ACE2 and TMPRSS2 immunolocalization and oral manifestations of COVID-19.

OBJECTIVES: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry into the host cells depends on the expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2). We investigated the distribution of ACE2- and TMPRSS2-expressing cells in various oral tissues to identify the underlying mechanism of oral manifestations in patients with coronavirus disease 2019. SUBJECTS: We analyzed the expression patterns of ACE2 and TMPRSS2 in the oral mucosa (tongue, palate, and buccal mucosa), trigeminal ganglion, vessels, and salivary glands of 9 Sprague-Dawley rats using immunohistochemistry and immunofluorescence. RESULTS: ACE2 and TMPRSS2 were strongly expressed in the intermediate layer of the squamous epithelia of tongue papillae and buccal mucosa. ACE2- and TMPRSS2-positive cells were observed in the taste buds of the tongue. Additionally, ACE2 and TMPRSS2 were co-expressed in the ductal epithelium and acinar cells of salivary glands. Furthermore, both ACE2 and TMPRSS2 were stained in the neuronal cell body of trigeminal ganglia, but not in Schwann cells. Moreover, ACE2 and TMPRSS2 were expressed in capillaries, but not in venules/arterioles. CONCLUSIONS: SARS-CoV-2 can spread the suprabasal area of squamous epithelia of the oral mucosa, invades taste bud, trigeminal nerve, parotid gland, and microvessel, resulting in oral manifestations.

Crocin suppresses LPS-stimulated expression of inducible nitric oxide synthase by upregulation of heme oxygenase-1 via calcium/calmodulin-dependent protein kinase 4.

Crocin is a water-soluble carotenoid pigment that is primarily used in various cuisines as a seasoning and coloring agent, as well as in traditional medicines for the treatment of edema, fever, and hepatic disorder. In this study, we demonstrated that crocin markedly induces the expression of heme oxygenase-1 (HO-1) which leads to an anti-inflammatory response. Crocin inhibited inducible nitric oxide synthase (iNOS) expression and nitric oxide production via downregulation of nuclear factor kappa B activity in lipopolysaccharide- (LPS-) stimulated RAW 264.7 macrophages. These effects were abrogated by blocking of HO-1 expression or activity. Crocin also induced Ca(2+) mobilization from intracellular pools and phosphorylation of Ca(2+)/calmodulin-dependent protein kinase 4 (CAMK4). CAMK4 knockdown and kinase-dead mutant inhibited crocin-mediated HO-1 expression, Nrf2 activation, and phosphorylation of Akt, indicating that HO-1 expression is mediated by CAMK4 and that Akt is a downstream mediator of CAMK4 in crocin signaling. Moreover, crocin-mediated suppression of iNOS expression was blocked by CAMK4 inhibition. Overall, these results suggest that crocin suppresses LPS-stimulated expression of iNOS by inducing HO-1 expression via Ca(2+)/calmodulin-CAMK4-PI3K/Akt-Nrf2 signaling cascades. Our findings provide a novel molecular mechanism for the inhibitory effects of crocin against endotoxin-mediated inflammation.

The Matthew Effect in Recovery from Smartphone Addiction in a 6-Month Longitudinal Study of Children and Adolescents.

The clinical course of problematic smartphone use (PSU) remains largely unknown due to a lack of longitudinal studies. We recruited 193 subjects with smartphone addiction problems for the present study. After providing informed consent, the subjects completed surveys and underwent comprehensive interviews regarding smartphone usage. A total of 56 subjects among the 193 initially recruited subjects were followed up for six months. We compared baseline characteristics between persistent addicted users and recovered users at the end of the 6-month follow-up. Persistent problematic smartphone users displayed higher baseline smartphone addiction severity and were more prone to develop mental health problems at the follow-up. However, baseline depressive or anxiety status did not significantly influence the course of PSU. PSU behaved more like an addictive disorder rather than a secondary psychiatric disorder. Harm avoidance, impulsivity, higher Internet use, and less conversation time with mothers were identified as poor prognostic factors in PSU. Lower quality of life, low perceived happiness, and goal instability also contributed to persistent PSU, while recovery increased these scores as well as measures of self-esteem. These findings suggest that the Matthew effect is found in the recovery of PSU with better premorbid psychosocial adjustment leading to a more successful recovery. Greater clinical resources are required for interventions in vulnerable populations to modify the course of this increasingly prevalent problematic behavior worldwide.

Aggression and Harm-Avoidant Trait Impede Recovery From Internet Gaming Disorder.

Background: Relatively little is known about which neuropsychological factors promote recovery from Internet gaming disorder (IGD). Methods: With informed consents, a cohort study was conducted in Seoul metropolitan area, South Korea, to investigate the course of IGD in youths. At baseline, we assessed psychosocial measures and gaming related measures such as Young's Internet Addiction Test (IAT) and the Aggression Questionnaire. The Balloon Analog Risk Task was also performed to study risk-taking behavior. A total of 60 subjects demonstrating three or greater criteria in the diagnostic interviews on IGD and the IAT score of 50 or above were included. After brief parental coaching at baseline, the participants were followed up at 3 and 6 months (n = 31). The baseline characteristics were compared between the non-improved group (<10% improvement in IAT score) and the improved group (≥30% improvement in IAT score) using Mann-Whitney U-test or chi-squared tests with a two-tailed statistical significance of 0.05. Results: The non-improved group and the improved group did not demonstrate significant differences regarding demographics or the IAT scores at baseline. However, the IAT scores were significantly higher in the non-improved group at both 3 and 6 months. The non-improved group was also more likely to display higher aggression and harm avoidance than the improved group at baseline. Discussion: Youths with excessive gaming problems should be evaluated for aggression and harm avoidance since they contributed to a worse prognosis. For those with high aggression or harm avoidance, more active therapeutic interventions should be considered.

Achyranthes japonica exhibits anti-inflammatory effect via NF-κB suppression and HO-1 induction in macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: The roots of Achyranthes japonica Nakai have been used in traditional herbal medicine for the treatment of edema and arthritis in Korea. AIM OF THE STUDY: In this study, we investigated the molecular mechanism responsible for anti-inflammatory effects of the aqueous extract of A. japonica roots (AJ) in LPS-stimulated macrophages. MATERIALS AND METHODS: Nitric oxide (NO) production and as inducible nitric oxide synthase (iNOS) expression were examined in TG-elicited peritoneal macrophages and RAW 264.7 cells. Cell viability was monitored by MTT assay. Protein and mRNA expressions were determined by Western blotting and RT-PCR, respectively. The activity of NF-κB and Nrf2 were examined by EMSA, immunocytochemistry or reporter assay. RESULTS: AJ inhibited LPS-induced NO secretion as well as iNOS expression, without affecting cell viability. Furthermore, AJ suppressed LPS-induced NF-κB activation, degradation of IκB-α, phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38. Further study demonstrated that AJ induced heme oxygenase-1 (HO-1) gene expression via nuclear translocation and transactivation of Nrf2. In addition, the inhibitory effects of AJ on iNOS expression were abrogated by small interfering RNA-mediated knock-down of HO-1. CONCLUSIONS: These results suggest that AJ suppresses LPS-induced NO production and iNOS expression in macrophages through the inhibition of IκB/NF-κB and MAPK as well as the Nrf2-mediated HO-1 induction. These findings provide the scientific rationale for anti-inflammatory therapeutic use of A. japonica roots.

The Stem Bark of Kalopanax pictus Exhibits Anti-inflammatory Effect through Heme Oxygenase-1 Induction and NF-κB Suppression.

BACKGROUND: The stem bark of Kalopanax pictus (KP) has been used in traditional medicine to treat rheumatoidal arthritis, neurotic pain and diabetes mellitus in China and Korea. In this study, the mechanism responsible for anti-inflammatory effects of KP was investigated. METHODS: We examined the effects of KP on NO production, nitric oxide synthase (iNOS) and HO-1 expression, NF-κB, Nrf2 and MAPK activation in mouse peritoneal macrophages. RESULTS: The aqueous extract of KP inhibited LPS-induced NO secretion as well as inducible iNOS expression, without affecting cell viability. KP suppressed LPS-induced NF-κB activation, phosphorylation and degradation of IκB-α, phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). Furthermore, KP induced HO-1 expression and Nrf2 nuclear translocation. CONCLUSION: These results suggest that KP has the inhibitory effects on LPS-induced NO production in macrophages through NF-κB suppression and HO-1 induction.