ABSTRACT
Estrogen and its receptors are involved in the pathogenesis of gastrointestinal diseases such as colitis. However, the role of the membrane estrogen receptor G-protein-coupled receptor 30 (GPR30) in colitis is poorly understood. We therefore investigated the effect of estrogen in dextran sulfate sodium (DSS)-induced colitis. Male C57BL/6 mice were administered 1.5% DSS for 5 days and treated with 17ß-estradiol (E2), GPR30 agonist (G1), or GPR30 antagonist (G15) for 8 days. Inflammation grade was evaluated by disease activity index (DAI) and histomorphological score. Colon tissues were immunohistochemically analyzed and revealed high expression of membrane GPR30, histone 3 lysine 36 dimethylation, and lysine 79 trimethylation in normal mouse colon epithelial cells but significantly decreased expression in DSS-treated mice, whereas the expression was partially preserved after treatment with E2 or G1. Colon shortening and DAI were significantly lower in E2- and G1-treated mice compared to DSS-treated mice. Caudal type homeobox 2 (CDX2) expression and cell proliferation differed in normal colon epithelial cells but overlapped in those of DSS-treated mice. Administration of E2 and G1 reduced CDX2 expression and cell proliferation. Altered expression of claudin-2 and occludin were observed in the colonic epithelium of DSS-treated mice, and these changes were significantly lower in the colon of E2- and G1-treated mice. These results indicate that estrogen regulates histone modification, cell proliferation, and CDX2 expression through GPR30, which affects intestinal epithelial barrier function. We conclude that estrogen protects against intestinal epithelial damage through GPR30 by enhancing intestinal epithelial barrier function in DSS-induced colitis in mice.
Subject(s)
Colitis , Lysine , Animals , Male , Mice , Colitis/chemically induced , Colitis/metabolism , Colitis/pathology , Colon/pathology , Dextran Sulfate/adverse effects , Dextran Sulfate/metabolism , Disease Models, Animal , Estrogens/pharmacology , Estrogens/metabolism , Intestinal Mucosa/metabolism , Lysine/metabolism , Mice, Inbred C57BL , Receptors, Estrogen/metabolism , Receptors, G-Protein-Coupled/metabolismABSTRACT
Su (var) 3-9, enhancer of seste, trithorax (SET)-domain bifurcated histone lysine methyltransferase (SETDB1) plays a crucial role in maintaining intestinal stem cell homeostasis; however, its physiological function in epithelial injury is largely unknown. In this study, we investigated the role of SETDB1 in epithelial regeneration using an intestinal ischemia/reperfusion injury (IRI) mouse model. Jejunum tissues were sampled after 75 min of ischemia followed by 3, 24, and 48 h of reperfusion. Morphological evaluations were performed using light microscopy and electron microscopy, and the involvement of SETDB1 in epithelial remodeling was investigated by immunohistochemistry. Expression of SETDB1 was increased following 24 h of reperfusion and localized in not only the crypt bottom but also in the transit amplifying zone and part of the villi. Changes in cell lineage, repression of cell adhesion molecule expression, and decreased histone H3 methylation status were detected in the crypts at the same time. Electron microscopy also revealed aberrant alignment of crypt nuclei and fusion of adjacent villi. Furthermore, increased SETDB1 expression and epithelial remodeling were confirmed with loss of stem cells, suggesting SETDB1 affects epithelial cell plasticity. In addition, crypt elongation and increased numbers of Ki-67 positive cells indicated active cell proliferation after IRI; however, the expression of PCNA was decreased compared to sham mouse jejunum. These morphological changes and the aberrant expression of proliferation markers were prevented by sinefungin, a histone methyltransferase inhibitor. In summary, SETDB1 plays a crucial role in changes in the epithelial structure after IRI-induced stem cell loss.
Subject(s)
Intestines , Reperfusion Injury , Mice , Animals , Histone-Lysine N-Methyltransferase/metabolism , Reperfusion Injury/metabolism , Epithelial Cells/metabolism , Ischemia/metabolismABSTRACT
High-mobility group box 2 (HMGB2) is a chromatin-associated protein that is an important regulator of gene transcription, recombination, and repair processes. The functional importance of HMGB2 has been reported in various organs, including the testis, heart, and cartilage. However, its role in the ovary is largely unknown. In this study, ovary tissues from wild-type (WT) and HMGB2-knock-out (KO) mice were examined by histopathological staining and immunohistochemistry. The ovary size and weight were significantly lower in HMGB2-KO mice than in age-matched WT littermates. Histopathological analysis revealed ovarian atrophy and progressive fibrosis in 10-month-old HMGB2-KO mouse ovaries. Compared to age-matched WT mice, the numbers of oocytes and developing follicles were significantly decreased at 2 months of age and were completely depleted at 10 months of age in HMGB2-KO mice. Immunohistochemistry revealed the expression of HMGB2 in the granulosa cells of developing follicles, oocytes, some corpora lutea, and stromal cells. Importantly, HMGB2-positive cells were co-localized with estrogen receptor beta (ERß), but not ERα. Estrogen response element-binding activity was demonstrated by southwestern histochemistry, and it was decreased in HMGB2-KO mouse ovaries. Cell proliferation activity was also decreased in HMGB2-KO mouse ovaries in parallel with the decreased folliculogenesis. These results indicated that the depletion of HMGB2 induced ovarian atrophy that was characterized by a decreased ovarian size and weight, progressive fibrosis, as well as decreased oocytes and folliculogenesis. In conclusion, we demonstrated the crucial role of HMGB2 in mouse ovarian folliculogenesis through ERß expression.
Subject(s)
Estrogen Receptor beta , HMGB2 Protein , Animals , Estrogen Receptor alpha/metabolism , Estrogen Receptor beta/analysis , Estrogen Receptor beta/genetics , Estrogen Receptor beta/metabolism , Female , Granulosa Cells , HMGB2 Protein/analysis , HMGB2 Protein/genetics , HMGB2 Protein/metabolism , Mice , Mice, Knockout , Ovary/metabolismABSTRACT
High-mobility group box 2, a chromatin-associated protein that interacts with deoxyribonucleic acid, is implicated in multiple biological processes, including gene transcription, replication, and repair. High-mobility group box 2 is expressed in several tissues, including the testis; however, its functional role is largely unknown. Here, we elucidated the role of high-mobility group box 2 in spermatogenesis. Paraffin-embedded testicular tissues were obtained from 8-week-old and 1-year-old wild-type and knock-out mice. Testis weight and number of seminiferous tubules were decreased, whereas atrophic tubules were increased in high-mobility group box 2-depleted mice. Immunohistochemistry revealed that atrophic tubules contained Sertoli cells, but not germ cells. Moreover, decreased cell proliferation and increased apoptosis were demonstrated in high-mobility group box 2-depleted mouse testis. To elucidate the cause of tubule atrophy, we examined the expression of androgen and estrogen receptors, and the results indicated aberrant expression of androgen receptor and estrogen receptor alpha in Sertoli and Leydig cells. Southwestern histochemistry detected decreased estrogen response element-binding sites in high-mobility group box 2-depleted mouse testis. High-mobility group box 1, which has highly similar structure and function as high-mobility group box 2, was examined by immunohistochemistry and western blotting, which indicated increased expression in testis. These findings indicate a compensatory increase in high-mobility group box 1 expression in high-mobility group box 2 knock-out mouse testis. In summary, depletion of high-mobility group box 2 induced aberrant expression of androgen receptor and estrogen receptor alpha, leading to decreased germ cell proliferation and increased apoptosis which resulted in focal seminiferous tubule atrophy.
Subject(s)
Gene Expression , Receptors, Androgen/genetics , Receptors, Estrogen/genetics , Seminiferous Tubules/pathology , Testicular Diseases/genetics , Animals , Male , Mice , Receptors, Androgen/metabolism , Receptors, Estrogen/metabolismABSTRACT
Rac signaling impacts a relatively large number of downstream targets; however, few studies have established an association between Rac pathways and pathological conditions. In the present study, we generated mice with double knockout of Rac1 and Rac3 (Atoh1-Cre;Rac1flox/flox;Rac3-/- ) in cerebellar granule neurons (CGNs). We observed impaired tangential migration at E16.5, as well as numerous apoptotic CGNs at the deepest layer of the external granule layer (EGL) in the medial cerebellum of Atoh1-Cre;Rac1flox/flox;Rac3-/- mice at P8. Atoh1-Cre;Rac1flox/flox;Rac3-/- CGNs differentiated normally until expression of p27kip1 and NeuN in the deep EGL at P5. Primary CGNs and cerebellar microexplants from Atoh1-Cre;Rac1flox/flox;Rac3-/- mice exhibited impaired neuritogenesis, which was more apparent in Map2-positive dendrites. Such findings suggest that impaired tangential migration and final differentiation of CGNs have resulted in decreased cerebellum size and agenesis of the medial internal granule layer, respectively. Furthermore, Rac depleted/deleted cells exhibited decreased levels of Mid1 and impaired mTORC1 signaling. Mid1 depletion in CGNs produced mild impairments in neuritogenesis and reductions in mTORC1 signaling. Thus, a novel Rac-signaling pathway (Rac1-Mid1-mTORC1) may be involved in medial cerebellar development.
Subject(s)
Cerebellum/embryology , Proteins/physiology , rac GTP-Binding Proteins/physiology , Animals , Cell Differentiation/genetics , Cells, Cultured , Cerebellum/metabolism , HEK293 Cells , Humans , Mechanistic Target of Rapamycin Complex 1 , Mice , Mice, Knockout , Multiprotein Complexes/physiology , Neurogenesis/genetics , Organogenesis/genetics , Proteins/genetics , Signal Transduction/genetics , TOR Serine-Threonine Kinases/physiology , Ubiquitin-Protein Ligases , rac GTP-Binding Proteins/geneticsABSTRACT
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ABSTRACT
BACKGROUND: Exposure to dietary constituents through the mucosal surface of the gastrointestinal tract generates oral tolerance that prevents deleterious T cell-mediated immunity. Although oral tolerance is an active process that involves emergence of CD4+ forkhead box p3 (Foxp3)+ regulatory T (Treg) cells in gut-associated lymphoid tissues (GALTs) for suppression of effector T (Teff) cells, how antigen-presenting cells initiate this process remains unclear. OBJECTIVE: We sought to determine the role of plasmacytoid dendritic cells (pDCs), which are known as unconventional antigen-presenting cells, in establishment of oral tolerance. METHODS: GALT-associated pDCs in wild-type mice were examined for their ability to induce differentiation of CD4+ Teff cells and CD4+Foxp3+ Treg cells in vitro. Wild-type and pDC-ablated mice were fed oral antigen to compare their intestinal generation of CD4+Foxp3+ Treg cells and induction of oral tolerance to protect against Teff cell-mediated allergic inflammation. RESULTS: GALT-associated pDCs preferentially generate CD4+Foxp3+ Treg cells rather than CD4+ Teff cells, and such generation requires an autocrine loop of TGF-ß for its robust production. A deficiency of pDCs abrogates antigen-specific de novo generation of CD4+Foxp3+ Treg cells occurring in GALT after antigenic feeding. Furthermore, the absence of pDCs impairs development of oral tolerance, which ameliorates the progression of delayed-type hypersensitivity and systemic anaphylaxis, as well as allergic asthma, accompanied by an enhanced antigen-specific CD4+ Teff cell response and antibody production. CONCLUSION: pDCs are required for establishing oral tolerance to prevent undesirable allergic responses, and they might serve a key role in maintaining gastrointestinal immune homeostasis.
Subject(s)
Dendritic Cells/immunology , Immune Tolerance/immunology , Immunity, Mucosal/immunology , Intestinal Mucosa/immunology , Animals , CD4-Positive T-Lymphocytes/immunology , Cell Differentiation/immunology , Lymphoid Tissue/immunology , MiceABSTRACT
BACKGROUND: More than 140 million people drink arsenic-contaminated groundwater. It is unknown how much arsenic exposure is necessary to cause neurological impairment. Here, we evaluate the relationship between neurological impairments and the arsenic concentration in drinking water (ACDW). PARTICIPANTS AND METHODS: A cross-sectional study design was employed. We performed medical examinations of 1867 residents in seven villages in the Thabaung township in Myanmar. Medical examinations consisted of interviews regarding subjective neurological symptoms and objective neurological examinations of sensory disturbances. For subjective neurological symptoms, we ascertained the presence or absence of defects in smell, vision, taste, and hearing; the feeling of weakness; and chronic numbness or pain. For objective sensory disturbances, we examined defects in pain sensation, vibration sensation, and two-point discrimination. We analyzed the relationship between the subjective symptoms, objective sensory disturbances, and ACDW. RESULTS: Residents with ACDW ≥ 10 parts per billion (ppb) had experienced a "feeling of weakness" and "chronic numbness or pain" significantly more often than those with ACDW < 10 ppb. Residents with ACDW ≥ 50 ppb had three types of sensory disturbances significantly more often than those with ACDW < 50 ppb. In children, there was no significant association between symptoms or signs and ACDW. CONCLUSION: Subjective symptoms, probably due to peripheral neuropathy, occurred at very low ACDW (around 10 ppb). Objective peripheral nerve disturbances of both small and large fibers occurred at low ACDW (> 50 ppb). These data suggest a threshold for the occurrence of peripheral neuropathy due to arsenic exposure, and indicate that the arsenic concentration in drinking water should be less than 10 ppb to ensure human health.
Subject(s)
Arsenic/toxicity , Dietary Exposure/adverse effects , Drinking Water/adverse effects , Drinking Water/chemistry , Peripheral Nervous System Diseases/chemically induced , Water Pollutants, Chemical/toxicity , Adolescent , Adult , Arsenic/analysis , Cross-Sectional Studies , Dose-Response Relationship, Drug , Female , Groundwater/chemistry , Humans , Male , Middle Aged , Myanmar/epidemiology , Peripheral Nervous System Diseases/epidemiology , Peripheral Nervous System Diseases/physiopathology , Sensation Disorders/chemically induced , Sensation Disorders/epidemiology , Sensation Disorders/physiopathology , Water Pollutants, Chemical/analysis , Young AdultABSTRACT
A series of phosphorus porphyrin complexes ([(RO)2P(tpp)]Cl, tppâ¯=â¯tetraphenylporphyrinato group, Râ¯=â¯-(CH2CH2O)m(CH2)nH; 1a: mâ¯=â¯2, nâ¯=â¯2; 1b: mâ¯=â¯2, nâ¯=â¯4; 1c: mâ¯=â¯2, nâ¯=â¯6; 1d: mâ¯=â¯3, nâ¯=â¯6) were used for the photodynamic therapy (PDT) of human biliary cancer cell line (NOZ) when exposed to the irradiation of light emitting diodes (LEDs). A Dulbecco's modified Eagle's medium (DMEM) containing NOZ cells (2000â¯cellâ¯well-1) and 1 (0-100â¯nM) was introduced into a 96-well microplate and incubated for 24â¯h to accumulate 1 into the NOZ cells and to multiply the NOZ cells until the cell number reached 104â¯cellsâ¯well-1. After replacing the DMEM medium containing 1 with a fresh DMEM medium without 1, the plates were irradiated for 30â¯min at 610â¯nm. After incubation was performed for 24â¯h in dark conditions, the cell viability of the NOZ cells was determined using the MTT assay. The half maximum inhibitory concentrations 50 (IC50) of 1a-1d were found to be in the range of 33.7-58.7â¯nM for NOZ. These IC50 values for the NOZ were one hundredth the IC50 value (7.57⯵M) for mono-l-aspartyl chlorin e6 (laserphyrin®). Thus, it was found that the PDT activity of 1a-1d was much higher than the mono-l-aspartyl chlorin e6. Similarly, IC50 vales of 1a-1d for HeLa cells were found to be 27.8-52.5â¯nM. This showed that 1a-1d had high photodynamic activity in cancer cells. At the same time, it was speculated that an LED is a useful light source for deactivating the cancer cells because it can excite the sensitizers with peak width in their absorption spectra using the light of the specified wave length with band width of 10-20â¯nm; LEDs provide a homogeneous light distribution for the target cells.
Subject(s)
Light , Photochemotherapy , Porphyrins/pharmacology , Cell Survival/drug effects , Dose-Response Relationship, Drug , HeLa Cells , Humans , Molecular Structure , Porphyrins/chemical synthesis , Porphyrins/chemistry , Structure-Activity Relationship , Tumor Cells, CulturedABSTRACT
Cdc42 is a key regulator of dynamic actin organization. However, little is known about how Cdc42-dependent actin regulation influences steady-state actin structures in differentiated epithelia. We employed inner ear hair-cell-specific conditional knockout to analyze the role of Cdc42 in hair cells possessing highly elaborate stable actin protrusions (stereocilia). Hair cells of Atoh1-Cre;Cdc42(flox/flox) mice developed normally but progressively degenerated after maturation, resulting in progressive hearing loss particularly at high frequencies. Cochlear hair cell degeneration was more robust in inner hair cells than in outer hair cells, and began as stereocilia fusion and depletion, accompanied by a thinning and waving circumferential actin belt at apical junctional complexes (AJCs). Adenovirus-encoded GFP-Cdc42 expression in hair cells and fluorescence resonance energy transfer (FRET) imaging of hair cells from transgenic mice expressing a Cdc42-FRET biosensor indicated Cdc42 presence and activation at stereociliary membranes and AJCs in cochlear hair cells. Cdc42-knockdown in MDCK cells produced phenotypes similar to those of Cdc42-deleted hair cells, including abnormal microvilli and disrupted AJCs, and downregulated actin turnover represented by enhanced levels of phosphorylated cofilin. Thus, Cdc42 influenced the maintenance of stable actin structures through elaborate tuning of actin turnover, and maintained function and viability of cochlear hair cells.
Subject(s)
Hair Cells, Auditory/metabolism , cdc42 GTP-Binding Protein/metabolism , Actins/metabolism , Animals , Biosensing Techniques , Cochlea/cytology , Cochlea/metabolism , Dogs , Fluorescence Resonance Energy Transfer , Humans , Immunohistochemistry , In Situ Hybridization , Madin Darby Canine Kidney Cells , Mice , Microscopy, Electrochemical, Scanning , Microscopy, Electron, Transmission , Organ Culture Techniques/methods , cdc42 GTP-Binding Protein/geneticsABSTRACT
Liver regeneration is a well-orchestrated compensatory process that is regulated by multiple factors. We recently reported the importance of the chromatin protein, a high-mobility group box 2 (HMGB2) in mouse liver regeneration. However, the molecular mechanism remains unclear. In this study, we aimed to study how HMGB2 regulates hepatocyte proliferation during liver regeneration. Seventy-percent partial hepatectomy (PHx) was performed in wild-type (WT) and HMGB2-knockout (KO) mice, and the liver tissues were used for microarray, immunohistochemistry, quantitative polymerase chain reaction (qPCR), and Western blotting analyses. In the WT mice, HMGB2-positive hepatocytes colocalized with cell proliferation markers. In the HMGB2-KO mice, hepatocyte proliferation was significantly decreased. Oil Red O staining revealed the transient accumulation of lipid droplets at 12-24 hr after PHx in the WT mouse livers. In contrast, decreased amount of lipid droplets were found in HMGB2-KO mouse livers, and it was preserved until 36 hr. The microarray, immunohistochemistry, and qPCR results demonstrated that the expression of lipid metabolism-related genes was significantly decreased in the HMGB2-KO mouse livers. The in vitro experiments demonstrated that a decrease in the amount of lipid droplets correlated with decreased cell proliferation activity in HMGB2-knockdown cells. HMGB2 promotes de novo lipogenesis to accelerate hepatocyte proliferation during liver regeneration.
Subject(s)
HMGB2 Protein , Liver Regeneration , Mice , Animals , Liver Regeneration/genetics , HMGB2 Protein/genetics , HMGB2 Protein/metabolism , Lipogenesis , Liver/metabolism , Cell Proliferation , Hepatocytes , Mice, Knockout , Transcription Factors/metabolism , Mice, Inbred C57BLABSTRACT
Introduction Photodynamic therapy (PDT) is a salvage treatment for local failure after chemoradiotherapy for esophageal cancer. Salvage PDT is the treatment available for vulnerable patients with various comorbidities at risk of salvage esophagectomy. This study assessed the impact of the Charlson comorbidity index (CCI) on the outcomes of salvage PDT using talaporfin sodium (TS) for esophageal cancer. Metohds Consecutive patients with esophageal cancer who underwent salvage TS-PDT from 2016 to 2022 were included in this retrospective study. We investigated the local complete response (L-CR), progression-free survival (PFS) and overall survival (OS) and evaluated the relationship between the CCI and therapeutic efficacy. Results In total, 25 patients were enrolled in this study. Overall, 12 patients (48%) achieved an L-CR, and the 2-year PFS and OS rates were 24.9% and 59.4%, respectively. In a multivariate analysis, a CCI ≥1 (p=0.041) and deeper invasion (p=0.048) were found to be significant independent risk factors for not achieving an L-CR. To evaluate the efficacy associated with comorbidities, we divided the patients into the CCI=0 group (n=11) and the CCI ≥1 group (n=14). The rate of an L-CR (p=0.035) and the 2-year PFS (p=0.029) and OS (p=0.018) rates in the CCI ≥1 group were significantly lower than those in the CCI=0 group. Conclusion This study found that the CCI was negatively associated with the efficacy of salvage TS-PDT for esophageal cancer.
Subject(s)
Esophageal Neoplasms , Photochemotherapy , Porphyrins , Humans , Photosensitizing Agents/therapeutic use , Photochemotherapy/methods , Salvage Therapy/methods , Retrospective Studies , Esophageal Neoplasms/drug therapy , Comorbidity , Treatment OutcomeABSTRACT
Clec4A4 is a C-type lectin receptor (CLR) exclusively expressed on murine conventional dendritic cells (cDC) to regulate their activation status. However, the functional role of murine Clec4A4 (mClec4A4) in antitumor immunity remains unclear. Here, we show that mClec4A4 serves as a negative immune checkpoint regulator to impair antitumor immune responses. Deficiency of mClec4A4 lead to a reduction in tumor development, accompanied by enhanced antitumor immune responses and amelioration of the immunosuppressive tumor microenvironment (TME) mediated through the enforced activation of cDCs in tumor-bearing mice. Furthermore, antagonistic mAb to human CLEC4A (hCLEC4A), which is the functional orthologue of mClec4A4, exerted protection against established tumors without any apparent signs of immune-related adverse events in hCLEC4A-transgenic mice. Thus, our findings highlight the critical role of mClec4A4 expressed on cDCs as a negative immune checkpoint molecule in the control of tumor progression and provide support for hCLEC4A as a potential target for immune checkpoint blockade in tumor immunotherapy.
ABSTRACT
Objective The extracellular volume (ECV) calculated based on contrast-enhanced computed tomography (CT) has been reported as a novel imaging parameter reflecting the morphological change of fibrosis in several parenchymal organs. Our retrospective study assessed the validity of the ECV fraction for diagnosing pancreatic fibrosis and the appropriate imaging condition as the "equilibrium phase". Methods In 27 patients undergoing multiphasic CT and subsequent pancreaticoduodenectomy, we investigated pathological fibrotic changes related to the ECV fraction and conducted analyses using the value obtained by subtracting the equilibrium CT value of the portal vein from that of the abdominal aorta (Ao-PVequilibrium) to estimate eligibility of the equilibrium phase. Results In all patients, the ECV fraction showed a weak positive correlation with the collagenous compartment ratio (r=0.388, p=0.045). All patients were divided into two groups - the high-Ao-PVequilibrium group and low-Ao-PVequilibrium group - based on the median value. No significant correlation was found in the high-Ao-PVequilibrium group, whereas a significant correlation was observed in the low-Ao-PVequilibrium group (r=0.566, p=0.035). Conclusion The ECV fraction is a possible predictive factor for histopathological pancreatic fibrosis. In its clinical application, the eligibility of the "equilibrium phase" may affect the diagnostic capability. It will be necessary to verify the imaging conditions in order to improve the accuracy of the diagnosis.
Subject(s)
Pancreatic Diseases , Tomography, X-Ray Computed , Humans , Retrospective Studies , Tomography, X-Ray Computed/methods , Fibrosis , Pancreatic Diseases/diagnostic imaging , Pancreatic Diseases/pathology , Aorta, Abdominal , Contrast Media , Myocardium/pathologyABSTRACT
While dysbiosis in the gut is implicated in the impaired induction of oral tolerance generated in mesenteric lymph nodes (MesLNs), how dysbiosis affects this process remains unclear. Here, we describe that antibiotic-driven gut dysbiosis causes the dysfunction of CD11c+CD103+ conventional dendritic cells (cDCs) in MesLNs, preventing the establishment of oral tolerance. Deficiency of CD11c+CD103+ cDCs abrogates the generation of regulatory T cells in MesLNs to establish oral tolerance. Antibiotic treatment triggers the intestinal dysbiosis linked to the impaired generation of colony-stimulating factor 2 (Csf2)-producing group 3 innate lymphoid cells (ILC3s) for regulating the tolerogenesis of CD11c+CD103+ cDCs and the reduced expression of tumor necrosis factor (TNF)-like ligand 1A (TL1A) on CD11c+CD103+ cDCs for generating Csf2-producing ILC3s. Thus, antibiotic-driven intestinal dysbiosis leads to the breakdown of crosstalk between CD11c+CD103+ cDCs and ILC3s for maintaining the tolerogenesis of CD11c+CD103+ cDCs in MesLNs, responsible for the failed establishment of oral tolerance.
Subject(s)
Dysbiosis , Immunity, Innate , Humans , Dysbiosis/metabolism , Lymphocytes/metabolism , Integrin alpha Chains/metabolism , Dendritic Cells/metabolism , Anti-Bacterial Agents/metabolism , Intestinal Mucosa/metabolismABSTRACT
Rac small GTPases play important roles during embryonic development of the inner ear; however, little is known regarding their function in cochlear hair cells (HCs) after specification. Here, we revealed the localization and activation of Racs in cochlear HCs using GFP-tagged Rac plasmids and transgenic mice expressing a Rac1-fluorescence resonance energy transfer (FRET) biosensor. Furthermore, we employed Rac1-knockout (Rac1-KO, Atoh1-Cre;Rac1flox/flox) and Rac1 and Rac3 double KO (Rac1/Rac3-DKO, Atoh1-Cre;Rac1flox/flox;Rac3-/-) mice, under the control of the Atoh1 promoter. However, both Rac1-KO and Rac1/Rac3-DKO mice exhibited normal cochlear HC morphology at 13 weeks of age and normal hearing function at 24 weeks of age. No hearing vulnerability was observed in young adult (6-week-old) Rac1/Rac3-DKO mice even after intense noise exposure. Consistent with prior reports, the results from Atoh1-Cre;tdTomato mice confirmed that the Atoh1 promoter became functional only after embryonic day 14 when the sensory HC precursors exit the cell cycle. Taken together, these findings indicate that although Rac1 and Rac3 contribute to the early development of sensory epithelia in cochleae, as previously shown, they are dispensable for the maturation of cochlear HCs in the postmitotic state or for hearing maintenance following HC maturation. KEY MESSAGES: Mice with Rac1 and Rac3 deletion were generated after HC specification. Knockout mice exhibit normal cochlear hair cell morphology and hearing. Racs are dispensable for hair cells in the postmitotic state after specification. Racs are dispensable for hearing maintenance after HC maturation.
Subject(s)
rac GTP-Binding Proteins , rac1 GTP-Binding Protein , Animals , Mice , rac GTP-Binding Proteins/genetics , rac GTP-Binding Proteins/metabolism , Mice, Knockout , rac1 GTP-Binding Protein/genetics , rac1 GTP-Binding Protein/metabolism , Hair Cells, Auditory/metabolism , Mice, TransgenicABSTRACT
Background: Oxaliplatin (OX)-based chemotherapy induces sinusoidal obstruction syndrome (SOS) in the nontumorous liver parenchyma, which can increase the risk of liver resection due to colorectal liver metastasis (CRLM). The extracellular volume (ECV) calculated from contrast-enhanced computed tomography (CT) has been reported to reflect the morphological change of hepatic fibrosis. The present retrospective study aimed to evaluate the ECV fraction as a predictive factor for OX-induced SOS. Methods: Our study included 26 patients who underwent liver resection for CRLM after OX-based chemotherapy with a preoperative dynamic CT of appropriate quality. We investigated the relationship between the pathological SOS grade and the ECV fraction. Results: Overall, 26 specimens from the patients were graded with the SOS classification of Rubbia-Brandt et al. as follows: grade 0, n = 17 (65.4%); grade 1, n = 4 (15.4%); and grade 2, n = 5 (19.2%). No specimens showed grade 3 SOS. In a univariate analysis, the ECV fraction in grade 0 SOS was significantly lower than that in grade 1 + 2 SOS (26.3 ± 3.4% vs. 30.6 ± 7.0%; P = 0.025). The cutoff value and AUC value of the ECV fraction to distinguish between grades 0 and 1 + 2 were 27.5% and 0.771, respectively. Conclusions: Measurement of the ECV fraction was found to be a potential noninvasive diagnostic method for determining early-stage histopathological sinusoidal injury induced by OX-based chemotherapy.
ABSTRACT
Bone remodeling is an extraordinarily complex process involving a variety of factors, such as genetic, metabolic, and environmental components. Although genetic factors play a particularly important role, many have not been identified. In this study, we investigated the role of transmembrane 161a (Tmem161a) in bone structure and function using wild-type (WT) and Tmem161a-depleted (Tmem161aGT/GT) mice. Mice femurs were examined by histological, morphological, and bone strength analyses. Osteoblast differentiation and mineral deposition were examined in Tmem161a-overexpressed, -knockdown and -knockout MC3T3-e1 cells. In WT mice, Tmem161a was expressed in osteoblasts of femurs; however, it was depleted in Tmem161aGT/GT mice. Cortical bone mineral density, thickness, and bone strength were significantly increased in Tmem161aGT/GT mice femurs. In MC3T3-e1 cells, decreased expression of alkaline phosphatase (ALP) and Osterix were found in Tmem161a overexpression, and these findings were reversed in Tmem161a-knockdown or -knockout cells. Microarray and western blot analyses revealed upregulation of the P38 MAPK pathway in Tmem161a-knockout cells, which referred as stress-activated protein kinases. ALP and flow cytometry analyses revealed that Tmem161a-knockout cells were resistant to oxidative stress. In summary, Tmem161a is an important regulator of P38 MAPK signaling, and depletion of Tmem161a induces thicker and stronger bones in mice.
Subject(s)
Craniocerebral Trauma , Osteogenesis , Animals , Mice , Bone Density , Osteoblasts , Oxidative Stress , Alkaline Phosphatase , Coloring AgentsABSTRACT
Although constipation is very common during pregnancy, the exact mechanism is unknown. We hypothesized that the involvement of estrogen receptor (ER) in the regulation of electrolyte transporter in the colon leads to constipation. In this study, the intestines of normal female ICR mouse and pregnant mice were examined for the expression of ERα and ERß by immunohistochemistry and in situ hybridization. ERß, but not ERα, was expressed in surface epithelial cells of the proximal, but not distal, colon on pregnancy days 10, 15, and 18, but not day 5, and the number of ERß-positive cells increased significantly during pregnancy. Expression of NHE3, the gene that harbors estrogen response element, examined by immunohistochemistry and western blotting, was localized in the surface epithelial cells of the proximal colon and increased in parallel with ERß expression. In ovariectomized mice, NHE3 expression was only marginal and was up-regulated after treatment with 17ß-estradiol (E(2)), but not E(2) + ICI 182,780 (estrogen receptor antagonist). Moreover, knock-down of ERß expression by electroporetically transfected siRNA resulted in a significant reduction of NHE3 expression. These results indicate that ERß regulates the expression of NHE3 in the proximal colon of pregnant mice through estrogen action, suggesting the involvement of increased sodium absorption by up-regulated NHE3 in constipation during pregnancy.