CFTR expression in human salivary gland acinar cells.

The key role of CFTR in secretory epithelia has been extensively documented. Additionally, CFTR plays a significant role in ion absorption in exocrine glands, including salivary and sweat glands. Most of the knowledge about CFTR expression comes from animal models such as the mouse or the rat, but there is limited information about CFTR expression in human tissues. In the present study, we assessed the expression of CFTR in human submandibular and parotid glands. Consistent with findings in rodent salivary glands, our immunolocalization studies show that CFTR is expressed in duct cells. However, CFTR expression in human salivary glands differs from that in rodents, as immunolocalization and single-cell RNA sequencing analysis from a previous study performed in the human parotid gland revealed the presence of CFTR protein and transcripts within a distinct cell cluster. Based on cell marker expression, this cluster corresponds to acinar cells. To obtain functional evidence supporting CFTR expression, we isolated human parotid acinar cells through collagenase digestion. Acinar cells displayed an anion conductance that was activated in response to cAMP-increasing agents and was effectively blocked by CFTRInh172, a known CFTR blocker. This study provides novel evidence of CFTR expression within acinar cells of human salivary glands. This finding challenges the established model positioning CFTR exclusively in duct cells from exocrine glands.NEW & NOTEWORTHY This study addresses the uncertainty about the impact of CFTR on human salivary gland function. We found CFTR transcripts in a subset of duct cells known as ionocytes, as well as in acinar cells. Isolated human parotid acinar cells exhibited Cl- conductance consistent with CFTR activity. This marks the first documented evidence of functional CFTR expression in human salivary gland acinar cells.

miRNA-27a is essential for bone remodeling by modulating p62-mediated osteoclast signaling.

The ability to simultaneously modulate a set of genes for lineage-specific development has made miRNA an ideal master regulator for organogenesis. However, most miRNA deletions do not exhibit obvious phenotypic defects possibly due to functional redundancy. miRNAs are known to regulate skeletal lineages as the loss of their maturation enzyme Dicer impairs bone remodeling processes. Therefore, it is important to identify specific miRNA essential for bone homeostasis. We report the loss of MIR27a causing severe osteoporosis in mice. MIR27a affects osteoclast-mediated bone resorption but not osteoblast-mediated bone formation during skeletal remodeling. Gene profiling and bioinformatics further identify the specific targets of MIR27a in osteoclast cells. MIR27a exerts its effects on osteoclast differentiation through modulation of Squstm1/p62 whose mutations have been linked to Paget's disease of bone. Our findings reveal a new MIR27a-p62 axis necessary and sufficient to mediate osteoclast differentiation and highlight a therapeutic implication for osteoporosis.

Short-term and bystander effects of radiation on murine submandibular glands.

Many patients treated for head and neck cancers experience salivary gland hypofunction due to radiation damage. Understanding the mechanisms of cellular damage induced by radiation treatment is important in order to design methods of radioprotection. In addition, it is crucial to recognize the indirect effects of irradiation and the systemic responses that may alter saliva secretion. In this study, radiation was delivered to murine submandibular glands (SMGs) bilaterally, using a 137Cs gamma ray irradiator, or unilaterally, using a small-animal radiation research platform (SARRP). Analysis at 3, 24 and 48 h showed dynamic changes in mRNA and protein expression in SMGs irradiated bilaterally. Unilateral irradiation using the SARRP caused similar changes in the irradiated SMGs, as well as significant off-target, bystander effects in the non-irradiated contralateral SMGs.

A Case of Large Sarcoid Choroidal Granuloma Treated with Steroid Pulse Therapy.

PURPOSE: To report a case of large sarcoid choroidal granuloma that was successfully treated with steroid pulse therapy. CASE REPORT: A 38-year-old man presented with the primary complaint of decreased visual acuity (VA) in his left eye. Upon examination, a large white protruding lesion of 10 × 8 papilla diameter in size was observed in the macular region, and slightly temporal to it, in the patient's left eye. Whole-body contrast-enhanced computed tomography performed for differential diagnosis detected numerous enlarged lymph nodes throughout the body, including the bilateral hilar regions. Sarcoidosis was diagnosed by biopsy of the right cervical lymph nodes showing noncaseating epithelioid cell granuloma. The fundus lesion was found to be a choroidal granuloma caused by sarcoidosis, and steroid pulse therapy was started. The granuloma was considerably decreased, and the VA in the left eye improved to 0.7 after 2 months. CONCLUSION: Steroid pulse therapy was found to be effective as an initial treatment for a large sarcoid choroidal granuloma.

The requirement of SUMO2/3 for SENP2 mediated extraembryonic and embryonic development.

Small ubiquitin-related modifier (SUMO)-specific protease 2 (SENP2) is essential for the development of healthy placenta. The loss of SENP2 causes severe placental deficiencies and leads to embryonic death that is associated with heart and brain deformities. However, tissue-specific disruption of SENP2 demonstrates its dispensable role in embryogenesis and the embryonic defects are secondary to placental insufficiency. SENP2 regulates SUMO1 modification of Mdm2, which controls p53 activities critical for trophoblast cell proliferation and differentiation. Here we use genetic analyses to examine the involvement of SUMO2 and SUMO3 for SENP2-mediated placentation. The results indicate that hyper-SUMOylation caused by SENP2 deficiency can be compensated by reducing the level of SUMO modifiers. The placental deficiencies caused by the loss of SENP2 can be alleviated by the inactivation of gene encoding SUMO2 or SUMO3. Our findings demonstrate that SENP2 genetically interacts with SUMO2 and SUMO3 pivotal for the development of three major trophoblast layers. The alleviation of placental defects in the SENP2 knockouts further leads to the proper formation of the heart structures, including atrioventricular cushion and myocardium. SUMO2 and SUMO3 modifications regulate placentation and organogenesis mediated by SENP2.

A case of mediastinitis with an exposed artificial blood vessel that was associated with right ventricular wall damage during treatment.

We report a serious case of right ventricular wall damage during mediastinitis treatment, which was successfully treated with negative-pressure wound therapy with continuous instillation (NPWT-CI).

Appropriate Use of Intravenous Unfractionated Heparin after Digital Replantation: A Randomized Controlled Trial Involving Three Groups.

BACKGROUND: The purpose of this study was to clarify the appropriate use of unfractionated heparin as an anticoagulation agent after digital replantation. METHODS: This study was a prospective, randomized, single-blind, blinded-endpoint method, three-arm, parallel-group, controlled clinical trial conducted at a single institution. A total of 88 patients (101 fingers) following digital amputation and subsequent repair by anastomosis of both arteries and veins were randomly allocated into three groups: (1) control group (no heparin dose), (2) low-dose heparin group (10,000 IU/day), and (3) high-dose heparin group (start at 15,000 IU/day, then adjust the dose to achieve an activated partial thromboplastin time of 1.5 to 2.5 times the baseline). The outcomes were assessed regarding the proportion of success at 2 weeks after replantation of amputated digits, total or partial necrosis, and occurrence of complications. RESULTS: No significant differences were found among the three groups, except for complications of congestion. The odds ratio of the heparin group compared with the control group for a success proportion was 5.40 (95 percent CI, 0.85 to 34.20; p = 0.027) in subjects aged 50 years or older. Significant elevations of activated partial thromboplastin time, aspartate transaminase, and alanine aminotransferase occurred in high-dose heparin groups on day 7. CONCLUSION: Unfractionated heparin administration is considered effective for patients aged 50 years or older, although the routine use of unfractionated heparin is not necessary after digital replantation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Familial exudative vitreoretinopathy complicated with full thickness macular hole: A case report.

RATIONALE: To report a case of familial exudative vitreoretinopathy (FEVR) complicated with full-thickness macular hole (FTMH). PATIENT CONCERNS: A 39-year-old male presented after becoming aware of metamorphopsia in his left eye. DIAGNOSES: Fundus examination showed a retinal avascular area, retinal vascular abnormality, and yellow exudation at the peripheral retina in both eyes. Optical coherence tomography findings revealed impending MH (IMH) due to posterior vitreous detachment (PVD) in his left eye. Despite of the occurrence of spontaneous complete PVD, an FTMH developed at 4 months after the onset of IMH. INTERVENTIONS: To treat the FTMH, vitreous surgery was performed. Intraoperative findings revealed that the thick posterior vitreous membrane (PVM) had no adhesions with the edge of the FTMH. However, a thin epiretinal membrane (ERM) was observed around the MH. OUTCOMES: Postoperatively, the FTMH was closed, and the patient's corrected visual acuity improved from (0.4) to (0.8). LESSONS: In this present case, an IMH developed via traction by a thick PVM, characteristic of FEVR, with FTMH then developing via traction by a thin ERM. Our findings reveal that it is vital to fully understand these anatomical features before performing vitreous surgery for FTMH complicated with FEVR.

Maggot debridement therapy with a direct dressing can cause compression injuries in patients with chronic limb ischemia.

While there are no reports regarding dressing-associated iatrogenic skin ulcer as an adverse event of maggot debridement therapy (MDT), MDT is clinically used on patients with critical limb ischaemia with dermal fragility. Herein we report causes and counter measures for a case of iatrogenic skin ulcer induced by MDT dressing.

Extraembryonic but not embryonic SUMO-specific protease 2 is required for heart development.

SUMO-specific protease 2 (SENP2) activities to remove SUMO from its substrates is essential for development of trophoblast stem cells, niches and lineages. Global deletion of SENP2 leads to midgestation lethality, and causes severe defects in the placenta which is accompanied by embryonic brain and heart abnormalities. Because of the placental deficiencies, the role of SENP2 in development of the embryonic tissues has not been properly determined. The brain and heart abnormalities may be secondary to placental insufficiency. Here we have created a new mouse strain permitting conditional inactivation of SENP2. Mice homozygous for germline deletion of the conditional allele exhibit trophoblast defects and embryonic abnormalities resembling the global SENP2 knockout. However, tissue-specific disruptions of SENP2 demonstrate its dispensable role in embryogenesis. Placental expression of SENP2 is necessary and sufficient for embryonic heart and brain development. Using a protease deficient model, we further demonstrate the requirement of SENP2-dependent SUMO modification in development of all major trophoblast lineages. SENP2 regulates sumoylation of Mdm2 which controls p53 activities critical for G-S transition of mitotic division and endoreduplication in trophoblast proliferation and differentiation, respectively. The differentiation of trophoblasts is also dependent on SENP2-mediated activation of p57(Kip2), a CDK-specific inhibitor required for endoreduplication.

Cell-Specific Cre Strains For Genetic Manipulation in Salivary Glands.

The secretory acinar cells of the salivary gland are essential for saliva secretion, but are also the cell type preferentially lost following radiation treatment for head and neck cancer. The source of replacement acinar cells is currently a matter of debate. There is evidence for the presence of adult stem cells located within specific ductal regions of the salivary glands, but our laboratory recently demonstrated that differentiated acinar cells are maintained without significant stem cell contribution. To enable further investigation of salivary gland cell lineages and their origins, we generated three cell-specific Cre driver mouse strains. For genetic manipulation in acinar cells, an inducible Cre recombinase (Cre-ER) was targeted to the prolactin-induced protein (Pip) gene locus. Targeting of the Dcpp1 gene, encoding demilune cell and parotid protein, labels intercalated duct cells, a putative site of salivary gland stem cells, and serous demilune cells of the sublingual gland. Duct cell-specific Cre expression was attempted by targeting the inducible Cre to the Tcfcp2l1 gene locus. Using the R26Tomato Red reporter mouse, we demonstrate that these strains direct inducible, cell-specific expression. Genetic tracing of acinar cells using PipGCE supports the recent finding that differentiated acinar cells clonally expand. Moreover, tracing of intercalated duct cells expressing DcppGCE confirms evidence of duct cell proliferation, but further analysis is required to establish that renewal of secretory acinar cells is dependent on stem cells within these ducts.

Disruption of SUMO-specific protease 2 induces mitochondria mediated neurodegeneration.

Post-translational modification of proteins by small ubiquitin-related modifier (SUMO) is reversible and highly evolutionarily conserved from yeasts to humans. Unlike ubiquitination with a well-established role in protein degradation, sumoylation may alter protein function, activity, stability and subcellular localization. Members of SUMO-specific protease (SENP) family, capable of SUMO removal, are involved in the reversed conjugation process. Although SUMO-specific proteases are known to reverse sumoylation in many well-defined systems, their importance in mammalian development and pathogenesis remains largely elusive. In patients with neurodegenerative diseases, aberrant accumulation of SUMO-conjugated proteins has been widely described. Several aggregation-prone proteins modulated by SUMO have been implicated in neurodegeneration, but there is no evidence supporting a direct involvement of SUMO modification enzymes in human diseases. Here we show that mice with neural-specific disruption of SENP2 develop movement difficulties which ultimately results in paralysis. The disruption induces neurodegeneration where mitochondrial dynamics is dysregulated. SENP2 regulates Drp1 sumoylation and stability critical for mitochondrial morphogenesis in an isoform-specific manner. Although dispensable for development of neural cell types, this regulatory mechanism is necessary for their survival. Our findings provide a causal link of SUMO modification enzymes to apoptosis of neural cells, suggesting a new pathogenic mechanism for neurodegeneration. Exploring the protective effect of SENP2 on neuronal cell death may uncover important preventive and therapeutic strategies for neurodegenerative diseases.

Gpr177 deficiency impairs mammary development and prohibits Wnt-induced tumorigenesis.

Aberrant regulation of the Wnt pathway, essential for various developmental processes, is tightly linked to human breast cancers. By hijacking this evolutionary conserved signaling pathway, cancer cells acquire sustaining proliferation ability, leading to modification of physiologic properties necessary for tumor initiation and progression. An enormous wealth of knowledge on the importance of Wnt signaling in breast development and cancer has been obtained, but the cell types responsible for production of this proliferative signal operating within normal and malignant tissues remains poorly understood. Here we report that Wnt production mediated by Gpr177 is essential for mammary morphogenesis. The loss of Gpr177 interferes with mammary stem cells, leading to deficiencies in cell proliferation and differentiation. Genetic analysis further demonstrates an indispensable role of Gpr177 in Wnt-induced tumorigenesis. The Gpr177-deficiency mice are resistant to malignant transformation. This study not only demonstrates the necessity of Wnt in mammary organogenesis but also provides a proof-of-principle for targeting of Gpr177 as a potential new treatment for human diseases with aberrant Wnt stimulation.

The actin family member Arp6 and the histone variant H2A.Z are required for spatial positioning of chromatin in chicken cell nuclei.

The spatial organization of chromatin in the nucleus contributes to genome function and is altered during the differentiation of normal and tumorigenic cells. Although nuclear actin-related proteins (Arps) have roles in the local alteration of chromatin structure, it is unclear whether they are involved in the spatial positioning of chromatin. In the interphase nucleus of vertebrate cells, gene-dense and gene-poor chromosome territories (CTs) are located in the center and periphery, respectively. We analyzed chicken DT40 cells in which Arp6 had been knocked out conditionally, and showed that the radial distribution of CTs was impaired in these knockout cells. Arp6 is an essential component of the SRCAP chromatin remodeling complex, which deposits the histone variant H2A.Z into chromatin. The redistribution of CTs was also observed in H2A.Z-deficient cells for gene-rich microchromosomes, but to lesser extent for gene-poor macrochromosomes. These results indicate that Arp6 and H2A.Z contribute to the radial distribution of CTs through different mechanisms. Microarray analysis suggested that the localization of chromatin to the nuclear periphery per se is insufficient for the repression of most genes.

Derivation of mouse trophoblast stem cells from blastocysts.

Specification of the trophectoderm is one of the earliest differentiation events of mammalian development. The trophoblast lineage derived from the trophectoderm mediates implantation and generates the fetal part of the placenta. As a result, the development of this lineage is essential for embryo survival. Derivation of trophoblast stem (TS) cells from mouse blastocysts was first described by Tanaka et al. 1998. The ability of TS cells to preserve the trophoblast specific property and their expression of stage- and cell type-specific markers after proper stimulation provides a valuable model system to investigate trophoblast lineage development whereby recapitulating early placentation events. Furthermore, trophoblast cells are one of the few somatic cell types undergoing natural genome amplification. Although the molecular pathways underlying trophoblast polyploidization have begun to unravel, the physiological role and advantage of trophoblast genome amplification remains largely elusive. The development of diploid stem cells into polyploid trophoblast cells in culture makes this ex vivo system an excellent tool for elucidating the regulatory mechanism of genome replication and instability in health and disease. Here we describe a protocol based on previous reports with modification published in Chiu et al. 2008.