Multiomics Approach Reveals Serum Biomarker Candidates for Congenital Zika Syndrome

The Zika virus (ZIKV) can be vertically transmitted, causing congenital Zika syndrome (CZS) in fetuses. ZIKV infection in early gestational trimesters increases the chances of developing CZS. This syndrome involves several pathologies with a complex diagnosis. In this work, we aim to identify biological processes and molecular pathways related to CZS and propose a series of putative protein and metabolite biomarkers for CZS prognosis in early pregnancy trimesters. We analyzed serum samples of healthy pregnant women and ZIKV-infected pregnant women bearing nonmicrocephalic and microcephalic fetuses. A total of 1090 proteins and 512 metabolites were identified by bottom-up proteomics and untargeted metabolomics, respectively. Univariate and multivariate statistical approaches were applied to find CZS differentially abundant proteins (DAP) and metabolites (DAM). Enrichment analysis (i.e., biological processes and molecular pathways) of the DAP and the DAM allowed us to identify the ECM organization and proteoglycans, amino acid metabolism, and arachidonic acid metabolism as CZS signatures. Five proteins and four metabolites were selected as CZS biomarker candidates. Serum multiomics analysis led us to propose nine putative biomarkers for CZS prognosis with high sensitivity and specificity.

POS0023 PREVALENCE AND IMPACT OF FIBROMYALGIA SYNDROME IN A COHORT OF PATIENTS WITH INFLAMMATORY BOWEL DISEASE

Background

Fibromyalgia (FM) is a common chronic disorder characterized by widespread pain, fatigue, sleep disturbances and functional symptoms, reaching a prevalence of 2–3% worldwide. It can present as a comorbidity in patients with concomitant chronic disease and can have a significant impact on the quality of life. There are very few studies on the prevalence and the impact of FM in patients with inflammatory bowel disease (IBD).

Objectives

The aims of this study were to assess the prevalence of FM in a cohort of patients with IBD, and to evaluate the impact of FM on the quality of life of those patients.

Methods

Consecutive patients with IBD were enrolled from August to November 2021 in two IBD units, patients with severe disease activity according to the Crohn’s disease activity index (CDAI) and to the Mayo score for UC, or with other concomitant chronic diseases were excluded. Clinical and demographic data and Patient Reported Outcomes (PROs) (Widespread Pain Index (WPI), Symptom Severity Score (SSS), IBD Questionnaire (IBD-Q), Depression anxiety stress scales-21 (DASS-21), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Impact of event scale-revised (IES-R), Pittsburgh Sleep Quality Index (PSQI)) were collected. FM was diagnosed according to 2011 ACR classification criteria by an expert rheumatologist. Mann-Whitney test, chi-square test, and Student t test were used for statistical analyses. A multivariate analysis was performed to estimate the effect of independent variables (BMI, age, CRP, CDAI, Mayo score, WPI, DASS-21, FACIT-F, PSQI) on patients’ quality of life (IBD-Q). A p value < 0.05 was considered as significant.

Results

A total of 196 IBD patients were enrolled (86 female (44%) with a mean age of 50 ± 15 yo), 105 with Crohn’s disease (CD) and 91 with ulcerative colitis (UC). 147 patients were in remission, 35 had low disease activity and 14 moderate disease activity. The overall prevalence of FM in the IBD cohort was 17/196 (8.7%) [95% IC 5% – 13%], 10 (11.6%) women and 7 (6.3%) men; with a prevalence of 7.6% (8/105) in CD and 9.9% (9/91) in UC.

In Table 1 are indicated the characteristics of patients with IBD + FM and IBD alone. No significant demographic and clinical differences between the two groups were detected.

Table 1.IBD + FM (n=17)IBD without FM (n=179)pFemale/Male (%)10/7 (59%/41%)75/102 (42%/58%)0.19Age, years (SD)56.8 (± 13)48.5 (± 17)0.06BMI (SD)21 (± 8.7)23.7 (± 4.8)0.46CD (%)/UC (%)8 (47%)/9 (53%)97 (54%)/82 (46%)0.57CRP, median (SD)0.16 mg/dL (± 2.8)0.2 mg/dL (± 1.5)0.87IBD remission14 (82%)133 (74%)0.33IBD low disease activity1 (6%)34 (19%)IBD moderate disease activity2 (12%)12 (7%)Ongoing conventional treatment6 (35%)70 (39%)0.27Ongoing biological treatment11 (65%)112 (63%)0.42 PROsIBD-Q150.3176.9<0.001DASS-21 DEPRESSION15.38.24<0.001DASS-21 ANXIETY16.69.13<0.001DASS-21 STRESS13.46.13<0.001FACIT-F25.538.2<0.001IES-R36.916.3<0.001

The quality of life among IBD patients and IBD + FM patients, assessed with IBD-Q, appear significantly lower (p <0.001) in the second group. Similar results were obtained evaluating depression, anxiety, stress, chronic fatigue, and patients’ discomfort (Table 1).

The multivariate analysis demonstrated that the variables influencing the quality of life (IBD-Q) were the disease activity (CDAI) (p 0.0256), the chronic fatigue (FACIT-F) (p 0.0061) and sleep disturbances (PSQI) (p 0.0440), for CD; while for UC the only variable that correlate with IBD-Q was the disease activity (Mayo score) (p 0.0129).

Conclusion

FM is a common disorder especially in patients with other concomitant chronic diseases. This study reported a prevalence of FM of 8.7% in IBD patients without any significant differences between CD and UC. Moreover, the comorbidity of FM in IBD can have a considerable impact on quality of life and on measures of disease severity, with worst values in all PROs measurements.

Disclosure of Interests

None declared

Cell-based therapies for the surgical treatment of periodontal intrabony defects: a systematic review

OBJECTIVE

The aim of the study is to investigate the efficacy of cell-based therapy in the surgical treatment of periodontal intrabony defects.

MATERIALS AND METHODS

PRISMA guidelines were followed, and the study protocol was regis-tered in PROSPERO. Electronic and hand searches were carried out on electronic databases and major international journals of periodontology. All randomized clinical trials (RCTs) comparing cell-based therapies com-bined with surgery to surgery alone for the treatment of periodontal intrabony defects were considered. Quality assessment was performed using the Cochrane Risk of Bias Tool for randomized clinical trials (RoB 2). Quantitative evaluation of data was performed by meta-analysis.

RESULTS

Five hundred twenty-eight records were initially screened and 5 RCTs fulfilling the eligibility criteria were included. Periodontal ligament stem cells, dental pulp stem cells, periosteum-derived stem cells, gingival fibroblasts and their associated stem cells were used in combination with different surgical techniques to treat intrabony periodontal defects. Meta-analysis showed a statistically signif-icant effect in favor of cell-based groups for clinical attachment level gain (p=0.004), with a difference in means of 1.7 mm (95% CI 0.5; 2.9). This was replicated for intrabony defect depth reduction (p=0.006), with a difference in means of 1.3 (95% CI 0.4; 2.3).

CONCLUSIONS

Cell-based therapies have been positively applied for the surgical treatment of intrabony periodontal defects with promising results. However, the results obtained should be interpreted with caution due to the low number of available RCTs, the study design heterogeneity, and the limited extension of the follow-up.

Efficacy of locally delivered statins as an adjunct to scaling and root planning in the treatment of periodontitis: a systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review is to assess the efficacy of locally delivered statins used in adjunct to scaling and root planing (SRP), compared with SRP alone.

MATERIALS AND METHODS

An electronic and hand search was carried out up to April 2020. Only randomized controlled trials (RCTs) were included. Clinical attachment level gain (CALgain) and probing depth reduction (PDred), modified sulcular bleeding index reduction (mSBIred), and intrabony defect reduction (IBDred) were the investigated outcomes. Meta-analysis was performed, and the power of the meta-analytic findings was determined by trial sequential analysis (TSA). Studies were also sub-grouped based on the type of statin used. Statistical heterogeneity and publication bias were assessed.

RESULTS

Twenty RCTs were included (1212 patients, 1289 defects). An overall statistically significant effect size in favor of statins for CALgain and PDred was found. As opposed to atorvastatin and rosuvastatin, simvastatin did not reach statistical significance for these outcomes, as shown by the sub-group analysis.

CONCLUSIONS

Within the limits of the available studies, the local administration of statins (in particular, atorvastatin and rosuvastatin) in adjunct to SRP may result in additional significant improvement in terms of CALgain and PDred compared with SRP alone. The high heterogeneity of data and the high risk of bias found, however, impose caution. No approved preparations, moreover, exist, and further well-designed RCTs from independent research centers are needed to confirm the beneficial effects of the different statins and their mutual differences in the non-surgical periodontal treatment.

The role of bone anabolic drugs in the management of periodontitis: a scoping review

The aim of this scoping review was to summarise current knowledge about the effects of bone anabolic drugs on periodontitis, in order to identify new therapeutic strategies for preventing disease progression and reducing tooth loss. A technical expert panel (TEP) was established of 11 medical specialists, including periodontists and bone specialists that followed the PRISMA-ScR model to perform the scoping review and considered for eligibility both pre-clinical and clinical studies published in the English language up to September 2020. 716 items were initially found. After duplicate removal and screening of articles for eligibility criteria, 25 articles published between 2001 and 2019 were selected. Only studies concerning teriparatide, strontium ranelate, sclerostin antibodies and DKK1 antibodies met the eligibility criteria. In particular, only for teriparatide were there both clinical studies and experimental studies available, while for other bone anabolic drugs only animal studies were found. Available evidence about the use of bone anabolic drugs in periodontology demonstrates beneficial effects of these agents on biological pathways and histological parameters involved in periodontal tissue regeneration that suggest relevant clinical implications for the management of periodontitis.

Molecular alterations in the extracellular matrix in the brains of newborns with congenital Zika syndrome

Zika virus (ZIKV) infection during pregnancy can cause a set of severe abnormalities in the fetus known as congenital Zika syndrome (CZS). Experiments with animal models and in vitro systems have substantially contributed to our understanding of the pathophysiology of ZIKV infection. Here, to investigate the molecular basis of CZS in humans, we used a systems biology approach to integrate transcriptomic, proteomic, and genomic data from the postmortem brains of neonates with CZS. We observed that collagens were greatly reduced in expression in CZS brains at both the RNA and protein levels and that neonates with CZS had several single-nucleotide polymorphisms in collagen-encoding genes that are associated with osteogenesis imperfecta and arthrogryposis. These findings were validated by immunohistochemistry and comparative analysis of collagen abundance in ZIKV-infected and uninfected samples. In addition, we showed a ZIKV-dependent increase in the expression of cell adhesion factors that are essential for neurite outgrowth and axon guidance, findings that are consistent with the neuronal migration defects observed in CZS. Together, these findings provide insights into the underlying molecular alterations in the ZIKV-infected brain and reveal host genes associated with CZS susceptibility.

Sella turcica and craniofacial morphology in patients with palatally displaced canines: a retrospective study

BACKGROUND

The aim of the study was to evaluate the sella and craniofacial morphological features in growing patients with palatally displaced canines compared to controls.

MATERIALS AND METHODS

Twenty-two subjects with palatally displaced canines were retrospectively selected and compared to 22 controls matched for age and gender. Lateral cephalograms were collected and sagittal and vertical cephalometric variables were measured, together with sella interclinoid distance, sella depth, and sella diameter. The independent samples T-test or Mann-Whitney U-test were used to compare all the variables between the two groups. A Pearson correlation was computed for the craniofacial and sella variables that differed significantly (p < 0.05) between the groups.

RESULTS

Patients with palatally displaced canines showed a smaller interclinoid distance and a greater SNA angle than control subjects. The interclinoid distance and the SNA angle were negatively correlated (-0.52, p = 0.017) in the experimental group.

CONCLUSIONS

Growing patients with palatally displaced canines had smaller sella interclinoid distances and a greater SNA angle than control subjects.

Challenges for molecular and serological ZIKV infection confirmation

BACKGROUND

Zika Virus (ZIKV), member of Flaviviridae family and Flavivirus genus, has recently emerged as international public health emergency after its association with neonatal microcephaly cases. Clinical diagnosis hindrance involves symptom similarities produced by other arbovirus infections, therefore laboratory confirmation is of paramount importance.

DISCUSSION

The most reliable test available is based on ZIKV RNA detection from body fluid samples. However, short viremia window periods and asymptomatic infections diminish the success rate for RT-PCR positivity. Beyond molecular detection, all serology tests in areas where other Flavivirus circulates proved to be a difficult task due to the broad range of cross-reactivity, especially with dengue pre-exposed individuals.

CONCLUSION

Altogether, lack of serological diagnostic tools brings limitations to any retrospective evaluation. Those studies are central in the context of congenital infection that could occur asymptomatically and mask prevalence and risk rates.

Prenatal stress from trawl capture affects mothers and neonates: a case study using the southern fiddler ray (Trygonorrhina dumerilii)

Assessing fishing effects on chondrichthyan populations has predominantly focused on quantifying mortality rates. Consequently, sub-lethal effects of capture stress on the reproductive capacity of chondrichthyans are largely unknown. We investigated the reproductive consequences of capture on pregnant southern fiddler rays (Trygonorrhina dumerilii) collected from Swan Bay, Australia, in response to laboratory-simulated trawl capture (8 h) followed immediately by air exposure (30 min). Immediately prior to, and for up to 28 days post trawling, all females were measured for body mass (BM), sex steroid concentrations (17-β estradiol, progesterone, testosterone) and granulocyte to lymphocyte (G:L) ratio. At parturition, neonates were measured for total length (TL), BM and G:L ratio. Trawling reduced maternal BM and elevated the G:L ratio for up to 28 days. Trawling did not significantly affect any sex steroid concentrations relative to controls. Neonates from trawled mothers were significantly lower in BM and TL than control animals, and had an elevated G:L ratio. Our results show that capture of pregnant T. dumerilii can influence their reproductive potential and affect the fitness of neonates. We suggest other viviparous species are likely to be similarly affected. Sub-lethal effects of capture, particularly on reproduction, require further study to improve fisheries management and conservation of chondrichthyans.

Performance of Polymerase Chain Reaction Analysis of the Amniotic Fluid of Pregnant Women for Diagnosis of Congenital Toxoplasmosis: A Systematic Review and Meta-Analysis

Introduction

Congenital infection caused by Toxoplasma gondii can cause serious damage that can be diagnosed in utero or at birth, although most infants are asymptomatic at birth. Prenatal diagnosis of congenital toxoplasmosis considerably improves the prognosis and outcome for infected infants. For this reason, an assay for the quick, sensitive, and safe diagnosis of fetal toxoplasmosis is desirable.

Goal

To systematically review the performance of polymerase chain reaction (PCR) analysis of the amniotic fluid of pregnant women with recent serological toxoplasmosis diagnoses for the diagnosis of fetal toxoplasmosis.

Method

A systematic literature review was conducted via a search of electronic databases; the literature included primary studies of the diagnostic accuracy of PCR analysis of amniotic fluid from pregnant women who seroconverted during pregnancy. The PCR test was compared to a gold standard for diagnosis.

Results

A total of 1.269 summaries were obtained from the electronic database and reviewed, and 20 studies, comprising 4.171 samples, met the established inclusion criteria and were included in the review. The following results were obtained: studies about PCR assays for fetal toxoplasmosis are generally susceptible to bias; reports of the tests’ use lack critical information; the protocols varied among studies; the heterogeneity among studies was concentrated in the tests’ sensitivity; there was evidence that the sensitivity of the tests increases with time, as represented by the trimester; and there was more heterogeneity among studies in which there was more time between maternal diagnosis and fetal testing. The sensitivity of the method, if performed up to five weeks after maternal diagnosis, was 87% and specificity was 99%.

Conclusion

The global sensitivity heterogeneity of the PCR test in this review was 66.5% (I²). The tests show low evidence of heterogeneity with a sensitivity of 87% and specificity of 99% when performed up to five weeks after maternal diagnosis. The test has a known performance and could be recommended for use up to five weeks after maternal diagnosis, when there is suspicion of fetal toxoplasmosis.

Conserved transcription factor binding sites suggest an activator basal promoter and a distal inhibitor in the galanin gene promoter in mouse ES cells

Galanin and its receptors have been shown to be expressed in undifferentiated mouse embryonic stem (ES) cells through transcriptome and proteomic analyses. Although transcriptional regulation of galanin has been extensively studied, the regulatory proteins that mediate galanin expression in mouse ES cells have not yet been determined. Through sequence alignments, we have found a high degree of similarity between mouse and human galanin upstream sequences at -146 bp/+69 bp (proximal region) and -2,408 bp/-2,186 bp (distal region). These regions could be recognized by ES cell nuclear proteins, and EMSA analysis suggests a specific functionality. Analysis of the proximal region (PR) using EMSA and ChIP assays showed that the CREB protein interacts with the galanin promoter both in vitro and in vivo. Additional EMSA analysis revealed that an SP1 consensus site mediated protein-DNA complex formation. Reporter assays showed that CREB is an activator of galanin expression and works cooperatively with SP1. Furthermore, analysis of the distal region (DR) using EMSA assays demonstrated that both HOX-F and PAX 4/6 consensus sites mediated protein-DNA complex formation, and both sites inhibited luciferase activity in reporter assays. These data together suggest that CRE and SP1 act as activators at the basal promoter, while HOX-F and PAX 4/6 act as silencers of transcription. The interplay of these transcription factors (TF) may drive regulated galanin expression in mouse ES cells.

IL-1 Gene Cluster is Not Linked to Aggressive Periodontitis

The interleukin-1 (IL-1) gene family has been associated with susceptibility to periodontal diseases, including aggressive periodontitis (AgP); however, the results are still conflicting. The present study investigated the association between IL-1 genes and AgP using 70 markers spanning the 1.1-Mb region, where the IL-1 gene family maps, and exploring both the linkage disequilibrium (LD) and the haplotype structure in a case-control study including 95 patients and 121 control individuals. No association between AgP and IL1A, IL1B, and IL1RN genes was found in either single-point or haplotype analyses. Also, the LD map of the region 2q13–14 under the Malécot model for multiple markers showed no causal association between AgP and polymorphisms within the region (p = 0.207). In conclusion, our findings failed to support the existence of a causative variant for generalized AgP within the 2q13–14 region in an Italian Caucasian population.

Acetylsalicylic acid inhibits proliferation of human bone marrow stromal cells and matrix mineralization

Acetylsalicylic acid (ASA) and other non-steroidal anti-inflammatory drugs have been shown to potentially inhibit bone healing and bone formation in both animal and clinical studies. Due to the extensive diffusion of ASA-based long-term therapies, the implications of such a side-effect are of interest in all types of bone surgery, including bone grafting procedures and dental implant placement. In this study, we investigate the effect of ASA at therapeutic concentrations on the proliferation and osteogenic differentiation of human bone marrow stromal cells (BMSCs). Primary cultures of BMSCs were isolated and expanded. Their proliferation in response to ASA 50, 100 and 200 microg/ml was evaluated by MTT assay and 3H-thymidine incorporation. Cell cycle machinery was also investigated by FACS and analysis of inhibitors of cyclin-dependent kinases (CDKIs). ASA inhibited BMSC proliferation and DNA synthesis in a dose-dependent manner down to 60% of control (ASA 200 mcg/ml) at 72 h. Cell cycle analysis showed a decrease of BMSCs in the S and G2/M phases with a concomitant accumulation in G0/1 in ASA treated cells. The finding was associated to increased levels of some CDKIs, namely p27(Kip1) and p21(Cip1), whereas ASA did not affected p16(Ink4A) level at any of the concentrations employed. The matrix mineralization, that represents the major feature of the osteogenic commitment, was assessed by a specific staining procedure (von Kossa) and by calcium content determination. Both the methods demonstrated an extensive reduction (greater than 90 percent) of extracellular calcification at 200 microg/ml ASA. On the basis of our results, we can hypothesize that the widely reported inhibition of bone healing by ASA might be sustained both by a direct anti-proliferative effect on BMSCs and by an alteration of the extracellular calcification.

Cardiac structure and function and arterial circulation in hypertensive patients with and without metabolic syndrome

High blood pressure (BP) is one of the crucial determinants of the metabolic syndrome (MS). The extent to which MS, diagnosed according to the criteria of the International Federation of Diabetes, impacts on cardiovascular organ damage, independently of BP, is debated. Three hundred and forty hypertensive patients and 100 normotensive controls underwent the following procedures: (1) physical examination and resting BP measurements, (2) 24 h ambulatory BP monitoring, (3) laboratory routine examination, (4) echocardiography, (5) carotid ultrasonography and (6) ankle-brachial BP index. The syndrome was found in 104 of the 340 hypertensive patients (30.6). In comparison to those without MS, those with MS had significantly higher prevalence of left ventricular (LV) hypertrophy by mass/height(2.7) criteria (46 vs 42%, P<0.01) but not by LV mass/body surface criteria (30 vs 31%); the ratio between early-to-late peak velocities of the LV filling waves (E/A) was higher (E/A=0.99+/-0.14 vs 0.89+/-0.15, P<0.01) and left atrium was larger (3.8+/-0.3 vs 3.5+/-0.5 cm, P<0.01). Both hypertensive groups had significantly greater LVM and carotid intima-media thickness than normotensives, without between-group-difference. In this hypertension outpatient clinic almost one-third hypertensive patients have MS. They show a deterioration in structure and function of the heart in comparison to hypertensive patients without MS, but no difference was detected in the carotid and peripheral arterial circulation.

Bone grafting with platelet-rich plasma in alveolar cleft. Case report

Bone grafting of the alveolus has become an essential part of the contemporary surgical management of oral clefts. The benefits of this procedure are the stabilization of the maxillary arch, elimination of oronasal fistulae, the reconstruction of the soft tissue nasal base support, creation of bony support for subsequent tooth eruption or, when they are not present or not preserved, for implants application. The authors show a case of bone grafting with the aid of platelet-rich plasma (PRP). Because of the difficulties due to the oral cleft and to its surgical reparation (big size of bone defect, hard scars and sclerotic soft tissue) the authors decided to add PRP to a bone graft taken from the chin. PRP contains a high concentration of growth factors and is able to stimulate both wound and bone regeneration. Infact, the authors have observed very good results both in bone integration and in soft tissue reparation.

Effects of Emdogain on osteoblast gene expression

OBJECTIVE

Emdogain (EMD) is a protein extract purified from porcine enamel and has been introduced in clinical practice to obtain periodontal regeneration. EMD is composed mainly of amelogenins (90%), while the remaining 10% is composed of non-amelogenin enamel matrix proteins such as enamelins, tuftelin, amelin and ameloblastin. Enamel matrix proteins seem to be involved in root formation. EMD has been reported to promote proliferation, migration, adhesion and differentiation of cells associated with healing periodontal tissues in vivo.

DESIGN

How this protein acts on osteoblasts is poorly understood. We therefore attempted to address this question by using a microarray technique to identify genes that are differently regulated in osteoblasts exposed to enamel matrix proteins.

RESULTS

By using DNA microarrays containing 20,000 genes, we identified several upregulated and downregulated genes in the osteoblast-like cell line (MG-63) cultured with enamel matrix proteins (Emd). The differentially expressed genes cover a broad range of functional activities: (i) signaling transduction, (ii) transcription, (iii) translation, (iv) cell cycle regulation, proliferation and apoptosis, (v) immune system, (vi) vesicular transport and lysosome activity, and (vii) cytoskeleton, cell adhesion and extracellular matrix production.

CONCLUSIONS

The data reported are the first genome-wide scan of the effect of enamel matrix proteins on osteoblast-like cells. These results can contribute to our understanding of the molecular mechanisms of bone regeneration and as a model for comparing other materials with similar clinical effects.

In vitrocell-type specific biological response of human periodontally related cells to platelet-rich plasma

OBJECTIVES

Platelet-rich plasma is a blood-derived fraction containing high concentrations of platelets and growth factors. Applied in the form of a gel on surgical wounds, it is able to stimulate hard and soft tissue repair and has been proposed for use in the field of periodontal regeneration. However to date, little is known about the biological interactions between platelet-rich plasma and periodontally related cells. In this study, we investigated the effects between platelet-rich plasma and cell populations involved in periodontal regeneration, namely primary human periodontal ligament cells, gingival fibroblasts and keratinocytes.

MATERIAL AND METHODS

The proliferation of human periodontal ligament cells, gingival fibroblasts and keratinocytes by [3H]thymidine incorporation was assessed. The alkaline phosphatase activity and type I collagen levels of human periodontal ligament cells were also evaluated by a spectrophotometric assay and western blot analysis, respectively.

RESULTS

Incubation of human periodontal ligament cells with platelet-rich plasma resulted in time-dependent growth stimulation (up to fourfold of control at 72 h). Likewise, an increase in the specific activity of alkaline phosphatase (fourfold at 6 days) and collagen (twofold at 7 days) was observed. Platelet-rich plasma also enhanced human gingival fibroblasts proliferation by twofold, whereas it inhibited human keratinocytes growth by 40%, with respect to their own controls at 72 h.

CONCLUSION

Cell populations related to periodontal tissue were differently affected by platelet-rich plasma. In fact, a strong stimulation of human periodontal ligament cells proliferation, a minor increase in the growth rate of human gingival fibroblasts and a marked decrease of human keratinocytes proliferation were evident. In addition, in human periodontal ligament cells increased collagen and alkaline phosphatase activity levels were observed. These findings appear interesting in view of platelet-rich plasma utilization in periodontal regeneration.

Ex vivo expansion of bone marrow stromal cells by platelet-rich plasma: a promising strategy in maxillo-facial surgery

The aim of our study is to evaluate in vitro the response of bone marrow stromal cells (BMSCs) to platelet-rich plasma (PRP), in order to clarify the potential role of their combined use in a preclinical phase preceding BMSCs transplantation for bone repair and regeneration procedures. The incubation of BMSCs with PRP promoted a remarkable, dose- and time- dependent, growth stimulation, that was paralleled to a strong increase in the quantity of type I collagen and to a significant decrease in the activity of the early osteoblastic differentiation marker, alkaline phosphatase (AP). Once PRP was removed and osteogenic inducers were added, AP returned to levels comparable to the control, while the late phenotypic markers, osteocalcin and matrix calcification, were enhanced to higher levels than in controls. Our data demonstrate that PRP induces a remarkable ex vivo enrichment of BMSCs maintaining their differentiative potential. Thus PRP represents a valid preclinical tool for obtaining an effective, rapid and safe ex vivo expansion of BMSCs prior to their clinical utilization in bone engineering.

Clinic and ambulatory pulse pressure segregate a cluster of cardiovascular risk factors

Office pulse pressure (PP) has been found to be independently associated with cardiovascular morbidity and mortality. While there is evidence that 24 h blood pressure (BP) is a better marker of the cardiovascular complications of hypertension than office BP, this information is still lacking in regard to PP. The aim of the present study was, therefore, to evaluate possible differences between office and 24 h PP in their relationship with cardiovascular risk profile. This cross-sectional study was performed in a group of 175 (104 M, 71 F) hypertensives (43 never treated before the study) free of clinical evidence of target organ disease. BP was measured at rest and during 24 h monitoring; cardiac structure and function was studied by ultrasounds; biochemical analyses were performed to evaluate some parameters of lipid and carbohydrate metabolism. Patients were divided into tertiles of office PP and of 24 h PP. Those in the highest tertile of PP had a significantly higher office and 24 h systolic BP along with a reduction in peripheral insulin sensitivity. Regarding cardiac structure and function, a significantly higher prevalence of concentric left ventricular hypertrophy (23 vs 55%; P=0.05) and an initial impairment of diastolic function with increase of the A wave was detected in hypertensives with higher PP. No difference between office and 24 h PP in detecting patients at higher cardiovascular risk was observed. In conclusion, office and 24 h pulse pressures were both able to segregate patients with a cluster of cardiovascular risk factors.

Serum cholesterol affects blood pressure regulation

A close relationship between abnormalities of the lipid metabolism and arterial hypertension has been observed in several epidemiological studies. The aim of the present study was to investigate whether serum cholesterol might affect blood pressure (BP) levels at rest, during ambulatory monitoring or during sympathetic stimulation-independently of other variables such as body weight or serum insulin-thus influencing the outcome of hypertensive complications. Seventy-three patients with sustained newly-discovered and never-treated hypertension were divided into tertiles according to their serum cholesterol levels and their resting BP, 24-h BP and BP during isometric exercise (handgrip) were compared. Cardiac mass and carotid wall thickness were measured by echographic technique. The results were that tertiles were similar for body weight, blood glucose and serum insulin, but different for serum cholesterol and triglycerides. BP at rest and during 24-h monitoring was similar in the three groups, whilst a significant difference was detected during sympathetic stimulation by handgrip, with systolic and diastolic BP increasing by 16/12, 28/19 and 30/23 mm Hg (P < 0.01) in lower, medium and higher tertiles, respectively. Intima-media layer of the carotid arteries was also significantly thickened in the groups with higher cholesterol levels (0.54 +/- 0.07, 0.67 +/- 0.14, 0.68 +/- 0.15, P < 0.05). These data support the conclusion that even in patients with recently discovered hypertension, cholesterol levels may influence the BP response to adrenergic stimulation as well as the outcome of target organ disease.

A self-restricted CD38-connexin 43 cross-talk affects NAD+ and cyclic ADP-ribose metabolism and regulates intracellular calcium in 3T3 fibroblasts

Connexin 43 (Cx43) hexameric hemichannels, recently demonstrated to mediate NAD(+) transport, functionally interact in the plasma membrane of several cells with the ectoenzyme CD38 that converts NAD(+) to the universal calcium mobilizer cyclic ADP-ribose (cADPR). Here we demonstrate that functional uncoupling between CD38 and Cx43 in CD38-transfected 3T3 murine fibroblasts is paralleled by decreased [Ca(2+)](i) levels as a result of reduced intracellular conversion of NAD(+) to cADPR. A sharp inverse correlation emerged between [Ca(2+)](i) levels and NAD(+) transport (measured as influx into cells and as efflux therefrom), both in the CD38(+) cells (high [Ca(2+)](i), low transport) and in the CD38(-) fibroblasts (low [Ca(2+)](i), high transport). These differences were correlated with distinctive extents of Cx43 phosphorylation in the two cell populations, a lower phosphorylation with high NAD(+) transport (CD38(-) cells) and vice versa (CD38(+) cells). Conversion of NAD(+)-permeable Cx43 to the phosphorylated, NAD(+)-impermeable form occurs via Ca(2+)-stimulated protein kinase C (PKC). Thus, a self-regulatory loop emerged in CD38(+) fibroblasts whereby high [Ca(2+)](i) restricts further Ca(2+) mobilization by cADPR via PKC-mediated disruption of the Cx43-CD38 cross-talk. This mechanism may avoid: (i) leakage of NAD(+) from cells; (ii) depletion of intracellular NAD(+) by CD38; (iii) overproduction of intracellular cADPR resulting in potentially cytotoxic [Ca(2+)](i).

The temperature-signaling cascade in sponges involves a heat-gated cation channel, abscisic acid, and cyclic ADP-ribose

Sponges (phylum Porifera) are the phylogenetically oldest metazoan animals, their evolution dating back to 600 million years ago. Here we demonstrate that sponges express ADP-ribosyl cyclase activity, which converts NAD(+) into cyclic ADP-ribose, a potent and universal intracellular Ca(2+) mobilizer. In Axinella polypoides (Demospongiae, Axinellidae), ADP-ribosyl cyclase was activated by temperature increases by means of an abscisic acid-induced, protein kinase A-dependent mechanism. The thermosensor triggering this signaling cascade was a heat-activated cation channel. Elucidation of the complete thermosensing pathway in sponges highlights a number of features conserved in higher organisms: (i) the cation channel thermoreceptor, sensitive to heat, mechanical stress, phosphorylation, and anesthetics, shares all of the functional characteristics of the mammalian heat-activated background K(+) channel responsible for central and peripheral thermosensing; (ii) involvement of the phytohormone abscisic acid and cyclic ADP-ribose as its second messenger is reminiscent of the drought stress signaling pathway in plants. These results suggest an ancient evolutionary origin of this stress-signaling cascade in a common precursor of modern Metazoa and Metaphyta.

Insulin resistance, ventricular mass and function in normoglycaemic hypertensives

BACKGROUND AND AIM

To investigate the possible relationship between insulin sensitivity and the main non-invasively determined parameters of left ventricular structure and function in an early phase of hypertensive disease.

METHODS AND RESULTS

We studied a group of 60 patients with previously untreated primary arterial hypertension of recent onset. Insulin sensitivity was evaluated by means of homeostasis model assessment (HOMA), and cardiac structure and function by means of ultrasonography. The patients were subsequently divided on the basis of HOMA tertiles and the between-group differences were statistically evaluated using one-way analysis of variance. No difference was found in the main demographic parameters, but high-density lipoprotein (HDL)-cholesterol was significantly higher (1.43 +/- 0.4, 1.16 +/- 0.2, 1.16 +/- 0.2 mmol/L; p < 0.05) and total triglycerides significantly lower (0.94 +/- 0.3, 1.41 +/- 0.8, 1.54 +/- 0.7 mmol/L; p < 0.05) in the first tertile. In relation to the non-invasive parameters of diastolic function, the E wave was significantly reduced in the third tertile (0.64 +/- 0.1, 0.63 +/- 0.1, 0.52 +/- 0.1 m/s; p < 0.05), with a concomitant significant increase in AFF (0.51 +/- 0.03, 0.51 +/- 0.06, 0.56 +/- 0.03; p < 0.05). The E wave (r = 0.326, p < 0.05), E/A wave ratio (r = -0.277, p < 0.05) and AFF (r = 0.432, p < 0.001) were significantly related to HOMA, regardless of age, body mass index, heart rate, left ventricular mass and blood pressure.

CONCLUSIONS

Our results indicate that hypertensive patients in the third HOMA tertile (i.e. those with reduced insulin sensitivity) have early diastolic left ventricular abnormalities.

Paracrine roles of NAD+ and cyclic ADP-ribose in increasing intracellular calcium and enhancing cell proliferation of 3T3 fibroblasts

CD38 is a bifunctional ectoenzyme synthesizing from NAD(+) (ADP-ribosyl cyclase) and degrading (hydrolase) cyclic ADP-ribose (cADPR), a powerful universal calcium mobilizer from intracellular stores. Recently, hexameric connexin 43 (Cx43) hemichannels have been shown to release cytosolic NAD(+) from isolated murine fibroblasts (Bruzzone, S., Guida, L., Zocchi, E., Franco, L. and De Flora, A. (2001) FASEB J. 15, 10-12), making this dinucleotide available to the ectocellular active site of CD38. Here we investigated transwell co-cultures of CD38(+) (transfected) and CD38(-) 3T3 cells in order to establish the role of extracellular NAD(+) and cADPR on [Ca(2+)](i) levels and on proliferation of the CD38(-) target cells. CD38(+), but not CD38(-), feeder cells induced a [Ca(2+)](i) increase in the CD38(-) target cells which was comparable to that observed with extracellular cADPR alone and inhibitable by NAD(+)-glycohydrolase or by the cADPR antagonist 8-NH(2)-cADPR. Addition of recombinant ADP-ribosyl cyclase to the medium of CD38(-) feeders induced sustained [Ca(2+)](i) increases in CD38(-) target cells. Co-culture on CD38(+) feeders enhanced the proliferation of CD38(-) target cells over control values and significantly shortened the S phase of cell cycle. These results demonstrate a paracrine process based on Cx43-mediated release of NAD(+), its CD38-catalyzed conversion to extracellular cADPR, and influx of this nucleotide into responsive cells to increase [Ca(2+)](i) and stimulate cell proliferation.

Nicotine effects on polymorphonuclear cell apoptosis and lipopolysaccharide-induced monocyte functions. A possible role in periodontal disease?

Apoptosis provides a mechanism for clearance of unwanted cells in a variety of situations in which programmed or physiological cell death occurs; but the premature death of defensive cells could promote infection, inflammation and concomitant disease. We detected high values of apoptosis in polymorphonuclear cells (PMN) elicited from crevicular sulci of smokers affected by adult periodontitis. To learn more about the effects of nicotine on the periodontal environment, we studied its ability to modulate the apoptosis of two phagocytic lines, PMN and mononuclear cells, which are continuously recruited from gingival vessels to prevent or control plaque extension. Brief exposure of PMN to nicotine concentrations ranging from 0.01 to 0.3% shortened, in a dose-dependent relationship, the lag culture time required to observe at fluorescent microscopy the morphological traces of apoptosis. These observations were confirmed by specific tools of apoptosis: DNA fragmentation on gel electrophoresis and expression of the apoptosis-signaling receptor Fas/Apo-1. The apoptotic effect excited by nicotine on these first line defensive cells may be an important feature of the pathogenesis of periodontal disease. As for mononuclear leukocytes, nicotine was unable to induce apoptotic modifications on cells observed up to 72 h culture time, but the drug inhibited IL-1beta release and procoagulant activity (PCA) expression. The conflicting role played by these lipopolysaccharide (LPS)-induced monocyte functions in the inflammatory process is a further intrigue in the mechanism by which nicotine compromises the oral health.

Extracellular cyclic ADP-ribose potentiates ACh-induced contraction in bovine tracheal smooth muscle

Cyclic ADP-ribose (cADPR), a universal calcium releaser, is generated from NAD(+) by an ADP-ribosyl cyclase and is degraded to ADP-ribose by a cADPR hydrolase. In mammals, both activities are expressed as ectoenzymes by the transmembrane glycoprotein CD38. CD38 was identified in both epithelial cells and smooth myocytes isolated from bovine trachea. Intact tracheal smooth myocytes (TSMs) responded to extracellular cADPR (100 microM) with an increase in intracellular calcium concentration ([Ca(2+)](i)) both at baseline and after acetylcholine (ACh) stimulation. The nonhydrolyzable analog 3-deaza-cADPR (10 nM) elicited the same effects as cADPR, whereas the cADPR antagonist 8-NH(2)-cADPR (10 microM) inhibited both basal and ACh-stimulated [Ca(2+)](i) levels. Extracellular cADPR or 3-deaza-cADPR caused a significant increase of ACh-induced contraction in tracheal smooth muscle strips, whereas 8-NH(2)-cADPR decreased it. Tracheal mucosa strips, by releasing NAD(+), enhanced [Ca(2+)](i) in isolated TSMs, and this increase was abrogated by either NAD(+)-ase or 8-NH(2)-cADPR. These data suggest the existence of a paracrine mechanism whereby mucosa-released extracellular NAD(+) plays a hormonelike function and cADPR behaves as second messenger regulating calcium-related contractility in TSMs.

Connexin 43 hemi channels mediate Ca2+-regulated transmembrane NAD+ fluxes in intact cells

A previously unrecognized passive transport for pyridine dinucleotides has been described recently in the plasmamembrane of several mammalian cells. Despite elucidation of some functional and kinetic properties of this transport system, it is still undefined at the molecular level. Therefore, we have addressed the molecular characterization of the NAD+ transporter and identified it as connexin 43 (Cx43). This is a structural component of hexameric hemichannels that, when juxtaposed on adjacent cells, builds up intercellular gap junctions and mediates exchange of molecules between cells. However, the role of connexin hemichannels as potential pores in individual, noncoupled cells remains elusive. Bidirectional NAD+ transport in isolated Cx43-expressing mur ine 3T3 fibroblasts was affected by known modulators of connexin-mediated intercellular coupling and was completely inhibited by treatment of the cells with a Cx43-antisense oligonucleotide. NAD+ transport in proteoliposomes reconstituted with 3T3 membrane proteins was inhibited in the presence of a monoclonal anti-Cx43 antibody. Finally, Cx43 immunopurified to homogeneity was reconstituted in unilamellar proteoliposomes, which displayed full NAD+-transporting activity. This finding is the first evidence that connexin hemichannels can mediate transmembrane fluxes of a nucleotide in whole cells: The pleiotropy of NAD+-dependent cellular events, including redox reactions, signaling, and DNA repair, implicates Cx43 hemichannels in intercellular NAD+ trafficking, which suggests new paracrine functions of NAD.

Extracellular cyclic ADP-ribose increases intracellular free calcium concentration and stimulates proliferation of human hemopoietic progenitors

Cyclic ADP-ribose (cADPR) is a universal second messenger that regulates many calcium-related cellular events by releasing calcium from intracellular stores. Since these events include enhanced cell proliferation and since the bone marrow harbors both ectoenzymes that generate cADPR from NAD(+) (CD38 and BST-1), we investigated the effects of extracellular cADPR on human hemopoietic progenitors (HP). Exposure of HP to 100 microM cADPR for 24 h induced a significant increase in colony output (P<0.01) and colony size (P<0.003). A horizontal expansion of HP, as demonstrated by a markedly increased replating efficiency in semisolid medium (up to 700 times compared to controls), was also observed, indicating that cADPR priming can affect cell growth for multiple generations over several weeks after exposure. Influx of extracellular cADPR into the cells was demonstrated, and a causal relationship between the functional effects and the increase of intracellular free calcium concentration induced by cADPR on HP was established through the use of specific antagonists. Similar effects on HP were produced by nanomolar concentrations of the nonhydrolyzable cADPR analog 3-deaza-cADPR. These data demonstrate that extracellular cADPR behaves as a cytokine enhancing the proliferation of human HP, a finding that may have biomedical applications for the ex vivo expansion of hemopoietic cells.

Olive oil and reduced need for antihypertensive medications

BACKGROUND

The blood pressure (BP) effects of changing the total fat intake and saturated-unsaturated fat ratio are still controversial, despite evidence that saturated fat-enriched diets are associated with higher BP levels. This double-blind, randomized crossover study evaluated a possible difference between antihypertensive effects of monounsaturated (MUFA) (extra-virgin olive oil) and polyunsaturated fatty acids (PUFA) (sunflower oil).

METHODS

Twenty-three hypertensive patients were assigned randomly to MUFA or PUFA diet for 6 months and then crossed over to the other diet; effects were evaluated on the basis of daily antihypertensives needed.

RESULTS

Diets high in MUFA and PUFA differed from the habitual diet for reduced total and saturated fats, whereas they differed from each other for MUFA (17.2% vs 10.5%) and PUFA content (3.8% vs 10.5%). Resting BP was significantly lower (P = .05 for systolic BP; P = .01 for diastolic BP) at the end of the MUFA diet compared with the PUFA diet. Blood pressure responses during sympathetic stimulation with the cold pressor test and isometric exercise were similar. Daily drug dosage was significantly reduced during the MUFA but not the PUFA diet (-48% vs - 4%, P<.005). All patients receiving the PUFA diet required antihypertensive treatment, whereas 8 of those receiving the MUFA diet needed no drug therapy.

CONCLUSIONS

A slight reduction in saturated fat intake, along with the use of extra-virgin olive oil, markedly lowers daily antihypertensive dosage requirement, possibly through enhanced nitric oxide levels stimulated by polyphenols.

Sex-related influence of body size and sexual maturation on blood pressure in adolescents

OBJECTIVE

This study is aimed at investigating the influence of body size, body fat and sexual maturation on blood pressure (BP) in adolescents.

DESIGN

A cross-sectional study.

SETTING

A suburban student population of Southern Italy.

SUBJECTS

One hundred ninety students attending the first and second year of a secondary school. Five were excluded because they were affected by major diseases. The remaining were 98 M and 87 F (mean age for either group = 12.0+/-0.8 y).

METHODS

Blood pressure was measured by a mercury sphygmomanometer, body weight by a platform beamscale, other measurements included height, biceps, triceps, subscapular and suprailiac skinfolds by a caliper; sexual maturation was evaluated according to Tanner.

RESULTS

Body size was greater than in Tanner's population: in particular body weight (but not height) in our sample markedly exceeded that of the children of the same age in Tanner's population. Boys had higher systolic blood pressure (SBP) than girls (BP = 109/64+/-12/10 vs. 103/63+/-11/8 mm Hg, P<0.02 for SBP), while heart rate and waist/hip ratio were lower. During puberty evaluated on the basis of pubic hair growth BP in girls was higher than in the prepubertal phase (107/66+/-9/7 vs. 99/61+/-10/7, P<0.01). Pubertal boys showed a reduced percent of body fat (calculated from four skinfold measurements) in comparison to prepubertal ones (21.0%+/-4.5 vs. 24.5%+/-7.1, P<0.01). In linear correlation analysis, height, BW, BMI and lean body mass were found to be significantly associated with SBP in both sexes and to diastolic blood pressure (DBP) in girls. Percent body fat was correlated with SBP in boys, while sexual maturation was associated to SBP and DBP in girls only. Multiple regression analysis indicated a significant contribution of body size to BP variability, particularly in the girls. Sexual maturation was excluded from the final regression equations when height, BW or lean body mass were present.

CONCLUSIONS

These data indicate that body weight in these adolescents is greater that in Tanner's population of the same age and sex. Body size appears to be a major determinant of BP, whereas sexual maturation seems to influence BP levels mainly through body growth. The influence of percent body fat on BP setting seems to be of limited importance.

Clinic-daytime blood pressure difference and cardiovascular damage

OBJECTIVE

To investigate whether the clinic-daytime blood pressure difference can provide information on vascular reactivity to stress comparable to that of simple noninvasive stimuli such as a cold pressor test and isometric exercise, and whether there is any relationship between this blood pressure difference and noninvasive measurements of the left ventricular mass and carotid arterial wall.

DESIGN

Patients with newly discovered, never-treated, sustained hypertension were included in the study after a 1 month run-in, during which time their blood pressure was measured three times at 2 week intervals.

METHODS

Blood pressure was measured by a noninvasive procedure at rest and during a cold pressor test and an isometric exercise. The difference was calculated for systolic, diastolic and mean blood pressure as resting minus daytime ambulatory blood pressure. Parameters of the posterior wall and septal thickness of the left ventricle, aortic root and left atrium were studied by M-mode echocardiography. Carotid wall thickness and diameter were measured using ultrasound.

RESULTS

The 90 patients enrolled in the study were divided into tertiles of clinic-daytime blood pressure difference. The composition of the groups differed in sex, since the majority of women were in the highest tertile, but was comparable for age, body mass index, renin-aldosterone axis and lipid and carbohydrate metabolism. Blood pressure responses to cold and isometric exercise were more pronounced in patients in the lowest tertile of blood pressure difference. No intergroup differences were detected in echocardiographic parameters of ventricular (left ventricular mass, tertiles I-III: 46.5 +/- 10, 42.3 +/- 8, 44.8 +/- 13 g/m2.7, respectively) and carotid (intima-media thickness, tertiles I-III 0.58 +/- 0.1, 0.54 +/- 0.1, 0.62 +/- 0.1 mm, respectively) structure.

CONCLUSIONS

The present study indicates that the clinic-daytime blood pressure difference provides different information on cardiovascular reactivity compared with that obtained from the cold pressor test and isometric exercise. Moreover, it does not seem to have any relationship with ventricular hypertrophy and/or carotid wall thickening.

Ligand-induced internalization of CD38 results in intracellular Ca2+ mobilization: role of NAD+ transport across cell membranes

CD38, a transmembrane glycoprotein widely expressed in vertebrate cells, is a bifunctional ectoenzyme catalyzing the synthesis and hydrolysis of cyclic ADP-ribose (cADPR). cADPR is a universal second messenger that releases calcium from intracellular stores. Since cADPR is generated by CD38 at the outer surface of many cells, where it acts intracellularly, increasing attention is paid to addressing this topological paradox. Recently, we demonstrated that CD38 is a catalytically active, unidirectional transmembrane transporter of cADPR, which then reaches its receptor-operated intracellular calcium stores. Moreover, CD38 was reported to undergo a selective and extensive internalization through non clathrin-coated endocytotic vesicles upon incubating CD38(+) cells with either NAD+ or thiol compounds: these endocytotic vesicles can convert cytosolic NAD into cADPR despite an asymmetric unfavorable orientation that makes the active site of CD38 intravesicular. Here we demonstrate that the cADPR-generating activity of the endocytotic vesicles results in remarkable and sustained increases of intracellular free calcium concentration in different cells exposed to either NAD+, or GSH, or N-acetylcysteine. This effect of CD38-internalizing ligands on intracellular calcium levels was found to involve a two-step mechanism: 1) influx of cytosolic NAD+ into the endocytotic vesicles, mediated by a hitherto unrecognized dinucleotide transport system that is saturable, bidirectional, inhibitable by 8-N3-NAD+, and characterized by poor dinucleotide specificity, low affinity, and high efficiency; 2) intravesicular CD38-catalyzed conversion of NAD+ to cADPR, followed by outpumping of the cyclic nucleotide into the cytosol and subsequent release of calcium from thapsigargin-sensitive stores. This unknown intracellular trafficking of NAD+ and cADPR based on two distinctive and specific transmembrane carriers for either nucleotide can affect the intracellular calcium homeostasis in CD38(+) cells.

The transmembrane glycoprotein CD38 is a catalytically active transporter responsible for generation and influx of the second messenger cyclic ADP-ribose across membranes

CD38 is a type II transmembrane glycoprotein expressed in many vertebrate cells. It is a bifunctional ectoenzyme that catalyzes both the synthesis of Cyclic ADP-ribose (cADPR) from NAD+ and the degradation of cADPR to ADP-ribose by means of its ADP-ribosyl cyclase and cADPR-hydrolase activities, respectively. The cyclase also converts NGD+ to cyclic GDP-ribose (cGDPR), which is refractory to cADPR-hydrolase. cADPR, but not cGDPR, is a potent calcium mobilizer from intracellular stores. It has been demonstrated to be a new second messenger involved in the regulation of calcium homeostasis in many cell types, from plants to mammals. The number of physiological processes shown to be regulated by cADPR is steadily increasing. A topological paradox exists because ectocellularly generated cADPR acts intracellularly. Here we demonstrate that the catalytic functioning of CD38 is accompanied by a cADPR (cGDPR) -transporting activity across natural and artificial membranes. In resealed membranes from CD38(+) human erythrocytes, transport of catalytically generated cADPR or cGDPR was saturation dependent and occurred against a concentration gradient. Likewise, CD38-reconstituted proteoliposomes were active in concentrating NAD+ (NGD+) -derived cADPR (cGDPR) inside the vesicle compartment. Moreover, the cADPR-transporting activity in CD38 proteoliposomes prevented the hydrolase-catalyzed degradation to ADPR that occurs conversely with detergent-solubilized CD38, resulting in selective influx of cADPR. In the CD38 proteoliposomes, catalytically active CD38 exhibited monomeric, dimeric, and tetrameric structures. In CD38 sense- but not in antisense-transfected HeLa cells, externally added NAD+ resulted in significant, transient increases in cytosolic calcium. These data suggest that transmembrane juxtaposition of two or four CD38 monomers can generate a catalytically active channel for selective formation and influx of cADPR (cGDPR) to reach cADPR-responsive intracellular calcium stores.

Cardiovascular abnormalities in never-treated hypertensives according to nondipper status

Ambulatory blood pressure monitoring allows a better understanding of blood pressure fluctuations over 24 h than simple clinic measurements. In this way the diagnosis of "white coat" versus "sustained" hypertension and that of "dipper" (patient with blood pressure fall during nighttime > 10% of daytime levels) versus "nondipper" status were made possible. This pilot study has been undertaken to investigate whether patients with recently discovered, never-treated, mild, sustained hypertension have cardiovascular abnormalities according to their dipper/nondipper status. Patients with long-standing (n = 123) and newly discovered (n = 56) sustained hypertension were classified according to their nighttime blood pressure fall, and compared with normotensive controls. Ambulatory blood pressure monitoring was performed noninvasively. Parameters of left ventricular structure, cardiac systolic and diastolic function, and carotid anatomy were determined noninvasively by echographic methods. Significant increases in parameters of cardiac structure as well as abnormalities in diastolic function were observed in patients with long-standing hypertension, regardless of their dipper status. In the group with newly discovered hypertension, left atrium (3.4+/-0.3, 3.7+/-0.5, 3.2+/-0.4 cm in dippers, nondippers, and controls, respectively), end-diastolic diameter index (2.9+/-0.3, 3.0+/-0.2, 2.8+/-0.2 cm/m), and atrial filling fraction (0.50+/-0.07, 0.52+/-0.05, 0.42+/-0.04) were significantly altered only in the nondipper subgroup, in comparison with controls. Significant changes in cardiac structure and diastolic function were observed in nondipper patients with recently discovered hypertension, who, at variance with dippers, show changes similar to those in patients with long-standing hypertension. Hypertensives with the observed abnormalities may benefit from active antihypertensive treatment, which appears, therefore, justified even in an early phase of mild hypertension, in terms of potential reduction of end-organ complications as well as cost-effectiveness.

Dimeric and tetrameric forms of catalytically active transmembrane CD38 in transfected HeLa cells

CD38, a type II transmembrane glycoprotein, behaves as a catalytically active transporter responsible for ectocellular generation of cyclic ADP-ribose (cADPR) from NAD+ and for subsequent influx of cADPR across membranes [Franco, L., Guida, L., Bruzzone, S., Zocchi, E., Usai, C. and De Flora, A. (1998) FASEB J. in press]. cADPR regulates intracellular calcium homeostasis by releasing calcium from responsive stores. The cADPR-transporting function of CD38 requires channel-generating oligomeric forms of the protein rather than the 46 kDa monomers that have been described so far in CD38+ cells. Here we demonstrate that CD38, both in reconstituted proteoliposomes and in CD38-transfected HeLa cells, is a mixture of catalytically active monomers, homodimers and homotetramers. A soluble recombinant form of CD38 corresponding to its ectocellular region proved to be monomeric. Thus, association of native CD38 with either artificial or natural membranes seems to result in a reversible juxtaposition of monomers suitable to cADPR-transporting activity.

Expression of CD38 increases intracellular calcium concentration and reduces doubling time in HeLa and 3T3 cells

CD38 is a bifunctional ectoenzyme, predominantly expressed on hematopoietic cells during differentiation, that catalyzes the synthesis (cyclase) and the degradation (hydrolase) of cyclic ADP-ribose (cADPR), a powerful calcium mobilizer from intracellular stores. Due to the well established role of calcium levels in the regulation of apoptosis, proliferation, and differentiation, the CD38/cADPR system seems to be a likely candidate involved in the control of these fundamental processes. The ectocellular localization of the cyclase activity, however, contrasts with the intracellular site of action of cADPR. Here we demonstrate that ectocellular expression of human CD38 in CD38(-) HeLa and 3T3 cells results in intracellular CD38 substrate (NAD+ + NADH) consumption and product (cADPR) accumulation. Furthermore, a causal relationship is established between presence of intracellular cADPR, partial depletion of thapsigargin-sensitive calcium stores, increase in basal free cytoplasmic calcium concentration, and decrease of cell doubling time. The significant shortening of the S phase in CD38(+) HeLa cells, as compared with controls, demonstrates an effect of intracellular cADPR on the mammalian cell cycle.

Ectocellular CD38-catalyzed synthesis and intracellular Ca(2+)-mobilizing activity of cyclic ADP-ribose

CD38 is a type-II transmembrane glycoprotein occurring in several hematopoietic and mature blood cells as well as in other cell types, including neurons. Although classified as an orphan receptor, CD38 is also a bifunctional ectoenzyme that catalyzes both the conversion of NAD+ to nicotinamide and cyclic ADP-ribose (cADPR), via an ADP-ribosyl cyclase reaction, and also the hydrolysis of cADPR to ADP-ribose (hydrolase). Major unresolved questions concern the correlation between receptor and catalytic properties of CD38, and also the apparent contradiction between ectocellular generation and intracellular Ca(2+)-mobilizing activity of cADPR. Results are presented that provide some explanations to this topological paradox in two different cell types. In cultured rat cerebellar granule neurons, extracellular cADPR (either generated by CD38 or directly added) elicited an enhanced intracellular Ca(2+)-response to KCl-induced depolarization, a process that can be qualified as a Ca(2+)-induced Ca2+ release (CICR) mechanism. On the other hand, in the CD38+ human Namalwa B lymphoid cells, NAD+ (and thiol compounds as well) induced a two-step process of self-aggregation followed by endocytosis of CD38, which resulted in a shift of cADPR metabolism from the cell surface to the cytosol. Both distinctive types of cellular responses to extracellular NAD+ seem to be suitable to elicit changes in the intracellular Ca2+ homeostasis.

The CD38/cyclic ADP-ribose system: a topological paradox

CD38 was first identified as a lymphocyte differentiation antigen that showed typical properties of an orphan receptor involved in many programs of cell proliferation and activation. However, CD38 proved also to be a bifunctional ectoenzyme that catalyzes the transient formation of cyclic ADP-ribose (cADPR) in a variety of cell types. This property raises many intriguing and so far unanswered questions, since cADPR is a new second messenger molecule directly involved in the control of calcium homeostasis by means of receptor-mediated release of calcium from ryanodine-sensitive intracellular stores. The relationship between receptor-like and enzymatic properties of CD38 is still unknown. The apparent topological paradox of ectocellular synthesis and intracellular activity of cADPR might be explained by: (a) influx of cADPR across the plasma membrane to reach its target stores, as suggested by experiments on cerebellar granule cells; and (b) NAD(+)-induced internalization, following membrane oligomerization, of CD38 with consequent partial import of cADPR metabolism to an intracellular compartment, as recently observed in lymphoid B cells. These two distinct mechanisms and other potential ones (e.g. binding of ectocellularly formed cADPR to cell surface receptors and initiation of signal-transducing pathways across the plasmamembrane) seem to be paradigmatic of processes affecting different types of cells. Although in some biological systems, such as Aplysia and sea urchin egg, cADPR metabolism is restricted to the intracellular environment, in mammalian cells the CD38/cADPR system provides new challenges in terms of subcellular compartmentation and qualifies as an unusual example of "ectobiochemistry" with potential, still unrecognized, properties of cellular regulation.

Isolated office hypertension and end-organ damage

BACKGROUND

Patients with elevated blood pressure levels in the doctor's office but normal blood pressures at other times have recently been described as having 'isolated office hypertension' (IOH). There is debate concerning whether this condition is really benign and thus not in need of treatment. Most of the previous studies on this topic included patients who had already been administered antihypertensive treatment, which unavoidably alters their cardiovascular profile.

OBJECTIVE

To evaluate whether recently discovered and never-treated patients with isolated office hypertension have structural or functional abnormalities in comparison with normotensive controls.

METHODS

Patients included in the study underwent 24 h ambulatory blood pressure monitoring, M-mode echocardiography and high-resolution echography of carotid arteries. Parameters of lipid and carbohydrate metabolism were also determined.

RESULTS

We investigated 76 patients (20 with IOH and 56 with sustained hypertension) who had recently been diagnosed hypertensive but never been administered antihypertensive treatment and 32 matched controls. No changes were detected in left ventricular mass (LVM h2.7, 41.5 +/- 11, 44.5 +/- 10 and 41.5 +/- 10 g/cm2.7 in IOH, sustained hypertension and controls, respectively) and in intimal-medial thickness (IMT, 0.54 +/- 0.13, 0.59 +/- 0.14 and 0.55 +/- 0.16 mm, respectively). However, the left ventricular diastolic function was significantly different (E/A = 1.08 +/- 0.3, 1.04 +/- 0.3 and 1.43 +/- 0.3, respectively, P = 0.02) and the carotid diameter significantly lower than that expected from the pressure-diameter relationship for normotensives.

CONCLUSIONS

These results, at variance with those of others, suggest that IOH affects the cardiovascular system even during the early phases of the disease and indicate the need for prospective clinical trials to evaluate the benefit from early treatment of IOH patients.