The Brassica napus boron deficient inflorescence transcriptome resembles a wounding and infection response

Oilseed rape and other crops of Brassica napus have a high demand for boron (B). Boron deficiencies result in the inhibition of root growth, and eventually premature flower abortion. Understanding the genetic mechanisms underlying flower abortion in B-limiting conditions could provide the basis to enhance B-efficiency and prevent B-deficiency-related yield losses. In this study, we assessed transcriptomic responses to B-deficiency in diverse inflorescence tissues at multiple time points of soil-grown plants that were phenotypically unaffected by B-deficiency until early flowering. Whilst transcript levels of known B transporters were higher in B-deficient samples, these remained remarkably stable as the duration of B-deficiency increased. Meanwhile, GO-term enrichment analysis indicated a growing response resembling that of a pathogen or pest attack, escalating to a huge transcriptome response in shoot heads at mid-flowering. Grouping differentially expressed genes within this tissue into MapMan functional bins indicated enrichment of genes related to wounding, jasmonic acid and WRKY transcription factors. Individual candidate genes for controlling the "flowering-without-seed-setting" phenotype from within MapMan biotic stress bins include those of the metacaspase family, which have been implicated in orchestrating programmed cell death. Overall temporal expression patterns observed here imply a dynamic response to B-deficiency, first increasing expression of B transporters before recruiting various biotic stress-related pathways to coordinate targeted cell death, likely in response to as yet unidentified B-deficiency induced damage-associated molecular patterns (DAMPs). This response indicates new pathways to target and dissect to control B-deficiency-induced flower abortion and to develop more B-efficient crops.

Functional evolution of nodulin 26-like intrinsic proteins: from bacterial arsenic detoxification to plant nutrient transport

Nodulin 26-like intrinsic proteins (NIPs) play essential roles in transporting the nutrients silicon and boron in seed plants, but the evolutionary origin of this transport function and the co-permeability to toxic arsenic remains enigmatic. Horizontal gene transfer of a yet uncharacterised bacterial AqpN-aquaporin group was the starting-point for plant NIP evolution. We combined intense sequence, phylogenetic and genetic context analyses and a mutational approach with various transport assays in oocytes and plants to resolve the transorganismal and functional evolution of bacterial and algal and terrestrial plant NIPs and to reveal their molecular transport specificity features. We discovered that aqpN genes are prevalently located in arsenic resistance operons of various prokaryotic phyla. We provided genetic and functional evidence that these proteins contribute to the arsenic detoxification machinery. We identified NIPs with the ancestral bacterial AqpN selectivity filter composition in algae, liverworts, moss, hornworts and ferns and demonstrated that these archetype plant NIPs and their prokaryotic progenitors are almost impermeable to water and silicon but transport arsenic and boron. With a mutational approach, we demonstrated that during evolution, ancestral NIP selectivity shifted to allow subfunctionalisations. Together, our data provided evidence that evolution converted bacterial arsenic efflux channels into essential seed plant nutrient transporters.

Boron demanding tissues of Brassica napus express specific sets of functional Nodulin26-like Intrinsic Proteins and BOR1 transporters

The sophisticated uptake and translocation regulation of the essential element boron (B) in plants is ensured by two transmembrane transporter families: the Nodulin26-like Intrinsic Protein (NIP) and BOR transporter family. Though the agriculturally important crop Brassica napus is highly sensitive to B deficiency, and NIPs and BORs have been suggested to be responsible for B efficiency in this species, functional information of these transporter subfamilies is extremely rare. Here, we molecularly characterized the NIP and BOR1 transporter family in the European winter-type cv. Darmor-PBY018. Our transport assays in the heterologous oocyte and yeast expression systems as well as in growth complementation assays in planta demonstrated B transport activity of NIP5, NIP6, NIP7 and BOR1 isoforms. Moreover, we provided functional and quantitative evidence that also members of the NIP2, NIP3 and NIP4 groups facilitate the transport of B. A detailed B- and tissue-dependent B-transporter expression map was generated by quantitative polymerase chain reaction. We showed that NIP5 isoforms are highly upregulated under B-deficient conditions in roots, but also in shoot tissues. Moreover, we detected transcripts of several B-permeable NIPs from various groups in floral tissues that contribute to the B distribution within the highly B deficiency-sensitive flowers.

Major depression and atrial natriuretic peptide: The role of adverse childhood experiences

Atrial natriuretic peptide (ANP) exerts anxiolytic effects in animals and humans. Patients with anxiety, trauma-associated and depressive disorders exhibit lower ANP plasma levels compared to healthy individuals. However, the role of ANP in patients with major depressive disorder (MDD) with and without concomitant adverse childhood experiences (ACE) and in healthy individuals with and without ACE is not clear. We recruited a total of 93 women: 23 women with MDD and ACE, 24 women with MDD without ACE, 22 women with ACE but no current or lifetime MDD, and 24 healthy women without ACE. ANP plasma levels were measured with a radioimmunoassay. The four groups did not differ in demographic and clinical variables. We found a positive correlation between age and plasma levels of ANP (r = .39; p <  .001). After controlling for age, there was no significant main effect of MDD or ACE on ANP plasma levels, but a significant interaction between MDD and ACE such that ACE was associated with reduced basal ANP levels in the absence of MDD. We assume that low plasma ANP might be a consequence of ACE in the absence of current psychopathology. Therefore, future studies are needed to replicate our findings and to characterize the influencing factors of ACE on ANP more comprehensively, for example by including a comprehensive trauma and comorbidity anamnesis as well as cardiovascular state and risk factors.

Different yet similar? Prisoners versus psychiatric patients - A comparison of their mental health

BACKGROUND

Previous research indicates that prisoners have severe psychological distress. To assess their distress level and potential need for treatment, the present study compared the subjective psychological distress of long- and short-term prisoners with that of psychiatric and forensic patients.

METHODS

Long- (n=98) and short-term prisoners (n=94) and forensic (n=102) and psychiatric (n=199) patients completed the German versions of the Symptom Checklist Revised (SCL-90-R) and Brief Symptom Inventory (BSI).

RESULTS

In general, long-term prisoners showed the same level of mental distress as psychiatric patients and more than that reported by forensic patients. Short-term prisoners reported the least level of distress. Long- but not short-term prisoners showed clinically significant results on the scales for depression, paranoid ideation, and psychosis.

CONCLUSIONS

The improvements in psychiatric treatment for inmates demanded by many stakeholders need to differentiate between long- and short-term prisoners. Because depression seems to cause the most psychological distress among inmates, suicide prevention seems to be an important issue in prisons.

Role of SKD1 Regulators LIP5 and IST1-LIKE1 in Endosomal Sorting and Plant Development

SKD1 is a core component of the mechanism that degrades plasma membrane proteins via the Endosomal Sorting Complex Required for Transport (ESCRT) pathway. Its ATPase activity and endosomal recruitment are regulated by the ESCRT components LIP5 and IST1. How LIP5 and IST1 affect ESCRT-mediated endosomal trafficking and development in plants is not known. Here we use Arabidopsis mutants to demonstrate that LIP5 controls the constitutive degradation of plasma membrane proteins and the formation of endosomal intraluminal vesicles. Although lip5 mutants were able to polarize the auxin efflux facilitators PIN2 and PIN3, both proteins were mis-sorted to the tonoplast in lip5 root cells. In addition, lip5 root cells over-accumulated PIN2 at the plasma membrane. Consistently with the trafficking defects of PIN proteins, the lip5 roots showed abnormal gravitropism with an enhanced response within the first 4 h after gravistimulation. LIP5 physically interacts with IST1-LIKE1 (ISTL1), a protein predicted to be the Arabidopsis homolog of yeast IST1. However, we found that Arabidopsis contains 12 genes coding for predicted IST1-domain containing proteins (ISTL1-12). Within the ISTL1-6 group, ISTL1 showed the strongest interaction with LIP5, SKD1, and the ESCRT-III-related proteins CHMP1A in yeast two hybrid assays. Through the analysis of single and double mutants, we found that the synthetic interaction of LIP5 with ISTL1, but not with ISTL2, 3, or 6, is essential for normal plant growth, repression of spontaneous cell death, and post-embryonic lethality.

The endosomal protein CHARGED MULTIVESICULAR BODY PROTEIN1 regulates the autophagic turnover of plastids in Arabidopsis

Endosomal Sorting Complex Required for Transport (ESCRT)-III proteins mediate membrane remodeling and the release of endosomal intraluminal vesicles into multivesicular bodies. Here, we show that the ESCRT-III subunit paralogs CHARGED MULTIVESICULAR BODY PROTEIN1 (CHMP1A) and CHMP1B are required for autophagic degradation of plastid proteins in Arabidopsis thaliana. Similar to autophagy mutants, chmp1a chmp1b (chmp1) plants hyperaccumulated plastid components, including proteins involved in plastid division. The autophagy machinery directed the release of bodies containing plastid material into the cytoplasm, whereas CHMP1A and B were required for delivery of these bodies to the vacuole. Autophagy was upregulated in chmp1 as indicated by an increase in vacuolar green fluorescent protein (GFP) cleavage from the autophagic reporter GFP-ATG8. However, autophagic degradation of the stromal cargo RECA-GFP was drastically reduced in the chmp1 plants upon starvation, suggesting that CHMP1 mediates the efficient delivery of autophagic plastid cargo to the vacuole. Consistent with the compromised degradation of plastid proteins, chmp1 plastids show severe morphological defects and aberrant division. We propose that CHMP1 plays a direct role in the autophagic turnover of plastid constituents.

Association between cortisol awakening response and memory function in major depression

BACKGROUND

While impaired memory and altered cortisol secretion are characteristic features of major depression, much less is known regarding the impact of antidepressant medication. We examined whether the cortisol awakening response (CAR) is increased in depressed patients with and without medication compared with healthy controls (HC) and whether CAR is associated with memory function in each group.

METHOD

We examined 21 patients with major depression without medication, 20 depressed patients on antidepressant treatment, and 41 age-, sex- and education-matched healthy subjects. We tested verbal (Auditory Verbal Learning Task) and visuospatial (Rey figure) memory and measured CAR on two consecutive days.

RESULTS

Patient groups did not differ in severity of depression. We found a significant effect of group (p = 0.03) for CAR. Unmedicated patients exhibited a greater CAR compared with medicated patients (p = 0.04) with no differences between patient groups and HC. We found a significant effect of group for verbal (p = 0.03) and non-verbal memory (p = 0.04). Unmedicated patients performed worse compared with medicated patients and HC in both memory domains. Medicated patients and HC did not differ. Regression analyses revealed a negative association between CAR and memory function in depressed patients, but not in HC.

CONCLUSIONS

While in unmedicated depressed patients the magnitude of CAR is associated with impaired memory, medicated patients showed a smaller CAR and unimpaired cognitive function compared with HC. Our findings are compatible with the idea that antidepressants reduce CAR and partially restore memory function even if depressive psychopathology is still present.

[Repeated measurement of memory with valenced test items: verbal memory, working memory and autobiographic memory]

A large number of questions in clinical and/or experimental neuropsychology require the multiple repetition of memory tests at relatively short intervals. Studies on the impact of the associated exercise and interference effects on the validity of the test results are rare. Moreover, hardly any neuropsychological instruments exist to date to record the memory performance with several parallel versions in which the emotional valence of the test material is also taken into consideration. The aim of the present study was to test whether a working memory test (WST, a digit-span task with neutral or negative distraction stimuli) devised by our workgroup can be used with repeated measurements. This question was also examined in parallel versions of a wordlist learning paradigm and an autobiographical memory test (AMT). Both tests contained stimuli with neutral, positive and negative valence. Twenty-four participants completed the memory testing including the working memory test and three versions of a wordlist and the AMT at intervals of a week apiece (measuring points 1. - 3.). The results reveal consistent performances across the three measuring points in the working and autobiographical memory test. The valence of the stimulus material did not influence the memory performance. In the delayed recall of the wordlist an improvement in memory performance over time was seen. The tests on working memory presented and the parallel versions for the declarative and autobiographical memory constitute informal economic instruments within the scope of the measurement repeatability designs. While the WST and AMT are appropriate for study designs with repeated measurements at relatively short intervals, longer intervals might seem more favourable for the use of wordlist learning paradigms.

[Depression and neurological diseases]

In many neurological diseases a depressive syndrome is a characteristic sign of the primary disease or is an important comorbidity. Post-stroke depression, for example, is a common and relevant complication following ischemic brain infarction. Approximately 4 out of every 10 stroke patients develop depressive disorders in the course of the disease which have a disadvantageous effect on the course and the prognosis. On the other hand depression is also a risk factor for certain neurological diseases as was recently demonstrated in a meta-analysis of prospective cohort studies which revealed a much higher stroke risk for depressive patients. Furthermore, depression plays an important role in other neurological diseases with respect to the course and quality of life, such as Parkinson's disease, multiple sclerosis and epilepsy. This article gives a review of the most important epidemiological, pathophysiological and therapeutic aspects of depressive disorders as a comorbidity of neurological diseases and as a risk factor for neurological diseases.

CCF treatment in PSA: insights and recommendations from reviewing procedures

Probabilistic Safety Assessments (PSAs) in Germany have primarily been conducted in the framework of Periodic Safety Reviews (PSRs). For some time, PSAs following the recommendations given by the reviewer with the final statement in the 1st PSR have been submitted and reviewed, like the probabilistic analyses of internal fires as well as Low Power and Shutdown States. From the very beginning, the review of the adequateness of the common cause failures (CCF) treatment represented a key element in the respective regulatory procedures – given the large impact on the results depending on the CCF assessment. In this paper, our experiences and insights from the reviewing procedures in the course of time are described – also addressing background and objectives as well as working programme and results with reference to reviewer's CCF projects. Finally, possible ways and procedures are presented related to a further development in CCF treatment in PSAs according to practical requests.

Integral analysis of low power and shutdown operation: insights and outcome

Probabilistic Safety Assessments (PSAs) in Germany have essentially been conducted in the framework of recurrent Safety Reviews (SRs). Besides, probabilistic investigations have also been submitted and reviewed in the usual regulatory procedures. Significant safety relevant insights have e. g. been gained from the Human Reliability Assessment (HRA) in the context of Low Power and Shutdown (LPS) PSAs whose performance has been launched by the regulatory body. In this paper major insights and results together with the practical outcome particularly from Human Factor (HF) and safety relevance points of view are described. Thereby, general key issues on HRA as well as substantial insights and conclusions derived from LPS HRAs are addressed. Further, a specific example with respect to the design and review of a complete set of operating procedures specifically dedicated to the shutdown operation is illustrated by outlining the general approach as well as the overall outcome achieved. Finally, conclusions are drawn regarding the relevance of probabilistic investigations, the appropriateness of a symptom oriented proceeding related to shutdown operation and the potential of utilising an advanced HF methodology.

Effects of cortisol on memory in women with borderline personality disorder: role of co-morbid post-traumatic stress disorder and major depression

BACKGROUND

Stress and cortisol administration are known to have impairing effects on memory retrieval in healthy humans. These effects are reported to be altered in patients with major depressive disorder (MDD) and post-traumatic stress disorder (PTSD) but they have not yet been investigated in borderline personality disorder (BPD).

METHOD

In a placebo-controlled cross-over study, 71 women with BPD and 40 healthy controls received either placebo or 10 mg of hydrocortisone orally before undertaking a declarative memory retrieval task (word list learning) and an autobiographical memory test (AMT). A working memory test was also applied.

RESULTS

Overall, opposing effects of cortisol on memory were observed when comparing patients with controls. In controls, cortisol had impairing effects on memory retrieval whereas in BPD patients cortisol had enhancing effects on memory retrieval of words, autobiographical memory and working memory. These effects were most pronounced for specificity of autobiographical memory retrieval. Patients with BPD alone and those with co-morbid PTSD showed this effect. We also found that co-morbid MDD influenced the cortisol effects: in this subgroup (BPD + MDD) the effects of cortisol on memory were absent.

CONCLUSIONS

The present results demonstrate beneficial effects of acute cortisol elevations on hippocampal-mediated memory processes in BPD. The absence of these effects in patients with co-morbid MDD suggests that these patients differ from other BPD patients in terms of their sensitivity to glucocorticoids (GCs).

Reliability of the emotional Stroop task: an investigation of patients with panic disorder

Despite its popularity in clinical research, the emotional Stroop task's reliability in patient groups is unknown. Given the low reliability of interference scores in healthy subjects, correlations with other variables pose a problem, especially as reliability in clinical samples is unknown. To assess reliability in panic disorder for the first time, we used the spilt-half method in two independent samples of patients and controls. As expected, only patients showed the behavioral interference effect. Reliability of interference scores (i.e. mean response latency emotional minus neutral words) was insufficiently low for patient and control samples; however, reliability scores derived from the conditions' response latencies (i.e. mean response latency emotional or neutral words) were much higher. The assumption that reliability scores in patients might differ from controls was not supported. This finding questions the use of correlations with external variables and suggests the use of response latencies instead of interference scores.

Dissociation and emotion regulation in borderline personality disorder

BACKGROUND

Although some evidence suggests that borderline personality disorder (BPD) is primarily a disorder of the emotion regulation system, findings remain inconsistent. One potential explanation for this is the moderating role of dissociation.

METHOD

In this study, 33 female subjects with BPD and 26 healthy controls (HC; matched by education level and nicotine intake) were presented idiographic aversive, standard unpleasant and neutral scripts. Modulation of startle reflex and electrodermal responses (skin conductance level; SCL) were measured during imagery of emotional and neutral scripts. Additionally, self-reports of emotional experience (valence and arousal) and present-state dissociation were assessed.

RESULTS

Patients with BPD showed elevated levels of dissociative experiences during testing. Present-state dissociation mediated group differences in SCL and startle response between the HC and BPD groups.

CONCLUSIONS

These results suggest that careful attention must be paid to the moderating effect of dissociative symptoms on the psychophysiological responses of BPD patients. Furthermore, the findings have important implications for the assessment and treatment of BPD, including the need to carefully assess BPD patients for dissociative symptoms and to incorporate the treatment of dissociation.

[Familial transmission of depression: the importance of harm avoidance]

BACKGROUND

Previous research about the aetiology of depression has analysed how depression-associated personality traits influence familial transmission. Using the community-based sample of the Greifswald Family Study, we investigated longitudinally to which extent the temperament factor harm avoidance influences the correlation between parent's depression and the depression of their offspring (with regard to possible sex differences).

METHODS

To test this familial transmission a structural equation model was conducted with the data of 193 children (mean age 19.5, SD=2.41) and their biological parents. Depression was assessed with structured clinical interviews, and harm avoidance with Cloninger's Temperament and Character Inventory (TCI, JTCI).

RESULTS

The harm avoidance scores of the mothers were significantly correlated with the harm avoidance scores of their children, but the correlation of the father's and children's scores did not reach significance. The extent of harm avoidance at the first assessment of the 14-year-old children predicted depression 5 years later.

CONCLUSION

These results indicate the importance of personality as a vulnerability marker for developing affective disorders. The results are discussed with respect to prevention programmes for children and parents with depression, especially if they exhibit strongly avoidant or anxious behaviour.

Interactome of the plant-specific ESCRT-III component AtVPS2.2 in Arabidopsis thaliana

The endosomal sorting complexes required for transport (ESCRT) guides transmembrane proteins to domains that bud away from the cytoplasm. The ESCRT machinery consists of four complexes. ESCRT complexes 0–II are important for cargo recognition and concentration via ubiquitin binding. Most of the membrane bending function is mediated by the large multimeric ESCRT-III complex and associated proteins. Here we present the first in vivo proteome analysis of a member of the ESCRT-III complex which is unique to the plant kingdom. We show with LC–MS/MS, yeast-two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) that coimmunoprecipitated proteins from Arabidopsisthaliana roots expressing a functional GFP-tagged VACUOLAR PROTEIN SORTING 2.2 (AtVPS2.2) protein are members of the ESCRT-III complex and associated proteins. Therefore we propose that at least in plants the large ESCRT-III membrane scaffolding complex consists of a mixture of SNF7, VPS2 and the associated VPS46 and VPS60 proteins. Apart from transmembrane proteins, numerous membrane-associated but also nuclear and extracellular proteins have been identified, indicating that AtVPS2.2 might be involved in processes beyond the classical ESCRT role. This study is the first in vivo proteome analysis with a tagged ESCRT-III component demonstrating the feasibility of this approach and provides numerous starting points for the investigation of the biological process in which AtVPS2.2 is involved.

The endosomal sorting complexes required for transport (ESCRT) guides transmembrane proteins to domains that bud away from the cytoplasm. Most of the membrane bending function is mediated by the ESCRT-III complex. Proteomic analysis was used to identify novel ESCRT-III interactors of Arabidopsis thaliana seedlings expressing a functional GFP-tagged VACUOLAR PROTEIN SORTING2.2 as bait. Some intractors were confirmed by yeast-two-hybrid and bimolecular fluorescence complementation and others will be the target for future investigations.

Association of airflow limitation with trauma exposure and post-traumatic stress disorder

Trauma exposure and post-traumatic stress disorder (PTSD) are associated with self-reported asthma and chronic obstructive pulmonary disease. However, these conditions have not yet been related to objective measures of lung function. 1,772 adults from the general population were assessed regarding their medical histories and spirometric lung function. Additionally, they were administered a PTSD interview, and assigned to three groups: no trauma; trauma, but no PTSD; and trauma with PTSD. Adjusting for sociodemographic, clinical and lifestyle factors, subjects with PTSD had significantly higher odds ratios for most asthma-related symptoms than PTSD-negative participants (OR 3.2-8.8). The mean ratio of forced expiratory volume in 1 s (FEV₁) to forced vital capacity (FVC) was lowest in the PTSD group and highest in those without trauma exposure. Traumatic stress was independently associated with FEV₁ and FEV₁/FVC. Participants with PTSD, compared with those without, had a significantly increased risk for airflow limitation independent of its definition (OR 4.2-7.8). This is the first study relating traumatic stress and PTSD, respectively, to objective parameters of lung function. Our findings suggest an association of trauma exposure and PTSD with airflow limitation, which may be mediated by inflammatory processes.

[Modified procedure for patient registration for navigation control instruments in ENT surgery]

PROBLEM

Surgical navigation and navigation-controlled instruments demand a robust and precise patient registration process. For navigation in the skull, a bite-splint-based registration method has been widely applied, which had to be manufactured by dental technicians. The additional cost and time could be avoided by directly using the manufactured imprint, which is prepared by the ENT surgeon in one step.

MATERIAL AND METHODS

This study examined the re-positioning accuracy for three silicon materials in a laboratory study with a 3D measuring device (Faro-arm) after several re-positioning cycles (simulating erosion) in comparison to the gold standard.

RESULTS

The mean deviation after two cycles was lower for all three materials compared to the gold standard. Only C-Silikon Optosil was better then the gold standard after all cycles and with a deviation of 0.17 mm it well below that of the conventional bite-splint (0.28 mm). The additional cost benefits of 10 euro per imprint compared to the bite-splint with >100 euro favor this material for clinical application.

CONCLUSIONS

As a consequence of this investigation Optosil was successfully used in 6 patients during the period from 01.09.2007 to 30.11.2007. The bite-splint was manufactured completely in the ENT department and could be used during the planning CT and surgery. The resulting accuracy corresponded to the experiences gained in previous surgery with a maximum deviation of 0.87 mm. The favorable ergonomic characteristics for patient and surgeon could be confirmed. As a result of this study this clinic now exclusively uses the procedure described in this article for bite-splint-based registration.

[Psychiatric disorders and childhood trauma in prisoners with antisocial personality disorder]

Previous studies indicate high prevalence rates of mental disorders and trauma among prisoners. Based on a sample of 102 male German prisoners, the comorbidity and childhood trauma experiences in 72 criminals with antisocial personality disorder were investigated. Furthermore, associations of antisocial personality disorder and early traumatic experiences with the age at first conviction and the lifetime months of imprisonment were examined. Subjects had high rates of comorbid lifetime and current disorders as well as childhood trauma experiences. Physical abuse in childhood and adolescence was identified as a predictor for lifetime months of imprisonment, antisocial personality disorder was found to be a predictor for the age at first conviction. Our findings confirm the hypothesis of prisoners with antisocial personality disorder being a severely traumatized population with serious mental disorders. Traumatic childhood experiences and antisocial personality disorder are associated with criminality variables. This has important implications on preventive treatments as well as on how prison services are addressing these problems.

The ESCRT-related CHMP1A and B proteins mediate multivesicular body sorting of auxin carriers in Arabidopsis and are required for plant development

Plasma membrane proteins internalized by endocytosis and targeted for degradation are sorted into lumenal vesicles of multivesicular bodies (MVBs) by the endosomal sorting complexes required for transport (ESCRT) machinery. Here, we show that the Arabidopsis thaliana ESCRT-related CHARGED MULTIVESICULAR BODY PROTEIN/CHROMATIN MODIFYING PROTEIN1A (CHMP1A) and CHMP1B proteins are essential for embryo and seedling development. Double homozygous chmp1a chmp1b mutant embryos showed limited polar differentiation and failed to establish bilateral symmetry. Mutant seedlings show disorganized apical meristems and rudimentary true leaves with clustered stomata and abnormal vein patterns. Mutant embryos failed to establish normal auxin gradients. Three proteins involved in auxin transport, PINFORMED1 (PIN1), PIN2, and AUXIN-RESISTANT1 (AUX1) mislocalized to the vacuolar membrane of the mutant. PIN1 was detected in MVB lumenal vesicles of control cells but remained in the limiting membrane of chmp1a chmp1b MVBs. The chmp1a chmp1b mutant forms significantly fewer MVB lumenal vesicles than the wild type. Furthermore, CHMP1A interacts in vitro with the ESCRT-related proteins At SKD1 and At LIP5. Thus, Arabidopsis CHMP1A and B are ESCRT-related proteins with conserved endosomal functions, and the auxin carriers PIN1, PIN2, and AUX1 are ESCRT cargo proteins in the MVB sorting pathway.

A SNARE complex unique to seed plants is required for protein storage vacuole biogenesis and seed development of Arabidopsis thaliana

The SNARE complex is a key regulator of vesicular traffic, executing membrane fusion between transport vesicles or organelles and target membranes. A functional SNARE complex consists of four coiled-coil helical bundles, three of which are supplied by Q-SNAREs and another from an R-SNARE. Arabidopsis thaliana VAMP727 is an R-SNARE, with homologs only in seed plants. We have found that VAMP727 colocalizes with SYP22/ VAM3, a Q-SNARE, on a subpopulation of prevacuolar compartments/endosomes closely associated with the vacuolar membrane. Genetic and biochemical analyses, including examination of a synergistic interaction of vamp727 and syp22 mutations, histological examination of protein localization, and coimmunoprecipitation from Arabidopsis lysates indicate that VAMP727 forms a complex with SYP22, VTI11, and SYP51 and that this complex plays a crucial role in vacuolar transport, seed maturation, and vacuole biogenesis. We suggest that the VAMP727 complex mediates the membrane fusion between the prevacuolar compartment and the vacuole and that this process has evolved as an essential step for seed development.

Endosomal functions in plants

Plant endosomes are highly dynamic organelles that are involved in the constitutive recycling of plasma membrane cargo and the trafficking of polarized plasma membrane proteins such as auxin carriers. In addition, recent studies have shown that surface receptors such as the plant defense-related FLS2 receptor and the brassinosteroid receptor BRI1 appear to signal from endosomes upon ligand binding and internalization. In yeast and mammals, endosomes are also known to recycle vacuolar cargo receptors back to the trans Golgi network and sort membrane proteins for degradation in the vacuole/lysosome. Some of these sorting mechanisms are mediated by the retromer and endosomal sorting complex required for transport (ESCRT) complexes. Plants contain orthologs of all major retromer and ESCRT complex subunits, but they have also evolved variations in endosomal functions connected to plant-specific features such as the diversity of vacuolar transport pathways. This review focuses on recent studies in plants dealing with the regulation of endosomal recycling functions, architecture and formation of multivesicular bodies, ligand-mediated endocytosis and receptor signaling from endosomes as well as novel endosomal markers and the function of endosomes in the transport and processing of soluble vacuolar proteins.

Association between depression and subclinical carotid atherosclerosis in patients with Type 1 diabetes

AIMS

Recent studies have suggested an association between depression and subclinical atherosclerosis as measured by presence of carotid atherosclerotic plaque and increased intima-media thickening in non-clinical populations. Given the high prevalence of depression in patients with Type 1 diabetes and the diabetes-related risk factors for atherosclerosis, we hypothesized that this relation might also be of special relevance in Type 1 diabetic patients.

METHODS

Intima-media thickness (IMT) and the presence of plaques in the carotid arteries were quantitatively assessed by high-resolution ultrasound in 175 adults (89 men, 86 women) with an established diagnosis of Type 1 diabetes. Having been treated for depression or current Beck Depression Inventory scores > 10 were considered to indicate depression.

RESULTS

In men, the risk of plaque was higher in depressed subjects relative to non-depressed participants after adjustment for age, smoking status, systolic blood pressure, dyslipidaemia and body mass index [odds ratio (OR) 5.19; 95% confidence interval (CI) 1.29, 20.81]. Depressed women did not have an increased risk of plaque compared with non-depressed women (OR 0.97; 95% 95% CI 0.22, 4.34). We did not observe an association between depression and IMT, in men or in women.

CONCLUSIONS

In line with previous research, our findings suggest a link between depression and subclinical atherosclerosis in Type 1 diabetic men, but not in women.

[Categorical versus dimensional classification of personality disorders: are dimensional models the future?]

The classification of personality disorders (PD) according to ICD-10 and DSM-IV has been critisized for several reasons. For example, those who have attempted to validate the presence of a non-arbitrary distinction between normal and abnormal personality functioning have suggested that no such distinction exists. Furthermore, PDs frequently co-occur with a number of Axis-I conditions and other Axis-II disorders leading to multiple diagnoses. Therefore, many have suggested classifying PDs dimensionally, rather than categorically. However, there are only a few studies that have investigated the applicability of these models with respect to PDs, and most of these studies used the Big Five. In this study we investigated the applicability of the Seven-Factor model of temperament and character for the classification of PDs. Our results show that the Seven-Factor model discriminates well between PDs and healthy controls, as well as between PDs and Axis-I disorders. We discuss our findings and present a modified scheme to diagnose PDs.

The Arabidopsis elch mutant reveals functions of an ESCRT component in cytokinesis

Recently, an alternative route to the proteasomal protein-degradation pathway was discovered that specifically targets transmembrane proteins marked with a single ubiquitin to the endosomal multivesicular body (MVB) and, subsequently, to the vacuole (yeast) or lysosome (animals), where they are degraded by proteases. Vps23p/TSG101 is a key component of the ESCRT I-III machinery in yeast and animals that recognizes mono-ubiquitylated proteins and sorts them into the MVB. Here, we report that the Arabidopsis ELCH (ELC) gene encodes a Vps23p/TSG101 homolog, and that homologs of all known ESCRT I-III components are present in the Arabidopsis genome. As with its animal and yeast counterparts, ELC binds ubiquitin and localizes to endosomes. Gel-filtration experiments indicate that ELC is a component of a high-molecular-weight complex. Yeast two-hybrid and immunoprecipitation assays showed that ELC interacts with Arabidopsis homologs of the ESCRT I complex. The elc mutant shows multiple nuclei in various cell types, indicating a role in cytokinesis. Double-mutant analysis with kaktus shows that increased ploidy levels do not influence the cytokinesis effect of elc mutants, suggesting that ELC is only important during the first endoreduplication cycle. Double mutants with tubulin folding cofactor a mutants show a synergistic phenotype, suggesting that ELC regulates cytokinesis through the microtubule cytoskeleton.