts, viral suppression, HIV treatment adherence self-efficacy, and quality of life. Intention-to-treat analysis with generalized linear mixed models was used to evaluate the intervention's effect. RESULTS: A total of 576 participants were enrolled, including 288 participants assigned in the intervention arm and 288 assigned in the control arm. Most were ≤ 40 years old (79.9%) and initiated ART ≤ 3 years (60.4%). After intervention, the proportion of participants achieving optimal ART adherence in the intervention arm was higher than in the control arm (82.9% vs 71.1%). The differentiated digital intervention significantly improved ART adherence (RR = 1.74, 95%CI 1.21-2.50). Subgroup analysis showed one-to-one instant message-based intervention significantly improved ART adherence (RR = 2.40, 95% CI 1.39-4.17). CONCLUSIONS: The differentiated digital intervention improved ART adherence among MSM living with HIV in China, which could be integrated into people living with HIV (PLWH) management and further promoted in areas where PLWH can access text messaging and instant messaging services. TRIAL REGISTRATION: ChiCTR2000041282. Retrospectively registered on 23 December 2020