Differential contributions of G protein- or arrestin subtype-mediated signalling underlie urocortin 3-induced somatostatin secretion in pancreatic δ cells

BACKGROUND AND PURPOSE

Pancreatic islets are modulated by cross-talk among different cell types and paracrine signalling plays important roles in maintaining glucose homeostasis. Urocortin 3 (UCN3) secreted by pancreatic β cells activates the CRF2 receptor (CRF2R) and downstream pathways mediated by different G protein or arrestin subtypes in δ cells to cause somatostatin (SST) secretion, and constitutes an important feedback circuit for glucose homeostasis.

EXPERIMENTAL APPROACH

Here, we used Arrb1-/-, Arrb2-/-, Gsfl/fl and Gqfl/fl knockout mice, the G11-shRNA-GFPfl/fl lentivirus, as well as functional assays and pharmacological characterization to study how the coupling of Gs, G11 and β-arrestin1 to CRF2R contributed to UCN3-induced SST secretion in pancreatic δ cells.

KEY RESULTS

Our study showed that CRF2R coupled to a panel of G protein and arrestin subtypes in response to UCN3 engagement. While RyR3 phosphorylation by PKA at the S156, S2706 and S4697 sites may underlie the Gs-mediated UCN3- CRF2R axis for SST secretion, the interaction of SYT1 with β-arrestin1 is also essential for efficient SST secretion downstream of CRF2R. The specific expression of the transcription factor Stat6 may contribute to G11 expression in pancreatic δ cells. Furthermore, we found that different UCN3 concentrations may have distinct effects on glucose homeostasis, and these effects may depend on different CRF2R downstream effectors.

CONCLUSIONS AND IMPLICATIONS

Collectively, our results provide a landscape view of signalling mediated by different G protein or arrestin subtypes downstream of paracrine UCN3- CRF2R signalling in pancreatic β-δ-cell circuits, which may facilitate the understanding of fine-tuned glucose homeostasis networks.

A distinctive subcortical functional connectivity pattern linking negative affect and treatment outcome in major depressive disorder

Major depressive disorder (MDD) is associated with functional disturbances in subcortical regions. In this naturalistic prospective study (NCT03294525), we aimed to investigate relationships among subcortical functional connectivity (FC), mood symptom profiles and treatment outcome in MDD using multivariate methods. Medication-free participants with MDD (n = 135) underwent a functional magnetic resonance imaging scan at baseline and completed posttreatment clinical assessment after 8 weeks of antidepressant monotherapy. We used partial least squares (PLS) correlation analysis to explore the association between subcortical FC and mood symptom profiles. FC score, reflecting the weighted representation of each individual in this association, was computed. Replication analysis was undertaken in an independent sample (n = 74). We also investigated the relationship between FC score and treatment outcome in the main sample. A distinctive subcortical connectivity pattern was found to be associated with negative affect. In general, higher FC between the caudate, putamen and thalamus was associated with greater negative affect. This association was partly replicated in the independent sample (similarity between the two samples: r = 0.66 for subcortical connectivity, r = 0.75 for mood symptom profile). Lower FC score predicted both remission and response to treatment after 8 weeks of antidepressant monotherapy. The emphasis here on the role of dorsal striatum and thalamus consolidates prior work of subcortical connectivity in MDD. The findings provide insight into the pathogenesis of MDD, linking subcortical FC with negative affect. However, while the FC score significantly predicted treatment outcome, the low odds ratio suggests that finding predictive biomarkers for depression remains an aspiration.

The prevalence and clinical correlates of suicide attempts in patients with bipolar disorder misdiagnosed with major depressive disorder: Results from a national survey in China

BACKGROUND AND AIM

Suicide is nearly always associated with underlying mental disorders. Risk factors for suicide attempts (SAs) in patients with bipolar disorder (BD) misdiagnosed with major depressive disorder (MDD) remain unelucidated. This study was to evaluate the prevalence and clinical risk factors of SAs in Chinese patients with BD misdiagnosed with MDD.

METHODS

A total of 1487 patients with MDD from 13 mental health institutions in China were enrolled. Mini International Neuropsychiatric Interview (MINI) was used to identify patients with BD who are misdiagnosed as MDD. The general sociodemographic and clinical data of the patients were collected and MINI suicide module was used to identify patients with SAs in these misdiagnosed patients.

RESULTS

In China, 20.6% of patients with BD were incorrectly diagnosed as having MDD. Among these misdiagnosed patients, 26.5% had attempted suicide. These patients tended to be older, had a higher number of hospitalizations, and were more likely to experience frequent and seasonal depressive episodes with atypical features, psychotic symptoms, and suicidal thoughts. Frequent depressive episodes and suicidal thoughts during depression were identified as independent risk factors for SAs. Additionally, significant sociodemographic and clinical differences were found between individuals misdiagnosed with MDD in BD and patients with MDD who have attempted suicide.

CONCLUSIONS

This study highlights the importance of accurate diagnosis in individuals with BD and provide valuable insights for the targeted identification and intervention of individuals with BD misdiagnosed as having MDD and those with genuine MDD, particularly in relation to suicidal behavior.

[Clinical pathological and genetic mutation characteristics of conjunctival lymphoepithelial carcinoma]

Objective: To analyze the clinical pathological and genetic mutation characteristics of conjunctival lymphoepithelial carcinoma. Methods: A retrospective case series study was conducted. Data from three patients diagnosed with conjunctival lymphoepithelial carcinoma and treated with tumor resection surgery at Tianjin Eye Hospital from January 2006 to December 2022 were collected. Four paraffin specimens (including one patient undergoing two surgeries) were subjected to immunohistochemical staining for epithelial antigen and lymphocytic antigen. Epstein-Barr virus (EBV)-encoded RNA (EBER) was detected using in situ hybridization, and whole-exome sequencing was performed on three specimens from two patients using next-generation sequencing methods. Results: All three patients were males aged over 65, with a disease duration ranging from 3 to 44 months. The tumors were unilateral, located on the bulbar or limbal conjunctiva, appearing red, with a maximum diameter of 4-20 mm. Imaging examinations revealed anterior location of the tumors with no involvement of the orbital bone, extraocular muscles, optic nerve, or paranasal sinuses. No local lymph node metastasis was observed in any patient. Pathological findings included undifferentiated carcinoma nests with significant reactive lymphocytic and plasma cell infiltration. Tumor cells were positive for pan-cytokeratin (CK-pan), epithelial membrane antigen (EMA), tumor protein 40 (p40), and tumor protein 63 (p63), with a cell proliferation index (Ki67) exceeding 80%. Cluster of differentiation 20 (CD20), CD3, and CD8 were positive for lymphocytes. In situ hybridization showed partial tumor cell expression of EBER in two specimens of one patient. Whole-exome sequencing revealed 58, 50, and 36 mutated genes in the three specimens, with enriched signaling pathways including melanoma signaling pathway, Notch1 signaling pathway, and RHOQ GTP cycle; enriched biochemical processes included amino acid starvation response, programmed cell death, regulation of lipid synthesis, sodium ion transport, and chromosome segregation. The common mutated gene in all three specimens was SZT2, and SZT2 was involved in the amino acid starvation response. One patient underwent a second complete resection surgery 40 months after partial excision, while the other two underwent complete resection surgery without recurrence. Two patients did not undergo radiation or chemotherapy, and one was lost to follow-up. Conclusions: Conjunctival lymphoepithelial carcinoma is associated with prominent lymphocytic and plasma cell infiltration, some cases are associated with EBV infection, and SZT2 mutations are present in conjunctival lymphoepithelial carcinoma.

High-Thermal Stable Epoxy Resin through Blending Nanoarchitectonics with Double-Decker-Shaped Polyhedral Silsesquioxane-Functionalized Benzoxazine Derivatives

A series of di-functional benzoxazine (BZ) monomers was synthesized, specifically the double-decker silsesquioxane (DDSQ) cage structure (DDSQ-BZ). Comparative analyses were conducted between DDSQ-BZ monomers and the most commonly utilized bisphenol A-functionalized bifunctional benzoxazine (BPA-BZ) monomer. DDSQ-BZ compounds possess better thermal properties such as high char yield and high thermal decomposition temperature (Td10) after thermal ring-opening polymerization (ROP) because the inorganic DDSQ cage nanostructure features a nano-reinforcement effect. In addition, blending inorganic DDSQ-BZ compounds with epoxy resin was explored to form organic/inorganic hybrids with enhanced thermal and mechanical properties following thermal ROP. The improvement in mechanical properties is primarily attributed to the network structure formed by the cross-linking between DDSQ-BZ and the epoxy resin during thermal ROP, as well as hydrogen bonding interactions formed between the hydroxyl groups generated during thermal ROP and the Si-O-Si bonds in the DDSQ structure.

[Clinical characteristics analysis of patients with severe immune checkpoint inhibitors related myocarditis]

Objective: To analyze the clinical characteristics of patients with severe immune checkpoint inhibitors (ICIs) related myocarditis. Methods: A retrospective study was conducted on the 50 patients with ICIs-related myocarditis in the multidisciplinary cardio-oncology clinic of Zhongshan Hospital affiliated to Fudan University from April 2020 to April 2022. The age of patients was (63.7±10.8) years old, including 37 males and 13 females. The patients were divided into the mild group (n=37) and the severe group (n=13) according to severity. The differences of basic characteristics, clinical manifestations, laboratory tests, auxiliary examination, combined irAEs, treatment and outcomes between the two groups of patients were analyzed. Results: The immunotherapy time [M(Q1,Q3)] of patients in the mild group and severe group were 81 (49, 134) and 24 (20, 116) days, respectively (P<0.05). In the severe group, the levels of cTnT [0.605 (0.317, 1.072) μg/L], NT-proBNP [1 126 (386, 1 744) ng/L], CK-MB [78 (48, 238) U/L], and CK-MM [240 (45, 6 543) U/L] were higher than those in the mild group [0.104 (0.045, 0.189) μg/L, 237 (39, 785) ng/L, 24 (20, 33) U/L, 108 (72, 168) U/L, respectively] (all P<0.05). The left ventricular ejection fraction of the severe group [64% (57%, 65%)] was lower than that of the mild group [66% (63%, 69%)] (P<0.05), and the incidence of conduction block (n=4, 4/13) and abnormal ventricular wall motion (n=4, 4/13), the incidence of ICIs-related myositis (n=10, 10/13), ICIs-related hepatitis (n=4, 4/13) and ICIs-related neurotoxicity (n=4, 4/13) were higher than those in the mild group (n=1, 2.7%; n=2, 5.4%; n=16, 43.2%; n=2, 5.4%; n=1, 2.7%, respectively) (all P<0.05). The proportion of patients receiving intensified immunosuppressive therapy and mortality rate in the severe group were 12/13 (n=12) and 4/13 (n=4), which were both higher than those in the mild group [10.8% (n=4) and 0] (both P<0.05). Conclusions: The incidence of ICIs-related myocarditis is not high, but the severe rate and mortality are high. The differential diagnosis of severe ICIs related myocarditis should be combined with myocardial markers, electrocardiogram and echocardiogram, and early diagnosis and treatment can improve the prognosis of patients.

[Clinical pathological characteristics analysis of ocular adnexal follicular lymphoma]

Objective: To investigate the clinical pathological characteristics of ocular adnexal follicular lymphoma (OAFL). Methods: A retrospective case series study was conducted. Clinical data of 10 OAFL patients diagnosed at Tianjin Eye Hospital from January 1990 to May 2022 were collected. The study analyzed general patient information, medical history, site of involvement, imaging, histopathology, and molecular detection. Among them, 7 cases underwent Epstein-Barr virus-encoded small RNA (EBER) and B-cell lymphoma protein 2 (BCL-2)/immunoglobulin heavy chain gene (IgH) translocation gene detection. Treatment and prognosis of patients were followed up. Results: All 10 patients (10 eyes) had unilateral involvement, including 5 males and 5 females, with an age range of 58 (43, 68) years. Clinical manifestations included eyelid swelling, pink conjunctival thickening, painless slow-growing masses in the lacrimal gland area, extraconal muscle cone, conjunctiva, lacrimal sac, or a combination of lacrimal sac and conjunctiva. Among them, 8 cases were primary, and 2 cases were secondary. According to the Ann Arbor staging, 8 cases were stage Ⅰ-Ⅱ E, and 2 cases were stage Ⅲ E. Histopathological grading revealed 6 cases of grade 1-2 and 3 cases of grade 3A. One case showed grade 3B in the lacrimal sac area and grade 1-2 in the conjunctiva. The predominant subtype was follicular in 4 cases, diffuse in 3 cases, and mixed in 2 cases. One case had a mixed subtype involving the lacrimal sac and conjunctiva. All patients expressed positivity for leukocyte differentiation antigens (CD) 20, CD21, and CD23. Nine cases were positive for CD10, with 1 case showing partial CD10 positivity. All patients were positive for B-cell lymphoma protein 6 (BCL-6), and 9 cases were positive for BCL-2. Specific markers CyclinD1 and Multiple Myeloma Oncogene Protein 1 (MUM-1) were negatively expressed in all cases. The Ki-67 proliferation index ranged from 10% to 90%. Molecular detection was performed in 7 patients, with none showing positive EBER in situ hybridization. However, 5 cases exhibited BCL2/IgH gene fusion. Among 7 patients with follow-up data, the median follow-up time was 17 (6, 34) months. Four patients achieved complete remission, 2 had partial remission, and 1 patient died due to lung infection. Conclusions: OAFL is a tumor originating from follicular center B-cells, characterized by positive expression of BCL-2, CD10, and BCL-6. It can involve the lacrimal gland, extraconal muscles, lacrimal sac, and conjunctiva. Patients generally have a favorable prognosis.

The Use of Problem-Based Learning Curriculum to Increase Medical Student Exposure to Radiation Oncology

PURPOSE/OBJECTIVE(S)

In recent years, there has been a decline in the number of radiation oncology residency applicants. New techniques to recruit students to the field are necessary. Early exposure to oncology care in pre-clinical years may translate to increased student interest in oncology-related fields and improved understanding of oncologic treatment modalities. We propose that a cancer-specific problem-based learning (PBL) case will increase exposure to oncology during pre-clinical years.

MATERIALS/METHODS

A PBL case regarding pancreatic cancer was created by a radiation oncology resident/faculty member and the gastrointestinal course director for first-year medical students (n = 140) at a single institution. The one-hour small group case focused on oncologic work up, multi-disciplinary care and radiotherapy concepts. Students were provided with a case prompt and resources to review prior to the PBL session. Volunteer radiation oncology facilitators then guided students through the case to achieve desired learning objectives. Following the PBL, students completed an optional nine-question survey regarding their experience.

RESULTS

A total of 76 (54%) medical students completed the post-PBL survey. The majority (89%) of students reported that the case motivated them to learn more about oncology, and almost all (99%) noted improved understanding of the multidisciplinary nature of cancer care. 75 (99%) students reported increased understanding of how radiotherapy is delivered. 62 (82%) students reported increased motivation to learn about radiation oncology. 38 (50%) students reported that they plan to participate in an elective in oncology. 36 (47%) reported that they are considering pursuing an oncologic field. There was an increase in the number of subscribers to the Oncology Interest Group (43% increase from previous year) and positive feedback was noted from free-text responses from participants.

CONCLUSION

Integrating a cancer-specific PBL case facilitated by radiation oncology educators into the pre-clinical curriculum is an effective avenue to introduce oncology concepts and stimulate interest in oncology amongst first-year medical students.

Intrinsic functional connectivity correlates of cognitive deficits involving sustained attention and executive function in bipolar disorder

BACKGROUND

The neural correlate of cognitive deficits in bipolar disorder (BD) is an issue that warrants further investigation. However, relatively few studies have examined the intrinsic functional connectivity (FC) underlying cognitive deficits involving sustained attention and executive function at both the region and network levels, as well as the different relationships between connectivity patterns and cognitive performance, in BD patients and healthy controls (HCs).

METHODS

Patients with BD (n = 59) and HCs (n = 52) underwent structural and resting-state functional magnetic resonance imaging and completed the Wisconsin Card Sorting Test (WCST), the continuous performance test and a clinical assessment. A seed-based approach was used to evaluate the intrinsic FC alterations in three core neurocognitive networks (the default mode network [DMN], the central executive network [CEN] and the salience network [SN]). Finally, we examined the relationship between FC and cognitive performance by using linear regression analyses.

RESULTS

Decreased FC was observed within the DMN, in the DMN-SN and DMN-CEN and increased FC was observed in the SN-CEN in BD. The alteration direction of regional FC was consistent with that of FC at the brain network level. Decreased FC between the left posterior cingulate cortex and right anterior cingulate cortex was associated with longer WCST completion time in BD patients (but not in HCs).

CONCLUSIONS

These findings emphasize the dominant role of the DMN in the psychopathology of BD and provide evidence that cognitive deficits in BD may be associated with aberrant FC between the anterior and posterior DMN.

[Clinical and pathological analysis of 35 cases of ocular adnexal solitary fibrous tumor]

Objective: To analyze the clinical and pathological characteristics and prognosis of 35 cases of solitary fibrous tumor of ocular adnexal (SFT). Methods: This was a retrospective case series study. The clinical data of 35 cases of ocular adnexal SFT was collected in Tianjin Eye Hospital from January 2000 to December 2020. The clinical manifestations, imaging examination results, pathological characteristics, treatment of patients were analyzed, and patients were followed up. All cases were classified according to the 2013 classification of World Health Organization of tumors of soft tissue and bone. Results: There were 21 males (60.0%) and 14 females (40.0%). The age range was 17 to 83 years, and the median age was 44 (35, 54)years. All patients were unilateral, with 23 (65.7%) in the right eye and 12 (34.3%) in the left eye. The course of disease ranged from 2 months to 11 years, with an a median duration of 12(6,36)months. Clinical manifestations included exophthalmos, limited eye movements, diplopia, and tearing. All patients underwent surgical treatment of complete resection of the tumor. Ocular adnexal SFT mostly occurred in the upper orbit (19 cases, 73.1%). On imaging examination, the tumor showed well-circumscribed space occupying lesion that heterogeneously enhanced with contrast, and abundant blood flow signals in the tumors. MRI showed isointensity or low signal on T1WI, and significantly enhanced on T2WI, presenting intermediate-to-high heterogeneous signals. The tumor diameter was 2.1 (1.5, 2.6) cm. There were 23 cases (65.7%) of classic subtype, 2 cases (5.7%) of giant cell subtype, 8 cases (22.9%) of myxoid subtype, and 2 cases (5.7%) of malignancy. Immunohistochemical staining showed that Vimentin, CD34 and STAT6 were positively expressed in all patients. Twenty-one cases (60.0%) showed positive expression of BCL-2, and Ki-67 positive index ranged from 1.0% to 10.0%. Tumors in this group were all low-risk according to the Demicco risk stratification. Follow-up was available for 25 patients with a duration of 2 years to 14 years and 7 months, and the median follow-up time was 88 (61, 124) months. Two patients relapsed, and no distant metastasis or death was observed. Conclusions: Ocular adnexal SFT mainly presents as a painless, slow-growing mass. And most of them are typical SFT. The imaging manifestations are varied Ocular adnexal SFT generally follows a benign course, with a good prognosis after complete excision. Recurrence could occur many years after surgery which requiring careful and long-term follow-up.

[The clinicopathological features of adult orbital xanthogranulomatous disease with lacrimal gland reactive lymphoid hyperplasia]

Objective: To investigate the clinicopathological features of adult orbital xanthogranulomatous disease (AOXGD) with lacrimal gland reactive lymphoid hyperplasia. Methods: Retrospective case series study. The clinical and pathological data of AOXGD cases diagnosed and treated in Tianjin Eye Hospital from January 2002 to December 2021 was reviewed, and the clinical characteristics, radiologic findings and pathological characteristics of periocular and lacrimal gland lesions of 5 cases were retrospectively analyzed. The expression of IgG4 and IgG protein in periocular and lacrimal gland lesions was detected by immunohistochemical staining, and the role of IgG4 in AOXGD was preliminarily studied. Results: There were four females and one male with an average age of 53.8 years (39 to 77 years). Among the five AOXGD cases, there were three cases of adult-onset xanthogranuloma, one case of adult-onset asthma and periocular xanthogranuloma, and one case of necrobiotic xanthogranuloma. All cases involved both eyes. The swelling of eyelids was observed in five cases, and the yellow or pale yellow eyelid skin was found in two cases. Imaging examinations showed the tumor mainly involved the eyelids, subcutaneous tissues, anterior orbit and lacrimal gland. A large number of foam cells and typical Touton giant cells were found in the periorbital lesions, accompanied by different degrees of fibrosis. The fibrinoid necrosis was detected in one case of necrobiotic xanthogranuloma. The lacrimal gland lesions showed different types of reactive lymphoid hyperplasia, including IgG4-related disease in two cases, follicular lymphoid hyperplasia in two cases and focal lymphoid hyperplasia in one case. IgG4 levels of periorbital and lacrimal gland lesions were elevated in four cases. Asthma and elevated serum IgG4 were found in one case of adult-onset periocular xanthogranuloma. Three patients underwent surgical resection and adjuvant hormone or immunosuppressive therapy, and two patients underwent simple surgical resection. The patients were followed up for 1.5 to 10.0 years, one patient was lost, and four patients had no recurrence. Conclusions: AOXGD with lacrimal gland reactive lymphoid hyperplasia is a group of rare diseases. The periorbital lesions of that are characterized by proliferation of foamy histiocytes and Touton giant cells, and the lacrimal gland lesions of that manifest as IgG4-related disease in some cases.

[Recommendations for diagnosis and treatment of psoriatic arthritis in China]

Psoriatic arthritis is a chronic systemic autoimmune disease, characterized by psoriasis skin lesions and inflammation of the spine and joint. It has complicated clinical manifestations and individual variations. Nearly half of the patients will have joints erosion in two years, which is crippling. The severity of the skin and joint disease frequently do not correlate with each other. Currently, the understanding of the disease is insufficient in China with the lack of standardized diagnosis and treatment. Therefore, researchers from the Chinese Rheumatology Association formulated this specification based on the diagnosis and management experience together with guidelines at home and abroad. The specification summarizes the present situation of domestic diagnosis and treatment, aiming to standardize the diagnosis process and treatment protocols of psoriatic arthritis. Furthermore, it can reduce misdiagnosis and missed diagnosis, as well as improve the prognosis.

Endogenous Lipid-GPR120 Signaling Modulates Pancreatic Islet Homeostasis to Different Extents

Long-chain fatty acids (LCFAs) are not only energy sources but also serve as signaling molecules. GPR120, an LCFA receptor, plays key roles in maintaining metabolic homeostasis. However, whether endogenous ligand-GPR120 circuits exist and how such circuits function in pancreatic islets are unclear. Here, we found that endogenous GPR120 activity in pancreatic δ-cells modulated islet functions. At least two unsaturated LCFAs, oleic acid (OA) and linoleic acid (LA), were identified as GPR120 agonists within pancreatic islets. These two LCFAs promoted insulin secretion by inhibiting somatostatin secretion and showed bias activation of GPR120 in a model system. Compared with OA, LA exerted higher potency in promoting insulin secretion, which is dependent on β-arrestin2 function. Moreover, GPR120 signaling was impaired in the diabetic db/db model, and replenishing OA and LA improved islet function in both the db/db and streptozotocin-treated diabetic models. Consistently, the administration of LA improved glucose metabolism in db/db mice. Collectively, our results reveal that endogenous LCFA-GPR120 circuits exist and modulate homeostasis in pancreatic islets. The contributions of phenotype differences caused by different LCFA-GPR120 circuits within islets highlight the roles of fine-tuned ligand-receptor signaling networks in maintaining islet homeostasis.

Autonomous sensing of the insulin peptide by an olfactory G protein-coupled receptor modulates glucose metabolism

Along with functionally intact insulin, diabetes-associated insulin peptides are secreted by β cells. By screening the expression and functional characterization of olfactory receptors (ORs) in pancreatic islets, we identified Olfr109 as the receptor that detects insulin peptides. The engagement of one insulin peptide, insB:9-23, with Olfr109 diminished insulin secretion through Gi-cAMP signaling and promoted islet-resident macrophage proliferation through a β cell-macrophage circuit and a β-arrestin-1-mediated CCL2 pathway, as evidenced by β-arrestin-1^-/- mouse models. Systemic Olfr109 deficiency or deficiency induced by Pdx1-Cre^+/-Olfr109^fl/fl specifically alleviated intra-islet inflammatory responses and improved glucose homeostasis in Akita- and high-fat diet (HFD)-fed mice. We further determined the binding mode between insB:9-23 and Olfr109. A pepducin-based Olfr109 antagonist improved glucose homeostasis in diabetic and obese mouse models. Collectively, we found that pancreatic β cells use Olfr109 to autonomously detect self-secreted insulin peptides, and this detection arrests insulin secretion and crosstalks with macrophages to increase intra-islet inflammation.

Anxiety symptom remission is associated with genetic variation of PTPRZ1 among patients with major depressive disorder treated with escitalopram

OBJECTIVES

Genome-wide analyses of antidepressant response have suggested that genes initially associated with risk for schizophrenia may also serve as promising candidates for selective serotonin reuptake inhibitor (SSRI) efficacy. Protein tyrosine phosphatase, receptor-type, zeta-1 (PTPRZ1) has previously been shown to be associated with schizophrenia, but it has not been investigated as a predictor of antidepressant efficacy. The main objective of the study was to assess whether SSRI-mediated depressive and anxiety symptom remission in Chinese patients with major depressive disorder (MDD) are associated with specific PTPRZ1 variants.

METHODS

Two independent cohorts were investigated, the first sample (N = 344) received an SSRI (i.e. fluoxetine, sertraline, citalopram, escitalopram, fluvoxamine, or paroxetine) for 8 weeks. The second sample (N = 160) only received escitalopram for 8 weeks. Hamilton Depression and Hamilton Anxiety Rating Scale scores at 8-weeks post-baseline in both cohorts were used to determine remission status. Five PTPRZ1 variants (rs12154537, rs6466810, rs6466808, rs6955395, and rs1918031) were genotyped in both cohorts.

RESULTS

Anxiety symptom remission was robustly associated with PTPRZ1 rs12154537 (P = 0.004) and the G-G-G-G haplotype (rs12154537-rs6466810-rs6466808-rs6955395; P = 0.005) in cohort 2 but not cohort 1 (mixed SSRI use). Associations with depressive symptom remission did not survive correction for multiple testing.

CONCLUSIONS

These findings suggest that PTPRZ1 variants may serve as a marker of escitalopram-mediated anxiety symptom remission in MDD.

An ionic lock and a hydrophobic zipper mediate the coupling between an insect pheromone receptor BmOR3 and downstream effectors

Pheromone receptors (PRs) recognize specific pheromone compounds to guide the behavioral outputs of insects, which are the most diverse group of animals on earth. The activation of PRs is known to couple to the calcium permeability of their coreceptor (Orco) or putatively with G proteins; however, the underlying mechanisms of this process are not yet fully understood. Moreover, whether this transverse seven transmembrane domain (7TM)-containing receptor is able to couple to arrestin, a common effector for many conventional 7TM receptors, is unknown. Herein, using the PR BmOR3 from the silk moth Bombyx mori and its coreceptor BmOrco as a template, we revealed that an agonist-induced conformational change of BmOR3 was transmitted to BmOrco through transmembrane segment 7 from both receptors, resulting in the activation of BmOrco. Key interactions, including an ionic lock and a hydrophobic zipper, are essential in mediating the functional coupling between BmOR3 and BmOrco. BmOR3 also selectively coupled with Gi proteins, which was dispensable for BmOrco coupling. Moreover, we demonstrated that trans-7TM BmOR3 recruited arrestin in an agonist-dependent manner, which indicates an important role for BmOR3–BmOrco complex formation in ionotropic functions. Collectively, our study identified the coupling of G protein and arrestin to a prototype trans-7TM PR, BmOR3, and provided important mechanistic insights into the coupling of active PRs to their downstream effectors, including coreceptors, G proteins, and arrestin.

Solid-State NMR Studies of the Succinate-Acetate Permease from Citrobacter Koseri in Liposomes and Native Nanodiscs

The succinate-acetate permease (SatP) is an anion channel with six transmembrane domains. It forms different oligomers, especially hexamers in the detergent as well as in the membrane. Solid-state NMR studies of SatP were carried out successfully on SatP complexes by reconstructing the protein into liposomes or retaining the protein in the native membrane of E. coli., where it was expressed. The comparison of ¹³C-¹³C 2D correlation spectra between the two samples showed great similarity, opening the possibility to further study the acetate transport mechanism of SatP in its native membrane environment. Solid-state NMR studies also revealed small chemical shift differences of SatP in the two different membrane systems, indicating the importance of the lipid environment in determining the membrane protein structures and dynamics. Combining different 2D SSNMR spectra, chemical shift assignments were made on some sites, consistent with the helical structures in the transmembrane domains. In the end, we pointed out the limitation in the sensitivity for membrane proteins with such a size, and also indicated possible ways to overcome it.

Clinical and histologic features associated with lentigo maligna clearance after imiquimod treatment

BACKGROUND

Imiquimod cream may be used as a non-surgical treatment for lentigo maligna or as adjuvant therapy following excision to decrease the risk of recurrence.

OBJECTIVES

To evaluate histologic and clinical factors associated with clinical clearance of lentigo maligna treated with imiquimod.

METHODS

We performed a retrospective review of all patients diagnosed with lentigo maligna and treated with imiquimod between 1997 and 2019 at our academic institution.

RESULTS

We observed clinical clearance in 93% (66/71) of participants who received adjuvant imiquimod following surgery and 79% (19/24) in the primary non-surgical treatment group over a median of 38 months of follow-up. In the adjuvant therapy group, positive surgical margins were associated with a decreased rate of clinical clearance when compared to cases with close (<1 mm) margins or background melanocytic dysplasia (83.3 vs. 100%, p = .01). The presence of an inflammatory response during treatment was associated with increased clearance (94.1 vs. 66.7%, p = .02).

CONCLUSIONS

Adjuvant imiquimod treatment may decrease LM recurrence rates in cases with background melanocytic dysplasia or close margins. LM cases with positive surgical margins need close clinical follow-up given higher recurrence rates.

[Clinical and pathological analysis of ocular adnexal diffuse large B-cell lymphoma]

Objective: To summarize the clinical and pathological characteristics of diffuse large B-cell lymphoma of ocular adnexal (OA-DLBCL). Methods: A retrospective case series study. Twenty-three cases of OA-DLBCL were collected in Tianjin Eye Hospital from January 2005 to December 2018. The clinical manifestations and imaging examination results were analyzed. The pathological characteristics and immune subtypes were analyzed with hematoxylin and eosin staining and immunohistochemistry. Eighteen patients completed the follow-up. Overall survival (OS) time was from the date of diagnosis to the date of death or the final follow-up (April 30, 2020). Clinical stages were analyzed by the Ann Arbor classification; Kaplan-Meier plots were used to visualize survival outcomes. The different risk groups were compared using Log-rank test. Results: There were 13 males and 10 females. The median age was 65 years (range, 43 to 82 years). Twenty-two patients had unilateral lymphoma (14 left eyes, 8 right eyes), and one patient had bilateral lymphoma. The OA-DLBCL was in the orbit in 14 patients, in the lacrimal gland in two patients, in both the lacrimal gland and the orbit in three patients, in both the lacrimal sac and the orbit in one patient, in the conjunctiva in one patient, in both the conjunctiva and the orbit in one patient, and in the skin of eyelids in one patient. Imaging examinations showed the tumors were of irregular soft tissue density. MRI showed the tumors were close to the extraocular muscles or ectocinerea. Centroblastic morphology was present in 21 specimens, and 2 specimens had immunoblastic morphology. Six patients were of germinal center B cell-like (GCB) type, and 17 were of non-GCB type. There were 2 patients with double expression of cellular-myelocytomatosis viral oncogene and B-cell lymphoma 2. The follow-up time ranged from 25 to 156 months, and the median follow-up time was 48 months. Five of them had primary OA-DLBCL, and 13 patients had secondary OA-DLBCL. Five patients were at the Ann Arbor clinical stage ⅠE, one was at stage ⅢE, and 12 were at stage ⅣE. During the follow-up, 8 patients survived, and 10 died. The 1-, 3-, and 5-year OS rates were 88.9%, 71.4% and 41.7%, respectively. Log-rank analysis indicated that the Ann Arbor clinical stage and age were related to the OS of OA-DLBCL (χ²=7.448, 8.804; both P<0.01). The gender, tumor size, molecular typing, Ki-67 index, and bone invasion were not related to the OS of OA-DLBCL (all P>0.05). Conclusions: OA-DLBCL mainly occurrs in the elderly population, unilaterally, and in the orbit. Most molecular types are non-GCB subtypes. The Ann Arbor clinical stage and age are associated with prognosis. (Chin J Ophthalmol, 2021, 57: 366-371).

The amyloid structure of mouse RIPK3 (receptor interacting protein kinase 3) in cell necroptosis

RIPK3 amyloid complex plays crucial roles during TNF-induced necroptosis and in response to immune defense in both human and mouse. Here, we have structurally characterized mouse RIPK3 homogeneous self-assembly using solid-state NMR, revealing a well-ordered N-shaped amyloid core structure featured with 3 parallel in-register β-sheets. This structure differs from previously published human RIPK1/RIPK3 hetero-amyloid complex structure, which adopted a serpentine fold. Functional studies indicate both RIPK1-RIPK3 binding and RIPK3 amyloid formation are essential but not sufficient for TNF-induced necroptosis. The structural integrity of RIPK3 fibril with three β-strands is necessary for signaling. Molecular dynamics simulations with a mouse RIPK1/RIPK3 model indicate that the hetero-amyloid is less stable when adopting the RIPK3 fibril conformation, suggesting a structural transformation of RIPK3 from RIPK1-RIPK3 binding to RIPK3 amyloid formation. This structural transformation would provide the missing link connecting RIPK1-RIPK3 binding to RIPK3 homo-oligomer formation in the signal transduction.

Receptor Interacting Protein Kinase 3 (RIPK3) has a key role in TNF-induced necroptosis. Here, the authors combine solid state NMR measurements, MD simulations and cell based assays to characterize mouse RIPK3 and they present the structure of the RIPK3 amyloid core.

Weighted Gene Coexpression Network Analysis Reveals Essential Genes and Pathways in Bipolar Disorder

Bipolar disorder (BD) is a major and highly heritable mental illness with severe psychosocial impairment, but its etiology and pathogenesis remains unclear. This study aimed to identify the essential pathways and genes involved in BD using weighted gene coexpression network analysis (WGCNA), a bioinformatic method studying the relationships between genes and phenotypes. Using two available BD gene expression datasets (GSE5388, GSE5389), we constructed a gene coexpression network and identified modules related to BD. The analyses of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways were performed to explore functional enrichment of the candidate modules. A protein-protein interaction (PPI) network was further constructed to identify the potential hub genes. Ten coexpression modules were identified from the top 5,000 genes in 77 samples and three modules were significantly associated with BD, which were involved in several biological processes (e.g., the actin filament-based process) and pathways (e.g., MAPK signaling). Four genes (NOTCH1, POMC, NGF, and DRD2) were identified as candidate hub genes by PPI analysis and CytoHubba. Finally, we carried out validation analyses in a separate dataset, GSE12649, and verified NOTCH1 as a hub gene and the involvement of several biological processes such as actin filament-based process and axon development. Taken together, our findings revealed several candidate pathways and genes (NOTCH1) in the pathogenesis of BD and call for further investigation for their potential research values in BD diagnosis and treatment.

Mental health outcomes among patients from Fangcang shelter hospitals exposed to coronavirus disease 2019: An observational cross-sectional study

Background

The coronavirus disease 2019 (COVID-19) is not only attacking physical health, but it is also increasing psychological suffering. This study aimed to observe the impact of the COVID-19 pandemic on mental health outcomes among patients with mild to moderate illness in Fangcang shelter hospitals.

Methods

We conducted an observational, cross-sectional study of 129 patients with mild to moderate illness from Jiangxia Fangcang shelter hospitals in Wuhan, China. The participants were assessed by quantifying their symptoms of depression, anxiety, insomnia, and stressful life events and analyzing potential risk factors associated with these symptoms. Using correlation analysis, we examined associations between exposure to COVID-19 and subsequent psychological distress in response to the outbreak.

Results

In total, 49.6% of participants had depressive or anxiety symptoms. The depressive and anxiety symptoms were highly related to sleep disturbances and hypochondriasis (all r > 0.50, P < 0.01). The impact of the event was positively related to depressive symptoms, anxiety symptoms, sleep disturbances, hypochondriasis and life events (all r > 0.35, P < 0.01) but was negatively related to psychological resilience (r = −0.41, P < 0.01). The presence of the COVID-19 infection in this setting was associated with increased anxiety, depression and stress levels, and decreased sleep quality, and seriously affected patients’ quality of life as well as adversely affecting the course and prognosis of physical diseases.

Conclusion

The sleep quality, anxiety, and depression of COVID-19 patients in Fangcang shelter hospitals were significantly related to the impact of the epidemic.

NR4A1 counteracts JNK activation incurred by ER stress or ROS in pancreatic β-cells for protection

Sustained hyperglycaemia and hyperlipidaemia incur endoplasmic reticulum stress (ER stress) and reactive oxygen species (ROS) overproduction in pancreatic β‐cells. ER stress or ROS causes c‐Jun N‐terminal kinase (JNK) activation, and the activated JNK triggers apoptosis in different cells. Nuclear receptor subfamily 4 group A member 1 (NR4A1) is an inducible multi‐stress response factor. The aim of this study was to explore the role of NR4A1 in counteracting JNK activation induced by ER stress or ROS and the related mechanism. qPCR, Western blotting, dual‐luciferase reporter and ChIP assays were applied to detect gene expression or regulation by NR4A1. Immunofluorescence was used to detect a specific protein expression in β‐cells. Our data showed that NR4A1 reduced the phosphorylated JNK (p‐JNK) in MIN6 cells encountering ER stress or ROS and reduced MKK4 protein in a proteasome‐dependent manner. We found that NR4A1 increased the expression of cbl‐b (an E3 ligase); knocking down cbl‐b expression increased MKK4 and p‐JNK levels under ER stress or ROS conditions. We elucidated that NR4A1 enhanced the transactivation of cbl‐b promoter by physical association. We further confirmed that cbl‐b expression in β‐cells was reduced in NR4A1‐knockout mice compared with WT mice. NR4A1 down‐regulates JNK activation by ER stress or ROS in β‐cells via enhancing cbl‐b expression.

Associations among serum markers of inflammation, life stress and suicide risk in patients with major depressive disorder

BACKGROUND

Patients with major depressive disorder (MDD) are at high risk for suicide. As the worst outcome of MDD and common self-concealment in patients with suicide risk, studies of biomarkers may provide useful tools for suicide prevention and treatment.

METHODS

This study recruited 168 patients with MDD from the Objective Diagnostic Markers and Personalized Intervention in MDD patients (ODMPIM), including 50 patients with suicide risk. Based on previous evidence and hypothesis, 23 targeted serum biomarkers involving immune-inflammation, neurotrophins, hypothalamic-pituitary-adrenal (HPA) axis and metabolism, were measured. We used path analysis and principal components analysis (PCA) to clarify the associations among serum biomarkers, childhood adversities, adulthood life events, severity of depression and suicide risk.

RESULTS

We identified that patients with suicide risk had a higher level of inflammatory markers in serum than patients without suicide risk (P < 0.001), especially chemokine (C-X-C motif) ligand 1 (CXCL-1). After using the Bonferroni correction, there were no differences in biomarkers related to neurotrophins, HPA-axis and metabolism. In addition, a higher proportion of patients with suicide risk had adulthood adversity (assessed by Life Events Scale) (P = 0.003). Intriguingly, path analysis demonstrated that the association between adulthood adversity and suicide risk mainly depended on severity of depression and inflammatory index.

CONCLUSION

This study highlights the possible role of inflammation involved in suicide risk of MDD patients. Inflammatory markers have the potential for early identification and then reducing suicidal behaviors or becoming novel treatment targets in suicide risk management.