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Bulkowstein Y, Nitzan-Luques A, Schnapp A, Barnoy N, Reif S, Gilboa T, Volovesky O. The manifestations of metabolic acidosis during acetazolamide treatment in a cohort of pediatric idiopathic intracranial hypertension. Pediatr Nephrol 2024; 39:185-191. [PMID: 37480382 DOI: 10.1007/s00467-023-06084-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 06/27/2023] [Accepted: 06/27/2023] [Indexed: 07/24/2023]
Abstract
BACKGROUND Idiopathic intracranial hypertension is characterized by increased intracranial pressure with unidentified pathology. Despite its use as the first-line treatment, data on acetazolamide's effectiveness and safety in pediatric idiopathic intracranial hypertension is sparse. This study's objective was to assess those issues and the need for routine blood gas monitoring during treatment. METHODS Retrospective observational cohort study, based on multicenter computerized medical charts of pediatric patients with idiopathic intracranial hypertension diagnosed between 2007-2018 in three medical centers serving one metropolitan area (an estimated population of 400,000 children). Clinical and laboratory data of children up to 18 years old, fulfilling the Friedman criteria and taking acetazolamide, were collected and analyzed. RESULTS Sixty-eight patients were included with a mean acetazolamide treatment duration of 8.5 months and a median maximal dose 18 mg/kg/d. Sixty-two children had mild (76%), moderate (13%), or severe (1.5%) metabolic acidosis. At least one adverse effect (neurologic, gastrointestinal, renal) was recorded among 27% of patients. No significant difference was found between the mean pH of children with or without clinical adverse effects (p = 0.35). No correlation was found between laboratory acidosis and adverse effect severity (p = 0.3), or between median acetazolamide dose and acidosis level (p = 0.57). CONCLUSIONS Although laboratory finding of metabolic acidosis is common among patients with idiopathic intracranial hypertension treated with acetazolamide, it is not correlated with clinics. Therefore, we recommend sending blood tests during acetazolamide treatment based on clinical judgment. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
| | - Adi Nitzan-Luques
- Pediatric Department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
- Pediatric Hematology Oncology Department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Aviad Schnapp
- Pediatric Department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Noa Barnoy
- Pediatric Neurology Unit, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Shimon Reif
- Pediatric Department, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Tal Gilboa
- Pediatric Neurology Unit, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Oded Volovesky
- Pediatric Nephrology Unit and Research Lab, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Israel.
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Ben-Moshe Y, Shlomovitz O, Atias-Varon D, Haskin O, Ben-Shalom E, Shasha Lavsky H, Volovelsky O, Mane S, Ben-Ruby D, Chowers G, Skorecki K, Borovitz Y, Kagan M, Mor N, Khavkin Y, Tzvi-Behr S, Pollack S, Toder MP, Geylis M, Schnapp A, Becker-Cohen R, Weissman I, Schreiber R, Davidovits M, Frishberg Y, Magen D, Barel O, Vivante A. Diagnostic Utility of Exome Sequencing Among Israeli Children With Kidney Failure. Kidney Int Rep 2023; 8:2126-2135. [PMID: 37850020 PMCID: PMC10577315 DOI: 10.1016/j.ekir.2023.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 07/18/2023] [Accepted: 07/24/2023] [Indexed: 10/19/2023] Open
Abstract
Introduction Genetic etiologies are estimated to account for a large portion of chronic kidney diseases (CKD) in children. However, data are lacking regarding the true prevalence of monogenic etiologies stemming from an unselected population screen of children with advanced CKD. Methods We conducted a national multicenter prospective study of all Israeli pediatric dialysis units to provide comprehensive "real-world" evidence for the genetic basis of childhood kidney failure in Israel. We performed exome sequencing and assessed the genetic diagnostic yield. Results Between 2019 and 2022, we recruited approximately 88% (n = 79) of the children on dialysis from all 6 Israeli pediatric dialysis units. We identified genetic etiologies in 36 of 79 (45%) participants. The most common subgroup of diagnostic variants was in congenital anomalies of the kidney and urinary tract causing genes (e.g., EYA1, HNF1B, PAX2, COL4A1, and NFIA) which together explain 28% of all monogenic etiologies. This was followed by mutations in genes causing renal cystic ciliopathies (e.g., NPHP1, NPHP4, PKHD1, and BBS9), steroid-resistant nephrotic syndrome (e.g., LAGE3, NPHS1, NPHS2, LMX1B, and SMARCAL1) and tubulopathies (e.g., CTNS and AQP2). The genetic diagnostic yield was higher among Arabs compared to Jewish individuals (55% vs. 29%) and in children from consanguineous compared to nonconsanguineous families (63% vs. 29%). In 5 participants (14%) with genetic diagnoses, the molecular diagnosis did not correspond with the pre-exome diagnosis. Genetic diagnosis has a potential influence on clinical management in 27 of 36 participants (75%). Conclusion Exome sequencing in an unbiased Israeli nationwide dialysis-treated kidney failure pediatric cohort resulted in a genetic diagnostic yield of 45% and can often affect clinical decision making.
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Affiliation(s)
- Yishay Ben-Moshe
- Department of Pediatrics B, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat-Gan, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Omer Shlomovitz
- Department of Pediatrics B, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat-Gan, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Danit Atias-Varon
- Department of Pediatrics B, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat-Gan, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Genetic Kidney Disease Research Laboratory, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel
| | - Orly Haskin
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Nephrology Institute, Schneider Children’s Medical Center of Israel, Petah Tikva, Israel
| | - Efrat Ben-Shalom
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hadas Shasha Lavsky
- Pediatric Nephrology Unit, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Oded Volovelsky
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Pediatric Nephrology Unit, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shrikant Mane
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Dror Ben-Ruby
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Genetic Kidney Disease Research Laboratory, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel
| | - Guy Chowers
- Department of Pediatrics B, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat-Gan, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Karl Skorecki
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Yael Borovitz
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Nephrology Institute, Schneider Children’s Medical Center of Israel, Petah Tikva, Israel
| | - Maayan Kagan
- Department of Pediatrics B, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat-Gan, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Nofar Mor
- Genomics Unit, Sheba Cancer Research Center, Sheba Medical Center, Tel-Hashomer, Israel
| | - Yulia Khavkin
- Genomics Unit, Sheba Cancer Research Center, Sheba Medical Center, Tel-Hashomer, Israel
| | - Shimrit Tzvi-Behr
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shirley Pollack
- Pediatric Nephrology Institute, Rambam Health Care Campus, Haifa, Israel
- Technion Faculty of Medicine, Ruth Rappaport Children's Hospital, Rambam Health Care Campus, Haifa, Israel
| | - Moran Plonsky Toder
- Pediatric Nephrology Institute, Rambam Health Care Campus, Haifa, Israel
- Technion Faculty of Medicine, Ruth Rappaport Children's Hospital, Rambam Health Care Campus, Haifa, Israel
| | - Michael Geylis
- Pediatric Nephrology Clinic, Soroka University Medical Center, Beer Sheva, Israel
- Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Aviad Schnapp
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Pediatric Nephrology Unit, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rachel Becker-Cohen
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Irith Weissman
- Pediatric Nephrology Unit, Galilee Medical Center, Nahariya, Israel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ruth Schreiber
- Pediatric Nephrology Clinic, Soroka University Medical Center, Beer Sheva, Israel
- Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Miriam Davidovits
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Nephrology Institute, Schneider Children’s Medical Center of Israel, Petah Tikva, Israel
| | - Yaacov Frishberg
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daniella Magen
- Pediatric Nephrology Institute, Rambam Health Care Campus, Haifa, Israel
- Technion Faculty of Medicine, Ruth Rappaport Children's Hospital, Rambam Health Care Campus, Haifa, Israel
| | - Ortal Barel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Genomics Unit, Sheba Cancer Research Center, Sheba Medical Center, Tel-Hashomer, Israel
| | - Asaf Vivante
- Department of Pediatrics B, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat-Gan, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Division of Pediatric Nephrology, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Tel-Hashomer, Israel
- Genetic Kidney Disease Research Laboratory, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel
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Schnapp A, Egger Y, Bignall ONR, Issler N, Volovelsky O. Estimated pediatric glomerular filtration rate presentation improves the detection rate of kidney impairment in children. Pediatr Nephrol 2023; 38:3091-3097. [PMID: 36988688 DOI: 10.1007/s00467-023-05934-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 03/03/2023] [Accepted: 03/03/2023] [Indexed: 03/30/2023]
Abstract
BACKGROUND Accurate interpretation of everyday laboratory work is crucial for the early detection of impaired kidney function. Bedside estimation of glomerular filtration rate (eGFR) in children is based on serum creatinine standardized for body mass, most commonly using the revised Schwartz equation using height. This study evaluates how data presentation affects the correct assessment of children's kidney function. METHODS In this survey-based study, 121 physicians treating children routinely in a tertiary hospital answered 11 clinical questions requiring assessment of kidney function based on serum creatinine with general (adult) or pediatric normal serum creatinine ranges, or by presented eGFR. The demographic data of the participants were collected. RESULTS Presenting eGFR values rather than the customary presentation of serum creatinine and anthropometric parameters more than quadrupled the number of physicians who accurately estimated pediatric kidney function; 38.8% of physicians correctly assessed kidney function when presented with eGFR values but misinterpreted it when equivalent creatinine values were presented (p < 0.001). Seniority, specialty, and self-reported frequency of pediatric kidney function assessment did not affect the interpretation. CONCLUSIONS Presenting physicians with calculated eGFR can dramatically improve the ability of the medical team to assess kidney function correctly in children. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Aviad Schnapp
- Department of Pediatrics, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Yonatan Egger
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - O N Ray Bignall
- Division of Nephrology and Hypertension, Nationwide Children's Hospital, Columbus, OH, USA
- The Ohio State University College of Medicine, Columbus, OH, USA
| | - Naomi Issler
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Pediatric Nephrology Unit and Research Lab, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Oded Volovelsky
- Department of Pediatrics, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Pediatric Nephrology Unit and Research Lab, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
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Schnapp A, Harel M, Cayam-Rand D, Cassuto H, Polyansky L, Aran A. A Placebo-Controlled Trial of Cannabinoid Treatment for Disruptive Behavior in Children and Adolescents with Autism Spectrum Disorder: Effects on Sleep Parameters as Measured by the CSHQ. Biomedicines 2022; 10:biomedicines10071685. [PMID: 35884990 PMCID: PMC9312464 DOI: 10.3390/biomedicines10071685] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 12/18/2022] Open
Abstract
Autism spectrum disorder (ASD) is often associated with debilitating sleep disturbances. While anecdotal evidence suggests the positive effect of cannabinoids, randomized studies are lacking. Here, we report the effects of cannabinoid treatment on the sleep of 150 children and adolescents with ASD, as part of a double-blind, placebo-controlled study that assessed the impact of cannabinoid treatment on behavior (NCT02956226). Participants were randomly assigned to one of the following three treatments: (1) whole-plant cannabis extract, containing cannabidiol (CBD) and Δ9-Tetrahydrocannabinol (THC) in a 20:1 ratio, (2) purified CBD and THC extract in the same ratio, and (3) an oral placebo. After 12 weeks of treatment (Period 1) and a 4-week washout period, participants crossed over to a predetermined, second 12-week treatment (Period 2). Sleep disturbances were assessed using the Children’s Sleep-Habit Questionnaire (CSHQ). We found that the CBD-rich cannabinoid treatment was not superior to the placebo treatment in all aspects of sleep measured by the CSHQ, including bedtime resistance, sleep-onset delay, and sleep duration. Notably, regardless of the treatment (cannabinoids or placebo), improvements in the CSHQ total score were associated with improvements in the autistic core symptoms, as indicated by the Social Responsiveness Scale total scores (Period 1: r = 0.266, p = 0.008; Period 2: r = 0.309, p = 0.004). While this study failed to demonstrate that sleep improvements were higher with cannabinoids than they were with the placebo treatment, further studies are required.
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Affiliation(s)
- Aviad Schnapp
- Department of Pediatrics, Hadassah Medical Center, Jerusalem 91120, Israel;
| | - Moria Harel
- Neuropediatric Unit, Shaare Zedek Medical Center, Jerusalem 9103102, Israel; (M.H.); (D.C.-R.); (L.P.)
| | - Dalit Cayam-Rand
- Neuropediatric Unit, Shaare Zedek Medical Center, Jerusalem 9103102, Israel; (M.H.); (D.C.-R.); (L.P.)
| | - Hanoch Cassuto
- Child Development Centers, Leumit Health Services, Jerusalem 9439221, Israel;
| | - Lola Polyansky
- Neuropediatric Unit, Shaare Zedek Medical Center, Jerusalem 9103102, Israel; (M.H.); (D.C.-R.); (L.P.)
| | - Adi Aran
- Neuropediatric Unit, Shaare Zedek Medical Center, Jerusalem 9103102, Israel; (M.H.); (D.C.-R.); (L.P.)
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
- Correspondence:
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Kagan M, Ben Moshe Y, Shlomovitz O, Atias-Varon D, Haskin O, Ben-Shalom E, Magen D, Schreiber R, Volovelsky O, Shasha-Lavsky H, Davidovits M, Borovitz Y, Mor N, Khavkin Y, Tzvi Behr S, Pollack S, Geylis M, Schnapp A, Weissman I, Barel O, Vivante A. FC035: Exome Sequencing of the Israeli Dialysis-Treated Pediatric Population Reveals Monogenic Etiology in ∼44% of Cases. Nephrol Dial Transplant 2022. [DOI: 10.1093/ndt/gfac102.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
BACKGROUND
Chronic kidney disease in children is estimated to be secondary to a monogenic etiology in ∼20% of patients and can arise from mutations in a multitude of different single-gene causes. Still, data are lacking on the true prevalence of genetic etiologies dates from a large scale unbiased population screen of children with advanced kidney disease.
METHOD
In order to provide comprehensive real-world evidence for monogenic etiologies of childhood end-stage kidney disease—on a national level—we initiated a nation-wide multicenter study of all pediatric Israeli dialysis units. Specifically, between 2020 and 2021, we recruited ∼90% (n = 66) of children on dialysis from all six dialysis units treating children in Israel. We conducted exome sequencing and diagnostic analysis for all patients. We assessed the diagnostic yield of genetic analysis and its relation to baseline clinical phenotypes.
RESULTS
Overall, the cohort comprises 66 individuals from different families with a first-degree consanguinity rate of 47%. Participants' mean age at renal replacement therapy initiation was 8.1 years (range 1-month to 20-years). Using exome sequencing we identified a genetic etiology in 29 out of 66 (44%) participants. The most common subgroup of diagnostic variants was in genes causing renal cystic ciliopathies (e.g. NPHP1, NPHP4, PKHD1 and BBS9), which together explain 31% of all monogenic etiologies. This was followed by mutations in genes causing CAKUT (e.g. EYA1, HNF1B, PAX2, COL4A1 and GREB1L), steroid-resistant nephrotic syndrome (e.g. LAGE3, NPHS1, NPHS2, LMX1B, SMARCAL1 and CRB2) and tubulopathies (e.g. CTNS, AQP2), which explain 21%, 21% and 17% of all genetic etiologies, respectively. The yield of exome sequencing was higher among non-Jewish compared with Jewish individuals (52% versus 29%) and in children from consanguineous families compared with non-consanguineous families (56% versus 31%). The final molecular diagnosis did not correspond with the pre-exome clinical diagnosis in 17% of cases.
CONCLUSION
Exome sequencing in an unbiased pediatric cohort with end-stage kidney disease yields a genetic diagnosis in 44% of cases and reveals many underappreciated monogenic etiologies. Surprisingly, renal cystic ciliopathies causing-genes were more common than CAKUT genes in our cohort. These results emphasize the importance of genetic testing among children with advanced chronic kidney disease and validate the role of exome sequencing as a standard routine diagnostic tool.
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Affiliation(s)
- Maayan Kagan
- Department of Pediatrics B, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Yishay Ben Moshe
- Department of Pediatrics B, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Omer Shlomovitz
- Department of Pediatrics B, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Danit Atias-Varon
- Department of Pediatrics B, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Orly Haskin
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
- Schneider Children's Medical Center of Israel, Nephrology Institute, Petah Tikva, Israel
| | - Efrat Ben-Shalom
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daniella Magen
- Rambam Health Care Campus, Pediatric Nephrology Institute, Haifa, Israel
| | - Ruth Schreiber
- Pediatric Nephrology Clinic, Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Oded Volovelsky
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Nephrology Unit and Research Lab, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | | | - Miriam Davidovits
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
- Schneider Children's Medical Center of Israel, Nephrology Institute, Petah Tikva, Israel
| | - Yael Borovitz
- Schneider Children's Medical Center of Israel, Nephrology Institute, Petah Tikva, Israel
| | - Nofar Mor
- Sheba Medical Center, Genomics Unit, Sheba Cancer Research Center, Tel-Hashomer, Israel
| | - Yulia Khavkin
- Sheba Medical Center, Genomics Unit, Sheba Cancer Research Center, Tel-Hashomer, Israel
| | - Shimrit Tzvi Behr
- Division of Pediatric Nephrology, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Shirley Pollack
- Rambam Health Care Campus, Pediatric Nephrology Institute, Haifa, Israel
| | - Michael Geylis
- Pediatric Nephrology Clinic, Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Aviad Schnapp
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- Nephrology Unit and Research Lab, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Irith Weissman
- Pediatric Nephrology Unit, Galilee Medical Center, Nahariya, Israel
| | - Ortal Barel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
- Sheba Medical Center, Genomics Unit, Sheba Cancer Research Center, Tel-Hashomer, Israel
| | - Asaf Vivante
- Department of Pediatrics B, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
- Division of Pediatric Nephrology, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
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Aran A, Harel M, Cassuto H, Polyansky L, Schnapp A, Wattad N, Shmueli D, Golan D, Castellanos FX. Cannabinoid treatment for autism: a proof-of-concept randomized trial. Mol Autism 2021; 12:6. [PMID: 33536055 PMCID: PMC7860205 DOI: 10.1186/s13229-021-00420-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 01/27/2021] [Indexed: 12/27/2022] Open
Abstract
Background Endocannabinoid dysfunction in animal models of autism spectrum disorder (ASD) and accumulating, albeit anecdotal, evidence for efficacy in humans motivated this placebo-controlled double-blind comparison of two oral cannabinoid solutions in 150 participants (age 5–21 years) with ASD. Methods We tested (1) BOL-DP-O-01-W, a whole-plant cannabis extract containing cannabidiol and Δ9-tetrahydrocannabinol at a 20:1 ratio and (2) BOL-DP-O-01, purified cannabidiol and Δ9-tetrahydrocannabinol at the same ratio. Participants (N = 150) received either placebo or cannabinoids for 12-weeks (testing efficacy) followed by a 4-week washout and predetermined cross-over for another 12 weeks to further assess tolerability. Registered primary efficacy outcome measures were improvement in behavioral problems (differences between whole-plant extract and placebo) on the Home Situation Questionnaire-ASD (HSQ-ASD) and the Clinical Global Impression-Improvement scale with disruptive behavior anchor points (CGI-I). Secondary measures were Social Responsiveness Scale (SRS-2) and Autism Parenting Stress Index (APSI). Results Changes in Total Scores of HSQ-ASD (primary-outcome) and APSI (secondary-outcome) did not differ among groups. Disruptive behavior on the CGI-I (co-primary outcome) was either much or very much improved in 49% on whole-plant extract (n = 45) versus 21% on placebo (n = 47; p = 0.005). Median SRS Total Score (secondary-outcome) improved by 14.9 on whole-plant extract (n = 34) versus 3.6 points after placebo (n = 36); p = 0.009). There were no treatment-related serious adverse events. Common adverse events included somnolence and decreased appetite, reported for 28% and 25% on whole-plant extract, respectively (n = 95); 23% and 21% on pure-cannabinoids (n = 93), and 8% and 15% on placebo (n = 94). Limitations Lack of pharmacokinetic data and a wide range of ages and functional levels among participants warrant caution when interpreting the results. Conclusions This interventional study provides evidence that BOL-DP-O-01-W and BOL-DP-O-01, administrated for 3 months, are well tolerated. Evidence for efficacy of these interventions are mixed and insufficient. Further testing of cannabinoids in ASD is recommended. Trial registration ClinicalTrials.gov: NCT02956226. Registered 06 November 2016, https://clinicaltrials.gov/ct2/show/NCT02956226
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Affiliation(s)
- Adi Aran
- Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031, Jerusalem, Israel.
| | - Moria Harel
- Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031, Jerusalem, Israel
| | - Hanoch Cassuto
- Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031, Jerusalem, Israel
| | - Lola Polyansky
- Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031, Jerusalem, Israel
| | - Aviad Schnapp
- Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031, Jerusalem, Israel
| | - Nadia Wattad
- Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031, Jerusalem, Israel
| | - Dorit Shmueli
- Child Development Centers, Clalit Health Services, Tel Aviv-Yafo, Israel
| | - Daphna Golan
- Child Development Centers, Maccabi Health Services, Jerusalem, Israel
| | - F Xavier Castellanos
- Department of Child and Adolescent Psychiatry, NYU Grossman School of Medicine, New York, NY, USA
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7
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Middelburg JG, Crijnen TEM, D'Antiga L, Verdoni L, Chikermane A, Garg P, Acharyya BC, Pruccoli G, Schnapp A, Rauf A, Middelburg RA. Association of Ethnicity With Multisystem Inflammatory Syndrome in Children Related to SARS-CoV-2 Infection: An International Case-Referent Study. Front Pediatr 2021; 9:707650. [PMID: 34722416 PMCID: PMC8555018 DOI: 10.3389/fped.2021.707650] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 09/20/2021] [Indexed: 11/17/2022] Open
Abstract
Background: It has been suggested that children and infants can develop multisystem inflammatory syndrome in children (MIS-C) in response to a SARS-CoV-2 infection and that Black children are overrepresented among cases. The aim of the current study was to quantify the association between Black, Asian, or other non-White genetic background and COVID-19-related MIS-C in children and infants. Methods: Eight different research groups contributed cases of MIS-C, potentially related to SARS-CoV-2 infection. Several sensitivity analyses were performed, including additional data available from the literature. Analyses were stratified by geographical region. Results: Seventy-three cases from nine distinct geographical regions were included in the primary analyses. In comparison to White children, the relative risk for developing MIS-C after SARS-CoV-2 infection was 15 [95% confidence interval (CI): 7.1 to 32] for Black children, 11 (CI: 2.2 to 57) for Asian, and 1.6 (CI: 0.58 to 4.2) for other ethnic background. Conclusion: Pediatricians should be aware of the fact that the risk of COVID-19-related MIS-C is severely increased in Black children.
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Affiliation(s)
- Judith G Middelburg
- Department of Medical Science, Middelburg Solutions, Oegstgeest, Netherlands
| | - Thomas E M Crijnen
- Paediatric Intensive Care Unit, Ziekenhuis Netwerk Antwerpen Queen Paola Children's Hospital, Antwerp, Belgium
| | - Lorenzo D'Antiga
- Paediatric Department, Hospital Papa Giovanni XXIII, Bergamo, Italy
| | - Lucio Verdoni
- Paediatric Department, Hospital Papa Giovanni XXIII, Bergamo, Italy
| | - Ashish Chikermane
- Department of Cardiology, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, United Kingdom
| | - Padma Garg
- Division of Pediatric Critical Care Medicine, University of Mississippi Medical Center, Jackson, MS, United States.,Division of Pediatric Infectious Disease, University of Mississippi Medical Center, Jackson, MS, United States.,Division of Pediatric Cardiology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Bhaswati C Acharyya
- Department of Pediatric Gastroenterology, AMRI Hospitals, Kolkata, India.,Department of Pediatrics, AMRI Hospitals, Kolkata, India.,Department of Pediatric Cardiology, AMRI Hospitals, Kolkata, India
| | - Giulia Pruccoli
- Department of Pediatric and Public Health Sciences, Regina Margherita Children's Hospital, University of Turin, Turin, Italy
| | - Aviad Schnapp
- Department of Pediatrics, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Abdul Rauf
- Department of Pediatrics, Baby Memorial Hospital, Calicut, India
| | - Rutger A Middelburg
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, Netherlands
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8
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Schnapp A, Abulhija H, Maly A, Armoni-Weiss G, Levin Y, Faitatziadou SM, Molho-Pessach V. Introductory histopathological findings may shed light on COVID-19 paediatric hyperinflammatory shock syndrome. J Eur Acad Dermatol Venereol 2020; 34:e665-e667. [PMID: 32535977 PMCID: PMC7323333 DOI: 10.1111/jdv.16749] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 05/31/2020] [Accepted: 06/03/2020] [Indexed: 01/18/2023]
Affiliation(s)
- A Schnapp
- Department of Pediatrics, The Faculty of Medicine, Hadassah Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
| | - H Abulhija
- Department of Pediatrics, The Faculty of Medicine, Hadassah Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
| | - A Maly
- Department of Pathology, The Faculty of Medicine, Hadassah Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
| | - G Armoni-Weiss
- Department of Dermatology, The Faculty of Medicine, Hadassah Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Y Levin
- Department of Pediatrics, The Faculty of Medicine, Hadassah Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
| | - S M Faitatziadou
- Department of Dermatology, The Faculty of Medicine, Hadassah Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
| | - V Molho-Pessach
- Department of Dermatology, The Faculty of Medicine, Hadassah Medical Center, Hebrew University of Jerusalem, Jerusalem, Israel
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9
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Aran A, Eylon M, Harel M, Polianski L, Nemirovski A, Tepper S, Schnapp A, Cassuto H, Wattad N, Tam J. Lower circulating endocannabinoid levels in children with autism spectrum disorder. Mol Autism 2019; 10:2. [PMID: 30728928 PMCID: PMC6354384 DOI: 10.1186/s13229-019-0256-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 01/18/2019] [Indexed: 12/27/2022] Open
Abstract
Background The endocannabinoid system (ECS) is a major regulator of synaptic plasticity and neuromodulation. Alterations of the ECS have been demonstrated in several animal models of autism spectrum disorder (ASD). In some of these models, activating the ECS rescued the social deficits. Evidence for dysregulations of the ECS in human ASD are emerging, but comprehensive assessments and correlations with disease characteristics have not been reported yet. Methods Serum levels of the main endocannabinoids, N-arachidonoylethanolamine (AEA or anandamide) and 2-arachidonoylglycerol (2-AG), and their related endogenous compounds, arachidonic acid (AA), N-palmitoylethanolamine (PEA), and N-oleoylethanolamine (OEA), were analyzed by liquid chromatography/tandem mass spectrometry in 93 children with ASD (age = 13.1 ± 4.1, range 6–21; 79% boys) and 93 age- and gender-matched neurotypical children (age = 11.8 ± 4.3, range 5.5–21; 79% boys). Results were associated with gender and use of medications, and were correlated with age, BMI, and adaptive functioning of ASD participants as reflected by scores of Autism Diagnostic Observation Schedule (ADOS-2), Vineland Adaptive Behavior Scale-II (VABS-II), and Social Responsiveness Scale-II (SRS-2). Results Children with ASD had lower levels (pmol/mL, mean ± SEM) of AEA (0.722 ± 0.045 vs. 1.252 ± 0.072, P < 0.0001, effect size 0.91), OEA (17.3 ± 0.80 vs. 27.8 ± 1.44, P < 0.0001, effect size 0.94), and PEA (4.93 ± 0.32 vs. 7.15 ± 0.37, P < 0.0001, effect size 0.65), but not AA and 2-AG. Serum levels of AEA, OEA, and PEA were not significantly associated or correlated with age, gender, BMI, medications, and adaptive functioning of ASD participants. In children with ASD, but not in the control group, younger age and lower BMI tended to correlate with lower AEA levels. However, these correlations were not statistically significant after a correction for multiple comparisons. Conclusions We found lower serum levels of AEA, PEA, and OEA in children with ASD. Further studies are needed to determine whether circulating endocannabinoid levels can be used as stratification biomarkers that identify clinically significant subgroups within the autism spectrum and if they reflect lower endocannabinoid “tone” in the brain, as found in animal models of ASD. Electronic supplementary material The online version of this article (10.1186/s13229-019-0256-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Adi Aran
- 1Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031 Jerusalem, Israel
| | - Maya Eylon
- 2Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Moria Harel
- 1Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031 Jerusalem, Israel
| | - Lola Polianski
- 1Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031 Jerusalem, Israel
| | - Alina Nemirovski
- 2Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sigal Tepper
- 3Department of Nutritional Sciences, Tel Hai Academic College, Upper Galilee, 1220800 Kiryat Shmona, Israel
| | - Aviad Schnapp
- 1Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031 Jerusalem, Israel
| | - Hanoch Cassuto
- 1Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031 Jerusalem, Israel
| | - Nadia Wattad
- 1Neuropediatric Unit, Shaare Zedek Medical Center, 12 Bayit Street, 91031 Jerusalem, Israel
| | - Joseph Tam
- 2Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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10
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Lamb DJ, Wollin SL, Schnapp A, Bischoff D, Erb KJ, Bouyssou T, Guilliard B, Strasser C, Wex E, Blum S, Thaler E, Nickel H, Radmacher O, Haas H, Swantek JL, Souza D, Canfield M, White D, Panzenbeck M, Kashem MA, Sanville-Ross M, Kono T, Sewald K, Braun A, Obernolte H, Danov O, Schaenzle G, Rast G, Maier GM, Hoffmann M. BI 1002494, a Novel Potent and Selective Oral Spleen Tyrosine Kinase Inhibitor, Displays Differential Potency in Human Basophils and B Cells. ACTA ACUST UNITED AC 2016; 357:554-61. [DOI: 10.1124/jpet.116.233155] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 03/31/2016] [Indexed: 01/29/2023]
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11
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Bouyssou T, Casarosa P, Naline E, Pestel S, Konetzki I, Devillier P, Schnapp A. Pharmacological Characterization of Olodaterol, a Novel Inhaled β2-Adrenoceptor Agonist Exerting a 24-Hour-Long Duration of Action in Preclinical Models. J Pharmacol Exp Ther 2010; 334:53-62. [DOI: 10.1124/jpet.110.167007] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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12
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Chaudhary NI, Roth GJ, Hilberg F, Müller-Quernheim J, Prasse A, Zissel G, Schnapp A, Park JE. Inhibition of PDGF, VEGF and FGF signalling attenuates fibrosis. Eur Respir J 2007; 29:976-85. [PMID: 17301095 DOI: 10.1183/09031936.00152106] [Citation(s) in RCA: 267] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BIBF 1000 is a small molecule inhibitor targeting the receptor kinases of platelet-derived growth factor (PDGF), basic fibroblast growth factor and vascular endothelial growth factor, which have known roles in the pathogenesis of pulmonary fibrosis. The anti-fibrotic potential of BIBF 1000 was determined in a rat model of bleomycin-induced lung fibrosis and in an ex vivo fibroblast differentiation assay. Rats exposed to a single intra-tracheal injection of bleomycin were treated with BIBF 1000 starting 10 days after bleomycin administration. To gauge for anti-fibrotic activity, collagen deposition and pro-fibrotic growth factor gene expression was analysed in isolated lungs. Furthermore, the activity of BIBF 1000 was compared with imatinib mesylate (combined PDGF receptor, c-kit and c-abl kinase inhibitor) and SB-431542 (transforming growth factor (TGF)-beta receptor I kinase inhibitor) in an ex vivo TGF-beta-driven fibroblast to myofibroblast differentiation assay, performed in primary human bronchial fibroblasts. Treatment of rats with BIBF 1000 resulted in the attenuation of fibrosis as assessed by the reduction of collagen deposition and the inhibition of pro-fibrotic gene expression. In the cellular assay both SB-431542 and BIBF 1000 showed dose-dependent inhibition of TGF-beta-induced differentiation, whereas imatinib mesylate was inactive. BIBF 1000, or related small molecules with a similar kinase inhibition profile, may represent a novel therapeutic approach for the treatment of idiopathic pulmonary fibrosis.
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Affiliation(s)
- N I Chaudhary
- Dept of Pulmonary Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorferstrasse 65, D-88937, Biberach an der Riss, Germany
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13
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Niedermeyer J, Garin-Chesa P, Kriz M, Hilberg F, Mueller E, Bamberger U, Rettig WJ, Schnapp A. Expression of the fibroblast activation protein during mouse embryo development. Int J Dev Biol 2001; 45:445-7. [PMID: 11330865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Human Fibroblast Activation Protein (FAP), a member of the serine prolyl oligopeptidase family, is a type II cell surface glycoprotein that acts as a dual-specificity dipeptidyl-peptidase (DPP) and collagenase in vitro. Its restricted expression pattern in embryonic mesenchyme, in wound healing and in reactive stromal fibroblasts of epithelial cancers, has suggested a role for the FAP protease in extracellular matrix degradation or growth factor activation in sites of tissue remodeling. The FAP homologue in Xenopus laevis has been reported to be induced in the thyroid hormone-induced tail resorption program during tadpole metamorphosis supporting a role for FAP in tissue remodeling processes during embryonic development. However, Fap-deficient mice show no overt developmental defects and are viable. To study the expression of FAP during mouse embryogenesis, a second Fap-deficient mouse strain expressing beta-Galactosidase under the control of the Fap promoter was generated by homologous recombination (Fap-/- lacZ mice). FAP deficiency was confirmed by the absence of FAP-specific dipeptidyl-peptidase activity in detergent-soluble extracts isolated from 17.5 d.p.c. Fap-/- lacZ embryos. We report that Fap-/- lacZ mice express beta-Galactosidase at regions of active tissue remodeling during embryogenesis including somites and perichondrial mesenchyme from cartilage primordia.
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Affiliation(s)
- J Niedermeyer
- Oncology Research Group, Boehringer Ingelheim Pharma KG, Biberach, Germany
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14
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Rippmann JF, Hobbie S, Daiber C, Guilliard B, Bauer M, Birk J, Nar H, Garin-Chesa P, Rettig WJ, Schnapp A. Phosphorylation-dependent proline isomerization catalyzed by Pin1 is essential for tumor cell survival and entry into mitosis. Cell Growth Differ 2000; 11:409-16. [PMID: 10939594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
Pin1, a member of the parvulin family of peptidyl-prolyl cis-trans isomerases (PPIases) has been implicated in the G2-M transition of the mammalian cell cycle. Pin1 interacts with a series of mitotic phosphoproteins, including Polo-like kinase-1, Cdc25C, and Cdc27, and is thought to act as a phosphorylation-dependent PPIase for these target molecules. Pin1 recognizes phosphorylated serine-proline or threonine-proline peptide-bonds in test substrates up to 1300-fold better than in the respective unphosphorylated peptides. To test directly whether Pin1 regulates the G2-M transition and/or progression through mitosis by catalyzing phosphorylation-dependent prolyl isomerization of essential mitotic targets, we examined the consequences of Pin1 depletion, achieved by (a) overexpression of Pin1 antisense RNA, (b) overexpression of dominant-negative Pin1, and (c) by a known small-molecule Pin1-PPIase inhibitor, juglone. The results of all of the three lines of investigation show that the catalytic activity of Pin1 is essential for tumor cell survival and entry into mitosis.
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Affiliation(s)
- J F Rippmann
- Department of Oncology Research, Boehringer Ingelheim Pharma KG, Biberach, Germany
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15
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Niedermeyer J, Kriz M, Hilberg F, Garin-Chesa P, Bamberger U, Lenter MC, Park J, Viertel B, Püschner H, Mauz M, Rettig WJ, Schnapp A. Targeted disruption of mouse fibroblast activation protein. Mol Cell Biol 2000; 20:1089-94. [PMID: 10629066 PMCID: PMC85226 DOI: 10.1128/mcb.20.3.1089-1094.2000] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Human fibroblast activation protein (FAP), a member of the serine prolyl oligopeptidase family, is a type II cell surface glycoprotein selectively expressed by fibroblastic cells in areas of active tissue remodeling, such as the embryonic mesenchyme, areas of wound healing, the gravid uterus, and the reactive stroma of epithelial cancers. Homologues of FAP have been identified in the mouse and Xenopus laevis. FAP is a dual-specificity enzyme that acts as a dipeptidyl peptidase and collagenase in vitro. To explore the role of FAP in vivo, Fap(-/-) mice were generated by homologous recombination. RNase protection analysis and reverse transcription-PCR confirmed the absence of full-length Fap transcripts in mouse embryonic tissues. No FAP protein was detected in Fap(-/-) animals by immunohistochemistry, and no FAP-specific dipeptidyl peptidase activity was found. We report that Fap(-/-) mice are fertile, show no overt developmental defects, and have no general change in cancer susceptibility.
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Affiliation(s)
- J Niedermeyer
- Department of Oncology Research, Boehringer Ingelheim Pharma KG, 88397 Biberach, Germany
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16
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Abstract
Human telomerase is a ribonucleoprotein (RNP) enzyme, comprising protein components and an RNA template that catalyses telomere elongation through the addition of TTAGGG repeats. Telomerase function has been implicated in aging and cancer cell immortalization. We report a rapid and efficient one-step purification protocol to obtain highly active telomerase from human cells. The purification is based on affinity chromatography of nuclear extracts with antisense oligonucleotides complementary to the template region of the human telomerase RNA component. Bound telomerase is eluted with a displacement oligonucleotide under mild conditions. The resulting affinity-purified telomerase is active in PCR-amplified telomerase assays. The purified telomerase complex has a molecular mass of approximately 550 kDa compared to the approximately 1000 kDa determined for the telomerase RNP in unfractionated nuclear extracts. The purification protocol provides a rapid and efficient tool for functional and structural studies of human telomerase.
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Affiliation(s)
- G Schnapp
- Department of Oncology Research, Boehringer Ingelheim Pharma KG, Birkendorfer Strasse 65,88397 Biberach an der Riss, Germany
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17
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Niedermeyer J, Enenkel B, Park JE, Lenter M, Rettig WJ, Damm K, Schnapp A. Mouse fibroblast-activation protein--conserved Fap gene organization and biochemical function as a serine protease. Eur J Biochem 1998; 254:650-4. [PMID: 9688278 DOI: 10.1046/j.1432-1327.1998.2540650.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The human fibroblast-activation protein (FAP), a member of the serine protease family, was discovered as an inducible type-II cell-surface glycoprotein selectively expressed by reactive stromal fibroblasts of epithelial cancers and healing wounds. Antibodies directed against human FAP have a clinical use for antibody-based tumor imaging. As part of an effort to generate animal models of FAP expression in epithelial tumorigenesis and wound healing, we previously cloned the cDNA encoding the mouse FAP homolog. In this study, we used PCR/restriction-fragment length polymorphism, identified in interspecific back-crosses between Mus musculus and Mus spretus, to map the Fap gene locus to a region of mouse chromosome 2, known to be syntenic to the previously identified FAP gene locus on human chromosome 2q23. The Fap gene spans approximately 60 kb and contains 26 exons ranging in size from 46 bp to 195 bp. This genomic organization is very similar to that of the human FAP locus. Similar to the gene encoding dipeptidyl peptidase IV (DPP IV), the nucleotides encoding the serine protease consensus motif, WGWSYGG, are split between two exons, a feature distinct from classical serine proteases. Consistent with the similarity to DPP IV, a chimeric FAP fusion protein expressed in a baculovirus system has dipeptidyl peptidase activity.
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Affiliation(s)
- J Niedermeyer
- Department of Oncology Research, Boehringer Ingelheim Pharma KG, Biberach an der Riss, Germany
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18
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Niedermeyer J, Scanlan MJ, Garin-Chesa P, Daiber C, Fiebig HH, Old LJ, Rettig WJ, Schnapp A. Mouse fibroblast activation protein: molecular cloning, alternative splicing and expression in the reactive stroma of epithelial cancers. Int J Cancer 1997; 71:383-9. [PMID: 9139873 DOI: 10.1002/(sici)1097-0215(19970502)71:3<383::aid-ijc14>3.0.co;2-h] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The growth of solid neoplasms requires the recruitment of a supporting stroma. In most epithelial cancers, this stromal compartment comprises newly formed blood vessels and abundant, reactive stromal fibroblasts. Tumor stromal fibroblasts are not transformed but differ from resting fibrocytes in normal adult tissues by an altered pattern of gene expression. In human cancers, this includes induction of the cell-surface-bound fibroblast-activation protein (FAP), a member of the serine protease family encoded by the FAP gene on chromosome 2. In this study, we have cloned a complementary DNA for Fap, the murine homologue of FAP. The predicted murine FAP protein, mFAP, shares 89% amino-acid-sequence identity with human FAP, including a perfectly conserved catalytic triad. Cultured mouse embryo fibroblasts and mouse embryonic tissues were found to express Fap transcripts. In addition, the host-derived, fibroblast-rich stroma of human epithelial-cancer xenografts grown in immunodeficient mice also expresses Fap. Sequencing of reverse-transcription-PCR products indicates that 3 distinct Fap splice variants can be detected in tissues. Our findings suggest a close similarity in structure and tissue expression of FAP in different species. By extending the analysis of FAP to the mouse, new in vivo test systems become available for genetic and therapeutic manipulations and for the study of FAP regulation and function in embryonic development and in epithelial cancers.
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MESH Headings
- Adenocarcinoma/pathology
- Alternative Splicing
- Amino Acid Sequence
- Animals
- Antigens, Neoplasm
- Base Sequence
- Biomarkers, Tumor
- Cell Line
- Chromosome Mapping
- Chromosomes, Human, Pair 2
- Cloning, Molecular
- Endopeptidases
- Epithelium
- Gelatinases
- Growth Substances/biosynthesis
- Growth Substances/chemistry
- Growth Substances/genetics
- Humans
- L Cells
- Membrane Proteins
- Mice
- Mice, Nude
- Molecular Sequence Data
- Neoplasms/genetics
- Neoplasms/metabolism
- Neoplasms/pathology
- Oligodeoxyribonucleotides
- Organ Specificity
- Pancreatic Neoplasms/pathology
- Polymerase Chain Reaction
- Rats
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/chemistry
- Sequence Homology, Amino Acid
- Serine Endopeptidases
- Transcription, Genetic
- Transplantation, Heterologous
- Tumor Cells, Cultured
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Affiliation(s)
- J Niedermeyer
- Oncology Research Group, Dr. Karl Thomae GmbH/Boehringer Ingelheim Pharma, Biberach, Germany
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19
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Affiliation(s)
- A Schnapp
- Division of Molecular Biology of the Cell II/0120, German Cancer Research Center, Heidelberg, Germany
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20
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Brambilla R, Schnapp A, Casagranda F, Labrador JP, Bergemann AD, Flanagan JG, Pasquale EB, Klein R. Membrane-bound LERK2 ligand can signal through three different Eph-related receptor tyrosine kinases. EMBO J 1995; 14:3116-26. [PMID: 7621826 PMCID: PMC394373 DOI: 10.1002/j.1460-2075.1995.tb07314.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The Eph-related family of receptor tyrosine kinases consists of at least 13 members, several of which display distinctive expression patterns in the developing and adult nervous system. Recently, a small family of ligands, structurally related to the B61 protein, was identified. Binding of these ligands to Eph-related receptors did not, however, elicit measurable biological signals in cultured cells. In order to study functional interactions between B61-related ligands and Eph-related receptors, we constructed chimeric receptors, containing an Eph-related ectodomain and the cytoplasmic domain of the TrkB neurotrophin receptor. Expression and activation of such chimeric receptors in NIH 3T3 cells induced transformation in focus formation assays. Membrane-bound LERK2 ligand is shown to signal through three different Eph-related receptors, namely Cek5, Cek10 and Elk. LERK2, however, fails to interact functionally with the Cek9 receptor. Quantitative analysis including binding assays indicates that Cek10 is the preferred LERK2 receptor. Preliminary mutagenesis of the LERK2 protein suggests a negative regulatory role for its cytoplasmic domain in LERK2 signaling.
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Affiliation(s)
- R Brambilla
- European Molecular Biology Laboratory, Differentiation Programme, Heidelberg, Germany
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21
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Abstract
We have characterized a transcription factor from Ehrlich ascites cells that is required for ribosomal gene transcription by RNA polymerase I (Pol I). This factor, termed TIF-IC, has a native molecular mass of 65 kDa, associates with Pol I, and is required both for the assembly of Sarkosyl-resistant initiation complexes and for the formation of the first internucleotide bonds. In addition to its function in transcription initiation, TIF-IC also plays a role in elongation of nascent RNA chains. At suboptimal levels of TIF-IC, transcripts with heterogeneous 3' ends are formed which are chased into full-length transcripts by the addition of more TIF-IC. Moreover, on a tailed template, which allows initiation in the absence of auxiliary factors, TIF-IC was found to stimulate the overall rate of transcription elongation and suppress pausing of Pol I. Thus TIF-IC appears to serve a function similar to the Pol II-specific factor TFIIF which is required for Pol II transcription initiation and elongation.
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Affiliation(s)
- G Schnapp
- Institute of Cell and Tumor Biology, German Cancer Research Center, Heidelberg
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22
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Smeyne RJ, Klein R, Schnapp A, Long LK, Bryant S, Lewin A, Lira SA, Barbacid M. Severe sensory and sympathetic neuropathies in mice carrying a disrupted Trk/NGF receptor gene. Nature 1994; 368:246-9. [PMID: 8145823 DOI: 10.1038/368246a0] [Citation(s) in RCA: 717] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Nerve growth factor (NGF) induces neurite outgrowth and promotes survival of embryonic sensory and sympathetic neurons in culture. In vivo, NGF decreases the extent of naturally occurring cell death in developing sympathetic ganglia and protects cholinergic neurons of the basal forebrain and caudatoputamen. NGF interacts with the low-affinity p75 receptor and with Trk, a receptor tyrosine kinase encoded by the trk proto-oncogene. To study the role of Trk in vivo, we have ablated the gene in embryonic stem cells by homologous recombination. Mice lacking Trk have severe sensory and sympathetic neuropathies and most die within one month of birth. They have extensive neuronal cell loss in trigeminal, sympathetic and dorsal root ganglia, as well as a decrease in the cholinergic basal forebrain projections to the hippocampus and cortex. These findings demonstrate that Trk is the primary mediator of the trophic actions of NGF in vivo and that this signalling pathway plays a crucial role in the development of both the peripheral and the central nervous systems.
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Affiliation(s)
- R J Smeyne
- Department of Molecular Biology, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543-4000
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Schnapp A, Schnapp G, Erny B, Grummt I. Function of the growth-regulated transcription initiation factor TIF-IA in initiation complex formation at the murine ribosomal gene promoter. Mol Cell Biol 1993; 13:6723-32. [PMID: 8413268 PMCID: PMC364735 DOI: 10.1128/mcb.13.11.6723-6732.1993] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Alterations in the rate of cell proliferation are accompanied by changes in the transcription of rRNA genes. In mammals, this growth-dependent regulation of transcription of genes coding for rRNA (rDNA) is due to reduction of the amount or activity of an essential transcription factor, called TIF-IA. Extracts prepared from quiescent cells lack this factor activity and, therefore, are transcriptionally inactive. We have purified TIF-IA from exponentially growing cells and have shown that it is a polypeptide with a molecular mass of 75 kDa which exists as a monomer in solution. Using a reconstituted transcription system consisting of purified transcription factors, we demonstrate that TIF-IA is a bona fide transcription initiation factor which interacts with RNA polymerase I. Preinitiation complexes can be assembled in the absence of TIF-IA, but formation of the first phosphodiester bonds of nascent rRNA is precluded. After initiation, TIF-IA is liberated from the initiation complex and facilitates transcription from templates bearing preinitiation complexes which lack TIF-IA. Despite the pronounced species specificity of class I gene transcription, this growth-dependent factor has been identified not only in mouse but also in human cells. Murine TIF-IA complements extracts from both growth-inhibited mouse and human cells. The analogous human activity appears to be similar or identical to that of TIF-IA. Therefore, despite the fact that the RNA polymerase transcription system has evolved sufficiently rapidly that an rDNA promoter from one species will not function in another species, the basic mechanisms that adapt ribosome synthesis to cell proliferation have been conserved.
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MESH Headings
- Animals
- Carcinoma, Ehrlich Tumor
- Cell Division
- Cell Nucleus/metabolism
- Chromatography, Gel
- Cytoplasm/metabolism
- DNA, Ribosomal/metabolism
- Electrophoresis, Polyacrylamide Gel
- Gene Expression Regulation, Neoplastic
- Genes, MHC Class I
- HeLa Cells
- Humans
- Kinetics
- Mice
- Promoter Regions, Genetic
- RNA, Ribosomal/genetics
- Templates, Genetic
- Transcription Factors/isolation & purification
- Transcription Factors/metabolism
- Transcription, Genetic
- Tumor Cells, Cultured
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Affiliation(s)
- A Schnapp
- Institute of Cell and Tumor Biology, German Cancer Research Center, Heidelberg
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Voit R, Schnapp A, Kuhn A, Rosenbauer H, Hirschmann P, Stunnenberg HG, Grummt I. The nucleolar transcription factor mUBF is phosphorylated by casein kinase II in the C-terminal hyperacidic tail which is essential for transactivation. EMBO J 1992; 11:2211-8. [PMID: 1600946 PMCID: PMC556688 DOI: 10.1002/j.1460-2075.1992.tb05280.x] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
UBF is a DNA binding protein which interacts with both the promoter and the enhancer of various vertebrate ribosomal RNA genes and functions as a transcription initiation factor for RNA polymerase I (pol I). We have purified murine UBF to apparent molecular homogeneity and demonstrate that its transactivating potential, but not its DNA binding activity, is modulated in response to cell growth. In vivo labelling experiments demonstrate that UBF is a phosphoprotein and that the phosphorylation state is different in growing and quiescent cells. We show that UBF is phosphorylated in vitro by a cellular protein kinase which by several criteria closely resembles casein kinase II (CKII). A major modification involves serine phosphoesterifications in the carboxy terminal hyperacidic tail of UBF. Deletions of this C-terminal domain severely decreases the UBF directed activation of transcription. The data suggest that phosphorylation of UBF by CKII may play an important role in growth dependent control of rRNA synthesis.
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Affiliation(s)
- R Voit
- Institute of Cell and Tumor Biology, German Cancer Research Center, Heidelberg
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Schnapp A, Grummt I. Transcription complex formation at the mouse rDNA promoter involves the stepwise association of four transcription factors and RNA polymerase I. J Biol Chem 1991; 266:24588-95. [PMID: 1761556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have used purified transcription factors and RNA polymerase I (pol I) to analyze the individual steps involved in the formation of transcription initiation complexes at the mouse ribosomal gene promoter in vitro. Complete assembly of transcription complexes requires pol I and at least four auxiliary factors, termed TIF-IA, TIF-IB, TIF-IC, and UBF. Preincubation and template commitment, as well as order of addition protocols, were used to discriminate between various intermediate complexes generated during assembly of the initiation complex. As a first step, TIF-IB binds to the core promoter, a process that is facilitated by the upstream control element and the upstream binding factor (UBF). Binding of TIF-IB to the rDNA promoter results in the formation of a functional preinitiation complex (complex 1), which is stable for many rounds of transcription. UBF, which on its own does not stably associate with the rDNA promoter, triggers a 5-10-fold increase in the overall amount of this primary complex. Following binding of TIF-IB and UBF to the template DNA, pol I and TIF-IC successively bind, yielding complexes 2 and 3, respectively. Transcription-competent initiation complexes are built up by the final association of the growth-regulated factor TIF-IA. The various complexes can be distinguished by their different sensitivity to Sarkosyl. Only the complete complex consisting of all four factors and pol I shows resistance to intermediate concentrations of Sarkosyl (0.045%) and is competent to catalyze the formation of the first phosphodiester bond. The initiated complex is, on the other hand, resistant to high concentrations of Sarkosyl (0.3%). The hierarchical nature of the different complexes formed suggests a model for transcription initiation and predicts functions for the individual factors.
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Affiliation(s)
- A Schnapp
- Institute of Cell and Tumor Biology, German Cancer Research Center, Heidelberg
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Schnapp A, Grummt I. Transcription complex formation at the mouse rDNA promoter involves the stepwise association of four transcription factors and RNA polymerase I. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54269-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Schnapp A, Rosenbauer H, Grummt I. Trans-acting factors involved in species-specificity and control of mouse ribosomal gene transcription. Mol Cell Biochem 1991; 104:137-47. [PMID: 1921992 DOI: 10.1007/bf00229813] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Faithful and efficient transcription initiation at the mouse ribosomal gene promoter requires besides RNA polymerase I (pol I) four polypeptide trans-acting factors, termed TIF-IA, TIF-IB, TIF-IC, and mUBF. We have partially purified these proteins from cultured Ehrlich ascites cells and show that in the presence of TIF-IA and TIF-IB, pol I directs very low amounts of specific transcripts. Neither TIF-IC nor mUBF on their own significantly stimulate the efficiency of template utilization. However, both factors together strongly activate transcription. Interestingly, factor TIF-IB - the murine homologue of human SL1 - fails to program a human extract to transcribe the murine template, but requires its homologous RNA polymerase I. This finding implicates that not only some rDNA transcription factors but also pol I exhibits species-specific differences. The growth-related factor TIF-IA, on the other hand, stimulates both mouse and human rDNA transcription. This regulatory factor whose amount or activity fluctuates according to the proliferation rate of the cells, is functionally inactivated by antibodies against cdc2 protein kinase. This result together with the observation that transcription is stimulated by ATP-gamma S, an ATP analogue which is a substrate for protein kinases but not for protein phosphatases, strongly suggests that post-translational protein modification is involved in rDNA transcription regulation.
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Affiliation(s)
- A Schnapp
- Institute of Cell and Tumor Biology, German Cancer Research Center, Heidelberg
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Schnapp A, Pfleiderer C, Rosenbauer H, Grummt I. A growth-dependent transcription initiation factor (TIF-IA) interacting with RNA polymerase I regulates mouse ribosomal RNA synthesis. EMBO J 1990; 9:2857-63. [PMID: 2390974 PMCID: PMC551998 DOI: 10.1002/j.1460-2075.1990.tb07475.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Control of mouse ribosomal RNA synthesis in response to extracellular signals is mediated by TIF-IA, a regulatory factor whose amount or activity correlates with cell proliferation. Factor TIF-IA interacts with RNA polymerase I (pol I), thus converting it into a transcriptionally active holoenzyme, which is able to initiate specifically at the rDNA promoter in the presence of the other auxiliary transcription initiation factors, designated TIF-IB, TIF-IC and UBF. With regard to several criteria, the growth-dependent factor TIF-IA behaves like a bacterial sigma factor: (i) it associates physically with pol I, (ii) it is required for initiation of transcription, (iii) it is present in limiting amounts and (iv) under certain salt conditions, it is chromatographically separable from the polymerase. In addition, evidence is presented that dephosphorylation of pol I abolishes in vitro transcription initiation from the ribosomal gene promoter without significantly affecting the polymerizing activity of the enzyme at nonspecific templates. The involvement of both a regulatory factor and post-translational modification of the transcribing enzyme provides an efficient and versatile mechanism of rDNA transcription regulation which enables the cell to adapt ribosome synthesis rapidly to a variety of extracellular signals.
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Affiliation(s)
- A Schnapp
- Institut für Biochemie, Würzburg, FRG
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Schnapp A, Clos J, Hädelt W, Schreck R, Cvekl A, Grummt I. Isolation and functional characterization of TIF-IB, a factor that confers promoter specificity to mouse RNA polymerase I. Nucleic Acids Res 1990; 18:1385-93. [PMID: 2326184 PMCID: PMC330501 DOI: 10.1093/nar/18.6.1385] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The murine ribosomal gene promoter contains two cis-acting control elements which operate in concert to promote efficient and accurate transcription initiation by RNA polymerase I. The start site proximal core element which is indispensable for promoter recognition by RNA polymerase I (pol I) encompasses sequences from position -39 to -1. An upstream control element (UCE) which is located between nucleotides -142 and -112 stimulates the efficiency of transcription initiation both in vivo and in vitro. Here we report the isolation and functional characterization of a specific rDNA binding protein, the transcription initiation factor TIF-IB, which specifically interacts with the core region of the mouse ribosomal RNA gene promoter. Highly purified TIF-IB complements transcriptional activity in the presence of two other essential initiation factors TIF-IA and TIF-IC. We demonstrate that the binding efficiency of purified TIF-IB to the core promoter is strongly enhanced by the presence in cis of the UCE. This positive effect of upstream sequences on TIF-IB binding is observed throughout the purification procedure suggesting that the synergistic action of the two distant promoter elements is not mediated by a protein different from TIF-IB. Increasing the distance between both control elements still facilitates stable factor binding but eliminates transcriptional activation. The results demonstrate that TIF-IB binding to the rDNA promoter is an essential early step in the assembly of a functional transcription initiation complex. The subsequent interaction of TIF-IB with other auxiliary transcription initiation factors, however, requires the correct spacing between the UCE and the core promoter element.
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Affiliation(s)
- A Schnapp
- Institute of Biochemistry, Würzburg, FRG
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