[Predictive capability of Cys112Arg single nucleotide polymorphisms of the apolipoprotein E gene in assessing the risk of immediate and early post-traumatic seizures].

This study is aimed at investigating epileptic seizures, one of the consequences of traumatic brain injury (TBI). Immediate and early post-traumatic seizures, as well as late post-traumatic epileptic seizures or post-traumatic epilepsy, can have different pathogenetic bases. The following key risk factors associated with post-traumatic epilepsy are known: duration of unconsciousness, gunshot wounds, intracranial hemorrhage, diffuse axonal injury, prolonged (more than 3 days) post-traumatic amnesia, acute subdural hematoma with surgical evacuation, immediate and early post-traumatic epileptic seizures, fracture of the skull bones. The role of genetic factors in post-traumatic seizures is poorly understood due to the complexity and multiple causal mechanisms. This paper addresses the role of genetic factors in the occurrence and severity of epileptic events in patients with TBI. In particular, we investigated the role of the Cys112Arg single nucleotide polymorphism of the apolipoprotein E gene. Apolipoprotein E is known for its role in the transport and metabolism of lipids and, therefore, the development of cardiovascular diseases; it is also associated with Alzheimer's disease and has recently been studied in the context of association with epilepsy. The study shows an association between this polymorphism and the risk of immediate and early epileptic seizures in patients with severe TBI.

Assessment of Optimal Arterial Pressure with Near-Infrared Spectroscopy in Traumatic Brain Injury Patients.

In patients with severe traumatic brain injury (TBI), simultaneous measurement of intracranial and arterial blood pressure (ICP and ABP, respectively) allows monitoring of cerebral perfusion pressure (CPP) and the assessment of cerebral autoregulation (CA). CPP, a difference between ICP and ABP, is the pressure gradient that drives oxygen delivery to cerebral tissue. CA is the ability of cerebral vasculature to maintain stable blood flow despite changes in CPP and thus, is an important homeostatic mechanism. Pressure reactivity index (PRx), a moving Pearson's correlation between slow waves in ICP and ABP, has been most frequently cited in literature over the past two decades as a tool for CA evaluation. However, in some clinical situations, ICP monitoring may be unavailable or contraindicated. In such cases, simultaneous mean arterial pressure (MAP) monitoring and near-infrared spectroscopy (NIRS) can be used for CA assessment by cerebral oximetry index (COx), allowing calculation of the optimal blood pressure (MAPOPT). The purpose of this study was to compare regional oxygen saturation (rSO2)-based CA (COx) with ICP/ABP-based CA (PRx) in TBI patients and to compare MAPOPT derived from both technologies. Three TBI patients were monitored at the bedside to measure CA using both PRx and COx. Patients were monitored daily for up to 3 days from TBI. Averaged PRx and COx-, and PRx and COx-based MAPOPT were compared using Pearson's correlation. Bias analysis was performed between these same CA metrics. Correlation between averaged values of COx and PRx was R = 0.35, p = 0.15. Correlation between optimal MAP calculated for COx and PRx was R = 0.49, p < 0.038. Bland-Altman analysis showed moderate agreement with a bias of 0.16 ± 0.23 for COx versus PRx and good agreement with a bias of 0.39 ± 7.89 for optimal MAP determined by COx versus PRx. Non-invasive measurement of CA by NIRS (COx) is not correlated with invasive ICP/ABP-based CA (PRx). However, the determination of MAPOPT using COx is correlated with MAPOPT derived from PRx. Obtained results demonstrate that COx is not an acceptable substitute for PRx in TBI patients. However, in some TBI cases, NIRS may be useful in determining MAP determination.

[Pupillometry as a method for monitoring of pupillary light reflex in ICU patients]. / Pupillometriya kak metod monitoringa fotoreaktsii v neiroreanimatsii.

This review is devoted to the modern method of monitoring of pupil diameter and reactivity in patients with acute brain injury. The authors present complete data on diagnostic and prognostic capabilities of automated infrared pupillometry, which should take its rightful place in comprehensive assessment of functional brain state in ICU patients. In authors' opinion, clinical introduction of pupillometry will improve prediction of outcomes following acute brain injury and quality of neurological monitoring in patients with cerebral edema and intracranial hypertension.

[The prognostic value of mri-classification of traumatic brain lesions level and localization depending on neuroimaging timing]. / Prognosticheskoe znachenie MRT-klassifikatsii urovnei i lokalizatsii travmaticheskogo povrezhdeniia mozga v zavisimosti ot srokov obsledovaniia patsientov.

OBJECTIVE: The aim of this study was to estimate the prognostic value of magnetic resonance imaging (MRI) classification of traumatic brain lesion localization and levels in patients with a brain injury of various severity in a few days to three weeks after the injury. MATERIAL AND METHODS: The cohort of 278 patients with traumatic brain injury (TBI) of various severity aged 8-74 y.o. (average -31.4±13.8, median - 29 (21.3; 37.0) was included in the analysis. The severity of TBI at admission varied from 3 to 15 Glasgow coma scores (GCS) (average - 8±4, median - 7 (5; 12). The main indications and conditions for MRI were: inconsistency between computed tomography (CT) data and neurological status, the necessity to clarify the location and type of brain damage, the absence of metal implants, the stabilization of the patient's vital functions, etc. MRI was performed during the first three weeks after the injury using T1, T2, T2-FLAIR, DWI, T2*GRE, SWAN sequences. The damage to the brain was classified according to 8 grades depending on the lesion levels (cortical-subcortical level, corpus callosum, basal ganglia and/or thalamus, and/or internal, and/or external capsules, uni- or bilateral brain stem injury at a different level). Outcomes were assessed by the Glasgow outcome scale (GOS) 6 months after injury. RESULTS: The significant correlations were found for the entire cohort between MRI grading and TBI severity (by GCS) and outcome (by GOS) of the injury (R=-0.66; p<0.0001; R=-0.69; p<0.0001, respectively). A high accuracy (77%), sensitivity (77%) and specificity (76%) of the proposed MRI classification in predicting injury outcomes (AUC=0.85) were confirmed using the logistic regression and ROC analysis. The assessment of MRI-classification prognostic value in subgroups of patients examined during the first, second, and third weeks after injury showed significant correlations between the GCS and the GOS as well as between MRI-grading and GCS, and GOS in all three subgroups. In the subgroup of patients examined during the first 14 days after the injury, the correlation coefficients were higher compared with those obtained in a subgroup examined 15-21 days after the injury. The highest correlations between MRI grading, TBI severity, and the outcome were found in the subgroup of patients who underwent MRI in the first three days after the injury (n=58). CONCLUSION: The proposed MRI classification of traumatic brain lesion levels and localization based on the use of different MR sequences reliably correlated with the clinical estimate of TBI severity by GCS and the outcomes by GOS in patients examined during the first three weeks after injury. The strongest correlation was observed for patients examined during the first three days after the injury.

[Perfusion-Metabolic Myocardial Scintigraphy in Prognosis of Left Ventricular Remodeling After Complex Surgical Treatment of Ischemic Cardiomyopathy].

PURPOSE: To study capabilities of perfusion-metabolic myocardial scintigraphy for prediction of the left ventricular (LV) reverse remodeling after comprehensive surgical treatment of ischemic cardiomyopathy (ICMP). METHODS: The study included ICMP patients aged 56±7 years (n=32) who underwent surgical correction of LV dysfunction (myocardial revascularization, LV reconstruction, and mitral valve restoration). Inclusion criteria were significant coronary artery disease; myocardial infarction; New York Heart Association (NYHA) class III-IV heart failure; LV ejection fraction (EF) ≤45%; LV end-systolic index (ESI) >60 mL/m2; and LV akinesia or dyskinesia according to echocardiography. Before surgery all patients were subjected to scintigraphy with 99mTc-MIBI (to assess perfusion) and with 123I-BMIPP (to assess myocardial metabolism). Scintigraphy results were expressed as median and lower; upper quartile (Me [lQ; hQ]). The clinical status and ventricular volume indicators were evaluated before surgery, in the early post-operative period (up to 4 weeks), and in the late post-operative period (12 months). RESULTS: At 12 months after intervention patients were divided into two groups: group 1 comprised patients (n=18) with beneficial outcome of the operation that stopped LV remodeling (ESI decreased, remained unchanged, or increased by.

[Optimization of antisecretory component of severe acute pancreatitis intensive management].

AIM: Improvement of complex intensive care of severe acute pancreatitis with use of continued intravenous infusion of octreotid. METHODS: 85 patients with severe acute pancreatitis were involved into the investigation, were divided into 2 groups. Patients of the control group (44 patients) got an intensive care according to severe acute pancreatitis treatment. Complex intensive treatment of the group of comparison (41 patients) included injections of octreotid (300 mcg 3 times a day). RESULTS: The change of octreotid usege scheme allowed to improve treatment resultes, wchis is the decrease of endotoxemia level and minimization of time spent at emergency department.

[Guidelines for the diagnosis and treatment of severe traumatic brain injury. Part 2. Intensive care and neuromonitoring].

Traumatic brain injury (TBI) is one of the major causes of death and disability in young and middle-aged people. The most problematic group is comprised of patients with severe TBI who are in a coma. The adequate diagnosis of primary brain injuries and timely prevention and treatment of the secondary injury mechanisms largely define the possibility of reducing mortality and severe disabling consequences. When developing these guidelines, we used our experience in the development of international and national recommendations for the diagnosis and treatment of mild traumatic brain injury, penetrating gunshot wounds to the skull and brain, severe traumatic brain injury, and severe consequences of brain injuries, including a vegetative state. In addition, we used international and national guidelines for the diagnosis, intensive care, and surgical treatment of severe traumatic brain injury, which had been published in recent years. The proposed guidelines concern intensive care of severe TBI in adults and are particularly intended for neurosurgeons, neurologists, neuroradiologists, anesthesiologists, and intensivists who are routinely involved in the treatment of these patients.

Towards the rational use of medicines.

BACKGROUND: Rational use of medicines remains to be one of the most challenging problems in health systems worldwide [1, 2]. ABC/VEN-analysis has been recommended for use by the World Health Organization (WHO) and has been used in health care practice globally since 1981. It represents the simple and effective method of analysis of medicine expenditures, identifying priority groups of medicines, the use of which, when improved, may provide the greatest clinical and economic impact. ABC analysis provides an accurate and objective picture of budget expenditures on medicines. VEN-analysis helps to prioritize between various medicines in their selection for procurement and use within a drug supply system [3-5]. OBJECTIVE: To assess the impact of introduction of evidence-based principles in the practice of medicine procurement and use on budget expenditures on medicines of a multidisciplinary health facility for the period of four years (2011-2014). METHODS: ABC/VEN analysis was carried out in a multidisciplinary health facility with over 1000 beds (an average number of beds for three years), which is responsible for provision of care to the population of about 1.4 million people. The analysis was carried out on the basis of information on medicine expenditures for 4 years: 2011 (1st year), 2012 (2nd year), 2013 (3rd year) and 2014 (4th year). When assigning VEN categories of medicines we used expert method: assignment of categories was carried out by clinical pharmacologists after reviewing all available evidence on effectiveness, safety and cost-effectiveness compared to other drugs in this group. In 2013, we implemented educational intervention, including detailed discussion of the results of the ABC/VEN-analysis for the years 2011-2012 from the standpoint of evidence-based pharmacology and recommendations for medicine procurement. In 2014, we delivered training workshop for the heads of clinical departments on evidence-based principles in clinical pharmacology and rational use of medicines. RESULTS: Medicines expenditures of the studied health facility for the year 2014 were less than for the year 2013, which was the important decrease reversing the trend of increasing medicines expenditures of the last three years: 2011 - 59,868,963 roubles; 2012 - 85,324,084 roubles, 2013 - 107 303 390 roubles, and 2014 - 74,416,692 roubles. The number of International Non-proprietary Names (INN) of medicines used in 2014 was 519, which was the highest number for the four years of the study: 2011 - 429 INN, 2012 - 432 INN, 2013 - 513 INN, and 2014 - 519 INN. Nearly 40% of the funds spent in 2014 on medicines have been used for Vital medicines: 2011 - 26%, 2012 - 39%, 2013 - 25%. Expenditures on Non-essential medicines in 2014 were about the same as in previous years - 14% of total medicine expenditures: 2011 - 16%, 2012 - 13%, 2013 - 15%. However in absolute numbers (roubles) expenditures on non-essential medicines decreased compared to the years 2013 and 2012: 2011 - 9,428,135 roubles, 2012 - 11,129,388 roubles, 2013 - 15,578,325 roubles, 2014 - 10,616,023 roubles.Expenditures on solutions for infusion (sodium chloride, Ringer's solution, dextran, glucose, hydroxyethyl starch) decreased as compared to the year 2013, but still remained high, thus indicating on the abuse of parenteral methods of drug administration. The portion of expenditures on isotonic sodium chloride solution and hydroxyethyl starch in 2014 decreased compared to the year 2013. We found a positive trend in the structure of expenditures on antibacterial agents: in 2014 expenditures on fluoroquinolones decreased nearly fivefold compared to 2013, expenditures on cephalosporins also decreased, but not so dramatically. However, there was a significant increase in expenditures on carbapenems, more than twofold compared with the year 2013. In 2014 we noted a twofold decrease in expenditures on medicines affecting blood, including antithrombotic agents, hemostatics and antianemic medicines, as compared to the values of the year 2013. In 2014 there was also a decrease in expenditures of cardio-vascular medicines, medicines affecting nervous system, alimentary tract and metabolism. CONCLUSIONS: Introduction of evidence-based principles through educational interventions at a multidisciplinary health facility resulted in a number of changes towards more rational medicine use. Regular educational interventions for practicing physicians and heads of clinical departments of health facilities that promote rational prescribing are needed.

[What do the doctors of different specialties know about sleep disorders and their treatment].

OBJECTIVE: To assessdoctor's knowledge on the relevance of the problem of sleep disorders, methods of their diagnosis and treatment. MATERIAL AND METHODS: The survey was conducted among90physicians of different the rapeuticspecialties of Kazan medical institutions. RESULTS: The doctors believe that main causes of sleep disorders are stressors (20%), depression (13%), neurosis (13%), chronic diseases (13%), asthenia (10%), pain (10%). An analysis of treatment prescribed to patients with sleep disorders revealed large differences. CONCLUSION: Physicians are not well informed about the problems of sleep disorders, have a small idea of the methods of sleepresearch and drugs for their treatment as well as of a sequence of operations that should be used to resolve this problem.

[Left and right ventricular diastolic dysfunction in patients with early rheumatoid arthritis before prescribing disease-modifying antirheumatic therapy].

AIM: To estimate the rate of diastolic dysfunction (DD) of the left and right ventricles (LV and RV) in patients with early rheumatoid arthritis (RA) before using disease-modifying antirheumatic drugs (DMARDs) therapy and to investigate its association with traditional risk factors (TRFs) for cardiovascular diseases (CVD) and inflammatory markers. SUBJECTS AND METHODS: The investigation enrolled 74 patients with a valid diagnosis of RA, including 56 (74%) women (median age, 54 years; disease duration, 7 months); the patients who were seropositive for rheumatoid factor (RF) (87%) and/or anti-cyclic citrullinated peptide (anti-CCP) antibodies (100%) who had not been on DMARDs or glucocorticosteroids. TRFs for CVD and carotid artery atherosclerosis were assessed from duplex scanning data and echocardiography was performed in all the patients with early RA before starting the therapy. The ratio of the maximum blood flow velocity during early diastolic filling (E) to that during atrial systole (A) was used as a criterion for LVDD and RVDD. There were 3 types of impaired ventricular filling: 1) E/A <1; 2) E/A = 1-2; 3) E/A > 2. RESULTS: LVDD and RVDD were detected in 35 (48%) and 17 (23%) patients, respectively. RVDD was recorded only in conjunction with LVDD. Among LVDD and RVDD, the former was prevalent. All the patients with early RA were divided into 3 groups: 1) patients with LVDD and RVDD; 2) those with LVDD; 3) those without ventricular DD. All the three groups were matched for the level of DAS28, anti-CCP antibodies, and RF. The incidence of arterial hypertension, dyslipidemia, and abdominal obesity was higher in the patients of Groups 1 and 2 than in those of Group 3. There was a progressive decrease in high-density lipoprotein (HDL) cholesterol concentrations and increases in triglyceride (TG) levels and atherogenic index from Group 3 to Group 1, with the concentrations of total cholesterol and low-density lipoprotein cholesterol being similar in the 3 groups. Coronary heart disease was recorded more frequently in Group 2 than in Group 3. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) proved to be also significantly higher in the patients with DD than in those without DD. Correlations were found between LV E/A and ESR, CRP, HDL cholesterol, TG, RV E/A and ESR, DAS28, TG. CONCLUSION: The patients with early-stage RA were found to have high incidence rates of LVDD and RVDD, which is related to the high prevalence of CVD, the high spread of TRF for CVD, and the high activity of an inflammatory process.

Improving survival by exploiting tumour dependence on stabilized mutant p53 for treatment.

Missense mutations in p53 generate aberrant proteins with abrogated tumour suppressor functions that can also acquire oncogenic gain-of-function activities that promote malignant progression, invasion, metastasis and chemoresistance. Mutant p53 (mutp53) proteins undergo massive constitutive stabilization specifically in tumours, which is the key requisite for the acquisition of gain-of-functions activities. Although currently 11 million patients worldwide live with tumours expressing highly stabilized mutp53, it is unknown whether mutp53 is a therapeutic target in vivo. Here we use a novel mutp53 mouse model expressing an inactivatable R248Q hotspot mutation (floxQ) to show that tumours depend on sustained mutp53 expression. Upon tamoxifen-induced mutp53 ablation, allotransplanted and autochthonous tumours curb their growth, thus extending animal survival by 37%, and advanced tumours undergo apoptosis and tumour regression or stagnation. The HSP90/HDAC6 chaperone machinery, which is significantly upregulated in cancer compared with normal tissues, is a major determinant of mutp53 stabilization. We show that long-term HSP90 inhibition significantly extends the survival of mutp53 Q/- (R248Q allele) and H/H (R172H allele) mice by 59% and 48%, respectively, but not their corresponding p53(-/-) littermates. This mutp53-dependent drug effect occurs in H/H mice treated with 17DMAG+SAHA and in H/H and Q/- mice treated with the potent Hsp90 inhibitor ganetespib. Notably, drug activity correlates with induction of mutp53 degradation, tumour apoptosis and prevention of T-cell lymphomagenesis. These proof-of-principle data identify mutp53 as an actionable cancer-specific drug target.

[Breast cancer developing during pregnancy--clinical cases and review of the literature].

The goal of the present paper is to discuss diagnosis, treatment approaches and histopathologic characteristics of breast cancer developing during pregnancy, based on our results and published literature data. We retrospectively evaluated clinical and pathologic features of tumors, treatment methods, decisions related to pregnancy and final outcome by eight pregnant patients with breast cancer. The patients' age varied from 26 to 36 years. At the last medical examination in October 2013, three among all eight patients were alive, two of them were without local and distant recurrence, and one patient has distant metastases and is carrying out a treatment. The aim of this paper was to discuss the characteristics of breast cancer developing during pregnancy. Retrospectively have been analyzed clinical-pathological characteristics of the tumors in eight pregnant women with breast cancer, the treatment, the management of the pregnancy, and the final outcome. The results are analyzed by comparing with data published in the literature.

Galantamine prevents long-lasting suppression of excitatory synaptic transmission in CA1 pyramidal neurons of soman-challenged guinea pigs.

Galantamine, a drug currently approved for the treatment of Alzheimer's disease, has recently emerged as an effective pretreatment against the acute toxicity and delayed cognitive deficits induced by organophosphorus (OP) nerve agents, including soman. Since cognitive deficits can result from impaired glutamatergic transmission in the hippocampus, the present study was designed to test the hypothesis that hippocampal glutamatergic transmission declines following an acute exposure to soman and that this effect can be prevented by galantamine. To test this hypothesis, spontaneous excitatory postsynaptic currents (EPSCs) were recorded from CA1 pyramidal neurons in hippocampal slices obtained at 1h, 24h, or 6-9 days after guinea pigs were injected with: (i) 1×LD50 soman (26.3µg/kg, s.c.); (ii) galantamine (8mg/kg, i.m.) followed 30min later by 1×LD50 soman, (iii) galantamine (8mg/kg, i.m.), or (iv) saline (0.5ml/kg, i.m.). In soman-injected guinea pigs that were not pretreated with galantamine, the frequency of EPSCs was significantly lower than that recorded from saline-injected animals. There was no correlation between the severity of soman-induced acute toxicity and the magnitude of soman-induced reduction of EPSC frequency. Pretreatment with galantamine prevented the reduction of EPSC frequency observed at 6-9 days after the soman challenge. Prevention of soman-induced long-lasting reduction of hippocampal glutamatergic synaptic transmission may be an important determinant of the ability of galantamine to counter cognitive deficits that develop long after an acute exposure to the nerve agent.

Fluorescent diagnosis and photodynamic therapy for C6 glioma in combination with antiangiogenic therapy in subcutaneous and intracranial tumor models.

OBJECTIVE: Investigating the distinctions pharmacokinetics of chlorin e6 conjugated with polyvinyl pyrrolidone photosensitizer (Ce6CPPPS)in healthy and tumor tissues of rat brain and evaluating the antitumor efficacy of combination treatment for C6 rat glioma including photodynamic (PDT) and antiangiogenic therapy (AAT). MATERIALS AND METHODS: The study was performed on 50 white random-bred rats in subcutaneous and intracranial models of C6 glioma. Photosensitizer (PS) Ce6CPPPS single injection at a dose of 2.5 mg/kg was made into the animal's caudal vein. The PS accumulation level in brain tissues and C6 rat glioma was measured with spectral fluorescence technique using LESA-01-Biospek spectrum analyser (Russian Federation, Moscow; λ = 632.8 nm). Photoirradiation of intracranial and subcutaneous C6 glioma was carried out with a light exposure dose of 50 J/cm(2) (IMAF-Axicon, Republic of Belarus; λ = 661 nm). AAT drug bevacizumab, single injection was made intravenously at a dose of 10 mg/kg 24 h after tumor photoirradiation. The criteria for efficacy evaluation were mean survival time (MST) and median survival of the animals in the study group vs the control and the -percentage of tumor necrosis areas induced by the above-mentioned treatment. RESULTS: The optimal time for photoirradiation of intracranial C6 glioma is 0.5 h after Ce6CPPPS injection. The combination therapy group demonstrated a statistically significant MST increase (38.4 ± 4.39 days) compared with the PDT group (29.2 ± 3.5 days) (p = 0.02) and the AAT group (27.1 ± 2.74 days) (p = 0.02). Necrosis areas in tumor tissue were as follows: the intact control - 10.0 ± 2.55%, PDT - 54.87 ± 6.95% (p = 0.003), AAT - 57.83 ± 6.53% (p = 0.003) and combination therapy - 89.43 ± 5.57% (p = 0.001). CONCLUSIONS: This paper is the first report about feasibility of efficient use of PDT with a PS of chlorin series and AAT with bevacizumab for the treatment of brain tumors in experimental models.

[Neuroanatomical basis for traumatic coma: clinical and magnetic resonance correlates].

In this paper, the relationship between brain lesion localization (verified by magnetic resonance imaging (MRI)) and the severity of traumatic brain injury (TBI) and its outcomes is presented. Magnetic resonance studies in different modes (T1, T2, FLAIR, DWI, DTI, T2 * GRE, SWAN) were performed in 162 patients with acute TBI. Statistical analysis was done using Statistica 6, 8 software and R programming language. A new advanced MRI-based classification of TBI was introduced implying the assessment of hemispheric and brainstem traumatic lesions level and localization. Statistically significant correlations were found between the Glasgow coma and outcome scales scores (p < 0.001), and the proposed MRI grading scale scores, which means a high prognostic value of the new classification. The knowledge of injured brain microanatomy coming from sensitive neuroimaging, in conjunction with the assessment of mechanisms, aggravating factors and clinical manifestation of brain trauma is the basis for the actual predictive model of TBI. The proposed advanced MRI classification contributes to this concept development.

[Neurotransmitter basis of consciousness and uncosciousness states].

Plenty of different studies are dedicated to consciousness recovery problem, such as neuroanatomical, neurophysiological, neuropsychiatric, neurosurgical, neurological points of view. However, neurotransmitter dysfunction is one of the main difficulties for consciousness and other neurological functions recovery after brain trauma. There are a lot of pharmacological agents modulating brain neurotransmitter activity, but no one precise clinical indication. So, the neurotransmitter mechanisms of consciousness recovery in patients with brain pathologies are very actual for studying with updating methods. This review concerns to the current understanding of unconsciousness, neuroanatomical and neurotransmitter bases of the last one.

p63 is a prosurvival factor in the adult mammary gland during post-lactational involution, affecting PI-MECs and ErbB2 tumorigenesis.

In embryogenesis, p63 is essential to develop mammary glands. In the adult mammary gland, p63 is highly expressed in the basal cell layer that comprises myoepithelial and interspersed stem/progenitor cells, and has limited expression in luminal epithelial cells. In adult skin, p63 has a crucial role in the maintenance of epithelial stem cells. However, it is unclear whether p63 also has an equivalent role as a stem/progenitor cell factor in adult mammary epithelium. We show that p63 is essential in vivo for the survival and maintenance of parity-identified mammary epithelial cells (PI-MECs), a pregnancy-induced heterogeneous population that survives post-lactational involution and contain multipotent progenitors that give rise to alveoli and ducts in subsequent pregnancies. p63+/- glands are normal in virgin, pregnant and lactating states. Importantly, however, during the apoptotic phase of post-lactational involution p63+/- glands show a threefold increase in epithelial cell death, concomitant with increased activation of the oncostatin M/Stat3 and p53 pro-apoptotic pathways, which are responsible for this phase. Thus, p63 is a physiologic antagonist of these pathways specifically in this regressive stage. After the restructuring phase when involution is complete, mammary glands of p63+/- mice again exhibit normal epithelial architecture by conventional histology. However, using Rosa(LSL-LacZ);WAP-Cre transgenics (LSL-LacZ, lox-stop-lox ß-galactosidase), a genetic in vivo labeling system for PI-MECs, we find that p63+/- glands have a 30% reduction in the number of PI-MEC progenitors and their derivatives. Importantly, PI-MECs are also cellular targets of pregnancy-promoted ErbB2 tumorigenesis. Consistent with their PI-MEC pool reduction, one-time pregnant p63+/- ErbB2 mice are partially protected from breast tumorigenesis, exhibiting extended tumor-free and overall survival, and reduced tumor multiplicity compared with their p63+/+ ErbB2 littermates. Conversely, in virgin ErbB2 mice p63 heterozygosity provides no survival advantage. In sum, our data establish that p63 is an important survival factor for pregnancy-identified PI-MEC progenitors in breast tissue in vivo.

ΔNp63 regulates select routes of reprogramming via multiple mechanisms.

Somatic cells can be converted into induced pluripotent stem cells (iPSCs) by forced expression of various combinations of transcription factors, but the molecular mechanisms of reprogramming are poorly understood. Specifically, evidence that the reprogramming process can take many distinct routes only begins to emerge. It is definitively established that p53 deficiency greatly enhances reprogramming, revealing p53's barrier function for induced pluripotency, but the role of its homologs p63 and p73 are unknown. Here we report that in stark contrast to p53, p73 has no role in reprogramming. However, p63 is an enabling (rather than a barrier) factor for Oct4, Sox2 and Klf4 (OSK) and Oct4 and Sox2 (OS), but not for Oct4 and Klf4 (OK) reprogramming of mouse embryonic fibroblasts. Specifically, p63 is essential during reprogramming for maximum efficiency, albeit not for the ability to reprogram per se, and is dispensable for maintaining stability and pluripotency of established iPSC colonies. ΔNp63, but not TAp63, is the principal isoform involved. Loss of p63 can affect reprogramming via several mechanisms such as reduced expression of mesenchymal-epithelial transition and pluripotency genes, hypoproliferation and loss of the most reprogrammable cell populations. During OSK and OS reprogramming, different mechanisms seem to be critical, such as regulation of epithelial and pluripotency genes in OSK reprogramming versus regulation of proliferation in OS reprogramming. Finally, our data reveal three different routes of reprogramming by OSK, OS or OK, based on their differential p63 requirements for iPSC efficiency and pluripotency marker expression. This supports the concept that many distinct routes of reprogramming exist.