CRISPR/Cas9-Induced Fam83h Knock-out Leads to Impaired Wnt/β-Catenin Pathway and Altered Expression of Tooth Mineralization Genes in Mice

Background

Dental enamel formation is a complex process that is regulated by various genes. One such gene, Family With Sequence Similarity 83 Member H (Fam83h), has been identified as an essential factor for dental enamel formation. Additionally, Fam83h has been found to be potentially linked to the Wnt/β-catenin pathway.

Objectives

This study aimed to investigate the effects of the Fam83h knockout gene on mineralization and formation of teeth, along with mediators of the Wnt/β-catenin pathway as a development aspect in mice.

Materials and Methods

To confirm the Fam83h-KnockOut mice, both Sanger sequencing and Western blot methods were used. then used qPCR to measure the expression levels of genes related to tooth mineralization and formation of dental root, including Fam20a, Dspp, Dmp1, Enam, Ambn, Sppl2a, Mmp20, and Wnt/β-catenin pathway mediators, in both the Fam83h-Knockout and wild-type mice at 5, 11 and 18 days of age. also the expression level of Fgf10 and mediators of the Wnt/β-catenin pathway was measured in the skin of both Knockout and wild-type mice using qPCR. A histological assessment was then performed to further investigate the results.

Results

A significant reduction in the expression levels of Ambn, Mmp20, Dspp, and Fgf10 in the dental root of Fam83h-Knockout mice compared to their wild-type counterparts was demonstrated by our results, indicating potential disruptions in tooth development. Significant down-regulation of CK1a, CK1e, and β-catenin in the dental root of Fam83h-Knockout mice was associated with a reduction in mineralization and formation-related gene. Additionally, the skin analysis of Fam83h-Knockout mice revealed reduced levels of Fgf10, CK1a, CK1e, and β-catenin. Further histological assessment confirmed that the concurrent reduction of Fgf10 expression level and Wnt/β-catenin genes were associated with alterations in hair follicle maturation.

Conclusions

The concurrent reduction in the expression level of both Wnt/β-catenin mediators and mineralization-related genes, resulting in the disruption of dental mineralization and formation, was caused by the deficiency of Fam83h. Our findings suggest a cumulative effect and multi-factorial interplay between Fam83h, Wnt/Β-Catenin signaling, and dental mineralization-related genes subsequently, during the dental formation process.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

BCL11B Is Involved in Stress-Induced Differentiation of Keratinocytes and Has A Potential Role in Psoriasis Pathogenesis

OBJECTIVE

Psoriasis is a common, auto-immune skin disease characterized by abnormal proliferation and differentiation of keratinocytes. Studies revealed the role of stress stimulators in the pathogenesis of psoriasis. Oxidative stress and heat shock are two important stress factors tuning differentiation and proliferation of keratinocytes, regarding to psoriasis disease. BCL11B is a transcription factor with critical role in embryonic keratinocyte differentiation and proliferation. Given this, in keratinocytes we have investigated potential role of BCL11B in stress-induced differentiation. Furthermore, we searched for a potential intercommunication between BCL11B expression and psoriasis-related keratinocyte stress factors.

MATERIALS AND METHODS

In this experimental study, data sets of psoriatic and healthy skin samples were downloaded in silico and BCL11B was chosen as a potential transcription factor to analyze. Next, a synchronized in vitro model was designed for keratinocyte proliferation and differentiation. Oxidative stress and heat shock treatments were employed on HaCaT keratinocytes in culture, and BCL11B expression level was measured. Cell proliferation rate and differentiation were analyzed by synchronized procedure test. Flow cytometry was done to analyze cell cycle alterations due to the oxidative stress.

RESULTS

Quantitative reverse transcription polymerase chain reaction (qRT-PCR) data revealed a significant upregulation of BCL11B expression in keratinocytes, by 24 hours after initiating differentiation. However, it was followed by a significant down-regulation in almost all the experiments, including the synchronized model. Flow cytometer data demonstrated a G1 cell cycle arrest in the treated cells.

CONCLUSION

Results indicated a remarkable role of BCL11B in differentiation and proliferation of HaCaT keratinocytes. This data along with the results of flow cytometer suggested a probable role for BCL11B in stress-induced differentiation, which is similar to what is happening during initiation and progression of normal differentiation.

Development of three-dimensional semi-solid hydrogel matrices for ratiometric fluorescence sensing of Amyloid β peptide and imaging in SH-SY5 cells: Improvement of point of care diagnosis of Alzheimer's disease biomarker

Alzheimer's is a neurodegenerative disease with high morbidity and mortality in the elderly, so, detection of its biomarker for definite diagnosis of Alzheimer's in the early stage of disease is a challenge. Amyloid beta peptide (Aβ) chosen as an Alzheimer's biomarker. Here, we developed novel, semi-solid, three-dimensional hydrogel matrices for ratiometric fluorescence detection of Aβ. This assay's great performance stems from the employment of a hybrid conjugate composed of Rhodamine B (RB), Carbon dots (CDs), and an Aβ probe entrapped in Polyvinyl alcohol (PVA), and then detection of fluorescence resonance energy transfer (FRET) that occurs in the presence of AuNP/target-Aβ, as a result of hybridization. The RB-CDs' fluorescence (at 582 nm and 675 nm under 430 nm excitation) is quenched in the presence of AuNPs, while the ratio of fluorescence (I₅₈₂/I₆₇₅) is increased by the addition of Aβ target, and shows a linear relationship in the range of 75 pM-250 nM, with a detection limit of 0.5 pM. Furthermore, the assay possesses strong selectivity for Aβ compared to other proteins, and different quantities of a human serum sample successfully analyzed with excellent sensitivity, satisfactory precision, and reliability. Due to distribution of Aβ in SH-SY5 human neuroblastoma cells, extending this UV-Vis-NIR full-range responsive CDs bio-probe to imaging of Aβ in cells. In both fixed and living SH-SY5 cells, the nanoprobe delivers a clear signal to the Aβ target. Because of its high sensitivity, selectivity, biocompatibility and affordability, this nanoprobe is a good option for early Alzheimer's disease diagnosis.

Mechanism and adverse effects of COVID-19 drugs: a basic review

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Coronavirus disease 2019 (COVID-19) is chronic, inflammatory. Although the exact mechanisms of COVID-19 have not been yet discovered some drugs are found helpful for its treatment. These drugs which are divided into some lines therapies, have demonstrated to be helpful for COVID-19 patients based on immune basic and its antiviral properties of the disease. Previous studies have been indicated that deterioration of COVID-19 condition is associated with a weaker immune system. Most of these therapies impact on the immune system and immune cells. Beside many beneficial effects of these drugs, some adverse effects (AE) have been reported in many experiments and clinical trials among patients suffering from COVID-19. In this review, we conclude some AEs of vitamin-D, zinc, remdesivir, hydroxychloroquine or chloroquine, azithromycin, dexamethasone, amantadine, aspirin reported in different papers and we continue the rest of the drugs in second part of our review article.

The serine hydroxymethyltransferase-2 (SHMT2) initiates lymphoma development through epigenetic tumor suppressor silencing

Cancer cells adapt their metabolic activities to support growth and proliferation. However, increased activity of metabolic enzymes is not usually considered an initiating event in the malignant process. Here, we investigate the possible role of the enzyme serine hydroxymethyltransferase-2 (SHMT2) in lymphoma initiation. SHMT2 localizes to the most frequent region of copy number gains at chromosome 12q14.1 in lymphoma. Elevated expression of SHMT2 cooperates with BCL2 in lymphoma development; loss or inhibition of SHMT2 impairs lymphoma cell survival. SHMT2 catalyzes the conversion of serine to glycine and produces an activated one-carbon unit that can be used to support S-adenosyl methionine synthesis. SHMT2 induces changes in DNA and histone methylation patterns leading to promoter silencing of previously uncharacterized mutational genes, such as SASH1 and PTPRM. Together, our findings reveal that amplification of SHMT2 in cooperation with BCL2 is sufficient in the initiation of lymphomagenesis through epigenetic tumor suppressor silencing.

Yb-fiber-pumped, high-beam-quality, idler-resonant mid-infrared picosecond optical parametric oscillator

We report an Yb-fiber-pumped picosecond optical parametric oscillator (OPO) delivering high average power in excellent beam quality throughout the mid-infrared (mid-IR). Using MgO:PPLN as the nonlinear crystal and configured as a singly-resonant oscillator in the mid-IR idler wave, the OPO provides up to 3.5 W average power in high spatial quality with M2<1.8 across a continuous tuning range of 4028-2198 nm, with M²<1.5 at 4000 nm. It can also deliver as much as 4.3 W of signal power in an output beam with M2<1.4 across 1446-2062 nm. The extracted idler exhibits a passive power stability better than 0.46% rms over 1 hour across the entire mid-IR tuning range. We have also investigated OPO cavity length detuning behavior about the zero-group-velocity-mismatch crossing point and its effects on output power.

Generation of Fam83h knockout mice by CRISPR/Cas9-mediated gene engineering

Family with sequence similarity 83 member H (FAM83H) protein-coding geneplay an essential role in the structural organization, calcification of developing enamel, and keratin cytoskeleton disassembly by recruiting Casein kinase 1 alpha (CSNK1A1) to keratin filaments. In this study, we have applied CRISPR Cas9 nickase (D10A) to knockout (KO) the Fam83h gene in NMRI outbred mice. We generated homozygous Fam83h KO mice ( Fam83h ^Ko/Ko ) through a premature termination codon, which was validated by Sanger sequencing in F0 generation. Next, we also bred the FAM83H KO for two generations. Reverse-transcription polymerase chain reaction and Western blot analysis approved the Fam83h KO mice. The Fam83h KO mice had evidence of normal morphology at the cervical loops, secretory and maturation stages, and mandibular molars. In comparison with the normal wild-type mice ( Fam83h ^W/W ), the F2 homozygous KO ( Fam83h ^Ko/Ko ) had sparse, scruffy coats with small body size and decreased general activity. Also, they had the natural reproductive ability and natural lifespan. In addition, delay in opening the eyes and dry eyes among infant mice were seen. The F1 heterozygous mice looked comparable to the normal wild-type mice ( Fam83h ^W/W ), which showed autosomal recessive inheritance of these phenotypes. The KO of FAM83H had controversial effects on the development of teeth and the formation of enamel. The phenotype defect in dental development and the enamel formation were seen in three mice among four generations. It can be concluded that null FAM83H in outbred mice not only showed the reported phenotypes in null inbred mouse but also showed normal lifespan and reproductive ability; dental deficiency in three homozygous mice; and the symptoms that were similar to the symptoms of dry eye syndrome and curly coat dog syndrome in all four evaluated KO generations.

Serum level measurement of progranulin in relapsing-remitting multiple sclerosis and neuromyelitis optica patients

BACKGROUND

Multiple sclerosis (MS) is a complex autoimmune disease of the central nervous system (CNS) with unknown etiology and variable clinical evolution. Although the role of serum progranulin levels in the pathogenesis of MS remains unclear, it is well known that progranulin is involved in several physiological and pathophysiological process of CNS including modulation of neurite outgrowth, neuronal differentiation, and neuronal survival. Therefore, in this study, we aimed to measure serum levels of progranulin in patients with neuromyelitis optica (NMO) and relapsing-remitting multiple sclerosis (RRMS) in comparison with healthy control subjects.

METHODS

In a case-control study, plasma was collected from healthy controls (n = 37) and also patients with RRMS (n = 115) and NMO (n = 33). Serum level measurement of progranulin was performed using a sandwich ELISA method.

RESULTS

The serum levels of progranulin were 65.07 ± 11.64, 56.81 ± 10.34, and 47.73 ± 10.37 in NMO and MS patients and healthy controls, respectively, showing a statistically significant difference between them (P = 0.00). Furthermore, we found a positive correlation between serum levels of progranulin and EDSS of patients (r = 0.79 and P = 0.00).

CONCLUSION

The present study demonstrated that progranulin is up-regulated in MS patients and our findings strengthen the evidence for progranulin being involved in the pathogenesis of MS. However, further studies will be required to establish progranulin as an important marker for MS.

Effect of fingolimod on white blood cell, lymphocyte and neutrophil counts in MS patients

INTRODUCTION

Fingolimod is an immunomodulating oral treatment used for treating relapsing-remitting multiple sclerosis (RRMS). The exact mechanism for its action in preventing relapses is unknown. Also, its affect on immune cell populations remains unestablished.

OBJECTIVES

This study will measure the changes in cell populations of WBCs, lymphocytes, and neutrophils in MS patients after one month of treatment.

METHODS

66 MS patients from Isfahan Province with RRMS were chosen based on certain exclusion criteria and eligibility for fingolimod oral treatment. Initial cell counts for WBC, lymphocyte, and neutrophil cell populations were achieved. Fingolimod .5 mg daily treatment was then initiated under the supervision of a physician. After one month of treatment, cell counts were repeated. Statistical analysis was performed using SPSS.

RESULTS

Both lymphocyte and WBC mean cell counts were significantly decreased in this patient cohort. Neutrophil average cell counts were significantly increased in this 66 patient cohort. Only the decrease of WBC populations was significant for both male and female cohorts individually. Only female sub-cohorts were significantly changed for neutrophils and lymphocytes, increased and decreased respectively. Male sub-cohorts maintained the same directionality but failed to produce statistical significance.

CONCLUSION

While fingolimod has been effectively proven as reducing lymphocyte cells in most patient populations, its effects on neutrophils have not been studied in abundance. Also, there may be sex-related differences in responses to fingolimod treatment with regards to lymphocytes and neutrophils, suggesting a possible difference in RRMS pathogenesis between males and females.

Improving the knowledge of pregnant women using a pre-eclampsia app: A controlled before and after study

OBJECTIVE

The objective of this study was to investigate the effect of a pre-eclampsia mobile application on the knowledge of pregnant women.

METHODS

Following development of a pre-eclampsia mobile application, we conducted a controlled before and after study during a three-month period in 2018. The study population consisted of pregnant women attended to obstetrician clinics and offices in Kerman, Iran of whom, 110 sample participants were divided into two intervention and control groups. The participants completed a questionnaire of pre-eclampsia knowledge at baseline and 1-month follow up. Data were analyzed using inferential statistics including chi-square, independent sample t-test, paired t-test and linear regression.

RESULTS

A total of 108 pregnant women with an average age of 28 years participated in this study. There was no significant difference between the scores of the two groups before the intervention (p=0.94). Their difference after the intervention was highly significant (p<0.001). The difference between the knowledge of the participants before and after the intervention was significant in the both groups (p<0.05). The results showed that the knowledge score of the participants after the intervention was significantly associated with their group and assessment score before the intervention (p<0.001).

CONCLUSION

The results showed that the use of a mobile-based educational application improves the knowledge of pregnant women about pre-eclampsia. Increasing women's knowledge about pre-eclampsia may enables them to identify its signs and symptoms, resulting in the early detection and management of this condition, and likely reduction of its adverse consequences.

TRIAL REGISTRATION

IRCT2017050633837N1.

Diabetes distress and its clinical determinants in patients with type II diabetes

AIM

The present study aimed to determine the status of diabetes distress and its clinical determinants in type II diabetes patients.

METHODS

This descriptive-analytical study was performed on 220 patients with t diabetes referred to Diabetes Clinic of Imam Khomeini Hospital in Ardabil, Iran. The samples were selected using convenience sampling method. Data collection tools included demographic and disease form and Diabetes Mellitus Scale (DDS). Data analysis was performed using SPSS software version 22 via descriptive (frequency, mean, standard deviation) and inferential statistics (compare means, Pearson correlation coefficient and stepwise multiple regression).

RESULTS

The average duration of diabetes was 7.64 (SD = 4.68) years. 63.7% of the patients had moderate to severe diabetes-related distress. Emotional burden dimension had the highest score among the subscales of diabetes distress. In addition, there was a correlation between positive family history (p = 0.017), duration of diabetes (p = 0.028) and type of treatment (p = 0.47) and diabetes distress. HemoglobinA1C levels, body mass index and triglyceride were the major predictors of diabetes distress.

CONCLUSIONS

Considering the high prevalence of diabetes distress in patients with type II diabetes, it seems that paying attention to clinical predictors of distress and screening of patients with diabetes is a reasonable and accessible method for health care providers and patients to improve their disease management.

Picosecond difference-frequency-generation in orientation-patterned gallium phosphide

We report the generation of tunable high-repetition-rate picosecond radiation in the mid-infrared using the new quasi-phase-matched nonlinear material of orientation-patterned gallium phosphide (OP-GaP). The source is realized by single-pass difference-frequency-generation (DFG) between the output signal of a picosecond optical parametric oscillator (OPO) tunable across 1609-1637 nm with input pump pulses at 1064 nm in OP-GaP, resulting in tunable radiation across 3040-3132 nm. Using a 40-mm-long crystal, we have generated up to 57 mW of DFG average power at ~80 MHz repetition rate for a pump power of 5 W and signal power of 0.9 W, with >30 mW over >50% of the tuning range. The DFG source exhibits a passive power stability better than 3.2% rms over 1 hour in good spatial beam quality. To the best of our knowledge, this is the first picosecond frequency conversion source based on OP-GaP.

Association study of CTLA-4 +49A/G gene polymorphism with recurrent pregnancy loss in the Iranian Azeri Turkish ethnic group

BACKGROUND/AIM

Recurrent pregnancy loss (RPL) is defined as two or more pregnancy losses. T-regulatory cells play an important role in the feto-maternal interface. Cytotoxic-T-lymphocyte antigen-4 (CTLA-4) is a molecule that downregulates the activation and proliferation of T cells. The objective of the current study was to investigate the possible association of CTLA-4+49A/G gene polymorphism with RPL among patients from the Iranian Azeri Turkish ethnic group.

MATERIALS AND METHODS

The study group/patients consisted of 101 women with the experience of two or more pregnancy losses and the control group consisted of 101 women with at least two live births, without any previous history of pregnancy loss and autoimmune diseases from the same ethnic group. The CTLA-4+49A/G was detected by polymerase chain reaction-restriction fragment length polymorphisms assay.

RESULTS

The distribution of CTLA-4+49A/G genotype was AA, 38.61%; AG, 51.48%; GG, 9.9% in patients and AA, 37.62%; AG, 47.52%; GG,14.85% in controls (P-value: 0.2). Furthermore, no association in G-allele was observed in the patient and control groups (P-value: 0.5).

CONCLUSION

The results of the present study suggest that CTLA-4 does not have any association with RPL in the Iranian Azeri Turkish ethnic group.

CREBBP Inactivation Promotes the Development of HDAC3-Dependent Lymphomas

Somatic mutations in CREBBP occur frequently in B-cell lymphoma. Here, we show that loss of CREBBP facilitates the development of germinal center (GC)-derived lymphomas in mice. In both human and murine lymphomas, CREBBP loss-of-function resulted in focal depletion of enhancer H3K27 acetylation and aberrant transcriptional silencing of genes that regulate B-cell signaling and immune responses, including class II MHC. Mechanistically, CREBBP-regulated enhancers are counter-regulated by the BCL6 transcriptional repressor in a complex with SMRT and HDAC3, which we found to bind extensively to MHC class II loci. HDAC3 loss-of-function rescued repression of these enhancers and corresponding genes, including MHC class II, and more profoundly suppressed CREBBP-mutant lymphomas in vitro and in vivo Hence, CREBBP loss-of-function contributes to lymphomagenesis by enabling unopposed suppression of enhancers by BCL6/SMRT/HDAC3 complexes, suggesting HDAC3-targeted therapy as a precision approach for CREBBP-mutant lymphomas.

SIGNIFICANCE

Our findings establish the tumor suppressor function of CREBBP in GC lymphomas in which CREBBP mutations disable acetylation and result in unopposed deacetylation by BCL6/SMRT/HDAC3 complexes at enhancers of B-cell signaling and immune response genes. Hence, inhibition of HDAC3 can restore the enhancer histone acetylation and may serve as a targeted therapy for CREBBP-mutant lymphomas. Cancer Discov; 7(1); 38-53. ©2016 AACR.See related commentary by Höpken, p. 14This article is highlighted in the In This Issue feature, p. 1.

Continuous-wave, single-pass, single-frequency second-harmonic-generation at 266 nm based on birefringent-multicrystal scheme

We report the implementation of a compact cascaded multicrystal scheme based on birefringent crystals in critical phase-matching, for the generation of continuous-wave (cw) radiation in the deep ultraviolet (UV). The approach comprises a cascade of 4 single-pass second-harmonic-generation (SHG) stages in β-BaB₂O₄ (BBO) pumped by a single-frequency cw green source at 532 nm. A deep-UV cw output power of 37.7 mW at 266 nm has been obtained with a high passive power stability of 0.12% rms over more than 4 hours. Characterization and optimization of the system in each stage has been systematically performed. Angular phase-matching acceptance bandwidth under tight focusing in BBO, and spectral properties of the deep-UV radiation, have been studied. Theoretical calculations for SHG in the cascaded scheme based on birefringent phase-matching have been performed, and enhancement in UV power compared to single-stage single-pass scheme are studied. Theoretical comparison of BBO with other potential crystals for deep-UV generation in cascaded multicrystal scheme is also presented.

Fiber-laser-based, green-pumped, picosecond optical parametric oscillator using fan-out grating PPKTP

We report a stable, Yb-fiber-laser-based, green-pumped, picosecond optical parametric oscillator (OPO) for the near-infrared based on periodically poled potassium titanyl phosphate (PPKTP) nonlinear crystal, using fan-out grating design and operating near room temperature. The OPO is continuously tunable across 726-955 nm in the signal and 1201-1998 nm in the idler, resulting in a total signal plus idler wavelength coverage of 1026 nm by grating tuning at a fixed temperature. The device generates up to 580 mW of average power in the signal at 765 nm and 300 mW in the idler at 1338 nm, with an overall extraction efficiency of up to 52% and a pump depletion >76%. The extracted signal at 765 nm and idler at 1746 nm exhibit excellent passive power stability better than 0.5% and 0.8% rms, respectively, over 1 h with good beam quality in TEM₀₀ mode profile. The output signal pulses have a Gaussian temporal duration of 13.2 ps, with a FWHM spectral bandwidth of 3.4 nm at 79.5 MHz repetition rate. Power scaling limitations of the OPO due to the material properties of PPKTP are studied.

Transient Inhibition of FGFR2b-ligands signaling leads to irreversible loss of cellular β-catenin organization and signaling in AER during mouse limb development

The vertebrate limbs develop through coordinated series of inductive, growth and patterning events. Fibroblast Growth Factor receptor 2b (FGFR2b) signaling controls the induction of the Apical Ectodermal Ridge (AER) but its putative roles in limb outgrowth and patterning, as well as in AER morphology and cell behavior have remained unclear. We have investigated these roles through graded and reversible expression of soluble dominant-negative FGFR2b molecules at various times during mouse limb development, using a doxycycline/transactivator/tet(O)-responsive system. Transient attenuation (≤24 hours) of FGFR2b-ligands signaling at E8.5, prior to limb bud induction, leads mostly to the loss or truncation of proximal skeletal elements with less severe impact on distal elements. Attenuation from E9.5 onwards, however, has an irreversible effect on the stability of the AER, resulting in a progressive loss of distal limb skeletal elements. The primary consequences of FGFR2b-ligands attenuation is a transient loss of cell adhesion and down-regulation of P63, β1-integrin and E-cadherin, and a permanent loss of cellular β-catenin organization and WNT signaling within the AER. Combined, these effects lead to the progressive transformation of the AER cells from pluristratified to squamous epithelial-like cells within 24 hours of doxycycline administration. These findings show that FGFR2b-ligands signaling has critical stage-specific roles in maintaining the AER during limb development.

Low-dose ionizing radiation-induced blood plasma metabolic response in a diverse genetic mouse population

Understanding the biological effects and biochemical mechanisms of low-dose ionizing radiation (LDIR) is important for setting exposure limits for the safe use of nuclear power and medical diagnostic procedures. Although several studies have highlighted the effects of ionizing radiation on metabolism, most studies have focused on uniform genetic mouse populations. Here, we report the metabolic response to LDIR (10 cGy X ray) on a genetically diverse mouse population (142 mice) generated from a cross of radiation-sensitive (BALB/c) and radiation-resistant (SPRET/EiJ) parental strains. GC-TOF profiling of plasma metabolites was used to compare exposed vs. sham animals. From this, 16 metabolites were significantly altered in the LDIR treated vs. sham group. Use of two significantly altered metabolites, thymine and 2-monostearin, was found to effectively segregate the two treatments. Multivariate statistical analysis was used to identify genetic polymorphisms correlated with metabolite abundance (e.g., amino acids, fatty acids, nucleotides and TCA cycle intermediates). Genetic analysis of metabolic phenotypes showed suggestive linkages for fatty acid and amino acid metabolism. However, metabolite abundance was found to be a function of low-dose ionizing radiation exposure, and not of the underlying genetic variation.

Contrasting expression of canonical Wnt signaling reporters TOPGAL, BATGAL and Axin2(LacZ) during murine lung development and repair

Canonical Wnt signaling plays multiple roles in lung organogenesis and repair by regulating early progenitor cell fates: investigation has been enhanced by canonical Wnt reporter mice, TOPGAL, BATGAL and Axin2^LacZ. Although widely used, it remains unclear whether these reporters convey the same information about canonical Wnt signaling. We therefore compared beta-galactosidase expression patterns in canonical Wnt signaling of these reporter mice in whole embryo versus isolated prenatal lungs. To determine if expression varied further during repair, we analyzed comparative pulmonary expression of beta-galactosidase after naphthalene injury. Our data show important differences between reporter mice. While TOPGAL and BATGAL lines demonstrate Wnt signaling well in early lung epithelium, BATGAL expression is markedly reduced in late embryonic and adult lungs. By contrast, Axin2^LacZ expression is sustained in embryonic lung mesenchyme as well as epithelium. Three days into repair after naphthalene, BATGAL expression is induced in bronchial epithelium as well as TOPGAL expression (already strongly expressed without injury). Axin2^LacZ expression is increased in bronchial epithelium of injured lungs. Interestingly, both TOPGAL and Axin2^LacZ are up regulated in parabronchial smooth muscle cells during repair. Therefore the optimal choice of Wnt reporter line depends on whether up- or down-regulation of canonical Wnt signal reporting in either lung epithelium or mesenchyme is being compared.

Signaling by FGFR2b controls the regenerative capacity of adult mouse incisors

Rodent incisors regenerate throughout the lifetime of the animal owing to the presence of epithelial and mesenchymal stem cells in the proximal region of the tooth. Enamel, the hardest component of the tooth, is continuously deposited by stem cell-derived ameloblasts exclusively on the labial, or outer, surface of the tooth. The epithelial stem cells that are the ameloblast progenitors reside in structures called cervical loops at the base of the incisors. Previous studies have suggested that FGF10, acting mainly through fibroblast growth factor receptor 2b (FGFR2b), is crucial for development of the epithelial stem cell population in mouse incisors. To explore the role of FGFR2b signaling during development and adult life, we used an rtTA transactivator/tetracycline promoter approach that allows inducible and reversible attenuation of FGFR2b signaling. Downregulation of FGFR2b signaling during embryonic stages led to abnormal development of the labial cervical loop and of the inner enamel epithelial layer. In addition, postnatal attenuation of signaling resulted in impaired incisor growth, characterized by failure of enamel formation and degradation of the incisors. At a cellular level, these changes were accompanied by decreased proliferation of the transit-amplifying cells that are progenitors of the ameloblasts. Upon release of the signaling blockade, the incisors resumed growth and reformed an enamel layer, demonstrating that survival of the stem cells was not compromised by transient postnatal attenuation of FGFR2b signaling. Taken together, our results demonstrate that FGFR2b signaling regulates both the establishment of the incisor stem cell niches in the embryo and the regenerative capacity of incisors in the adult.

Post-reperfusion Syndrome and Outcome Variables after Orthotopic Liver Transplantation

BACKGROUND

Post-reperfusion syndrome (PRS) is an important complication during liver transplantation.

OBJECTIVE

We studied the occurrence and severity of PRS in patients who underwent orthotopic liver transplantation (OLT) to investigate how PRS was correlated to clinical variables and outcomes.

METHODS

We retrospectively recorded intra- and peri-operative data for 184 adult patients who received cadaveric OLT during a 3-year period from 2005 to 2008. Patients were divided into two groups according to the severity of PRS: Group 1 (mild or no PRS) comprised 152 patients; and group 2 (significant PRS) consisted of 32 patients.

RESULTS

There were no significant differences in demographic and pre-operative data between groups. Group 2 had more total blood loss than group 1 (p=0.036), especially after reperfusion (p=0.023). Group 2 required more packed red cell transfusions (p=0.005), more fresh frozen plasma (p=0.003) and more platelets (p=0.043) than group 1. Fibrinolysis was more frequent in group 2 (p=0.004). Hospital stay in group 2 was significantly longer than in group 1 (p=0.034), but the frequencies of other outcomes including infection, retransplantation, dialysis, rejection and extended donor criteria did not differ significantly between groups.

CONCLUSIONS

Bleeding, blood transfusion and fibrinolysis occurred more often in the group of severe PRS after reperfusion. Although postoperative complications like rejection, infection and the dialysis rate were not significantly different in the two groups, hospital stay was more prolonged in the group with severe PRS.

Terminal end bud maintenance in mammary gland is dependent upon FGFR2b signaling

We previously demonstrated that Fibroblast Growth Factor 10 (FGF10) and its receptor FGFR2b play a key role in controlling the very early stages of mammary gland development during embryogenesis [Mailleux, A.A., Spencer-Dene, B., Dillon, C., Ndiaye, D., Savona-Baron, C., Itoh, N., Kato, S., Dickson, C., Thiery, J.P., and Bellusci, S. (2002). Role of FGF10/FGFR2b signaling during mammary gland development in the mouse embryo. Development 129, 53-60. Veltmaat, J. M., Relaix, F., Le, L.T., Kratochwil, K., Sala, F.G., van Veelen, W., Rice, R., Spencer-Dene, B., Mailleux, A.A., Rice, D.P., Thiery, J.P., and Bellusci, S. (2006). Gli3-mediated somitic Fgf10 expression gradients are required for the induction and patterning of mammary epithelium along the embryonic axes. Development 133, 2325-35.]. However, the role of FGFR2b signaling in postnatal mammary gland development is still elusive. We show that FGF10 is expressed at high level throughout the adipose tissue in the mammary gland of young virgin female mice whereas its main receptor FGFR2 is found mostly in the epithelium. Using a rtTA transactivator/tetracycline promoter approach allowing inducible and reversible attenuation of the FGFR2b signaling throughout the adult mouse, we are now reporting that FGFR2b signaling is also critical during postnatal mammary gland development. Ubiquitous attenuation of FGFR2b signaling in the postnatal mouse for 6 weeks starting immediately after birth is not lethal and leads to minor defects in the animal. Upon dissection of the mammary glands, a 40% reduction in size compared to the WT control is observed. Further examination shows a rudimentary mammary epithelial tree with completely absent terminal end buds (TEBs), compared to a well-branched structure observed in wild type. Transplantation of mammary gland explants into cleared fat pad of wild type mouse recipients indicates that the observed abnormal branching results from defective FGFR2b signaling in the epithelium. We also demonstrate that this rudimentary tree reforms TEBs and resumes branching upon removal of doxycycline suggesting that the regenerative capacities of the mammary epithelial progenitor cells were still functional despite long-term inactivation of the FGFR2b pathway. At the cellular level, upon FGFR2b attenuation, we show an increase in apoptosis associated with a decrease in the proliferation of the mammary luminal epithelium. We conclude that during puberty, there is a differential requirement for FGFR2b signaling in ductal vs. TEBs epithelium. FGFR2b signaling is crucial for the survival and proliferation of the mammary luminal epithelial cells, but does not affect the regenerative potential of the mammary epithelial progenitor cells.

Fgf10 dosage is critical for the amplification of epithelial cell progenitors and for the formation of multiple mesenchymal lineages during lung development

The key role played by Fgf10 during early lung development is clearly illustrated in Fgf10 knockout mice, which exhibit lung agenesis. However, Fgf10 is continuously expressed throughout lung development suggesting extended as well as additional roles for FGF10 at later stages of lung organogenesis. We previously reported that the enhancer trap Mlcv1v-nLacZ-24 transgenic mouse strain functions as a reporter for Fgf10 expression and displays decreased endogenous Fgf10 expression. In this paper, we have generated an allelic series to determine the impact of Fgf10 dosage on lung development. We report that 80% of the newborn Fgf10 hypomorphic mice die within 24 h of birth due to respiratory failure. These mutant mouse lungs display severe hypoplasia, dilation of the distal airways and large hemorrhagic areas. Epithelial differentiation and proliferation studies indicate a specific decrease in TTF1 and SP-B expressing cells correlating with reduced epithelial cell proliferation and associated with a decrease in activation of the canonical Wnt signaling in the epithelium. Analysis of vascular development shows a reduction in PECAM expression at E14.5, which is associated with a simplification of the vascular tree at E18.5. We also show a decrease in alpha-SMA expression in the respiratory airway suggesting defective smooth muscle cell formation. At the molecular level, these defects are associated with decrease in Vegfa and Pdgfa expression likely resulting from the decrease of the epithelial/mesenchymal ratio in the Fgf10 hypomorphic lungs. Thus, our results indicate that FGF10 plays a pivotal role in maintaining epithelial progenitor cell proliferation as well as coordinating alveolar smooth muscle cell formation and vascular development.

Anti-infectives-induced adverse drug reactions in hospitalized patients

OBJECTIVES

To assess the rate and seriousness of adverse drug reactions (ADRs) attributable to anti-infective agents in hospitalized patients; to estimate the likelihood of experiencing anti-infectives-induced ADRs at different length of drug usage in the hospital; to compare different classes of anti-infectives in inducing ADRs; to determine the impact of age and sex on anti-infectives-induced ADRs.

DESIGN

Prospective cohort study.

PARTICIPANTS

Patients admitted to the infectious diseases department at a university teaching hospital, on Sunday to Wednesday, over a 9 months period, who received at least one anti-infective agent were eligible to enter the study.

MAIN OUTCOME MEASURES

Any suspected noxious and untoward medical events, including laboratory tests abnormalities following anti-infective therapy.

METHODS

All patients admitted have received at least one anti-infective drug. Anti-infective agents induced ADRs were detected by interviewing patients and daily chart review. The seriousness, causality, and type of reactions were classified based on World Health Organization (WHO) definitions. Chi-square analysis was performed to assess the influence of sex and age on occurring ADRs. Both Kaplan-Meier and life table method were used to estimate the time to occur the ADR in anti-infective users. To compare the estimated risk of ADRs induced by different classes of anti-infectives, odds ratios were estimated. In all classes of anti-infectives, the odds ratio of each class was estimated with regard to anti-tuberculosis agents, which had the highest prevalence of ADRs.

RESULTS

During the study period, 460 patients were entered the study. During the same period, 38 ADRs were recognized of which 20 (42%) were serious. The most recognized ADRs were suspected to be induced by anti-tuberculosis agents (29.8%). However in comparing with anti-tuberculosis agents, anti-fungal agents were associated with the highest ADR rate (odds ratio [OR], 4.21; 95% confidence interval [CI], 1.41-1.256) whereas cephalosporines were associated with the lowest rate, (OR, 0.1; 95%CI, 0.04-0.26). The survival analysis shows that the likelihood of experiencing an ADR was increased at first 14 days of drug therapy. Also Chi-square analysis shows that greater risk of anti-infectives-induced ADRs was observed in women.

CONCLUSION

The rate of ADRs induced by anti-infective agents in this study was 8.2%. This is higher than a standard (5%) which has been reported in other studies. This study also shows that some of the classes of anti-infective agents like anti-fungals need more attention.