[Retracted] MicroRNA­25 protects nucleus pulposus cells against apoptosis via targeting SUMO2 in intervertebral disc degeneration.

Following the publication of this paper, the authors requested that the paper be retracted, specifically on account of deficiencies that were identified both in the documentation of patient records and in written consent pertaining to the data presented in Fig. 1. After having considered the authors' request, the Editor of Molecular Medicine Reports has agreed that this paper should be retracted from the Journal. All the authors are in agreement with the decision to retract this paper. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 24: 724, 2021; DOI: 10.3892/mmr.2021.12363].

Accurate Spatio-Temporal Delivery of Nitric Oxide Facilitates the Programmable Repair of Avascular Dense Connective Tissues Injury.

Avascular dense connective tissues (e.g., the annulus fibrosus (AF) rupture, the meniscus tear, and tendons and ligaments injury) repair remains a challenge due to the "biological barrier" that hinders traditional drug permeation and limits self-healing of the injured tissue. Here, accurate delivery of nitric oxide (NO) to penetrate the "AF biological barrier" is achieved thereby enabling programmable AF repair. NO-loaded BioMOFs are synthesized and mixed in a modified polyvinyl alcohol and PCL-composited electrospun fiber membrane with excellent reactive oxygen species-responsive capability (LN@PM). The results show that LN@PM could respond to the high oxidative stress environment at the injured tissue and realize continuous and substantial NO release. Based on low molecular weight and lipophilicity, NO could penetrate through the "biological barrier" for accurate AF drug delivery. Moreover, the dynamic characteristics of the LN@PM reaction can be matched with the pathological microenvironment to initiate programmable tissue repair including sequential remodeling microenvironment, reprogramming the immune environment, and finally promoting tissue regeneration. This tailored programmable treatment strategy that matches the pathological repair process significantly repairs AF, ultimately alleviating intervertebral disc degeneration. This study highlights a promising approach for avascular dense connective tissue treatment through intelligent NO release, effectively overcoming "AF biological barriers" and programmable treatment.

[Comparative Analysis of Influencing Factors of Health Service Utilization Among Urban and Rural Residents in Tibet].

Objective: To examine the differences and commonalities of factors influencing the utilization of health services among urban and rural residents in Tibet and to identify vulnerable populations in the utilization of health services, thereby providing references for the formulation of local health policies and the allocation of health resources. Methods: Using the Tibetan area data from the Sixth National Health Service Survey, we conducted statistical analysis of the health service utilization status of 8 297 residents of agro-pastoral areas and 2 179 residents of urban areas with χ 2 test and logistic regression model. Results: The two-week outpatient visit rates of residents in agro-pastoral areas and that of the urban residents were 65.3% and 57.1%, respectively, and the one-year hospitalization rates were 8.3% and 8.9%, respectively. The influencing factors of two-week outpatient visits for rural and pastoral residents included urban and rural health insurance coverage, Three Guarantees in One coverage, distance to medical facilities, chronic disease status, physical examination, family doctor contract status, employment status, and health status self-assessment. The influencing factors of two-week outpatient visit for urban residents included chronic disease status, urban and rural medical insurance coverage, health status self-assessment, health records, and physical examination. The factors influencing hospitalization for agro-pastoral residents were sex, age, marital status, urban and rural medical insurance coverage, Three Guarantees in One coverage, critical illness insurance, health self-assessment, mobility, health records, physical examination, and chronic disease status. The factors influencing the hospitalization of urban residents were sex, marital status, health status self-assessment, health records, urban employee medical insurance coverage, and chronic disease status. The factors influencing the hospitalization of urban residents were sex, marital status, health status self-assessment, health records, urban employee medical insurance coverage, and chronic disease status. Conclusion: The urban and rural residents in Tibet have relatively poor health and their awareness of seeking early medical help after they fall ill is relatively weak. The health institutions concerned should dedicate more attention to the vulnerable populations who have difficulty accessing health services, focus on the commonly shared influencing factors of health service utilization among urban and rural residents, take into account the differences, rationally allocate health resources, and improve the effective utilization rate of health services among residents in Tibet.

Inorganic arsenic exposure promotes malignant progression by HDAC6-mediated down-regulation of HTRA1.

Inorganic arsenic (iAs) has been a human health concern and is associated with intestinal malignancies. However, the molecular mechanisms of the iAs-induced oncogenic process in intestine epithelial cells remain elusive, partly because of the known hormesis effect of arsenic. Here, we established that six-month exposure to iAs at a concentration similar to those found in contaminated drinking water could promote malignant characteristics, including enhanced proliferation and migration, resistance to apoptosis, and mesenchymal-like transition in Caco-2 cells. Transcriptome analysis and mechanism study revealed that key genes and pathways involved in cell adhesion, inflammation and oncogenic regulation were altered during chronic iAs exposure. Specifically, we uncovered that down-regulation of HTRA1 was essential for the iAs-induced acquisition of the cancer hallmarks. Further, we evidenced that the loss of HTRA1 during iAs-exposure could be restored by HDAC6 inhibition. Caco-2 cells with chronic exposure to iAs exhibited enhanced sensitivity to WT-161, a specific inhibitor of HDAC6, when used alone than in combination with a chemotherapeutic agent. These findings provide valuable information for understanding the mechanisms of arsenic-induced carcinogenesis and facilitating the health management of populations in arsenic-polluted areas.

Asymptomatic Hyperuricemia Is Associated with Achilles Tendon Rupture through Disrupting the Normal Functions of Tendon Stem/Progenitor Cells.

Hyperuricemia is a metabolic disorder that is essential to the development of inflammatory gout, with increasing prevalence over recent years. Emerging clinical findings has evidenced remarkable tendon damage in individuals with longstanding asymptomatic hyperuricemia, yet the impact of hyperuricemia on tendon homeostasis and associated repercussions is largely unknown. Here, we investigated whether asymptomatic hyperuricemia was associated with spontaneous ruptures in the Achilles tendon and the pathological effect of hyperuricemia on the tendon stem/progenitor cells (TSPCs). Significantly higher serum uric acid (SUA) levels were found in 648 closed Achilles tendon rupture (ATR) patients comparing to those in 12559 healthy volunteers. In vitro study demonstrated that uric acid (UA) dose dependently reduced rat Achilles TSPC viability, decreased the expressions of tendon collagens, and deformed their structural organization while significantly increased the transcript levels of matrix degradative enzymes and proinflammatory factors. Consistently, marked disruptions in Achilles tendon tissue structural and functional integrity were found in a rat model of hyperuricemia, together with enhanced immune cell infiltration. Transcriptome analysis revealed a significant elevation in genes involved in metabolic stress and tissue degeneration in TSPCs challenged by hyperuricemia. Specifically, reduced activity of the AKT-mTOR pathway with enhanced autophagic signaling was confirmed. Our findings indicate that asymptomatic hyperuricemia may be a predisposition of ATR by impeding the normal functions of TSPCs. This information may provide theoretical and experimental basis for exploring the early prevention and care of ATR.

Inorganic polyphosphates stimulates matrix production in human annulus fibrosus cells.

INTRODUCTION: Ubiquitously found in all life forms, inorganic polyphosphates (polyP) are linear polymers of repeated orthophosphate units. Present in intervertebral disc tissue, polyP was previously shown to increase extracellular matrix production in nucleus pulposus (NP) cells. However, the effects of polyP on human annulus fibrosus (hAF) cell metabolism is not known. METHODS AND RESULTS: Here, hAF cells cultured in the presence of 0.5 to 1 mM polyP, chain length 22 (polyP-22), showed an increase in glycosaminoglycan content, proteoglycan and collagen synthesis, and aggrecan and collagen type 1 gene expression. Gene expression level of matrix metalloproteinases 1 was reduced while matrix metalloproteinases 3 level was increased in hAF cells treated with 1 mM polyP. Adenosine triphosphate (ATP) synthesis was also significantly increased in hAF cell culture 72 hours after the exposure to 1 mM polyP-22. CONCLUSIONS: PolyP thus has both anabolic and bioenergetic effects in AF cells, similar to that observed in NP cells. Together, these results suggest polyP as a potential energy source and a metabolic regulator of disc cells.

MicroRNA­25 protects nucleus pulposus cells against apoptosis via targeting SUMO2 in intervertebral disc degeneration.

It has been reported that microRNA (miRNA/miR)­25 is downregulated in patients with intervertebral disc degeneration (IVDD). However, the potential role of miR­25 in IVDD remains unclear. Therefore, the present study aimed to investigate the effects of miR­25 on human intervertebral disc nucleus pulposus cells (NPCs). The expression levels of miR­25 and those of small ubiquitin­related modifier 2 (SUMO2) were determined in human nucleus pulposus (NP) tissues by reverse transcription­quantitative PCR (RT­qPCR) and western blot analyses. Subsequently, the potential interaction between miR­25 and SUMO2 was validated via dual­luciferase reporter assay and RNA pull­down assay with biotinylated miRNA. The effects of miR­25 on NPC proliferation and apoptosis were evaluated using Cell Counting Kit­8 assay, 5­ethynyl­2'­deoxyuridine incorporation assay, and flow cytometry. The results showed that miR­25 was downregulated in patients with IVDD. In addition, miR­25 increased the proliferation of NPCs and inhibited their apoptosis. Furthermore, the current study verified that miR­25 could directly target SUMO2 and regulate its expression via the p53 signaling pathway. Additionally, the effects of miR­25 on NPCs were abrogated following SUMO2 overexpression. Overall, the results of the present study demonstrated that miR­25 could promote the proliferation and inhibit the apoptosis of NPCs via targeting SUMO2, suggesting that miR­25 may be a potential target in the treatment of IVDD.

Influences of circulatory factors on intervertebral disc aging phenotype.

Whether disc aging is influenced by factors beyond its local environment is an important unresolved question. Here we performed heterochronic parabiosis in mice to study the effects of circulating factors in young and old blood on age-associated intervertebral disc degeneration. Compared to young isochronic pairs (Y-Y), young mice paired with old mice (Y-O) showed significant increases in levels of disc MMP-13 and ADAMTS4, aggrecan fragmentation, and histologic tissue degeneration, but negligible changes in cellular senescence markers (p16INK4a, p21Cip1). Compared to old isochronic pairs (O-O), old mice paired with young mice (O-Y) exhibited a significant decrease in expression of cellular senescence markers (p16, p21, p53), but only marginal decreases in the levels of disc MMP-13 and ADAMTS4, aggrecan fragmentation, and histologic degeneration. Thus, exposing old mice to young blood circulation greatly suppressed disc cellular senescence, but only slightly decreased disc matrix imbalance and degeneration. Conversely, exposing young mice to old blood accelerated their disc matrix imbalance and tissue degeneration, with little effects on disc cellular senescence. Thus, non-cell autonomous effects of circulating factors on disc cellular senescence and matrix homeostasis are complex and suggest that disc matrix homeostasis is modulated by systemic factors and not solely through local disc cellular senescence.

Effects of suppressing bioavailability of insulin-like growth factor on age-associated intervertebral disc degeneration.

Suppression of the insulin-like growth factor-1 (IGF-1) signaling pathway reduces age-related disorders and increases lifespan across species, making the IGF-1 pathway a key regulator of aging. Previous in vitro intervertebral disc cell studies have reported the pro-anabolic effect of exogenously adding IGF-1 on matrix production. However, the overall effects of suppressing IGF-1 signaling on age-related intervertebral disc degeneration (IDD) is not known. Here, the effects of suppressing IGF-1 signaling on age-related IDD in vivo were examined using PAPPA -/- mice. These are animals with targeted deletion of pregnancy-associated plasma protein A (PAPPA), the major protease that cleaves inhibitory IGF binding proteins that control bioavailability of IGF-1 for cell signaling. Compared to age-matched wild-type (Wt) littermates, reduced levels of matrix proteoglycan (PG) and aggrecan were seen in discs of 23-month old PAPPA -/- mice. Decreased aggrecanolysis and expression of two key catabolic markers, matrix metalloproteinase-3 and a disintegrin and metalloproteinase with thrombospondin motifs-4, were also observed in discs of old PAPPA -/- mice compared to Wt littermates. Suppressing IGF-1 signaling has been implicated to shift cellular metabolism toward maintenance rather than growth and decreasing cellular senescence. Along this line, discs of old PAPPA -/- mice also exhibited lower cellular senescence, assessed by p53 and lamin B1 markers. Collectively, the data reveal complex regulation of disc matrix homeostasis by PAPPA/IGF-1 signaling during chronologic aging, that is, reduced IGF-1 bioavailability confers the benefit of decreasing disc cellular senescence and matrix catabolism but also the disadvantage of decreasing disc PG matrix anabolism. This pathway requires further mechanistic elucidation before IGF-1 could be considered as a therapeutic growth factor for treating IDD.

The Psychological Impact and Associated Factors of COVID-19 on the General Public in Hunan, China.

PURPOSE: This study aimed to assess the psychological impact of the COVID-19 pandemic among the general public in Hunan Province, China, which could help develop psychological interventions and mental health programs. PARTICIPANTS AND METHODS: This online cross-sectional study recruited 571 participants through snowball sampling between February 2 and February 5, 2020. Data were collected through a general information questionnaire, the Public Emergency Psychological State Questionnaire, the Simple Coping Style Questionnaire, and the Public Disease Awareness on COVID-19 Scale. RESULTS: The total mean score of the public emergency psychological state of the sample was 0.27 (0.31) points, with only 5.78% of participants (n = 33) developing psychological distress. Avoidant coping style and disease awareness were weakly positively correlated (rs = 0.257, p < 0.01) and weakly negatively correlated (rs = -0.124, p <0.01) with psychological responses, respectively. There were significant psychological differences among the following variables: occupation, symptoms of fever or fatigue, discernment of the authenticity of COVID-19 information, and level of concern regarding COVID-19 (p < 0.05). CONCLUSION: The COVID-19 pandemic appears to have had a minor psychological impact on the general population in Hunan Province. However, psychological health promotion in the general public is still required, especially for employees (such as company employees, migrant workers, and businessmen), individuals with COVID-19-like symptoms, limited discernment competence and unconcerned attitudes. IMPLICATIONS: The initiatives for improving psychological health among the general public could focus on delivering COVID-19 knowledge and alleviating avoidant coping styles. Our findings could provide important insight for the development of psychological support strategies in China, as well as in other places affected by the epidemic.