Atypical Smooth Muscle Cells Research Articles

Characterization of Ano1 expressing cells in the mouse corpus cavernosum

Background/objectives: Highly coordinated contraction and relaxation of smooth muscle cells (SMCs) is critical to penile function. The Ca2+-activated Cl− channel, Anoctamin-1 (Ano1) plays a role in this as antagonists of this channel inhibit contractile, electrical and intracellular Ca2+ activity. mRNA encoding Ano1 is highly expressed in whole rabbit corpus cavernosum (CC). Despite its significant contribution to erectile function, the specific cell type that expresses Ano1 has not been determined, with previous studies relying on morphological identification of cells alone. Atypical SMCs (ASMCs) expressing platelet derived growth factor receptor-a (PDGFRa; Pdgfra), myosin heavy chain ( Myh11) and Ano1 have been observed in the renal pelvis where they are thought to drive the activity in adjacent SMCs (Grainger et al. 2020; PMID: 32415739). Therefore, the objective of this study is to identify the cell type that expresses Ano1 in the CC. Methods: Cells were isolated from the CC of mice selectively expressing eGFP in PDGFRa+ cells (PDGFRa+-eGFP mice) and SMCs ( Myh11-eGFP mice). Cell suspensions were sorted using fluorescence activated cell sorting (FACS) and evaluated for expression of cell specific markers ( Pdgfra and Myh11) by qPCR. Enriched PDGFRa+ cells and SMCs were examined with ddPCR to determine the expression of Ano1. Protein expression was evaluated using immunofluorescent labeling of frozen CC sections with an antibody targeting Ano1. Results: FACS sorted Myh11-eGFP+ cells expressed Myh11 and Pdgfra. Sorting of PDGFRa-eGFP+ cells revealed two subpopulations, bright and dim. Examination of these two PDGFRa-eGFP+ subpopulations revealed that while both expressed similar levels of Pdgfra, the dim population also expressed Myh11 suggesting that these cells may be similar to ASMCs of the renal pelvis. ddPCR revealed that the PDGFRa-eGFP+ dim population had higher gene copy numbers of Ano1 compared to Myh11-eGFP+ cells. Immunofluorescent labeling of CC sections revealed that Ano1 protein was present in a subpopulation of PDGFRa+ cells. Conclusion: The data presented in this study demonstrates that Ano1 is expressed in mouse CC PDGFRa-eGFP+ dim populations that also express Pdgfra and Myh11; this is similar to ASMCs in the renal pelvis. Future directions include examining the relationship of PDGFRa-eGFP+ dim cells to SMCs and nerve terminals in the CC and to determine if these cells are also present in human CC. This cell population could represent a novel target for the treatment of erectile dysfunction in patients who do not respond to phosphodiesterase inhibitors. Funding: AUA Research Scholar Award to KIH, NIH DK129528 to CAC, NIH P20GM130459 for imaging and molecular cores. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Identifying peristaltic pacemaker cells in the upper urinary tract.

Urine expulsion from the upper urinary tract is a necessary process that eliminates waste, promotes renal filtration and prevents nephron damage. To facilitate the movement of urine boluses throughout the upper urinary tract, smooth muscle cells that line the renal pelvis contract in a coordinated effort to form peristaltic waves. Resident pacemaker cells in the renal pelvis are critical to this process and spontaneously evoke transient depolarizations that initiate each peristaltic wave and establish rhythmic contractions. Renal pacemakers have been termed atypical smooth muscle cells due to their low expression of smooth muscle myosin and poor organization of myofilaments compared to typical (or contractile) smooth muscle cells that perform peristalsis. Recent findings discovered that pacemaker cells also express the tyrosine kinase receptor PDGFRα, enabling their identification and purification amongst other renal pelvis cell types. Improved identification methods have determined that the calcium-activated chloride channel, ANO1, is expressed by pacemaker cells and may contribute to spontaneous depolarization. A greater understanding of pacemaker and peristaltic mechanisms is warranted since aberrant contractile function may underlie diseases such as hydronephrosis, a deleterious condition that can cause significant and irreversible nephron injury.

Recurrent Pneumothorax Caused by an Unexpected Lymphangioleiomyomatosis: A Case Report

Lymphangioleiomyomatosis is a rare disease characterized by the proliferation of atypical smooth muscle cells. Recurrent pneumothorax is a frequent complication of lymphangioleiomyomatosis. We present the case of a 41-year-old woman who presented with recurrent pneumothorax. Video-assisted thoracic surgery was performed. We did not suspect the possibility of lymphangioleiomyomatosis because of the presence of very few cysts on chest computed tomography.

MP27-04 IDENTIFICATION AND CHARACTERIZATION OF NOVEL ATYPICAL SMOOTH MUSCLE CELLS IN THE MOUSE CORPUS CAVERNOSUM

You have accessJournal of UrologyCME1 Apr 2023MP27-04 IDENTIFICATION AND CHARACTERIZATION OF NOVEL ATYPICAL SMOOTH MUSCLE CELLS IN THE MOUSE CORPUS CAVERNOSUM Karen I. Hannigan, Kenton M. Sanders, Sang Don Koh, and Caroline A. Cobine Karen I. HanniganKaren I. Hannigan More articles by this author , Kenton M. SandersKenton M. Sanders More articles by this author , Sang Don KohSang Don Koh More articles by this author , and Caroline A. CobineCaroline A. Cobine More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003255.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Highly coordinated relaxation of smooth muscle cells (SMCs) is a requirement for penile erection. Previous studies in the corpus cavernosum (CC) have shown that blocking the Ca2+ activated Cl- channel Ano1 inhibited contractile, electrical and intracellular Ca2+ activity. Penile activity is influenced by neural inputs with SMCs thought to be directly targeted by neurotransmitters due to their expression of soluble guanylate cyclase (sGC), the receptor for nitric oxide (NO). However, as the CC is sparsely innervated, a cellular mediator could be present between nerves and CCSMCs. Despite this, the specific cell type that expresses Ano1 has not been identified, with previous studies relying on morphological identification of SMCs alone. Platelet derived growth factor receptor-α (PDGFRα)+ cells have been identified in other visceral smooth muscles including the gastrointestinal and urinary tracts where they mediate inhibitory neurotransmission. In the renal pelvis, PDGFRα+ cells express Ano1. The aim of this study is to identify and characterize the cell type that expresses Ano1 and to determine whether these cells mediate neurotransmission in the CC. METHODS: Cells were isolated from the CC of mice expressing eGFP in PDGFRα+ cells (PDGFRα+-eGFP mice) and SMCs (SmMHC-eGFP mice). Isolated cells were sorted with FACS. Enriched PDGFRα and SMC populations were examined using qPCR for expression of cell specific markers (Pdfgra and smooth muscle myosin heavy chain (Myh11)) to ensure purity. Purified PDGFRα+ cells and SMCs were evaluated with ddPCR to examine the expression of Ano1 and genes encoding signaling proteins from the NO pathway. RESULTS: PDGFRα+ cells isolated with FACS belonged to bright and dim populations. While qPCR revealed that the bright and dim populations expressed similar levels of Pdgfra, the dim population also expressed Myh11. In contrast, SMCs purified using FACS expressed Myh11 and Pdgfra, similar to the dim population of PDGFRα+ cells. ddPCR revealed that both the dim population of PDGFRα+ cells and SMCs expressed Ano1 and genes encoding signaling proteins from the NO pathway. CONCLUSIONS: These data suggest that Ano1 is expressed by atypical SMCs that also express PDGFRα. Therefore, these cells are a potential novel target for the treatment of erectile dysfunction. Future directions of this project include investigating the interactions between PDGFRa+ cells, SMCs and neurons. Source of Funding: Urology Care Foundation Research Scholar Award, sponsored by the Sexual Medicine Society of North America © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e363 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Karen I. Hannigan More articles by this author Kenton M. Sanders More articles by this author Sang Don Koh More articles by this author Caroline A. Cobine More articles by this author Expand All Advertisement PDF downloadLoading ...

Functional heterogeneity of PDGFRα (+) cells in spontaneously active urogenital tissues.

As PDGFRα (+) cells appear not to suppress the excitability of detrusor smooth muscle by generating SK3-dependent hyperpolarising as proposed in the gastrointestinal tract, we further explored the functional roles of PDGFRα (+) cells in regulating the spontaneous activity of urogenital tissues. Using PDGFRα-eGFP mice, intracellular Ca2+ signaling in PDGFRα (+) cells of the bladder lamina propria, renal pelvis, and seminal vesicle were visualized using Cal-590 fluorescence. The distribution and SK3 expression of PDGFRα (+) cells were also examined by immunohistochemistry. In the bladder lamina propria, SK3 (-) PDGFRα (+) cells exhibited spontaneous Ca2+ transients and responded to stimulation of P2Y1 purinoceptors with MRS2365 (100 nM) or adenosine diphosphate (ADP) (100 μM) by developing Ca2+ transients. In the proximal renal pelvis, PDGFRα (+) cells were distributed in the mucosal, muscular and serosal layers but did not express SK3 immunoreactivity. PDGFRα (+) cells in the musculature resembling atypical smooth muscle cells generated spontaneous Ca2+ transients that were partially suppressed upon P2Y1-stimulation, while vigorously responding to human angiotensin II (100 nM). In the seminal vesicle, PDGFRα (+) cells in the musculature but not mucosa expressed SK3 immunoreactivity. In the mucosa, the P2Y1 stimulation evoked Ca2+ transients in both PDGFRα (+) cells and PDGFRα (-) cells. PDGFRα (+) cells in spontaneously active urogenital tissues display heterogeneity in terms of their SK3 expression and P2Y1-induced Ca2+ responses. Muscular PDGFRα (+) cells in the renal pelvis and mucosal PDGFRα (+) cells in the seminal vesicle may generate depolarizing signals to drive smooth muscle cells.

Identification and classification of interstitial cells in the mouse renal pelvis.

Platelet-derived growth factor receptor-α (PDGFRα) is a novel biomarker along with smooth myosin heavy chain for the pacemaker cells (previously termed 'atypical' smooth muscle cells) in the murine and cynomolgus monkey pelvis-kidney junction. PDGFRα+ cells present in adventitial and urothelial layers of murine renal pelvis do not express smooth muscle myosin heavy chain (smMHC) but are in close apposition to nerve fibres. Most c-Kit+ cells in the renal pelvis are mast cells. Mast cells (CD117+ /CD45+ ) are more abundant in the proximal renal pelvis and pelvis-kidney junction regions whereas c-Kit+ interstitial cells (CD117+ /CD45- ) are found predominantly in the distal renal pelvis and ureteropelvic junction. PDGFRα+ cells are distinct from c-Kit+ interstitial cells. A subset of PDGFRα+ cells express the Ca2+ -activated Cl- channel, anoctamin-1, across the entire renal pelvis. Spontaneous Ca2+ transients were observed in c-Kit+ interstitial cells, smMHC+ PDGFRα cells and smMHC- PDGFRα cells using mice expressing genetically encoded Ca2+ sensors. Rhythmic contractions of the renal pelvis transport urine from the kidneys into the ureter. Specialized pacemaker cells, termed atypical smooth muscle cells (ASMCs), are thought to drive the peristaltic contractions of typical smooth muscle cells (TSMCs) in the renal pelvis. Interstitial cells (ICs) in close proximity to ASMCs and TSMCs have been described, but the role of these cells is poorly understood. The presence and distributions of platelet-derived growth factor receptor-α+ (PDGFRα+ ) ICs in the pelvis-kidney junction (PKJ) and distal renal pelvis were evaluated. We found PDGFRα+ ICs in the adventitial layers of the pelvis, the muscle layer of the PKJ and the adventitia of the distal pelvis. PDGFRα+ ICs were distinct from c-Kit+ ICs in the renal pelvis. c-Kit+ ICs are a minor population of ICs in murine renal pelvis. The majority of c-Kit+ cells were mast cells. PDGFRα+ cells in the PKJ co-expressed smooth muscle myosin heavy chain (smMHC) and several other smooth muscle gene transcripts, indicating these cells are ASMCs, and PDGFRα is a novel biomarker for ASMCs. PDGFRα+ cells also express Ano1, which encodes a Ca2+ -activated Cl- conductance that serves as a primary pacemaker conductance in ICs of the GI tract. Spontaneous Ca2+ transients were observed in c-Kit+ ICs, smMHC+ PDGFRα cells and smMHC- PDGFRα cells using genetically encoded Ca2+ sensors. A reporter strain of mice with enhanced green fluorescent protein driven by the endogenous promotor for Pdgfra was shown to be a powerful new tool for isolating and characterizing the phenotype and functions of these cells in the renal pelvis.

Efficacy of hormonal suppression in a patient with chyluria due to lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare lung disease affecting almost exclusively young women, characterised by abnormal proliferation of atypical smooth muscle cells. We describe a young woman presenting with chyluria secondary to the presence of a large retroperitoneal lymph - angioleiomyoma. Immunohistochemical analysis revealed HMB45-negative LAM cells (HMB45 staining is absent only in rare cases) expressing low levels of estrogen receptors. Estrogen suppressive treatment with triptoreline, a synthetic analogue of Gn-RH, resulted in dramatic reduction of the retroperitoneal mass size. The role of estrogens in the pathogenesis of LAM remains poorly understood, and hormonal therapy is still debated, but this case suggests that at least in some LAM patients, possibly those with HMB45-negative disease and estrogen receptor expression, hormonal therapy may be effective in controlling the disease process.

AN UNUSUAL CASE OF A SPONTANEOUS PNEUMOTHORAX

SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Lymphangioleiomyomatosis (LAM) is a progressive, cystic lung disease that can either be sporadic or associated with Tuberous Sclerosis Complex (TSC) with many clinical, radiologic, and pathologic features identically represented between both variants. It predominantly affects young females and is characterized by proliferation of atypical smooth muscle cells, resulting in diffuse cysts throughout the pulmonary parenchyma. Due to the underlying damage, patients often present with a host of pulmonary complaints, including pneumothoraxes. CASE PRESENTATION: A 25-year-old female with a history of asthma, cerebral palsy, uncontrollable epilepsy, hydrocephalus with ventriculoperitoneal shunt and tuberous sclerosis presented to the emergency department for acute respiratory distress. The patient’s mother described the dyspnea as sudden-onset with worsening peripheral and central cyanosis. Paramedics were called and she was emergently intubated in the field. Initial chest x-ray revealed a large, left-sided pneumothorax with contralateral mediastinal shift. A chest tube was emergently placed with repeat imaging depicting lung expansion. The patient was admitted to the intensive care unit for monitoring. On day 2 of hospitalization, the patient underwent a computed tomography of the chest which depicted diffuse thin walled cysts with interlobular septal thickening, consistent with LAM. On day 7 of hospitalization she was extubated, with chest tube removed on day 10. Screening abdominal ultrasound revealed hepatic hemangiomas and renal angiomyolipomas. She was discharged in stable condition with close follow-up. DISCUSSION: LAM is a rare, multi-system disorder that is associated with mutations in TSC genes, particularly loss of function of the tuberous sclerosis protein TSC2. Furthermore, the predilection for females is supported by reports of disease exacerbation during menstruation, pregnancy and with estrogens. Common pulmonary presentations include exertional dyspnea, pleural effusions and recurrent spontaneous pneumothoraxes; however, as dyspnea is nonspecific, patients are often labeled as asthmatics. Evaluation consists of pulmonary function testing and high-resolution computed tomography (HRCT). LAM should be suspected in women presenting with spontaneous pneumothoraxes, and in those with TSC. Treatment of pulmonary LAM consists of targeting the mTOR protein with sirolimus and lung transplantation in severe disease. CONCLUSIONS: TSC associated LAM should be suspected in any female with a spontaneous pneumothorax. HRCT usually depicts diffuse cysts throughout the pulmonary parenchyma. Despite treatment with sirolimus, patients often require lung transplantation for long-term management. Reference #1: Johnson S. Lymphangioleiomyomatosis: clinical features, management and basic mechanisms. Thorax 1999;54:254-264 Reference #2: Lama A, Ferreiro L, Golpe A, et al. Characteristics of Patients with Lymphangioleiomyomatosis and Pleural Effusion: A Systematic Review. Respiration 2016; 91:256 DISCLOSURES: No relevant relationships by Sunil Chulani, source=Web Response No relevant relationships by Keith Guevarra, source=Web Response No relevant relationships by Amee Patrawalla, source=Web Response

Spontaneous Pneumopericardium in a Patient of Lymphangioleiomyomatosis and Pulmonary Tuberculosis- Rare Case Report

Pneumopericardium is a rare entity and is usually reported as a complication of trauma [1].We are reporting a rare case of Lymphangioleiomyomatosis (LAM) coexisting with sputum positive miliary tuberculosis presenting with pneumopericardium. LAM is a rare lung disease of unknown etiology, exclusively affecting women of reproductive age group and is characterised by proliferation and infiltration of pulmonary interstitium with atypical smooth muscle cell. LAM causes pleural complications especially pneumothorax and chylothorax, but it has not been reported to cause pneumopericardium. However pulmonary tuberculosis is known to cause pneumopericardium but coexistence of LAM with Pulmonary tuberculosis is a rare presentation.

Pacemaker Mechanisms Driving Pyeloureteric Peristalsis: Modulatory Role of Interstitial Cells.

The peristaltic pressure waves in the renal pelvis that propel urine expressed by the kidney into the ureter towards the bladder have long been considered to be 'myogenic', being little affected by blockers of nerve conduction or autonomic neurotransmission, but sustained by the intrinsic release of prostaglandins and sensory neurotransmitters. In uni-papilla mammals, the funnel-shaped renal pelvis consists of a lumen-forming urothelium and a stromal layer enveloped by a plexus of 'typical' smooth muscle cells (TSMCs), in multi-papillae kidneys a number of minor and major calyces fuse into a large renal pelvis. Electron microscopic, electrophysiological and Ca2+ imaging studies have established that the pacemaker cells driving pyeloureteric peristalsis are likely to be morphologically distinct 'atypical' smooth muscle cells (ASMCs) that fire Ca2+ transients and spontaneous transient depolarizations (STDs) which trigger propagating nifedipine-sensitive action potentials and Ca2+ waves in the TSMC layer. In uni-calyceal kidneys, ASMCs predominately locate on the serosal surface of the proximal renal pelvis while in multi-papillae kidneys they locate within the sub-urothelial space. 'Fibroblast-like' interstitial cells (ICs) located in the sub-urothelial space or adventitia are a mixed population of cells, having regional and species-dependent expression of various Cl-, K+, Ca2+ and cationic channels. ICs display asynchronous Ca2+ transients that periodically synchronize into bursts that accelerate ASMC Ca2+ transient firing. This review presents current knowledge of the architecture of the proximal renal pelvis, the role Ca2+ plays in renal pelvis peristalsis and the mechanisms by which ICs may sustain/accelerate ASMC pacemaking.

Mucosa-Dependent, Stretch-Sensitive Spontaneous Activity in Seminal Vesicle.

Seminal vesicles (SVs), a pair of male accessory glands, contract upon sympathetic nerve excitation during ejaculation while developing spontaneous phasic constrictions in the inter-ejaculatory storage phase. Recently, the fundamental role of the mucosa in generating spontaneous activity in SV of the guinea pig has been revealed. Stretching the mucosa-intact but not mucosa-denuded SV smooth muscle evokes spontaneous phasic contractions arising from action potential firing triggered by electrical slow waves and associated Ca2+ flashes. These spontaneous events primarily depend on sarco-endoplasmic reticulum (SR/ER) Ca2+ handling linked with the opening of Ca2+-activated chloride channels (CaCCs) resulting in the generation of slow waves. Slow waves in mucosa-intact SV smooth muscle are abolished upon blockade of gap junctions, suggesting that seminal smooth muscle cells are driven by cells distributed in the mucosa. In the SV mucosal preparations dissected free from the smooth muscle layer, a population of cells located just beneath the epithelium develop spontaneous Ca2+ transients relying on SR/ER Ca2+ handling. In the lamina propria of the SV mucosa, vimentin-immunoreactive interstitial cells including platelet-derived growth factor receptor α (PDGFRα)-immunoreactive cells are distributed, while known pacemaker cells in other smooth muscle tissues, e.g. c-Kit-positive interstitial cells or α-smooth muscle actin-positive atypical smooth muscle cells, are absent. The spontaneously-active subepithelial cells appear to drive spontaneous activity in SV smooth muscle either by sending depolarizing signals or by releasing humoral substances. Interstitial cells in the lamina propria may act as intermediaries of signal transmission from the subepithelial cells to the smooth muscle cells.

Interstitial cell modulation of pyeloureteric peristalsis in the mouse renal pelvis examined using FIBSEM tomography and calcium indicators.

Typical and atypical smooth muscle cells (TSMCs and ASMCs, respectively) and interstitial cells (ICs) within the pacemaker region of the mouse renal pelvis were examined using focused ion beam scanning electron (FIB SEM) tomography, immunohistochemistry and Ca2+ imaging. Individual cells within 500-900 electron micrograph stacks were volume rendered and associations with their neighbours established. 'Ribbon-shaped', Ano1 Cl- channel immuno-reactive ICs were present in the adventitia and the sub-urothelial space adjacent to the TSMC layer. ICs in the proximal renal pelvis were immuno-reactive to antibodies for CaV3.1 and hyperpolarization-activated cation nucleotide-gated isoform 3 (HCN3) channel sub-units, while basal-epithelial cells (BECs) were intensely immuno-reactive to Kv7.5 channel antibodies. Adventitial to the TSMC layer, ASMCs formed close appositions with TSMCs and ICs. The T-type Ca2+channel blocker, Ni2+ (10-200μM), reduced the frequency while the L-type Ca2+ channel blocker (1μM nifedipine) reduced the amplitude of propagating Ca2+ waves and contractions in the TSMC layer. Upon complete suppression of Ca2+ entry through TSMC Ca2+ channels, ASMCs displayed high-frequency (6min-1) Ca2+ transients, and ICs distributed into two populations of cells firing at 1 and 3min-1, respectively. IC Ca2+ transients periodically (every 3-5min-1) summed into bursts which doubled the frequency of ASMC Ca2+ transient firing. Synchronized IC bursting and the acceleration of ASMC firing were inhibited upon blockade of HCN channels with ZD7288 or cell-to-cell coupling with carbenoxolone. While ASMCs appear to be the primary pacemaker driving pyeloureteric peristalsis, it was concluded that sub-urothelial HCN3(+), CaV3.1(+) ICs can accelerate ASMC Ca2+ signalling.

Angiotensin receptor-1A knockout leads to hydronephrosis not associated with a loss of pyeloureteric peristalsis in the mouse renal pelvis.

The action of angiotensin II (AngII) on the Ca(2+) signals driving pyeloureteric peristalsis was investigated using both conventional and angiotensin receptor (ATr) ATr1A and ATr2 knockout ((-/-)) mice. Contractility in the renal pelvis of adult ATr1A(-/-) and ATr2(-/-) mice was compared to their respective wildtype (ATr1A(+/+) and ATr2(+/+)) controls of the same genetic background (FVB/N and C57Bl/6 respectively) using video microscopy. The effects of AngII on the Ca(2+) signals in typical and atypical smooth muscle cells (TSMCs and ASMCs, respectively) within the pelvic wall of conventional mice were recorded using Fluo-4 Ca(2+) imaging. Compared to ATr1A(+/+) , ATr2(+/+) and ATr2(-/-) mice, kidneys of the ATr1A(-/-) mouse were mildly-to-severely hydronephrotic, associated with an enlarged calyx, an atrophic papilla and a hypoplastic renal pelvis. Contraction frequencies in the renal pelvis of moderately hydronephrotic ATr1A(-/-) and unaffected ATr2(-/-) mice were not significantly different from their ATr1A(+/+), ATr2(+/+) controls. No contractions were observed in severely-hydronephrotic ATr1A(-/-) kidneys. AngII increased the spontaneous contraction frequency of the renal pelvis in ATr1A(+/+), ATr2(+/+) and ATr2(-/-) mice, but had little effect on the contractions in the mildly-hydronephrotic ATr1A(-/-) renal pelvis. The ATr1 blocker, candesartan prevented the positive chronotropic effects of AngII. AngII increased the frequency and synchronicity of Ca(2+) transients in both TSMCs and ASMCs. It was concluded that the hydronephrosis observed in ATr1A(-/-) mouse kidneys does not arise from a failure in the development of the essential pacemaker and contractile machinery driving pyeloureteric peristalsis.

A rare case of lymphangioleiomyomatosis with recurrent pneumothorax

Lymphangioleiomyomatosis (LAM) is a rare disease of unknown etiology that traditionally affects young women of childbearing or premenopausal age. It is characterized by proliferation of atypical smooth muscle cells, preferentially along bronchovascular structures that cause progressive respiratory failure. Owing to its unusual and nonspecific presenting symptoms, patients often receive missed or delayed diagnosis. This disease occurs sporadically or in association with the genetic disease-tuberous sclerosis complex. Recurrent pneumothorax is the hallmark of LAM. We present a 16-year-old young female having recurrent pneumothorax with LAM.

Structural links between the renal stem/progenitor cell niche and the organ capsule

A special feature of the renal stem/progenitor cell niche is its always close neighborhood to the capsule during organ development. To explore this link, neonatal kidney was investigated by histochemistry and transmission electron microscopy. For adequate contrasting, fixation of specimens was performed by glutaraldehyde including tannic acid. The immunohistochemical data illustrate that renal stem/progenitor cells are not distributed randomly but are positioned specially to the capsule. Epithelial stem/progenitor cells are found to be enclosed by the basal lamina at a collecting duct (CD) ampulla tip. Only few layers of mesenchymal cells are detected between epithelial cells and the capsule. Most impressive, numerous microfibers reacting with soybean agglutinin, anti-collagen I and III originate from the basal lamina at a CD ampulla tip and line between mesenchymal stem/progenitor cells to the inner side of the capsule. This specific arrangement holds together both types of stem/progenitor cells in a cage and fastens the niche as a whole at the capsule. Electron microscopy further illustrates that the stem/progenitor cell niche is in contact with a tunnel system widely spreading between atypical smooth muscle cells at the inner side of the capsule. It seems probable that stem/progenitor cells are supplied here by interstitial fluid.

Lymphangioleiomyomatosis: A rare case report

Lymphangioleiomyomatosis (LAM) is a rare disease of unknown etiology that traditionally affects young women of child bearing or premenopausal age. It is characterized by proliferation of atypical smooth muscle cells, preferentially along bronchovascular structures that causes progressive respiratory failure. Due to its unusual and nonspecific presenting symptoms, patients often receive missed or delayed diagnosis. This disease occurs sporadically or in association with the genetic disease tuberous sclerosis complex (TSC). We present 34-year-old young premenopausal woman with LAM.

Potassium and ANO1/ TMEM16A chloride channel profiles distinguish atypical and typical smooth muscle cells from interstitial cells in the mouse renal pelvis

Although atypical smooth muscle cells (SMCs) in the proximal renal pelvis are thought to generate the pacemaker signals that drive pyeloureteric peristalsis, their location and electrical properties remain obscure. Standard patch clamp, intracellular microelectrode and immunohistochemistry techniques were used. To unequivocally identify SMCs, transgenic mice with enhanced yellow fluorescent protein (eYFP) expressed in cells containing α-smooth muscle actin (α-SMA) were sometimes used. Atypical SMCs were distinguished from typical SMCs by the absence of both a transient 4-aminopyridine-sensitive K(+) current (I(KA) ) and spontaneous transient outward currents (STOCs) upon the opening of large-conductance Ca(2+) -activated K(+) (BK) channels. Many typical SMCs displayed a slowly activating, slowly decaying Cl(-) current blocked by niflumic acid (NFA). Immunostaining for K(V) 4.3 and ANO1/ TMEM16A Cl(-) channel subunits co-localized with α-SMA immunoreactive product predominately in the distal renal pelvis. Atypical SMCs fired spontaneous inward currents that were either selective for Cl(-) and blocked by NFA, or cation-selective and blocked by La(3+) . α-SMA(-) interstitial cells (ICs) were distinguished by the presence of a Xe991-sensitive K(V) 7 current, BK channel STOCs and Cl(-) selective, NFA-sensitive spontaneous transient inward currents (STICs). Intense ANO1/ TMEM16A and K(V) 7.5 immunostaining was present in Kit(-) α-SMA(-) ICs in the suburothelial and adventitial regions of the renal pelvis. We conclude that K(V) 4.3(+) α-SMA(+) SMCs are typical SMCs that facilitate muscle wall contraction, that ANO1/ TMEM16A and K(V) 7.5 immunoreactivity may be selective markers of Kit(-) ICs and that atypical SMCs which discharge spontaneous inward currents are the pelviureteric pacemakers.

Interval changes of an extrauterine adenomyoma on magnetic resonance imaging

Extrauterine adenomyomas are rare tumors that present as uterus-like masses. Uterine adenomyomas can show interval changes according to hormone status. However, interval changes in imaging studies have not been reported in adenomyomas. We report a rare case of an extrauterine adenomyoma showing unique interval changes in magnetic resonance imaging.

Evolução da função pulmonar após tratamento com goserelina em pacientes com linfangioleiomiomatose

In the atypical smooth muscle cells that are characteristic of lymphangioleiomyomatosis (LAM), there are estrogen and progesterone receptors. Therefore, anti-hormonal therapy, despite having produced controversial results, can be considered a treatment option. The objective of this retrospective study was to evaluate hormonal and spirometric data for nine women with LAM after one year of treatment with goserelin. The mean increase in FEV1 and FVC was 80 mL and 130 mL, respectively. There was effective blockage of the hormonal axis. It is still not possible to exclude a potential beneficial effect of the use of gonadotropin-releasing hormone analogues in LAM patients, which underscores the need for randomized trials.

Efficacy of hormonal suppression in a patient with chyluria due to lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare lung disease affecting almost exclusively young women, characterised by abnormal proliferation of atypical smooth muscle cells. We describe a young woman presenting with chyluria secondary to the presence of a large retroperitoneal lymphangioleiomyoma. Immunohistochemical analysis revealed HMB45-negative LAM cells (HMB45 staining is absent only in rare cases) expressing low levels of estrogen receptors. Estrogen suppressive treatment with triptoreline, a synthetic analogue of Gn-RH, resulted in dramatic reduction of the retroperitoneal mass size. The role of estrogens in the pathogenesis of LAM remains poorly understood, and hormonal therapy is still debated, but this case suggests that at least in some LAM patients, possibly those with HMB45-negative disease and estrogen receptor expression, hormonal therapy may be effective in controlling the disease process.