Faculty Bibliography

Esculetin is a coumarin compound, which belongs to the class of benzopyrone enriched in various plants such as Sonchus grandifolius, Aesculus turbinata, etc. Free radicals lead to the development of oxidative stress causing inflammation, arthritis, cancer, diabetes, fatty liver disease, etc. These further reduce the efficacy of anticancer drugs, activate inflammatory signaling pathways, degrade joints and cartilage, and disrupt the glycemic index and normal function of liver enzymes. For instance, the current treatment modalities used in arthritis such as non-steroidal anti-inflammatory drugs, disease-modifying anti-rheumatoid drugs, and lipoxygenase inhibitors present limited efficacy and adverse effects. Thus, there is a constant need to find newer and safer alternatives. Esculetin has an immense antioxidative potential thereby alleviating arthritis, diabetes, malignancies, and hepatic disorders. Structurally, esculetin contains two hydroxyl groups, which enhance its ability to function as an antioxidant by inhibiting oxidative stress in pathological conditions. Leukotriene B4 synthesis, NF-κB and MPAK pathway activation, and inflammatory cytokine production are the main causes of bone and joint deterioration in arthritis, whereas esculetin treatment reverses these factors and relieves the disease condition. In contrast, lipid peroxidation caused by upregulation of TGF-β-mediated expression and dysfunction of antioxidant enzymes is inhibited by esculetin therapy, thus reducing liver fibrosis by acting on the PI3K/FoxO1 pathway. Therefore, targeting NF-κB, pro-inflammatory cytokines, TGF-β and oxidative stress may be a therapeutic strategy to alleviate arthritis and liver fibrosis.

Unfolded protein response (UPR) is the mechanism by which cells control endoplasmic reticulum (ER) protein homeostasis. ER proteostasis is essential to adapt to cell proliferation and regeneration in development and tumorigenesis, but mechanisms linking UPR, growth control, and cancer progression remain unclear. Here, we report that the Ire1/Xbp1s pathway has surprisingly oncogenic and tumor-suppressive roles in a context-dependent manner. Activation of Ire1/Xbp1s up-regulates their downstream target Bip, which sequesters Yorkie (Yki), a Hippo pathway transducer, in the cytoplasm to restrict Yki transcriptional output. This regulation provides an endogenous defensive mechanism in organ size control, intestinal homeostasis, and regeneration. Unexpectedly, Xbp1 ablation promotes tumor overgrowth but suppresses invasiveness in a Drosophila cancer model. Mechanistically, hyperactivated Ire1/Xbp1s signaling in turn induces JNK-dependent developmental and oncogenic cell migration and epithelial-mesenchymal transition (EMT) via repression of Yki. In humans, a negative correlation between XBP1 and YAP (Yki ortholog) target gene expression specifically exists in triple-negative breast cancers (TNBCs), and those with high XBP1 or HSPA5 (Bip ortholog) expression have better clinical outcomes. In human TNBC cell lines and xenograft models, ectopic XBP1s or HSPA5 expression alleviates tumor growth but aggravates cell migration and invasion. These findings uncover a conserved crosstalk between the Ire1/Xbp1s and Hippo signaling pathways under physiological settings, as well as a crucial role of Bip-Yki interaction in tumorigenesis that is shared from Drosophila to humans.

T cell activation and function depend on Ca²⁺ signals mediated by store-operated Ca²⁺ entry (SOCE) through Ca²⁺ release-activated Ca²⁺ (CRAC) channels formed by ORAI1 proteins. We here investigated how SOCE controls T cell function in pulmonary inflammation during a T helper 1 (T_H1) cell-mediated response to influenza A virus (IAV) infection and T_H2 cell-mediated allergic airway inflammation. T cell-specific deletion of Orai1 did not exacerbate pulmonary inflammation and viral burdens following IAV infection but protected mice from house dust mite-induced allergic airway inflammation. ORAI1 controlled the expression of genes including p53 and E2F transcription factors that regulate the cell cycle in T_H2 cells in response to allergen stimulation and the expression of transcription factors and cytokines that regulate T_H2 cell function. Systemic application of a CRAC channel blocker suppressed allergic airway inflammation without compromising immunity to IAV infection, suggesting that inhibition of SOCE is a potential treatment for allergic airway disease.

The movement of lipids within and between membranes in bacteria is essential for building and maintaining the bacterial cell envelope. Moving lipids to their final destination is often energetically unfavorable and does not readily occur spontaneously. Bacteria have evolved several protein-mediated transport systems that bind specific lipid substrates and catalyze the transport of lipids across membranes and from one membrane to another. Specific protein flippases act in translocating lipids across the plasma membrane, overcoming the obstacle of moving relatively large and chemically diverse lipids between leaflets of the bilayer. Active transporters found in double-membraned bacteria have evolved sophisticated mechanisms to traffic lipids between the two membranes, including assembling to form large, multiprotein complexes that resemble bridges, shuttles, and tunnels, shielding lipids from the hydrophilic environment of the periplasm during transport. In this review, we explore our current understanding of the mechanisms thought to drive bacterial lipid transport. Expected final online publication date for the Annual Review of Cell and Developmental Biology Volume 38 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Mitochondria harbor an independent genome, called mitochondrial DNA (mtDNA), which contains essential metabolic genes. Although mtDNA mutations occur at high frequency, they are inherited infrequently, indicating that germline mechanisms limit their accumulation. To determine how germline mtDNA is regulated, we examined the control of mtDNA quantity and quality in C. elegans primordial germ cells (PGCs). We show that PGCs combine strategies to generate a low point in mtDNA number by segregating mitochondria into lobe-like protrusions that are cannibalized by adjacent cells, and by concurrently eliminating mitochondria through autophagy, reducing overall mtDNA content twofold. As PGCs exit quiescence and divide, mtDNAs replicate to maintain a set point of ~200 mtDNAs per germline stem cell. Whereas cannibalism and autophagy eliminate mtDNAs stochastically, we show that the kinase PTEN-induced kinase 1 (PINK1), operating independently of Parkin and autophagy, preferentially reduces the fraction of mutant mtDNAs. Thus, PGCs employ parallel mechanisms to control both the quantity and quality of the founding population of germline mtDNAs.

The placenta plays an essential role at the beginning of life, nourishing and supporting the fetus, but its life span is limited. In late pregnancy, the placenta develops signs of aging, including inflammation and impaired function, which may complicate pregnancy. Placentas also show another sign of aging - cells with extra or missing chromosomes. Chromosomally abnormal cells could gather in the placenta if they get stranded there and/or if the cells do not separate normally. Chromosome separation goes wrong in aging cells when the DNA sequences, which protect the ends of the chromosomes, erode. When chromosomes lose their protective caps, they fuse which leads to abnormal numbers of chromosomes. In this pilot study, for the first time, we found fusions between the caps in a human placenta when it reaches full term. More studies are needed to decide whether this has an influence on how the placenta works and outcomes of pregnancy.

OBJECTIVE:This study aims to refine Music Upper Limb Therapy - Integrated (MULT-I) to create a feasible enriched environment for stroke rehabilitation and compare its biological and behavioral effects to that of a home exercise program (HEP). DESIGN/METHODS:Randomized mixed-methods study of 30 adults with post-stroke hemiparesis. Serum brain derived neurotrophic factor (BDNF) and oxytocin levels measured biologic effects, and upper limb function, disability, quality of life and emotional well-being were assessed as behavioral outcomes. Participant experiences were explored using semi-structured interviews. RESULTS:MULT-I participants showed reduced depression from pre- to post- intervention as compared to HEP participants. BDNF levels significantly increased for MULT-I participants, but decreased for HEP participants, with a significant difference between groups after excluding those with post-stroke depression. MULT-I participants additionally improved quality of life and self-perceived physical strength, mobility, activity, participation, and recovery from pre- to post-intervention. HEP participants improved upper limb function. Qualitatively, MULT-I provided psychosocial support and enjoyment while HEP supported self-management of rehabilitation. CONCLUSIONS:Implementation of a music enriched environment is feasible, reduces post-stroke depression, and may enhance the neural environment for recovery via increases in BDNF levels. Self-management of rehabilitation through a home exercise program may further improve upper limb function.

Skin wounds in adult mammals typically heal with a fibrotic scar and fail to restore ectodermal appendages, such as hair follicles or adipose tissue. Intriguingly, new hair follicles regenerate in the center of large full-thickness wounds of mice in a process called wound-induced hair neogenesis (WIHN). WIHN is followed by neogenesis of dermal adipose tissue. Both neogenic events reactivate embryonic-like cellular and molecular programs. The WIHN model provides a platform for studying mammalian regeneration, and findings from this model could instruct future regenerative medicine interventions for treating wounds and alopecia. Since Ito et al. rediscovered WIHN 15 years ago, numerous investigators have worked on the WIHN model using varying wounding protocols and model interpretations. Because a variety of factors, including environmental variables and choice of mouse strains, can affect the outcomes of a WIHN study, the purpose of this article is to provide an overview of the experimental variables that impact WIHN so that experiments between laboratories can be compared in a meaningful manner.

Objective: DMSO alters the epigenetic state of mouse oocytes and human cultured cells. The effect of vitrification with DMSO containing cryoprotectant on gene and TE expression in human oocytes is unknown.
Material(s) and Method(s): A prospective paired controlled cohort laboratory study was performed from February - June 2021. Twenty-four discarded oocytes in the germinal vesical (GV) stage were donated from four patients. All oocytes were paired such that half of the oocytes from each patient were vitrified with DMSO-containing cryoprotectant, while the other half were frozen, unexposed to DMSO. All oocytes underwent RNA sequencing via Switching Mechanism At the end of the 5'-end of the RNA Transcript sequencing 2 (SMARTseq2). Reads containing adapters, bases that could not be determined >10% and low quality reads were excluded. Gene mapping to the human reference genome, followed by gene quantification, were performed. Next, differential gene expression analysis between the two cohorts was performed. Then functional enrichment analyses of dysregulated gene sets were performed with Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Human Disease Ontology (DO). Raw data obtained from RNA sequencing was used to analyze TE transcripts using the BonaFide-TEseq method, which were mapped to specific TE loci using Software for Quantifying Interspersed Repeat Expression (SQuIRE), to identify differentially expressed TEs. Real time-qPCR validated results of selected genes and TEs.
Result(s): Of the 27,837 genes identified by SMARTseq2, 7,331 (26.3%) were differentially expressed (p<0.05). Specifically, 3,987 genes were upregulated and 3,344 genes were downregulated in oocytes exposed to DMSO. Genes involved in chromatin and histone modification, and mitochondrial function, as well as WNT, insulin, MTOR, HIPPO and MAPK signaling pathways were affected by DMSO. There was no significant over expression of human disease ontology terms within our data set. Expression of a number of TEs was also affected by exposure to DMSO, including Alu, endogenous retrovirus family members 1 and K (ERV1, ERVK) and long interspersed nuclear elements 1 (LINE-1). Notably, the effects of DMSO on TE expression were most pronounced in the oldest patient. The expression of TEs was negatively correlated with age, and positively correlated with the expression of PIWI-like protein 2 (PIWIL2), DNA Methyltransferase (DNMT) 3A and 3B.
Conclusion(s): Vitrification with DMSO exposure leads to significant changes in gene and TE expression in human GV oocytes. Future experiments should determine whether MII oocytes respond similarly. Impact Statement: Oocyte vitrification with DMSO containing cryoprotectant induces significant transcriptome changes, including those involving TEs, in human GV oocytes. Further studies are needed to evaluate the clinical significance of these findings. Support: This study was supported by the Stanley H Kaplan Fund.
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Introduction: Nearly a quarter of older adults with inflammatory bowel disease (IBD) require surgery. Patients with IBD are at risk for complications postoperatively and this risk is increased in older adults. However, little is known about the risk factors leading to these complications.We assessed risk factors associated with adverse postoperative outcomes among older adults who underwent IBD-related surgery, as well as evaluated trends in emergency vs. elective surgery in this population.
Method(s): Using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, we identified adults >=60 years of age who underwent an IBD-related intestinal resection from 2005-2019. Our primary outcome included a 30-day composite of mortality, readmission, reoperation, and/or what we identified as serious complications listed in NSQIP.
Result(s): In total, 9,640 intestinal resections were performed among older adults with IBD from 2005-2019, with 48.3% having undergone resection for Crohn's disease (CD), and 51.7% for ulcerative colitis (UC). Nearly 37% experienced an adverse outcome, with the most common complication being infection (20.21%). From 2005 to 2015, there was no decrease in the number of emergent cases among older adults. On univariate analysis, higher rates of adverse postoperative outcomes were seen with increasing age (p< 0.001), with nearly 50% of those >=80 years of age having an adverse outcome. Patients who underwent an emergency surgery had a higher likelihood of postoperative complications (66.86%; p< 0.001). On multivariable analysis, albumin <=3 (aOR 1.99; 95%CI 1.69-2.33), the presence of two or more comorbidities (aOR, 1.50; 95%CI 1.27-1.76), totally dependent functional status as compared to those partially dependent or independent (aOR, 7.28; 95%CI 3.14-21.2), and emergency surgery (aOR, 1.70; 95% CI 1.36-2.11) significantly increased the odds of an adverse outcome. (Figure)
Conclusion(s): Overall 37% of older adults with IBD experienced an adverse outcome as a result of IBD-related surgery. Limited functional health status, low preoperative serum albumin levels, and those undergoing emergent surgery were associated with a significantly higher risk. This is particularly important as the number of older adults with IBD is increasing, with a persisting number of emergency cases over time. Given the high rate of surgery in this population, future research should focus on preoperative rehabilitation, nutritional optimization, and timely surgery to improve outcomes. (Table Presented)