DPSCs regulate epithelial-T cell interactions in oral submucous fibrosis

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous lesion characterized by fibrous tissue deposition, the incidence of which correlates positively with the frequency of betel nut chewing. Prolonged betel nut chewing can damage the integrity of the oral mucosal epithelium, leading to chronic inflammation and local immunological derangement. However, currently, the underlying cellular events driving fibrogenesis and dysfunction are incompletely understood, such that OSF has few treatment options with limited therapeutic effectiveness. Dental pulp stem cells (DPSCs) have been recognized for their anti-inflammatory and anti-fibrosis capabilities, making them promising candidates to treat a range of immune, inflammatory, and fibrotic diseases. However, the application of DPSCs in OSF is inconclusive. Therefore, this study aimed to explore the pathogenic mechanism of OSF and, based on this, to explore new treatment options.

METHODS

A human cell atlas of oral mucosal tissues was compiled using single-cell RNA sequencing to delve into the underlying mechanisms. Epithelial cells were reclustered to observe the heterogeneity of OSF epithelial cells and their communication with immune cells. The results were validated in vitro, in clinicopathological sections, and in animal models. In vivo, the therapeutic effect and mechanism of DPSCs were characterized by histological staining, immunohistochemical staining, scanning electron microscopy, and atomic force microscopy.

RESULTS

A unique epithelial cell population, Epi1.2, with proinflammatory and profibrotic functions, was predominantly found in OSF. Epi1.2 cells also induced the fibrotic process in fibroblasts by interacting with T cells through receptor-ligand crosstalk between macrophage migration inhibitory factor (MIF)-CD74 and C-X-C motif chemokine receptor 4 (CXCR4). Furthermore, we developed OSF animal models and simulated the clinical local injection process in the rat buccal mucosa using DPSCs to assess their therapeutic impact and mechanism. In the OSF rat model, DPSCs demonstrated superior therapeutic effects compared with the positive control (glucocorticoids), including reducing collagen deposition and promoting blood vessel regeneration. DPSCs mediated immune homeostasis primarily by regulating the numbers of KRT19 + MIF + epithelial cells and via epithelial-stromal crosstalk.

CONCLUSIONS

Given the current ambiguity surrounding the cause of OSF and the limited treatment options available, our study reveals that epithelial cells and their crosstalk with T cells play an important role in the mechanism of OSF and suggests the therapeutic promise of DPSCs.

Age-related hearing loss accelerates the decline in fast speech comprehension and the decompensation of cortical network connections

Patients with age-related hearing loss face hearing difficulties in daily life. The causes of age-related hearing loss are complex and include changes in peripheral hearing, central processing, and cognitive-related abilities. Furthermore, the factors by which aging relates to hearing loss via changes in auditory processing ability are still unclear. In this cross-sectional study, we evaluated 27 older adults (over 60 years old) with age-related hearing loss, 21 older adults (over 60 years old) with normal hearing, and 30 younger subjects (18-30 years old) with normal hearing. We used the outcome of the upper-threshold test, including the time-compressed threshold and the speech recognition threshold in noisy conditions, as a behavioral indicator of auditory processing ability. We also used electroencephalography to identify presbycusis-related abnormalities in the brain while the participants were in a spontaneous resting state. The time-compressed threshold and speech recognition threshold data indicated significant differences among the groups. In patients with age-related hearing loss, information masking (babble noise) had a greater effect than energy masking (speech-shaped noise) on processing difficulties. In terms of resting-state electroencephalography signals, we observed enhanced frontal lobe (Brodmann's area, BA11) activation in the older adults with normal hearing compared with the younger participants with normal hearing, and greater activation in the parietal (BA7) and occipital (BA19) lobes in the individuals with age-related hearing loss compared with the younger adults. Our functional connection analysis suggested that compared with younger people, the older adults with normal hearing exhibited enhanced connections among networks, including the default mode network, sensorimotor network, cingulo-opercular network, occipital network, and frontoparietal network. These results suggest that both normal aging and the development of age-related hearing loss have a negative effect on advanced auditory processing capabilities and that hearing loss accelerates the decline in speech comprehension, especially in speech competition situations. Older adults with normal hearing may have increased compensatory attentional resource recruitment represented by the top-down active listening mechanism, while those with age-related hearing loss exhibit decompensation of network connections involving multisensory integration.

[The mediating effect of resilience on anxiety and subjective well-being in occupational population]

Objective: To explore the current situation of anxiety, subjective well-being in occupational population and the mediating effect of resilience. Methods: From March 24th to 26th, 2020, a cross-sectional survey was conducted among occupational population aged ≥18 years old using online questionnaires. A total of 2134 valid questionnaires were obtained, with respondents from 30 provinces, autonomous regions, and municipalities directly under the Central Government. Their general demographic data, subjective well-being, anxiety, and resilience were collected. Pearson χ(2) test and Spearson correlation analysis were used for data analysis, and structural equation model was used to explore the mediating effect of resilience on anxiety and subjective well-being. Results: The age of the respondents ranged from 18 to 60 years old, with an average age of (31.19±7.09) years old, including 1075 (50.4%) women and 1059 (49.6%) men. The positive rates of low subjective well-being and anxiety were 46.5% (992/2134) and 28.4% (607/2134), respectively. Anxiety scores were significantly negatively correlated with subjective well-being scores and resilience scores (r(s)=-0.52, -0.41, P<0.05), while resilience was significantly positively correlated with subjective well-being (r(s)=0.32, P<0.05). Structural equation models showed that anxiety had a negative predictive effect on subjective well-being, while resilience not only had a positive predictive effect on subjective well-being, but also played a mediating role between anxiety and subjective well-being, with a mediating effect of 9.9%. Conclusion: The situation of anxiety and well-being in the occupational population is still not optimistic, and resilience has a mediating effect between anxiety and subjective well-being.

Secondary coronary artery ostial lesions: Three case reports

BACKGROUND

Atherosclerosis is one of the main causes of coronary artery ostial lesions seen clinically. Secondary coronary artery ostial lesions are rare, and cases reported previously were associated with syphilitic vasculitis and aortic dissection. Here, we report three rare cases of secondary coronary ostial lesions. Due to their rareness, these lesions can easily be neglected, which may lead to misdiagnosis and missed diagnosis.

CASE SUMMARY

We present three patients with acute myocardial infarction and unstable angina caused by secondary coronary artery ostial lesions. In Case 1, coronary angiography (CAG) revealed 90% stenosis of the left main coronary ostium. Chest contrast computed tomography (CT) suggested thymic carcinoma invading the left main coronary ostium. Coronary artery bypass grafting and tumor resection were performed. In Case 2, echocardiography revealed a sinus of Valsalva aneurysm (SVA)-like dilatation. CAG showed a right coronary sinus giant aneurysm and complete obstruction of the right coronary artery (RCA) ostium. Aortic contrast CT confirmed these findings. The Bentall procedure was performed. In Case 3, CT CAG identified an anomalous origin of the right coronary artery (AORCA) from the left sinus of Valsalva coursing between the aorta and pulmonary trunk, causing severe RCA ostium stenosis by compression. Surgical correction of the AORCA was performed.

CONCLUSION

The cases reported here suggest that we should consider other causes of coronary ostial lesions other than atherosclerosis.

[Current status of research on short-term urogenital function after transanal total mesorectal excision and laparoscopic total mesorectal excision]

Thanks to the new surgical approach, transanal total mesorectal excision (taTME) has a better operative field exposure than laparoscopic-assisted total mesorectal excision (laTME), especially for male patients with obesity, pelvic stenosis or prostate hypertrophy. Nevertheless, whether the urogenital function and quality of life after taTME are better as compared to laTME requires further study. According to the existing studies, taTME and laTME are not significantly different in symptoms of the urology system for male patients, but some large sample clinical studies show that the incidence of urethral mechanical injury after taTME is higher. Unfortunately, there is no elaboration on that for females. The sexual function of male patients after taTME and laTME is both impaired. The sexual function of male patients will be relieved to different degrees over time, but there is no significant difference. Compared with laTME, taTME shows advantages in the sexual function for female patients. There is no significant difference in short-term urogenital system function between taTME and laTME at present. As a new surgical approach, the impact on urogenital system function after taTME is acceptable. However, whether there is a significant difference in urogenital function between taTME and laTME needs further research. In addition, functional results still need comprehensive evaluation, and preoperative baseline evaluation also needs to be enhanced. The functional evaluation for male and female should be carried out separately rather than confused. Questionnaire for evaluation of functional results also needs to be verified.

[The development process and new requirements of structured training on transanal total mesorectal resection]

Due to the technical difficulty and long learning curve, the benefits of Transanal total mesorectal excision may be obscured by surgical complications that arise from rapid, large-scale development, therefore the surgeons need to receive sufficient training before performing this surgery. At present, a mature structured training system has been formed, but the development of structured training has not met the needs of existing surgical development. In order to standardize the development of transanal total mesorectal excision, the European Society of Colorectal Diseases and 14 international surgical societies recently launched the "International Expert Consensus Guidelines for the Indication, Implementation and Quality Evaluation of Transanal Total Mesorectum Resection". The consensus involves the requirements for trainees, the content and process of training, as well as the evaluation and registration of training results. Training in cadaver is the core of structured training. Beginners should receive repeated training and conduct the surgery under the guidance of instructors.

Development of BRAF V600E Mutation in NRAS Q61L Mutated Rectal Cancer

BRAF and NRAS are oncogenes in the RAS/RAF/MEK/MAP-kinase signaling pathway. Coexistent mutations of BRAF and NRAS in a single colorectal cancer patient have always been considered mutually exclusive or at least rare. The clinical outcome of these patients remains undetermined. Herein we report a 53-year-old man harboring an NRAS Q61L mutation in his primary rectal carcinoma, who presented with a concomitant mutation of BRAF V600E in his liver metastasis biopsy 55 months after the primary CRC surgical resection. Our findings suggest that a BRAF and NRAS developed co-mutation may lead to a distinct clinicopathological progression. BRAF-mutated CRCwill not benefit from anti-RAS targeted therapy.

[Moderating effect of sense of coherence between occupational stress and depression]

Objective: To explore the moderating effect of sense of coherence in the relationship between occupational stress and depression. Methods: From June to September in 2018, migrant workers were purposively selected from the urban (including office buildings, shopping malls, barber shops or restaurants and other service enterprises) and suburban (including microelectronics, internet, clothing processing and art design and other factories) areas of Shanghai. A total of 3 034 people were investigated and 2 573 valid questionnaires were collected. Patient health questionnaire (PHQ), sense of coherence questionnaire (SOC) and job content questionnaire (JCQ) were used to investigate the levels depression, sense of coherence and occupational stress. Hierarchical regression analysis was used to analyze the moderating effect of sense of coherence on occupational stress and depression, and SPSS PROCESS macro program and Bootstrap method were used to further explore the moderating effect of sense of coherence. Results: The age of total 2 573 migrant workers was (28.24±7.33) years old and 49.79% of them were males. The scores of depression, occupational stress and sense of coherence were 6.67±4.74, 28.45±4.38 and 62.02±10.89, respectively. The depression level was positively correlated with occupational stress (r=0.33, P=0.007), and negatively correlated with sense of coherence (r=-0.53, P=0.003). The hierarchy regression analysis suggested that the interaction between occupational stress and sense of coherence was associated with depression symptom (β=-0.07, P=0.001). Bootstrap analysis showed that occupational stress was not associated with depression symptom with high level of sense of sense of coherence (β=0.04, 95%CI=-0.01-0.10), while occupational stress was associated with depression symptom with low level of sense of sense of coherence (β=0.19, 95%CI=0.14-0.23). Conclusion: The high level of sense of coherence has a moderating effect on the relationship between occupational stress and depressive symptoms, while the low level of sense of coherence does not have this effect.

[CbCYP716A261, a New β-Amyrin 28-Hydroxylase Involved in Conyzasaponin Biosynthesis from Conyza blinii]

Conyzasaponins produced by the traditional Chinese herb Conyza blinii are oleanane-type saponins with a wide range of biological activities. Here, we identified a gene, designated CbCYP716A261, encoding a β-amyrin 28-hydroxylase in conyzasaponins biosynthesis. Ten full putative CYP sequences were isolated from Conyza blinii transcript tags. The CbCYP716A261 gene product was selected as the putative β-amyrin 28-hydroxylase by phylogenetic analysis and transcriptional activity analysis of methyl jasmonate-treated Conyza blinii. To identify the enzymatic activity, we performed enzymatic activity experiments in vitro and in vivo. The HPLC results revealed that CbCYP716A261 catalyzes the hydroxylation of β-amyrin at the C-28 position to yield oleanolic acid. Our findings provide new information about the conyzasaponin biosynthesis pathway and widen the list of isolated β-amyrin 28-hydroxylases.

[Current status of research on short-term quality of life after sphincteric-saving surgery in rectal cancer patients]

Sphincteric-saving surgery (SSS) is currently a hot spot in the treatment of mid-low rectal cancer. Although it preserves the anatomical continuity of the colon and anus, the postoperative functional outcomes and quality of life (QOL) remains to be confirmed. Current studies have shown that quality of life worsens at the first month after surgery, improves within 3-6 months, and stabilizes at about 1 year. The QOL was associated with patient-related factors, tumor-related factors, treatment-related factors and postoperative complications. For patient-related factors, younger patients have worse role function and sexual function but better cognitive function and physical function. Male patients deteriorate significantly in sexual and social function. For tumor-related factors, patients with lower rectal cancer have poorer defecation function. Those with advanced rectal cancer are more likely to suffer from side-effects related to chemotherapy. For treatment-related factors, patients undergoing intersphincteric resection have worse role function, body image and sexual interest. Preventive ileostomy results in the deterioration of role function, body image and sexual interest. Chemotherapy causes taste changes and chest pain. For postoperative complication, patients with anastomotic leakage have worse bowel function and psychological state. Patients with major low anterior resection syndrome and genitourinary dysfunction have worse global health score, social function and role function. In conclusion, short-term quality of life after sphincteric-saving surgery is acceptable. To improve QOL, specific intervention and guidance should be given to patients in this stage. Meanwhile, since many factors influence the quality of life simultaneously, researchers are confused about the questionnaire outcomes. Therefore, more specific and comprehensive tools are needed to evaluate QQL after sphincteric-saving surgery.

[Mediating effect of work engagement between job stress and depressive symptoms in State Grid employees]

Objective: To explore the relationship between job stress, work engagement and depressive symptoms of State Grid workers, and to analyze the mediating effect of work engagement between job stress and depressive symptoms. Methods: A cross-sectional survey was conducted to investigate 845 employees from a State Grid company, using the brief job stress questionnaire, the Patient Health Questionnaire (PHQ-9) and 9-item Utrecht Work Engagement Scale (UWES-9) in March 2017. Results: The average score of work engagement was 4.49±1.42, the mean value of job stress was 1.15±0.33, the average score of depressive symptoms was 6.44±4.30, and the positive rate of depressive symptoms was 66.9%.There was a negative correlation between work engagement with both job stress and depressive symptoms (r=-0.193, -0.397, both P<0.01) , and job stress was positively correlated with depressive symptoms (r=0.260, P<0.01) . The relationship between job stress and depressive symptoms was partly mediated by work engagement, and the mediating effect accounted for 27.2% of the total effect. Conclusion: The work engagement of State Grid staff acts as the mediator between job stress and depressive symptoms, alleviating the depressive symptoms caused by job stress.

[Association between Long Working Hours and Job Stress and Depression among Employees from a State Grid Company]

Objective: This study was to understand the current situation of long working hours and identify the association of long working hours and job stress and depression among workers from one district company of state grid. Methods: The project was done with the cross-sectional survey. All questionnaires were completed by self-administered with informed consent. Employees' weekly working hours was reported by themselves; Using the PHQ-9 scale to assess depression, the JDC Model to evaluate job stress, and SPSS software to analyze data, the single factor chi-square test and multivariate Logistic analysis were performed to identify the association between long working hours and job stress, depression. Results: there were 35.3 percent employees with over 44 hours a week. The association between increasing weekly working hours and job stress and depression was statistically significant. Compared to the reference group (≤44 h) , for those who worked more than 44 hours per week, the odds ratio of job stress was 2.02 (95%CI=1.27-3.23) times increased, and the odds ratio of depression was 1.60 (95%CI=1.01-2.55) times increased, especially for those (≥60 h) , the odds ratio was 3.69 (95%CI=1.45-9.41) and 2.76 (95%CI=1.09-7.03) respectively. Conclusion: Long working hours can significantly increase the risk of job stress and depression among workers. When their weekly working hours exceeds 60, long working hours will be the independent risk factor for both job stress and depression.

Linear-shear-current modified Schrödinger equation for gravity waves in finite water depth

A nonlinear Schrödinger equation for the propagation of two-dimensional surface gravity waves on linear shear currents in finite water depth is derived. In the derivation, linear shear currents are assumed to be a linear combination of depth-uniform currents and constant vorticity. Therefore, the equation includes the combined effects of depth-uniform currents and constant vorticity. Next, using the equation, the properties of the modulational instability of gravity waves on linear shear currents are investigated. It is showed that shear currents significantly modify the modulational instability properties of weakly nonlinear waves. Furthermore, the influence of linear shear currents on Peregrine breather which can be seen as a prototype of freak waves is also studied. It is demonstrated that depth-uniform opposing currents can reduce the breather extension in both the time and spatial domain in intermediate water depth, but following currents has the adverse impact, indicating that a wave packets with freak waves formed on following currents contain more hazardous waves in finite water depth. However, the corresponding and coexisting vorticity can counteract the influence of currents. Additionally, if the water depth is deep enough, shear currents have negligible effect on the characteristics of Peregrine breathers.

[Clinical treatment of metastatic papillary thyroid carcinoma in cervical lymph nodal with occult primary sites]

Objective:To discuss the diagnosis, treatment and prognosis of metastatic papillary thyroid carcinoma in cervical lymph nodal with occult primary sites. Method:The clinical data of 5 patients involved papillary thyroid carcinoma with cervical lymph nodal metastasis with occult primary sites from 2009 to 2015 were analyzed. Result:According to preoperation examinations, two of them only underwent neck lymph node resection and three patients underwent asubtotal or total thyroidectomy plus neck lymph node dissection. All the pathological results showed that there were metastatic papillary thyroid carcinoma in cervical lymph nodal, but the primary sites of thyroid tissue were normal. After 1 to 7 year follow-up, there was no recurrence. Conclusion:Whether to take the thyroidectomy need to be carefully considered thyroidectomy in patients with metastatic papillary thyroid carcinoma in cervical lymph nodal with occult primary sites.

[Workplace social capital and intention to stay among Chinese nurses: a structural equation model]

Objective: To explore a model that workplace social capital is associated with intention to stay (ITS) in the nursing profession and that this association is partially mediated by organizational commitment, job satisfaction, and job stress among Chinese nurses. Methods: A cross-sectional, observationalstudy was conducted in Shanghai, China between September and December 2014. Two thousandforty-two nurses from 23 healthcare organizations were recruited for the current study using a two-stage sampling process.Intention to stay, workplace social capital, job satisfaction, organizational commitment, and job stress was measured by validated scale. Measured variable path analysis (MVPA) was used to test their hypothesized relationships. Results: There were significant positive direct effects from workplace social capital (β=0.11, P<0.01) , organizational commitment (β=0.81, P<0.01) and job satisfaction (β=0.03, P<0.01) to ITS, and a negative direct effects from job strain to ITS (β=-0.03, P<0.01) . The model explained 84% of the variability in ITS. Additionally, workplace social capital had significant positive direct effects on organizational commitment (β=0.65, P<0.01) , job satisfaction (β=0.44, P<0.01) and negative direct effects on job strain (β=-0.35, P<0.01) . The indirect effect of social capital to ITS was 0.55. Job satisfaction was positively associated with organizational commitment (r=0.47, P<0.01) , and negtively associated with job stress (r=-0.12, P<0.01) . Job stress was negtively associated with organizational commitment (r=-0.20, P<0.01) . Conclusion: This study suggests that greater workplace social capital may lead to higher ITS in nursing primarily by increasing commitment to the nursing occupation and their job satisfaction and by reducing their sense of job stress.

[An adolescent with Hashimoto's encephalopathy after surgery and ¹³¹I radiotherapy for papillary thyroid carcinoma: one case report]

Hashimoto's encephalopathy is a rare brain disease. Its etiology is still unknown. In this paper, we reported a 15-year-old female patient underwent total thyroidectomy and lymph node dissection, due to a multifocal papilliferous carcinoma of the right lobus. Forty-two days after surgery, the patient was treated by ¹³¹I radiotherapy in another hospital and begun to have a headache after 48 hours. At last, the patient was diagnosed by HE on the basis of all considerations. She recovered from by i.v. Immunoglobulin. Till now, the patient has not relapsed for more than 4 years follow-up.

[Association between sense of coherence and occupational stress of workers in modern service industry in Shanghai, China]

Objective: To investigate understand the current status of the sense of coherence and occupational stress in modern service workers, and to analyze the association between occupational stress and the sense of coherence. Methods: From March to April, 2016, 834 modern service workers from 3 companies in Shanghai, China (in air transportation industry, marketing industry, and travel industry) were surveyed by non-ran-dom sampling. The self-completion questionnaires were filled out anonymously given the informed consent of the workers. The occupational stress questionnaire was used to evaluate occupational stress, and the Chinese version of the Sense of Coherence Scale (SOC-13) was used to assess the mental health. Results: The mean score for the sense of coherence of the respondents was 61.54±10.46, and 50.1% of them were self-rated as having occupational stress. There were significant differences in SOC score between groups with different ages, marital status, positions, lengths of service, family per capita monthly income, and weekly work hours (P<0.05). The occupational stress score differed significantly across groups with different marital status, lengths of service, and weekly work hours (P<0.05). The scores for working autonomy, social support, and occupational stress differed significantly between groups with different SOC levels (P<0.05). There were significant differences in SOC score and the distribution of low-SOC respondents between groups with different levels of working autonomy, social support, and occupational stress. High SOC is a protective factor for occupational stress (OR=0.39, 95%CI 0.26~ 0.59). Conclusion: Modern service workers in Shanghai have high SOC and moderate occupational stress. Therefore, improving SOC may reduce occupational stress.

CXCR1 Regulates Pulmonary Anti-Pseudomonas Host Defense

Pseudomonas aeruginosa is a key opportunistic pathogen causing disease in cystic fibrosis (CF) and other lung diseases such as chronic obstructive pulmonary disease (COPD). However, the pulmonary host defense mechanisms regulating anti-P. aeruginosa immunity remain incompletely understood. Here we demonstrate, by studying an airway P. aeruginosa infection model, in vivo bioluminescence imaging, neutrophil effector responses and human airway samples, that the chemokine receptor CXCR1 regulates pulmonary host defense against P. aeruginosa. Mechanistically, CXCR1 regulates anti-Pseudomonas neutrophil responses through modulation of reactive oxygen species and interference with Toll-like receptor 5 expression. These studies define CXCR1 as a novel, noncanonical chemokine receptor that regulates pulmonary anti-Pseudomonas host defense with broad implications for CF, COPD and other infectious lung diseases.

Role of IL-17 gene polymorphisms in the susceptibility to gastric cancer

We conducted a study to investigate the role of three IL-17 gene single nucleotide polymorphisms (SNP) (rs2275913G>A, rs3748067C>T, and rs763780 T>C) in the development of gastric cancer. A total of 252 patients with gastric cancer and 252 control subjects were collected between May 2012 and May 2014. The SNP genotyping of IL-17A rs2275913G>A and rs3748067C>T and IL-17F rs763780 T>C was performed using the Sequenom MassARRAY platform (Sequenom, San Diego, CA, USA) according to the manufacturer instructions. By conditional regression analysis, individuals carrying the AA and the GA+AA genotypes of rs2275913G>A were correlated with an elevated risk of gastric cancer when compared with those carrying the GG genotype, and the adjusted ORs (95%CIs) were 2.05 (1.13-3.76) for the AA genotype and 1.45 (1.03-2.08) for the GA+AA genotype. In conclusion, our results suggest that the IL-17A rs3748067C>T and IL-17F rs763780 T>C polymorphisms play an important role in the risk of gastric cancer in a Chinese population.

Optical and magneto-optical anisotropies in large-area two-dimensional Co antidots film

In this work, we investigate the plasmon-induced optical and magneto-optical anisotropies in the large-area square-ordered Co antidots film. It shows that both the outline of reflectivity spectrum and Kerr spectrum are significantly modified by surface plasmon polarition (SPP) resonances. Moreover, the magnitude of Kerr angle reaches to about 10 minutes at the azimuthal angle 45°, which is over 3 times of that of pure Co film. These phenomena are attributed to the SPP resonances with different diffraction orders of reciprocal lattice vectors.

Promoter methylation status of the tumor suppressor gene SOX11 is associated with cell growth and invasion in nasopharyngeal carcinoma

BACKGROUND

The transcription factor SOX11 is one of members of the SRY box-containing (SOX) family emerging as important transcriptional regulators. In recent years, up-regulation of SOX11 has been detected in various types of solid tumors. In this study, the effects of promoter methylation of the SOX11 gene on SOX11 expression and cell growth and invasion of nasopharyngeal carcinoma were investigated.

METHODS

In this study,methylation-specific PCR and real time quantitative PCR have been applied to investigate the effect of promoter methylation of the SOX11 gene on SOX11 expression in the nasopharyngeal carcinoma and chronic inflammation tissues. The nasopharyngeal carcinoma cell line (CNE2) was treated with 5-aza-2'-deoxycytidine. The effect of promoter methylation of SOX11 on growth and invasion of nasopharyngeal carcinoma cells was detected with MTT test and Boyden chamber Matrigel invasion assay.

RESULTS

No or weak expression of SOX11 mRNA was detected in the nasopharyngeal carcinoma tissues of SOX11 gene promoter methylation. Strong expression of SOX11 mRNA was detected in the nasopharyngeal carcinoma tissues of SOX11 gene promoter unmethylation and chronic inflammation tissues of pharynx nasalis. SOX11 mRNA and protein were re-expressed, SOX11 gene was demethylated, and growth and invasion of cells were inhibited in CNE2 cell line after 5-aza-2'-deoxycytidine treatment.

CONCLUSIONS

The results of the study indicate that expression of SOX11 mRNA and protein were related to SOX11 gene methylation status. SOX11 gene methylation may be plays a role in growth and invasion of nasopharyngeal carcinoma cells.

Increased prospective memory interference in normal and pathological aging: different roles of motor and verbal processing speed

This is a study on prospective memory (PM) and the PM interference effect in normal and pathological aging. One hundred and seven subjects, including 41 healthy young adults, 40 non-demented older adults and 26 patients with mild Alzheimer's disease (AD) participated in this study using a laboratory event-based PM task. PM task performance was comparable between the non-demented older and young adults, but impaired in the AD patients. The PM interference effect increased progressively from the healthy young adults, the non-demented older adults, to the AD patients. Path analysis revealed that the possible mechanism mediating the increased PM interference was the slow motor processing speed in normal aging, while it was the slow verbal speed in pathological aging. It is suggested that different neuropsychological mechanisms may underpin the affected performance of PM task in normal and pathological aging.

Sequence analysis of Theileria annulata surface protein in Chinese isolates

OBJECTIVE

To study the TaSP polymorphism in three Chinese isolates of Theileria annulata.

METHODS

The isolates from Inner Mongolia Autonomous Region, Ningxia Hui Autonomous Region and Xinjiang Uygur Autonomous Region were cultured in RPMI 1640 medium. TaSP gene was amplified from genomic DNA extracted from schizonts using polymerase chain reaction (PCR) and sequenced. Its amino acid sequence comparison was carried out with Clustal W2 multiple sequence alignment program. Molecular component and motif prediction were performed with online servers.

RESULTS

The comparison of TaSP amino acid sequences of the three isolates showed that the central region (aa position 38-161) predicted to be the highly immunogenetic domain was polymorphic both in size and amino acid sequence, while the N-terminal (first 37 aa) and C-terminal (last 154 aa) parts were strongly conserved. Phylogenetic analysis and percentage identity revealed that the Chinese isolates were closely related to the isolates from Turkey, but quite different from those of India, Morocco and Tunisia. More importantly, variability was noticed among Chinese isolates, which caused both the location and number's differences of motif (casein kinase II phosphorylation sites) among three TaSP sequences.

CONCLUSION

TaSP polymorphism exists in the Chinese isolates of T. annulata.

Qualitative and quantitative analyses of nucleosides and nucleobases in Ganoderma spp. by HPLC–DAD-MS

A high-performance liquid chromatography-diode array detector-mass spectrometry (HPLC-DAD-MS) analytical method was developed for detection of the nucleosides and nucleobases in two species of Lingzhi, the dried sporophore of Ganoderma lucidum and G. sinense. The method, combining advantages of both DAD and MS, was successfully used to qualitatively identify for six nucleosides namely, adenosine, cytidine, guanosine, inosine, thymidine, uridine and five nucleobases namely, adenine, guanine, hypoxanthine, thymine and uracil in Lingzhi samples. Quantitative analyses showed that uridine was the most abundant nucleoside in these Lingzhi samples and the contents of nine target analytes were found to be different in pileus and stipes of the fruiting bodies and among the different species of G. spp. The established method might apply as an alternative approach for the quality assessment of Lingzhi.

GC-MS fingerprint of Pogostemon cablin in China

Pogostemon cablin, originating in Malaysia and India, is cultivated in southern China including Guangdong and Hainan Province, which was called GuangHuoXiang to differentiate it from the HuoXiang of the north, the species Agastache rugosa, that it resembles. Essential oil of P. cablin mainly contributes to the pharmacological activities and the therapeutic properties of the essential oils are directly correlated with their qualitative and quantitative composition. For controlling the quality, standard fingerprint of P. cablin collected from different regions was developed by using GC-MS. Nine compounds including beta-patchoulene, caryophyllene, alpha-guaiene, seychellene, beta-guaiene, delta-guaiene, spathulenol, patchouli alcohol and pogostone were identified among 10 main peaks in P. cablin. Hierarchical clustering analysis based on characteristics of 10 investigated peaks in GC profiles showed that 18 samples were divided into three main clusters, patchouliol-type, pogostone-type and an interim-type, which was the one between the two chemotypes. The simulative mean chromatogram for the three types P. cablin was generated using the Computer Aided Similarity Evaluation System. The fingerprint can help to distinguish the substitute or adulterant, and further assess the differences of P. cablin grown in various areas of China.

The endogenous opioid spinorphin blocks fMet-Leu-Phe-induced neutrophil chemotaxis by acting as a specific antagonist at the N-formylpeptide receptor subtype FPR

Spinorphin is an endogenous heptapeptide (leucylvalylvalyltyrosylprolyltryptophylthreonine), first isolated from bovine spinal cord, whose sequence matches a conserved region of beta-hemoglobin. Also referred to as LVV-hemorphin-4 and a member of the nonclassical opioid hemorphin family, spinorphin inhibits enkephalin-degrading enzymes and is analgesic. Recently, spinorphin was reported to block neutrophil activation induced by the chemotactic N-formylpeptide N-formylmethionylleucylphenylalanine (fMLF), suggesting a potential role as an endogenous negative regulator of inflammation. Here we use both gain- and loss-of-function genetic tests to identify the specific mechanism of spinorphin action on neutrophils. Spinorphin induced calcium flux in normal mouse neutrophils, but was inactive in neutrophils from mice genetically deficient in the fMLF receptor subtype FPR (N-formylpeptide receptor). Consistent with this, spinorphin induced calcium flux in human embryonic kidney 293 cells transfected with mouse FPR, but had no effect on cells expressing the closely related fMLF receptor subtype FPR2. Despite acting as a calcium-mobilizing agonist at FPR, spinorphin was a weak chemotactic agonist and effectively blocked neutrophil chemotaxis induced by fMLF at concentrations selective for FPR. Spinorphin did not affect mouse neutrophil chemotaxis induced by concentrations of fMLF that selectively activate FPR2. Thus, spinorphin blocks fMLF-induced neutrophil chemotaxis by acting as a specific antagonist at the fMLF receptor subtype FPR.

Contrasting evolution of the human leukocyte N-formylpeptide receptor subtypes FPR and FPRL1R

N-formylpeptides are phagocyte chemoattractants that act by binding to two structurally related receptors, FPR (formylpeptide receptor) and FPRL1R (FPR-like-1 receptor), which are encoded by the human genes FPR1 and FPRL1. Single nucleotide polymorphisms (SNPs) in the FPR coding region have been reported and two have been associated with the disease juvenile periodontitis; however, their frequency and linkage relationships are unknown. Here we systematically analyzed polymorphism in the open reading frames of FPR1 and FPRL1 by direct sequencing of cloned alleles from random blood donors from North America. For FPR1 we detected five non-synonymous SNPs and two synonymous SNPs in a sample of 26 chromosomes one each from 17 Caucasian and nine black random blood donors. Although all five non-synonymous SNPs were common in Caucasians, Blacks, and Asians, notable differences in allele frequency were found for each SNP in the different racial groups, suggesting differential selective pressures. We found that the FPR1 polymorphisms are linked in 15 common haplotypes. No polymorphisms were detected in FPRL1 after sampling 44 chromosomes from 36 random blood donors from the same three racial groups. Thus FPR1 and FPRL1, though they originated from a common gene, appear to have undergone markedly different evolutionary events.

Synthetic peptide MMK-1 is a highly specific chemotactic agonist for leukocyte FPRL1

Human phagocytic leukocytes express the seven-transmembrane G-protein-coupled receptors formyl peptide receptor (FPR) and FPR-like 1 (FPRL1). MMK-1, a synthetic peptide derived from a random peptide library, is reported to induce calcium mobilization specifically in human FPRL1 gene-transfected cells. However, its actions on human phagocytic leukocytes remain poorly defined. We found that MMK-1 is a potent chemotactic and calcium-mobilizing agonist for human monocytes, neutrophils, and FPRL1-transfected human embryonic kidney (HEK) 293 cells but is inactive in cells transfected with FPR. MMK-1 also activated HEK 293 cells transfected with FPR2, a mouse counterpart of human FPRL1. Furthermore, MMK-1 increased pertussis toxin-sensitive production of inflammatory cytokines in human monocytes. MMK-1 signaling in human phagocytes was completely desensitized by a well-defined FPRL1 agonist, suggesting that FPRL1 is likely a receptor that mediates the action of MMK-1 in primary cells. Since MMK-1 is one of the most potent FPRL1-specific agonists identified so far, it can serve as a modulator of the host defense and a useful agent for further studying the signaling and function of FPRL1.

Amyloid-beta induces chemotaxis and oxidant stress by acting at formylpeptide receptor 2, a G protein-coupled receptor expressed in phagocytes and brain

Amyloid-beta, the pathologic protein in Alzheimer's disease, induces chemotaxis and production of reactive oxygen species in phagocytic cells, but mechanisms have not been fully defined. Here we provide three lines of evidence that the phagocyte G protein-coupled receptor (N-formylpeptide receptor 2 (FPR2)) mediates these amyloid-beta-dependent functions in phagocytic cells. First, transfection of FPR2, but not related receptors, including the other known N-formylpeptide receptor FPR, reconstituted amyloid-beta-dependent chemotaxis and calcium flux in HEK 293 cells. Second, amyloid-beta induced both calcium flux and chemotaxis in mouse neutrophils (which express endogenous FPR2) with similar potency as in FPR2-transfected HEK 293 cells. This activity could be specifically desensitized in both cell types by preincubation with a specific FPR2 agonist, which desensitizes the receptor, or with pertussis toxin, which uncouples it from G(i)-dependent signaling. Third, specific and reciprocal desensitization of superoxide production was observed when N-formylpeptides and amyloid-beta were used to sequentially stimulate neutrophils from FPR -/- mice, which express FPR2 normally. Potential biological relevance of these results to the neuroinflammation associated with Alzheimer's disease was suggested by two additional findings: first, FPR2 mRNA could be detected by PCR in mouse brain; second, induction of FPR2 expression correlated with induction of calcium flux and chemotaxis by amyloid-beta in the mouse microglial cell line N9. Further, in sequential stimulation experiments with N9 cells, N-formylpeptides and amyloid-beta were able to reciprocally cross-desensitize each other. Amyloid-beta was also a specific agonist at the human counterpart of FPR2, the FPR-like 1 receptor. These results suggest a unified signaling mechanism for linking amyloid-beta to phagocyte chemotaxis and oxidant stress in the brain.

NO mediated increase of Fos protein and NMDA1A R mRNA expression in rat spinal cord during morphine withdrawal

AIM

To investigate the effects of nitric oxide (NO) on activation of the rat spinal cord neurons during naloxone-precipitated morphine withdrawal.

METHODS

Fos immunocytochemistry, NADPH-d histochemistry, Fos/NADPH-d double-labeling, intrathecal injection, antisense oligonucleotides (AS-ONs) techniques, and RT-PCR were used.

RESULTS

Acute administration of naloxone and chronic administration of morphine did not change the expression of Fos protein and NADPH-d positive neurons, and there was no expression of Fos/NADPH-d double-labeled neurons in the spinal cord of rats. Morphine withdrawal increased the expression of Fos protein, NADPH-d positive, and Fos/NADPH-d double-labeled neurons, and they were observed in all the laminae of the rat spinal cord. Intrathecal injection of nNOS antisense oligonucleotides (nNOS-AS) inhibited the increase of Fos protein and NMDA(1A)R mRNA expression in the rat spinal cord during morphine withdrawal and decreased the scores of morphine withdrawal symptoms. The effect of nNOS-AS was greater than that of eNOS-AS. There was no effect in nNOS sense oligonucleotides (nNOS-S) group.

CONCLUSION

NO mediated the increase of Fos protein and NMDA1A R mRNA expression in the rat spinal cord during morphine withdrawal.

Involvement of the receptor for formylated peptides in the in vivo anti-migratory actions of annexin 1 and its mimetics

An innovative avenue for anti-inflammatory therapy is inhibition of neutrophil extravasation by potentiating the action of endogenous anti-inflammatory mediators. The glucocorticoid-inducible protein annexin 1 and derived peptides are effective in inhibiting neutrophil extravasation. Here we tested the hypothesis that an interaction with the receptor for formylated peptide (FPR), so far reported only in vitro, could be the mechanism for this in vivo action. In a model of mouse peritonitis, FPR antagonists abrogated the anti-migratory effects of peptides Ac2-26 and Ac2-12, with a partial reduction in annexin 1 effects. A similar result was obtained in FPR (knock-out) KO mice. Binding of annexin 1 to circulating leukocytes was reduced (>50%) in FPR KO mice. In vitro, annexin binding to peritoneal macrophages was also markedly reduced in FPR KO mice. Finally, evidence of direct annexin 1 binding to murine FPR was obtained with HEK-293 cells transfected with the receptor. Overall, these results indicate a functional role for FPR in the anti-migratory effect of annexin 1 and derived peptides.

Mice lacking the chemokine receptor CCR1 show increased susceptibility to Toxoplasma gondii infection

Chemokines are critical for the recruitment of effector immune cells to sites of infection. Mice lacking the chemokine receptor CCR1 have defects in neutrophil trafficking and proliferation. In the present study, we tested the susceptibility of CCR1 knockout mice to infection with the obligate intracellular protozoan parasite Toxoplasma gondii. In comparison with parental wild-type mice, CCR1(-/-) mice exhibited dramatically increased mortality to T. gondii in association with an increased tissue parasite load. No differences were observed in Ag-specific T cell proliferation or in cytokine responses between mutant and wild-type mice. However, the influx of PMNs to the peripheral blood and to the liver were reduced in CCR1(-/-) mice during early infection. Our results suggest that CCR1-dependent migration of neutrophils to the blood and tissues may have a significant impact in controlling parasite replication.

Cloning, mRNA distribution, and functional expression of an avian counterpart of the chemokine receptor/HIV coreceptor CXCR4

The chemokine signaling system, which coordinates the basal and emergency trafficking of leukocytes, presumably coevolved with the hematopoietic system. To study its phylogenetic origins, we used the open reading frame (ORF) of the human chemokine receptor CXCR4 as a genomic probe, since in mammals it is the most highly conserved chemokine receptor known. CXCR4 cross-hybridized to genomic DNA from mouse and chicken, but not zebrafish, Drosophila, or Caenorhabditis elegans. Accordingly, we cloned the corresponding chicken cDNA. The ORF is 359 codons long versus 352 for human CXCR4, and encodes a protein 82% identical to human CXCR4. In a calcium flux assay of receptor function, CHO-K1 cells stably transfected with the chicken cDNA responded specifically to human SDF-1, the specific ligand for CXCR4, but not to a panel of other chemokines tested at 100 nM. SDF-1 activated the cells in a dose-dependent manner (EC50 approximately 5 nM), whereas parental CHO-K1 cells did not respond. The CHO-K1 cell transfectants also bound 125I-SDF-1 specifically. Leukocytes from chicken peripheral blood expressed chCXCR4 mRNA and responded to human SDF-1 in a calcium flux assay with an EC50 similar to that for chCXCR4-transfected CHO cells, suggesting that this response is mediated by native chCXCR4. Analysis of chicken genomic DNA with the chicken cDNA as probe revealed a pattern consistent with a single copy gene, and the absence of any closely related genes. mRNA was detected in brain, bursa, liver, small and large intestine, embryonal fibroblasts, and blood leukocytes, but not in stomach or pancreas. These results, which identify the first functional non-viral, non-mammalian chemokine receptor, suggest that the origins of a functional chemokine system extend at least to birds and suggest that, as in mammals, CXCR4 functions in many avian tissues.

Amyloid (beta)42 activates a G-protein-coupled chemoattractant receptor, FPR-like-1

Amyloid beta (Abeta) is a major contributor to the pathogenesis of Alzheimer's disease (AD). Although Abeta has been reported to be directly neurotoxic, it also causes indirect neuronal damage by activating mononuclear phagocytes (microglia) that accumulate in and around senile plaques. In this study, we show that the 42 amino acid form of beta amyloid peptide, Abeta(42), is a chemotactic agonist for a seven-transmembrane, G-protein-coupled receptor named FPR-Like-1 (FPRL1), which is expressed on human mononuclear phagocytes. Moreover, FPRL1 is expressed at high levels by inflammatory cells infiltrating senile plaques in brain tissues from AD patients. Thus, FPRL1 may mediate inflammation seen in AD and is a potential target for developing therapeutic agents.

MIP-1alpha is produced but it does not control pulmonary inflammation in response to respiratory syncytial virus infection in mice

The intent of this study was to compare the cellular and biochemical inflammatory responses of mice infected with the paramyxovirus pathogens respiratory syncytial virus (RSV) and pneumonia virus of mice (PVM). Although RSV is not a natural pathogen of mice, it has been used extensively in mouse models of the human disease, as a limited respiratory infection can be established via intranasal inoculation of virus at high titer. In earlier work, we found that acute infection with the natural rodent pathogen, PVM, elicited a rapid and sustained pulmonary inflammatory response (peak, 1.7 x 10(6) leukocytes/ml BAL fluid) that was dependent on both local production of MIP-1alpha and signaling via its receptor, CCR1. We find here that MIP-1alpha is also produced in response to RSV, although relatively few leukocytes (<200 ml BAL fluid) are recruited to the lungs in response. Further experiments with CCR1-deficient mice confirm the finding that although MIP-1alpha is produced in response to RSV infection, leukocytes do not respond via this pathway. Among the explanations for these findings, we propose that there are other, as yet to be identified proinflammatory mediators elicited in response to PVM (but not in response to RSV) that serve to prime the leukocytes in vivo, thus enabling them to respond to MIP-1alpha signaling via CCR1. Furthermore, the differences in disease pathogenesis seen in response to each of these pneumovirus infections in mice raise questions regarding the extent to which primary RSV infection in mice can be used as a model of primary RSV infection in humans.

The chemokine macrophage-inflammatory protein-1 alpha and its receptor CCR1 control pulmonary inflammation and antiviral host defense in paramyxovirus infection

In this work, we explore the responses of specific gene-deleted mice to infection with the paramyxovirus pneumonia virus of mice (PVM). We have shown previously that infection of wild type mice with PVM results in pulmonary neutrophilia and eosinophilia accompanied by local production of macrophage-inflammatory protein-1 alpha (MIP-1 alpha). Here we examine the role of MIP-1 alpha in the pathogenesis of this disease using mice deficient in MIP-1 alpha or its receptor, CCR1. The inflammatory response to PVM in MIP-1 alpha-deficient mice was minimal, with approximately 10-60 neutrophils/ml and no eosinophils detected in bronchoalveolar lavage fluid. Higher levels of infectious virus were recovered from lung tissue excised from MIP-1 alpha-deficient than from fully competent mice, suggesting that the inflammatory response limits the rate of virus replication in vivo. PVM infection of CCR1-deficient mice was also associated with attenuated inflammation, with enhanced recovery of infectious virus, and with accelerated mortality. These results suggest that the MIP-1 alpha/CCR1-mediated acute inflammatory response protects mice by delaying the lethal sequelae of infection.

The HIV-1 cell entry inhibitor T-20 potently chemoattracts neutrophils by specifically activating the N-formylpeptide receptor

T-20, a synthetic peptide corresponding to the heptad repeat sequence of HIV-1 gp41, blocks HIV-1 entry by targeting gp41, and is currently in clinical trials as an anti-retroviral agent. We recently reported that in vitro T-20 also functions as a phagocyte chemoattractant and a chemotactic agonist at the phagocyte N-formylpeptide receptor (FPR). Here we show that T-20 is also a potent chemotactic agonist in vitro at a related human phagocyte receptor FPRL1R. To test the relative importance of FPR and FPRL1R in primary cells, we identified the corresponding mouse T-20 receptors, mFPR and FPR2, which are both expressed in neutrophils, and compared T-20 action on neutrophils from wild type and mFPR knockout mice. Surprisingly, although T-20 activates mFPR and FPR2 in transfected cells with equal potency and efficacy in both calcium flux and chemotaxis assays, neutrophils from mFPR knockout mice did not respond to T-20. These results provide genetic evidence that FPR is the major phagocyte T-20 receptor in vivo and point to the potential feasibility of studying T-20 effects on immunity in a mouse model. This may help define the cause of local inflammation after T-20 injection that has recently been reported in Phase I clinical trials.

Serum amyloid A is a chemotactic agonist at FPR2, a low-affinity N-formylpeptide receptor on mouse neutrophils

Serum amyloid A (SAA) is an acute-phase plasma protein and the source of amyloid A, which accumulates in lesions of secondary amyloidosis. SAA can induce phagocyte migration in vitro and in vivo, and is a specific chemotactic agonist for the human low-affinity N-formylpeptide receptor FPRL1R, a G-protein-coupled receptor expressed on phagocytes. Here we show that FPR2, a mouse counterpart of FPRL1R, is also an SAA receptor. SAA selectively induced calcium flux and chemotaxis in mouse PMN, which express FPR2, as well as in HEK 293 cells expressing recombinant FPR2 but not in HEK 293 cells expressing FPR, a closely related high affinity N-formylpeptide receptor. Consistent with this, SAA activity on PMN from FPR+/+ and FPR-/- mice was indistinguishable. Moreover, the prototype N-formylpeptide fMLF desensitized SAA-induced calcium flux in a dose-dependent manner in both mouse neutrophils and HEK 293/FPR2 transfectants. Our results suggest that FPR2 specifically mediates mouse neutrophil migration in response to SAA.

A synthetic peptide derived from human immunodeficiency virus type 1 gp120 downregulates the expression and function of chemokine receptors CCR5 and CXCR4 in monocytes by activating the 7-transmembrane G-protein-coupled receptor FPRL1/LXA4R

Because envelope gp120 of various strains of human immunodeficiency virus type 1 (HIV-1) downregulates the expression and function of a variety of chemoattractant receptors through a process of heterologous desensitization, we investigated whether epitopes derived from gp120 could mimic the effect. A synthetic peptide domain, designated F peptide, corresponding to amino acid residues 414-434 in the V4-C4 region of gp120 of the HIV-1 Bru strain, potently reduced monocyte binding and chemotaxis response to macrophage inflammatory protein 1beta (MIP-1beta) and stromal cell-derived factor 1alpha (SDF-1alpha), chemokines that use the receptors CCR5 and CXCR4, respectively. Further study showed that F peptide by itself is an inducer of chemotaxis and calcium mobilization in human monocytes and neutrophils. In cross-desensitization experiments, among the numerous chemoattractants tested, only the bacterial chemotactic peptide fMLF, when used at high concentrations, partially attenuated calcium mobilization induced by F peptide in phagocytes, suggesting that this peptide domain might share a 7-transmembrane, G-protein-coupled receptor with fMLF. By using cells transfected with cDNAs encoding receptors that interact with fMLF, we found that F peptide uses an fMLF receptor variant, FPRL1, as a functional receptor. The activation of monocytes by F peptide resulted in downregulation of the cell surface expression of CCR5 and CXCR4 in a protein kinase C-dependent manner. These results demonstrate that activation of FPRL1 on human moncytes by a peptide domain derived from HIV-1 gp120 could lead to desensitization of cell response to other chemoattractants. This may explain, at least in part, the initial activation of innate immune responses in HIV-1-infected patients followed by immune suppression.

Dominant myelopoietic effector functions mediated by chemokine receptor CCR1

Macrophage inflammatory protein (MIP)-1alpha, a CC chemokine, enhances proliferation of mature subsets of myeloid progenitor cells (MPCs), suppresses proliferation of immature MPCs, and mobilizes mature and immature MPCs to the blood. MIP-1alpha binds at least three chemokine receptors. To determine if CCR1 was dominantly mediating the above activities of MIP-1alpha, CCR1-deficient (-/-) mice, produced by targeted gene disruption, were used. MIP-1alpha enhanced colony formation of marrow granulocyte/macrophage colony-forming units (CFU-GM), responsive to stimulation by granulocyte/macrophage colony-stimulating factor (GM-CSF), and CFU-M, responsive to stimulation by M-CSF, from littermate control CCR1(+/+) but not CCR1(-/-) mice. Moreover, MIP-1alpha did not mobilize MPCs to the blood or synergize with G-CSF in this effect in CCR1(-/-) mice. However, CCR1(-/-) mice were increased in sensitivity to MPC mobilizing effects of G-CSF. Multi-growth factor-stimulated MPCs in CCR1(-/-) and CCR1(+/+) marrow were equally sensitive to inhibition by MIP-1alpha. These results implicate CCR1 as a dominant receptor for MIP-1alpha enhancement of proliferation of lineage-committed MPCs and for mobilization of MPCs to the blood. CCR1 is not a dominant receptor for MIP-1alpha suppression of MPC proliferation, but it does negatively impact G-CSF-induced MPC mobilization.

T20/DP178, an ectodomain peptide of human immunodeficiency virus type 1 gp41, is an activator of human phagocyte N-formyl peptide receptor

Human immunodeficiency virus type 1 (HIV-1) envelope protein gp41 mediates viral fusion with human host cells. The peptide segment T20/DP178, located in the C-terminus of the ectodomain of gp41, interacts with the N-terminal leucine zipper-like domain on gp41 to establish the fusogenic conformation of the virus. Synthetic T20/DP178 peptide is highly efficacious in inhibiting HIV-1 infection in vitro by disrupting the transformation of fusogenic status of viral gp41; thus, it has been proposed for clinical trial. We report that synthetic T20/DP178 is a chemoattractant and activator of human peripheral blood phagocytes but not of T lymphocytes. We further demonstrate that T20/DP178 specifically activates a seven-transmembrane, G-protein-coupled phagocyte receptor for N-formylated chemotactic peptides, formyl peptide receptor (FPR). Moreover, synthetic T20/DP178 analogs lacking N-terminal amino acids acted as FPR antagonists. Our results suggest that gp41 peptides regulate phagocyte function via FPR and identify a novel mechanism by which HIV-1 may modulate innate immunity.

Differential effects of leukotactin-1 and macrophage inflammatory protein-1 alpha on neutrophils mediated by CCR1

The human CC chemokine leukotactin-1 (Lkn-1) is both a strong chemoattractant for neutrophils, monocytes, and lymphocytes and a potent agonist for CCR1 and CCR3. However, human neutrophils do not migrate when the cells are stimulated with other human CC chemokines, such as human macrophage inflammatory protein-1 alpha (hMIP-1 alpha) and eotaxin, which also use the CCR1 and CCR3 as their receptors. In this report, we demonstrate that while hMIP-1 alpha induced a negligible level of calcium flux and chemotaxis, Lkn-1 produced a high level of calcium flux and chemotaxis in human neutrophils. Lkn-1 cross-desensitized hMIP-1 alpha-induced calcium flux, but hMIP-1 alpha had little effect on the Lkn-1-induced response in human neutrophils. The same pattern was observed in peritoneal neutrophils from wild-type mice, whereas neutrophils from CCR1-/- mice failed to respond to either MIP-1 alpha or Lkn-1. Scatchard analysis revealed a single class of receptor for both hMIP-1 alpha and Lkn-1 on human neutrophils with dissociation constants (Kd) of 3.2 nM and 1.1 nM, respectively. We conclude that CCR1 is a receptor mediating responses to both MIP-1 alpha and Lkn-1 on neutrophils and produces different biological responses depending on the ligand bound.

Impaired antibacterial host defense in mice lacking the N-formylpeptide receptor

N-formylpeptides derive from bacterial and mitochondrial proteins, and bind to specific receptors on mammalian phagocytes. Since binding induces chemotaxis and activation of phagocytes in vitro, it has been postulated that N-formylpeptide receptor signaling in vivo may be important in antimicrobial host defense, although direct proof has been lacking. Here we test this hypothesis in mice lacking the high affinity N-formylpeptide receptor (FPR), created by targeted gene disruption. FPR-/- mice developed normally, but had increased susceptibility to challenge with Listeria monocytogenes, as measured by increased mortality compared with wild-type littermates. FPR-/- mice also had increased bacterial load in spleen and liver 2 d after infection, which is before development of a specific cellular immune response, suggesting a defect in innate immunity. Consistent with this, neutrophil chemotaxis in vitro and neutrophil mobilization into peripheral blood in vivo in response to the prototype N-formylpeptide fMLF (formyl-methionyl-leucyl-phenylalanine) were both absent in FPR-/- mice. These results indicate that FPR functions in antibacterial host defense in vivo.

A seven-transmembrane, G protein-coupled receptor, FPRL1, mediates the chemotactic activity of serum amyloid A for human phagocytic cells

We have previously reported (Badolato, R., J.M. Wang, W.J. Murphy, A. R. Lloyd, D.F. Michiel, L.L. Bausserman, D.J. Kelvin, and J.J. Oppenheim. 1994. J. Exp. Med. 180:203; Xu, L., R. Badolato, W.J. Murphy, D.L. Longo, M. Anver, S. Hale, J.J. Oppenheim, and J.M. Wang. 1995. J. Immunol. 155:1184.) that the acute phase protein serum amyloid A (SAA) is a potent chemoattractant for human leukocytes in vitro and mouse phagocytes in vivo. To identify the signaling mechanisms, we evaluated patterns of cross-desensitization between SAA and other leukocyte chemoattractants. We found that the chemotactic bacterial peptide, N-formyl- methionyl-leucyl-phenylalanine (fMLP), was able to specifically attenuate Ca2+ mobilization in human phagocytes induced by SAA, but only at very high concentrations, suggesting that SAA uses a low affinity fMLP receptor. Here we demonstrate that SAA selectively induced Ca2+ mobilization and migration of HEK cells expressing FPRL1, a human seven-transmembrane domain phagocyte receptor with low affinity for fMLP, and high affinity for lipoxin A4. Furthermore, radiolabeled SAA specifically bound to human phagocytes and FPRL1-transfected 293 cells. In contrast, SAA was not a ligand or agonist for FPR, the high affinity fMLP receptor. Thus, SAA is the first chemotactic ligand identified for FPRL1. Our results suggest that FPRL1 mediates phagocyte migration in response to SAA.

Differential expansion of the N-formylpeptide receptor gene cluster in human and mouse

The human formylpeptide receptor (FPR) gene cluster has three members: FPR1 and FPRL1, which are expressed in neutrophils and monocytes and encode seven-transmembrane-domain chemotactic receptors specific for N-formylpeptides, and FPRL2, whose function is unknown. The FPRL1 receptor is also a lipoxin A4 receptor. Using probes for the three human genes we have cloned six distinct mouse genes, designated Fpr1 and Fpr-rs1 through Fpr-rs5, which form a cluster on chromosome 17 in a region of conserved synteny with human chromosome 19. Fpr1 encodes a functional receptor and is clearly the orthologue of FPR1. Both Fpr-rs1 and Fpr-rs2 have higher sequence homology to FPRL1 than to FPRL2; Fpr-rs1 is 97% identical in amino acid sequence to a previously reported cDNA that encodes a lipoxin A4 receptor, whereas the putative ligand for Fpr-rs2 is unknown. Fpr-rs3, Fpr-rs4, and Fpr-rs5 appear to lack human counterparts and are most similar in sequence to FPRL1. RNA for Fpr1, Fpr-rs1, and Fpr-rs2 is present in leukocytes, spleen, and lung, whereas RNA for Fpr-rs3 was detected only in skeletal muscle. We did not detect Fpr-rs4 or Fpr-rs5 RNA in any tissue tested. Moreover, Fpr-rs5 has a stop codon in the protein-coding region corresponding to transmembrane domain VI and may not encode a functional receptor. These results suggest that the FPR gene cluster has undergone differential expansion in mammals with FPRL2, Fpr-rs2, Fpr-rs3, Fpr-rs4, and Fpr-rs5 arising after divergence of human and mouse.