Signal thresholds and modular synergy during expression of costimulatory molecules in B lymphocytes

We analyzed intracellular pathways modulating surface densities of CD80 and CD86 in B cells activated through ligation of the Ag receptor, and the adhesion molecule CD54. Whereas B cell Ag receptor (BCR) cross-linking alone stimulated increased expression of CD86, up-regulation of CD80 required dual stimulation with anti-IgM and anti-CD54. The principal downstream component contributed by BCR signaling, toward both CD80 and CD86 induction, was the elevated concentration of free cytoplasmic Ca2+, recruited by way of capacitative influx. This alone was sufficient to generate an increase in CD86 levels. However, CD80 enhancement required the concerted action of both intracellular Ca2+ concentration and CD54-initiated pathways. The nexus between anti-IgM and anti-CD54 stimulation, in the context of CD80 regulation, was identified to involve a self-propagating process of sequential synergy. The first step involved amplified accumulation of intracellular cAMP, as a result of cross-talk between BCR-mobilized Ca2+ and CD54-derived signals. This then facilitated a second synergistic interaction between Ca2+ and cAMP, culminating in CD80 expression. Our findings of distinct signal transducer requirements, with the added consequences of cross-talk, offers an explanation for variable modulation of costimulatory molecule expression in response to diverse physiological stimuli. Importantly, these results also reveal how concentration threshold barriers for recruitment of individual second messengers can be overcome by constructive convergence of signaling modules

Regulation of transcript elongation through cooperative and ordered recruitment of cofactors

We studied the regulation of murine CD80, a gene whose basal transcriptional status was characterized by the presence of a stalled RNA polymerase II complex on the promoter-proximal region. Stimulus-induced activation of productive elongation involved a complex interplay of regulated events that included a synergy between ordered cofactor recruitment. This cascade of recruitments was initiated through the engagement of transcription factor NF-κB, leading to the temporal association of histone acetyltransferases and the consequent selective acetylation of a transcription start site downstream nucleosome. This in turn culminated into the nucleosomal association of Brd4-associated P-TEFb, a protein complex containing kinase specific for serine 2 of Rbp 1, the largest subunit of the carboxyl-terminal domain of RNA polymerase II. The consequent phosphorylation of serine 2 residues in CTD by CDK9 in the P-TEFb complex then facilitated escape of polymerase II into the productive elongation phase. Thus, the cooperative mechanisms that integrate between independent pathways characterize regulation of the elongation step of transcription, thereby providing another level at which specificity of gene regulation can be achieved

Transcription regulation from a TATA and INR-less promoter: spatial segregation of promoter function

The mode of regulation of class II genes that lack the known core promoter elements is presently unclear. Here, we studied one such example, the murine CD80 gene. An unusual mechanism was revealed wherein the pre-initiation complex (PIC) first assembled on an upstream, NF-κB enhancer element. Notably, this assembly occurred independent of contributions from the core promoter domain, and resulted in a PIC that was competent for transcription initiation. Positioning was subsequently achieved by exploiting the intrinsic architecture of the promoter, by virtue of which the tethered PIC was spatially juxtaposed with the transcription initiation site. Bridging interactions then ensued, through protein-protein contacts, which then enabled the elongation phase of CD80 transcription

The N Terminus of Sarcolipin Plays an Important Role in Uncoupling Sarco-endoplasmic Reticulum Ca²⁺-ATPase (SERCA) ATP Hydrolysis from Ca²⁺ Transport

The sarcoendoplasmic reticulum Ca(2+)-ATPase (SERCA) is responsible for intracellular Ca(2+) homeostasis. SERCA activity in muscle can be regulated by phospholamban (PLB), an affinity modulator, and sarcolipin (SLN), an uncoupler. Although PLB gets dislodged from Ca(2+)-bound SERCA, SLN continues to bind SERCA throughout its kinetic cycle and promotes uncoupling of Ca(2+) transport from ATP hydrolysis. To determine the structural regions of SLN that mediate uncoupling of SERCA, we employed mutagenesis and generated chimeras of PLB and SLN. In this study we demonstrate that deletion of SLN N-terminal residues (2)ERSTQ leads to loss of the uncoupling function even though the truncated peptide can target and constitutively bind SERCA. Furthermore, molecular dynamics simulations of SLN and SERCA interaction showed a rearrangement of SERCA residues that is altered when the SLN N terminus is deleted. Interestingly, transfer of the PLB cytosolic domain to the SLN transmembrane (TM) and luminal tail causes the chimeric protein to lose SLN-like function. Further introduction of the PLB TM region into this chimera resulted in conversion to full PLB-like function. We also found that swapping PLB N and C termini with those from SLN caused the resulting chimera to acquire SLN-like function. Swapping the C terminus alone was not sufficient for this conversion. These results suggest that domains can be switched between SLN and PLB without losing the ability to regulate SERCA activity; however, the resulting chimeras acquire functions different from the parent molecules. Importantly, our studies highlight that the N termini of SLN and PLB influence their respective unique functions

Germination and Graft Compatibilty Study of Wild Solanum spp and Brinjal Root Stocks with Tomato Scions

The experiment was conducted at Central Horticultural Experiment Station, ICAR- IIHR, Aiginia, Bhubaneswar, Odisha, India during kharif seasons of 2018 in collaboration with Odisha University of Agriculture and Technology, Bhubaneswar, to study the seed germination, days taken to reach grafting stage and grafting success (percentage) of rootstock and scion seeds used for grafting. The cultivated and wild species of brinjal and tomato were used as rootstocks with tomato Arka Rakshak F1 hybrid as scion. The experiment was conducted with 13 root stocks following statistical design CRD with three replications in pro trays to find out better root stock for grafting. A significant difference was recorded for the rootstock and scion parameters. Utkal Anushree had taken minimum number of days (6.67 days) for germination and the wild Solanum torvum had taken maximum number of days (16.67 days) to germinate, On the other hand, Arka Rakshak took least number of days (34.33 days) to reach grafting stage while the wild Solanum torvum reached to grafting stage within 56 days. The grafting success percentage ranged from 74.67 to 96 percent. Maximum grafting success (%) was recorded in Solanum torvum whereas minimum grafting success (%) was observed in S. sisymbriifolium wild solanum spp. root stock

Indian Association for Geriatric Mental Health's multicentric study on depression in elderly: Symptom profile and influence of gender, age of onset, age at presentation, and number of episodes on symptom profile

Aim of the Study: To assess the symptom profile of depression among elderly patients presenting to psychiatric outpatient settings. An additional aim was to evaluate the influence of gender, age of onset, age at presentation, and type of episode (i.e., the first episode versus recurrent depressive episodes) on symptom profile of geriatric depression. Materials and Methods: This multicentric study was conducted at eight centers in which 488 elderly patients (aged ≥60 years) with depression were evaluated on Geriatric Depression Scale (GDS-30), Generalized Anxiety Disorder-7 Scale (GAD-7), Patient Health Questionnaire-15 (PHQ-15) scale, and Columbia Suicide Severity Rating Scale. Results: Males had significantly higher prevalence of comorbid substance dependence, whereas females had significantly higher prevalence of comorbid psychiatric disorders. As per the GDS-30, about two-third or more of the study sample had symptoms of feeling helpless (71.7%), often getting restless and fidgety (70.1%), dropped many of their activities (68.4%), frequently feel like crying (67.4%), trouble concentrating (67%), feels pretty worthless (66.4%), often feeling downhearted and blue (65.8%), frequently getting upset over little things (64.8%), and not satisfied with life (62.9%). More than two-third of the sample had all the symptoms of anxiety as per the GAD-7 and 7 out of the 14 somatic symptoms as per the PHQ-15. When comparisons were made between males and females, significant difference in prevalence was noted for some of the depressive symptoms as assessed by the GDS-30 and somatic symptoms as assessed by the PHQ-15, but no differences emerged in terms of anxiety symptoms. Significantly higher proportion of females reported active suicidal ideation with specific plan and intent and had higher intensity of suicidal ideations. Differences in symptom profile were also noted with regard to age of onset (<60 and ≥60 years), age at presentation (<70 and ≥70 years), and type of depression (single versus multiple episodes). Conclusion: The present study suggests that somatic and anxiety symptoms are highly prevalent among elderly patients with depression. Further, it is evident that there are certain differences in the symptom profile of depression among male and female patients with depression. The present study also reveals that age of onset, age at presentation, and number of episodes could also influence the symptom profile of depression among the elderly

Prevalence of physical comorbidity and prescription patterns in elderly patients with depression: A multicentric study under the aegis of IAGMH

Aim of the Study: This study aims to evaluate the prevalence of physical comorbidities and prescription patterns in elderly patients with depression. Materials and Methods: This study included 488 elderly patients (aged ≥60 years) with depression recruited across eight centers. A self-designed physical comorbidity checklist was used to assess for the presence of various physical comorbidities and prescription of psychotropic medications was recorded. Results: More than three-fourth of the study sample (n = 384; 78.7%) had at least one physical comorbidities and one-third (36.7%) of the samples had at least three physical illnesses. About half of the study samples had hypertension (47.3%) and slightly more than one-fourth had diabetes mellitus (29%). The most common physical illness involved the cardiovascular system (51.5%), followed by endocrinological system (39.3%), orthopedic and joint-related diseases (35%), and ophthalmological problems (22.3%). Those with physical comorbidity had higher severity of depression, anxiety, and somatic symptom. Sertraline was the most preferred antidepressant followed by escitalopram and mirtazapine. Only 12.7% of the sample was prescribed antipsychotics of which quetiapine and olanzapine were the most commonly used agents. Benzodiazepines were prescribed to more than half of the study samples (56.55%), with clonazepam being the most preferred benzodiazepine followed by lorazepam. Compared to those without hypertension, those with hypertension were more commonly prescribed sertraline and escitalopram and less commonly prescribed fluoxetine. Similarly, compared to those without diabetes mellitus, those with diabetes mellitus were more commonly prescribed sertraline and less commonly prescribed fluoxetine. Conclusion: Comorbid physical illnesses are highly prevalent in elderly participants with depression with hypertension being the most common physical comorbidity followed by diabetes mellitus and osteoarthritis. The presence of physical comorbidity is associated with more frequent prescription of sertraline and escitalopram

Relationship of loneliness and social connectedness with depression in elderly: A multicentric study under the aegis of Indian Association for Geriatric Mental Health

Aim of the Study: This study aimed to evaluate the prevalence of loneliness and its relationship with social connectedness and depression in elderly. Additional aims were to evaluate the demographic and clinical factors associated with loneliness and social connectedness in elderly patients with depression. Methodology: The study sample comprised 488 elderly patients (age ≥60 years) with depression recruited across 8 centers. These patients were evaluated on Geriatric Depression Scale (GDS-30), Generalized Anxiety Disorder-7 Scale (GAD-7), Patient Health Questionnaire-15 (PHQ-15) Scale, Columbia Suicide Severity Rating Scale, UCLA Loneliness Scale (LS), and Revised Social Connectedness Scale. Results: About three-fourth (77.3%) of the entire sample reported the presence of loneliness. With respect to specific loneliness symptom, 62.5% reported lack of companionship, 58.7% reported being left out in life, and 56.5% of the individuals reported felt isolated from others. No gender differences were noted in the prevalence of any loneliness symptom. Higher loneliness scores had significant positive correlation with severity of depression, anxiety, and somatic symptoms as assessed by GDS-30, PHQ-15, and GAD-7, respectively, in individuals of both the genders. Higher social connectedness was associated with higher level of anxiety and lower loneliness in females only. Being currently single, older age, longer duration of illness, presence of family history of mental illness, presence of comorbid physical illness, and absence of substance abuse were associated with higher loneliness. With regard to suicidality, higher loneliness was associated with nonspecific active suicidal thoughts, active suicidal ideations with and without intent, nonsuicidal behavior, and higher intensity of suicidal ideations. Conclusions: About three-fourth of the elderly patients with depression also have associated loneliness. Loneliness is associated with higher severity of depression, anxiety, and somatic symptoms. Severity of depression is associated with loneliness but not with social connectedness. Lower social connectedness among elderly females with depression is associated with higher loneliness, but this is not true for elderly males with depression