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1.
In Vivo ; 36(5): 2255-2259, 2022.
Article in English | MEDLINE | ID: mdl-36099097

ABSTRACT

BACKGROUND/AIM: Magnetic resonance imaging (MRI) is an important diagnostic tool in the detection of breast cancer. The Breast Center of the municipal Hospital Holweide, Cologne, annually cares for and treats patients with changes in the breast. A special problem is posed by Breast Imaging-Reporting and Data System (BI-RADS) 4 lesions. If a BI-RADS 4 finding is present, is a vacuum biopsy indicated in every case or, if there is already an indication for surgery due to other findings, can the corresponding finding be removed openly without histological clarification? We require real world data regarding the actual in-center likelihood of a BIRADS 4 lesion to be DCIS (Ductal carcinoma in situ) or invasive disease. PATIENTS AND METHODS: This is a retrospective study of 1,641 patients who received MRI examination in the radiological department of the municipal hospital Holweide in 2012 and 2013. Each BI-RADS 4 finding (or higher) classified by MRI was compared with the final histological result. RESULTS: 347 MRIs showed BI-RADS 4 findings or higher and 280 (80.7%) cases showed benign histology. In 67 (19.3%) cases, histology showed DCIS or invasive carcinoma. CONCLUSION: BI-RADS 4 lesions have a low probability of malignancy based on real-world data from this center. If there is already an indication for surgery due to other lesions, the patient can also be offered a simultaneous open biopsy in the context of the already initiated surgical treatment. Each center should know the sensitivity and specificity of the MRI imaging performed and counsel patients based on that.


Subject(s)
Breast Neoplasms , Carcinoma, Intraductal, Noninfiltrating , Breast/diagnostic imaging , Breast/pathology , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/pathology , Carcinoma, Intraductal, Noninfiltrating/diagnostic imaging , Female , Humans , Magnetic Resonance Imaging/methods , Retrospective Studies
2.
Arch Gynecol Obstet ; 305(3): 631-639, 2022 03.
Article in English | MEDLINE | ID: mdl-34842976

ABSTRACT

PURPOSE: There is a novel surgical procedure, called cervicosacropexy (CESA) and vaginosacropexy (VASA) to treat pelvic organ prolapse and a concomitant urgency and mixed urinary incontinence. As there is little experience with the tapes so far and literature is scanty, the aim of this study was to investigate biomechanical properties for the fixation of the PVDF-tapes with three different fixation methods in context of apical fixations. METHODS: Evaluation was performed on porcine, fresh cadaver sacral spines. A total of 40 trials, divided into 4 subgroups, was performed on the anterior longitudinal ligament. Recorded biomechanical properties were displacement at failure, maximum load and stiffness in terms of the primary endpoints. The failure mode was a secondary endpoint. Group 4 was a reference group to compare single sutures on porcine tissue with those on human tissue. Biomechanical parameters for single sutures on the human anterior longitudinal ligament were evaluated in a previous work by Hachenberg et al. RESULTS: The maximum load for group 1 (two single sutures) was 65 ± 12 N, for group 2 (three titanium tacks arranged in a row) it was 25 ± 10 N and for group 3 (three titanium tacks arranged in a triangle) it was 38 ± 12 N. There was a significant difference between all three groups. The most common failure mode was a "mesh failure" in 9/10 trials for groups 1-3. CONCLUSION: The PVDF-tape fixation with two single sutures endures 2.6 times more load than titanium tacks arranged in a row and 1.7 times more load than titanium tacks arranged in a triangle. The presacral fixation with titanium tacks reduced surgical time compared to the fixation with sutures, nevertheless sutures represent the significantly stronger and cheaper fixation method.


Subject(s)
Laparoscopy , Pelvic Organ Prolapse , Animals , Biomechanical Phenomena , Humans , Laparoscopy/methods , Pelvic Organ Prolapse/complications , Pelvic Organ Prolapse/surgery , Sacrum/surgery , Suture Techniques , Sutures , Swine
3.
Nuklearmedizin ; 60(5): 368-374, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34169496

ABSTRACT

AIM: Probability of survival of patients with vulvar cancer directly depends on the lymph node status. Surgery of lymph nodes can be performed as radical inguinofemoral lymphadenectomy or in cases with certain conditions as sentinel lymph node surgery. The aim of this study is to obtain an overview of the intervention-related morbidity and quality of life in patients with vulvar carcinoma after lymphadenectomy. METHODS: Quality of life and morbidity was compared between patients who underwent radical inguinofemoral lymphadenectomy with those who underwent sentinel lymph node surgery. RESULTS: All recorded postoperative complications occur more frequently in the non-sentinel group, Significant difference was shown for the occurrence of lymphedema (p-value = 0.024) and sensitivity loss (p-value = 0.024). Recurrence of disease was more frequent in the non-sentinel group (38 % vs. 20 %, p = 0.621, n.s.) and satisfaction with groin surgery is slightly higher in the sentinel group (94 % vs. 89 %, p = 1.000, n.s.). CONCLUSION: We could demonstrate a significantly lower morbidity of sentinel lymphadenectomy compared to conventional inguinofemoral lymphadenectomy while maintaining the same oncological safety. The low morbidity of sentinel- lymphadenectomy does not seem to influence the postoperative quality of life significantly. However, recording of the individual burden of lymphadenectomy by questionnaires should be optimized.


Subject(s)
Vulvar Neoplasms , Female , Humans , Lymph Node Excision , Lymph Nodes/pathology , Lymph Nodes/surgery , Morbidity , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Quality of Life , Sentinel Lymph Node Biopsy , Vulvar Neoplasms/pathology , Vulvar Neoplasms/surgery
4.
In Vivo ; 34(4): 2015-2019, 2020.
Article in English | MEDLINE | ID: mdl-32606175

ABSTRACT

BACKGROUND/AIM: Surgical margin status remains an important determinant for recurrence of invasive breast cancer and ductal carcinoma in situ. We compared the number of positive margins in initial histology with rates of residual tumor in re-excision specimens. Furthermore, we analysed cost-effectiveness of re-excisions. PATIENTS AND METHODS: 101 patients treated with secondary surgery were included. The first group underwent breast conserving surgery and secondary mastectomy. The second group was primarily treated with subcutaneous mastectomy followed by secondary surgery. RESULTS: Within the first group, 22.7% did not show residual tumor in the re-excision specimen. Of the second group, 54.3% had no residual tumor. Consequentially 45.7% needed a re-excision to achieve R0 status. Cost-effectiveness was determined as secondary endpoint. If a patient needs a secondary mastectomy the hospital gains 602,65€ in comparison to a primary breast conserving operation. CONCLUSION: In every second patient who had first received a subcutaneous mastectomy, no tumor could be detected in the secondary operation despite a previous R1 status.


Subject(s)
Breast Neoplasms , Carcinoma, Ductal, Breast , Carcinoma, Intraductal, Noninfiltrating , Mastectomy, Subcutaneous , Breast Neoplasms/surgery , Carcinoma, Ductal, Breast/surgery , Carcinoma, Intraductal, Noninfiltrating/surgery , Female , Humans , Mastectomy , Neoplasm Recurrence, Local/surgery , Neoplasm, Residual/surgery , Reoperation , Retrospective Studies
5.
J Cancer Res Clin Oncol ; 146(10): 2709-2712, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32507972

ABSTRACT

PURPOSE: Squamous cell carcinoma of the vulva (SQCV) is the fifth common cancer in women. Necessity of inguinal lymph node surgery depends on the depth of stromal invasion, inducing lymph node surgery, if depth of invasion is more than 1 mm. In this study we tested the prediction of stromal infiltration depth by measurements in preoperative biopsies. METHODS: We analyzed whether a different operative strategy in respect to lymph node surgery would have been chosen based on the pre- or postoperative depth of stromal invasion for each patient. Examination of infiltration depth in preoperative biopsies and surgical specimen were compared. RESULTS: In total 77 patients were included in this study. Of those 89.6% showed different depths of stromal invasion comparing the pre- and postoperative specimen. Within seventeen patients (22.1%) preoperative depth was 1 mm or less and a postoperative depth was > 1 mm. CONCLUSION: We pointed, that only in 77.9% of the patients who should have undergo lymph node surgery based on the postoperative depth of infiltration underwent this procedure. Consequentially in 22.1% of the cases a second operation could not be prevented with a preoperative taken biopsy as indicator for the necessity of lymph node surgery.


Subject(s)
Carcinoma, Squamous Cell/pathology , Carcinoma, Squamous Cell/surgery , Lymph Nodes/pathology , Lymph Nodes/surgery , Vulvar Neoplasms/pathology , Vulvar Neoplasms/surgery , Adult , Aged , Aged, 80 and over , Biopsy/methods , Female , Humans , Lymph Node Excision , Lymphatic Metastasis , Middle Aged , Predictive Value of Tests , Preoperative Care/methods , Retrospective Studies , Tertiary Care Centers
6.
In Vivo ; 34(2): 923-928, 2020.
Article in English | MEDLINE | ID: mdl-32111805

ABSTRACT

BACKGROUND/AIM: Numerous risk factors have been reported to influence the development of urinary incontinence (UI). In this study, we took a closer look on the different forms of UI and tried to identify differences in regard to potential risk factors. Of special interest was the onset of UI symptoms and its relation to menopausal status. PATIENTS AND METHODS: This was a hospital-based analysis of patients who presented with urinary incontinence in the outpatient ward of a tertiary hospital. The diagnosis of urinary incontinence was based on the subjective complaints of patients. Data concerning menopausal status, hormone replacement therapy, prior hysterectomy were assessed. RESULTS: The mean age was 53.8 years in the SUI group, 62.7 years in the MUI group and 66.1 years in the UUI group, respectively (p<0.001). The proportion of patients with UUI was higher in the postmenopausal group, whereas the proportion of SUI was higher in the premenopausal group (p<0.001). The mean age in which complaints occurred was significantly lower in the SUI group (45.4 years) compared to the MUI (51.0 years) and UUI groups (54.7 years) (p<0.001). There was no correlation between menopausal status and onset of urinary incontinence (p=0.143). CONCLUSION: Additional anamnestic information help further characterize the different types of urinary incontinence that can lead to an optimization of treatment options. Younger age and premenopausal status were accompanied by milder forms of UI while menopausal status itself had no influence on the onset of UI symptoms indicating that age-related changes may lead to different types of incontinence.


Subject(s)
Menopause , Urinary Incontinence/epidemiology , Age of Onset , Aged , Female , Hospitalization , Humans , Middle Aged , Public Health Surveillance , Retrospective Studies , Risk Assessment , Risk Factors , Urinary Incontinence/diagnosis , Urinary Incontinence/etiology , Urinary Incontinence/therapy
7.
In Vivo ; 33(5): 1703-1706, 2019.
Article in English | MEDLINE | ID: mdl-31471427

ABSTRACT

BACKGROUND/AIM: For many years clinical research has been concerned with doppler sonography as a non-invasive tool for intrauterine fetal status assessment. A new focus is now placed on the measurement of cerebroplacental index (CPR) as a predictor of fetal outcome. Our aim was to investigate the relationship between the cerebroplacental ratio (CPR), the delivery mode and the fetal outcome in singleton pregnancies. PATIENTS AND METHODS: A retrospective cohort study of pregnancies in which doppler sonography of middle cerebral artery (MCA) and umbilical artery (UA) was conducted up to 9 weeks before delivery took place. Patients with pathological (CPR≤1.0) and normal CPR (>1.0) were compared by umbilical cord pH, APGAR scores, birth weight, delivery week and delivery mode. RESULTS: A total of 2,270 singleton pregnancies were included. The APGAR score for 1, 5 and 10 minutes and the gestational age at delivery were significantly lower in the group of patients with pathological CPR (p<0.001). Overall, 50% of the cohort had a cesarean section, the difference between the groups was statistically significant (p<0.001), with a higher amount of cesareans in the group of patients with pathological CPR. The multiple regression analysis showed a significantly improved pH of delivery when cesarean section (p<0.001), female sex of fetus (p=0.013) and higher CPR (p=0.035) were present. CONCLUSION: The measurement of CPR is an important, non-invasive predictive parameter and leads to the identification of a risk collective even in the non-selected patient population and thus probably to a reduction of perinatal morbidity.


Subject(s)
Anthropometry , Biomarkers , Brain/anatomy & histology , Placenta/anatomy & histology , Pregnancy Outcome , Apgar Score , Delivery, Obstetric , Female , Humans , Pregnancy
8.
J Cancer Res Clin Oncol ; 145(6): 1651-1660, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30972492

ABSTRACT

PURPOSE: Squamous cell carcinoma of the vulva (SQCV) is the fifth most common cancer in women and accounts for about 5% of all genital cancers in women. The PD-L1 signaling pathway is activated in many malignant neoplasms and its blockade enhances anti-cancer immunity. The aim of our study was to examine the protein expression of PD-L1 and PD-1 in squamous cell cancer of the vulva, its correlations with clinicopathologic features and prognostic value. METHODS: Patients with SQCV treated in one institution were used for the analyses. PD-L1 immunohistochemistry was performed on 4 µm-thick section of the respective FFPE tissue blocks using the 28-8 antibody. PD-L1 scoring was performed separately for tumour cells (TC) and tumour associated immune cells. DNA was extracted to determine HPV status. Kaplan-Meier estimates for disease-free-survival and overall-survival were calculated and compared by log-rank test. RESULTS: PD-L1 expression in tumour cells could be observed in 32.9% of the patients. The expression of PD-L1 in peritumoural immune cells was confirmed in 91.4% of the patients. A significant correlation between PD-L1 expression in tumour cells and tumour stage was detected (p = 0.007). PD-L1 expression was independent from HPV status. Using the log-rank test we could not prove any significant differences in disease-free survival (p = 0.434) and overall survival (p = 0.858). Regression analysis showed that nodal status is a predictive factor of survival (p < 0.001). CONCLUSION: The present study showed that a relevant amount of patients with squamous cell cancer of the vulva express PD-L1 in both, tumour cells and tumour-associated immune cells. Furthermore, the significant correlation of PD-L1 expression in TCs with tumour stage indicated the clinical impact of PD-L1 expression during tumour development. These data indicate that SQCV might be amenable to immune checkpoint-inhibition and constitute a rational for the future clinical trials.


Subject(s)
Carcinoma, Squamous Cell/metabolism , Programmed Cell Death 1 Receptor/biosynthesis , Vulvar Neoplasms/metabolism , Aged , B7-H1 Antigen/biosynthesis , B7-H1 Antigen/immunology , Biomarkers, Tumor/biosynthesis , Biomarkers, Tumor/immunology , Carcinoma, Squamous Cell/immunology , Carcinoma, Squamous Cell/pathology , Female , Humans , Immunohistochemistry , Middle Aged , Neoplasm Staging , Prognosis , Programmed Cell Death 1 Receptor/immunology , Vulvar Neoplasms/immunology , Vulvar Neoplasms/pathology
9.
In Vivo ; 33(2): 469-472, 2019.
Article in English | MEDLINE | ID: mdl-30804127

ABSTRACT

BACKGROUND: Retention of products of conception (RPOC) following delivery is rare. Clinicians often have the impression that a high proportion of patients with sonographically suspected RPOC following surgery have a negative histopathology. Hence, we aimed to report our single-center experience with suspected RPOC and histopathological outcome after surgery. PATIENTS AND METHODS: In this retrospective analysis, patients who underwent surgery due to suspected postpartum RPOC were analyzed for potential predictive clinical and sonographic parameters. RESULTS: A total of 32 patients with histopathologically-confirmed RPOC were compared with 21 patients with a negative histopathological report for RPOC. Endometrial hyperechogenic mass and clinical parameters such as pain, fever and bleedings were not predictive for RPOC. Increased age (p=0.001) and vaginal delivery (p=0.040) were significantly associated with RPOC. CONCLUSION: Clinical presentation alone is not predictive for RPOC. Vaginal delivery and younger age seem to be a risk factor and therefore have to be considered in patients with suspected RPOC.


Subject(s)
Delivery, Obstetric/adverse effects , Endometrium/surgery , Pregnancy Complications/physiopathology , Adult , Endometrium/physiopathology , Female , Gestational Age , Humans , Pregnancy , Pregnancy Complications/surgery , Retrospective Studies , Vagina/physiopathology , Vagina/surgery
10.
Anticancer Res ; 38(10): 6023-6026, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30275235

ABSTRACT

BACKGROUND: Breast cancer is a heterogenous and complex disease. A rare site of metastatic breast cancer disease is the neck. Data about supraclavicular metastases in patients with metastatic breast cancer are still lacking. Hence, our study aimed to analyze histological subtypes of supraclavicular metastases compared to the primary site. MATERIALS AND METHODS: This was a retrospective hospital-based cohort study of patients with breast cancer who developed supraclavicular metastases. Diagnosis of supraclavicular metastases was confirmed by biopsy or diagnostic lymph node extirpation. Histological subtypes were analyzed and Kaplan-Meier estimates were calculated for overall survival. RESULTS: A total of 20 patients were included in the analysis. The majority of the patients (12/20) had hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative supraclavicular metastases, disease in 3/20 patients was HR-positive/HER2-positive, HR-negative/HER2-positive in 1/20 patients and basal-like in 4/20 patients. Total discordance rates for estrogen receptor, progesterone receptor and HER2 between primary and metastatic tumors were 20.0%, 36.8% and 29.4%, respectively. The 5-year overall survival was 80%, whereas the 5-year survival after the onset of neck metastasis was 45%. CONCLUSION: As a rare site of metastatic breast cancer, supraclavicular metastases are associated with a worse median overall survival from their onset. The high rate of discordance of histological subtype stresses the necessity for biopsies in patients with supraclavicular metastasis.


Subject(s)
Biomarkers, Tumor/metabolism , Bone Neoplasms/mortality , Breast Neoplasms/mortality , Clavicle/pathology , Liver Neoplasms/mortality , Lung Neoplasms/mortality , Neoplasm Recurrence, Local/mortality , Adult , Aged , Bone Neoplasms/metabolism , Bone Neoplasms/secondary , Bone Neoplasms/surgery , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Clavicle/surgery , Female , Follow-Up Studies , Humans , Liver Neoplasms/metabolism , Liver Neoplasms/secondary , Liver Neoplasms/surgery , Lung Neoplasms/metabolism , Lung Neoplasms/secondary , Lung Neoplasms/surgery , Lymph Nodes/pathology , Lymph Nodes/surgery , Lymphatic Metastasis , Middle Aged , Neoplasm Recurrence, Local/metabolism , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/surgery , Prognosis , Receptor, ErbB-2/metabolism , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Retrospective Studies , Survival Rate , Young Adult
11.
Cell Rep ; 23(8): 2495-2508, 2018 05 22.
Article in English | MEDLINE | ID: mdl-29791858

ABSTRACT

Damage to and loss of glomerular podocytes has been identified as the culprit lesion in progressive kidney diseases. Here, we combine mass spectrometry-based proteomics with mRNA sequencing, bioinformatics, and hypothesis-driven studies to provide a comprehensive and quantitative map of mammalian podocytes that identifies unanticipated signaling pathways. Comparison of the in vivo datasets with proteomics data from podocyte cell cultures showed a limited value of available cell culture models. Moreover, in vivo stable isotope labeling by amino acids uncovered surprisingly rapid synthesis of mitochondrial proteins under steady-state conditions that was perturbed under autophagy-deficient, disease-susceptible conditions. Integration of acquired omics dimensions suggested FARP1 as a candidate essential for podocyte function, which could be substantiated by genetic analysis in humans and knockdown experiments in zebrafish. This work exemplifies how the integration of multi-omics datasets can identify a framework of cell-type-specific features relevant for organ health and disease.


Subject(s)
Gene Expression Regulation , Genetic Association Studies , Kidney Diseases/genetics , Podocytes/metabolism , Animals , Base Sequence , Cells, Cultured , Humans , Mice , Proteome/metabolism , Transcriptome/genetics , Zebrafish
12.
Hum Mol Genet ; 25(6): 1152-64, 2016 Mar 15.
Article in English | MEDLINE | ID: mdl-26740551

ABSTRACT

Genetic diseases constitute the most important cause for end-stage renal disease in children and adolescents. Mutations in the ACTN4 gene, encoding the actin-binding protein α-actinin-4, are a rare cause of autosomal dominant familial focal segmental glomerulosclerosis (FSGS). Here, we report the identification of a novel, disease-causing ACTN4 mutation (p.G195D, de novo) in a sporadic case of childhood FSGS using next generation sequencing. Proteome analysis by quantitative mass spectrometry (MS) of patient-derived urinary epithelial cells indicated that ACTN4 levels were significantly decreased when compared with healthy controls. By resolving the peptide bearing the mutated residue, we could proof that the mutant protein is less abundant when compared with the wild-type protein. Further analyses revealed that the decreased stability of p.G195D is associated with increased ubiquitylation in the vicinity of the mutation site. We next defined the ACTN4 interactome, which was predominantly composed of cytoskeletal modulators and LIM domain-containing proteins. Interestingly, this entire group of proteins, including several highly specific ACTN4 interactors, was globally decreased in the patient-derived cells. Taken together, these data suggest a mechanistic link between ACTN4 instability and proteome perturbations of the ACTN4 interactome. Our findings advance the understanding of dominant effects exerted by ACTN4 mutations in FSGS. This study illustrates the potential of genomics and complementary, high-resolution proteomics analyses to study the pathogenicity of rare gene variants.


Subject(s)
Actinin/genetics , Glomerulosclerosis, Focal Segmental/genetics , Kidney Failure, Chronic/genetics , Actinin/metabolism , Actins/metabolism , Adolescent , Amino Acid Sequence , Cytoskeleton/metabolism , Female , Glomerulosclerosis, Focal Segmental/metabolism , High-Throughput Nucleotide Sequencing , Humans , Kidney Failure, Chronic/metabolism , Microfilament Proteins/metabolism , Proteomics
13.
Proteomics ; 15(7): 1326-31, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25420462

ABSTRACT

Glomerular biology is dependent on tightly controlled signal transduction networks that control phosphorylation of signaling proteins such as cytoskeletal regulators or slit diaphragm proteins of kidney podocytes. Cross-species comparison of phosphorylation events is a powerful mean to functionally prioritize and identify physiologically meaningful phosphorylation sites. Here, we present the result of phosphoproteomic analyses of cow and rat glomeruli to allow cross-species comparisons. We discovered several phosphorylation sites with potentially high biological relevance, e.g. tyrosine phosphorylation of the cytoskeletal regulator synaptopodin and the slit diaphragm protein neph-1 (Kirrel). Moreover, cross-species comparisons revealed conserved phosphorylation of the slit diaphragm protein nephrin on an acidic cluster at the intracellular terminus and conserved podocin phosphorylation on the very carboxyl terminus of the protein. We studied a highly conserved podocin phosphorylation site in greater detail and show that phosphorylation regulates affinity of the interaction with nephrin and CD2AP. Taken together, these results suggest that species comparisons of phosphoproteomic data may reveal regulatory principles in glomerular biology. All MS data have been deposited in the ProteomeXchange with identifier PXD001005 (http://proteomecentral.proteomexchange.org/dataset/PXD001005).


Subject(s)
Intracellular Signaling Peptides and Proteins/metabolism , Kidney Glomerulus/metabolism , Membrane Proteins/metabolism , Protein Processing, Post-Translational , Amino Acid Sequence , Animals , Conserved Sequence , Humans , Molecular Sequence Data , Phosphoproteins/metabolism , Phosphorylation , Protein Structure, Tertiary , Proteome , Proteomics , Species Specificity
14.
J Am Soc Nephrol ; 25(7): 1509-22, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24511133

ABSTRACT

Diseases of the kidney filtration barrier are a leading cause of ESRD. Most disorders affect the podocytes, polarized cells with a limited capacity for self-renewal that require tightly controlled signaling to maintain their integrity, viability, and function. Here, we provide an atlas of in vivo phosphorylated, glomerulus-expressed proteins, including podocyte-specific gene products, identified in an unbiased tandem mass spectrometry-based approach. We discovered 2449 phosphorylated proteins corresponding to 4079 identified high-confidence phosphorylated residues and performed a systematic bioinformatics analysis of this dataset. We discovered 146 phosphorylation sites on proteins abundantly expressed in podocytes. The prohibitin homology domain of the slit diaphragm protein podocin contained one such site, threonine 234 (T234), located within a phosphorylation motif that is mutated in human genetic forms of proteinuria. The T234 site resides at the interface of podocin dimers. Free energy calculation through molecular dynamic simulations revealed a role for T234 in regulating podocin dimerization. We show that phosphorylation critically regulates formation of high molecular weight complexes and that this may represent a general principle for the assembly of proteins containing prohibitin homology domains.


Subject(s)
Glomerular Filtration Barrier/physiology , Phosphoproteins/analysis , Phosphoproteins/physiology , Proteomics , Animals , Female , Intracellular Signaling Peptides and Proteins/physiology , Membrane Proteins/physiology , Mice , Phosphorylation , Podocytes/physiology
15.
Am J Physiol Cell Physiol ; 306(9): C805-18, 2014 May 01.
Article in English | MEDLINE | ID: mdl-24573087

ABSTRACT

The function of an individual protein is typically defined by protein-protein interactions orchestrating the formation of large complexes critical for a wide variety of biological processes. Over the last decade the analysis of purified protein complexes by mass spectrometry became a key technique to identify protein-protein interactions. We present a fast and straightforward approach for analyses of interacting proteins combining a Flp-in single-copy cellular integration system and single-step affinity purification with single-shot mass spectrometry analysis. We applied this protocol to the analysis of the YAP and TAZ interactome. YAP and TAZ are the downstream effectors of the mammalian Hippo tumor suppressor pathway. Our study provides comprehensive interactomes for both YAP and TAZ and does not only confirm the majority of previously described interactors but, strikingly, revealed uncharacterized interaction partners that affect YAP/TAZ TEAD-dependent transcription. Among these newly identified candidates are Rassf8, thymopoetin, and the transcription factors CCAAT/enhancer-binding protein (C/EBP)ß/δ and core-binding factor subunit ß (Cbfb). In addition, our data allowed insights into complex stoichiometry and uncovered discrepancies between the YAP and TAZ interactomes. Taken together, the stringent approach presented here could help to significantly sharpen the understanding of protein-protein networks.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Phosphoproteins/metabolism , Protein Interaction Mapping , Protein Interaction Maps , Proteomics , Transcription Factors/metabolism , Acyltransferases , Adaptor Proteins, Signal Transducing/genetics , Amino Acid Sequence , Animals , Cell Cycle Proteins , Cluster Analysis , Computational Biology , Gene Expression Regulation , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , HEK293 Cells , Hippo Signaling Pathway , Humans , Immunoprecipitation , Mice , Molecular Sequence Data , NIH 3T3 Cells , Phosphoproteins/genetics , Protein Binding , Protein Interaction Mapping/methods , Protein Serine-Threonine Kinases/metabolism , Proteomics/methods , Recombinant Fusion Proteins/metabolism , Signal Transduction , Tandem Mass Spectrometry , Transcription Factors/genetics , Transfection , YAP-Signaling Proteins
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