Research
Abstract
Hypertension and transient increases in blood pressure from extreme exertion are risk factors for aortic dissection in patients with age-related vascular degeneration or inherited connective tissue disorders. Yet, a common experimental model of angiotensin II-induced aortopathy in mice appears independent of high blood pressure as lesions do not occur in response to an alternative vasoconstrictor, norepinephrine, and are not prevented by co-treatment with a vasodilator, hydralazine. We investigated vasoconstrictor administration to adult mice following 1 week of disrupted TGFβ signaling in smooth muscle cells (SMCs). Norepinephrine increased blood pressure and induced aortic dissection by 7 days and even within 30 minutes (as did angiotensin II) that was prevented by hydralazine. Initial medial injury manifested as blood extravasation among SMCs and fibrillar matrix, progressive delamination from accumulation of blood, and stretched or ruptured SMCs with persistent attachments to elastic fibers. Altered regulatory contractile molecule expression was not of pathological importance. Rather, reduced synthesis of extracellular matrix yielded a vulnerable aortic phenotype by decreasing medial collagen, most dynamically basement membrane-associated multiplexin collagen, and impairing cell-matrix adhesion. We conclude that transient and sustained increases in blood pressure can cause dissection in aortas rendered vulnerable by inhibition of TGFβ-driven extracellular matrix production by SMCs.
Authors
Bo Jiang, Pengwei Ren, Changshun He, Mo Wang, Sae-Il Murtada, María Jesús Ruiz-Rodríguez, Yu Chen, Abhay B. Ramachandra, Guangxin Li, Lingfeng Qin, Roland Assi, Martin A. Schwartz, Jay D. Humphrey, George Tellides
Abstract
Glioblastoma (GBM) is one of the most lethal adult brain tumors with limited effective therapeutic options. Immunotherapy targeting B7-H3 (CD276) has shown promising efficacy in the treatment of gliomas. However, the response to this treatment varies among glioma patients due to individual differences. It’s necessary to find an effective strategy to improve the efficacy of targeting B7-H3 immunotherapy for non-responders. In this study, we demonstrated a strong correlation between aurora kinase A (AURKA) and CD276 expression in glioma tissue samples. Additionally, both AURKA knockdown and overexpression resulted in parallel changes in B7-H3 expression levels in glioma cells. Mechanistically, AURKA elevated B7-H3 expression by promoting epidermal growth factor receptor (EGFR) phosphorylation, which was validated in glioma cell lines and primary GBM cells. What’s more, the combination of AURKA inhibitor (alisertib) and anti-B7-H3 antibody markedly reduced tumor size and promoted CD8+ T cell infiltration and activation in mouse orthotopic syngeneic glioma models. To our knowledge, this study is the first to demonstrate AURKA-mediated B7-H3 upregulation in glioma cells; moreover, it proposes a promising therapeutic strategy combining the AURKA inhibitor alisertib with B7-H3-specific blocking mAbs.
Authors
Jinqiu Liu, Yuxuan Deng, Zhuonan Pu, Yazhou Miao, Zhaonian Hao, Herui Wang, Shaodong Zhang, Hanjie Liu, Jiejun Wang, Yifan Lv, Boyi Hu, Hong Wan, Zhengping Zhuang, Tai Sun, Shuyu Hao, Nan Ji, Jie Feng
Abstract
Tacrolimus-induced chronic nephrotoxicity (TICN) hinders its long-term use, but its mechanism remains unclear. Tacrolimus exerts its pharmacological effect by inhibiting calcineurin and its substrate NFAT. Whether the inhibition of other calcineurin substrates is related to TICN remains to be explored. Transcription factor EB (TFEB), a substrate of calcineurin, plays a crucial role in various homeostasis. Herein, we found that tacrolimus inhibited TFEB nuclear translocation and activity in mouse kidneys and HK-2 cells. Then, TFEB gain- and loss-of-function rescued the effect of tacrolimus in HK-2 cells. Furthermore, TFEB activation both by phosphorylation sites mutation and agonist rescued TICN in mice. To elucidate the mechanism of TFEB, we analyzed ChIP-seq data. Growth arrest and DNA damage-inducible 45α (GADD45α) was identified as a transcriptional target of TFEB via chromatin immunoprecipitation and dual luciferase reporter assays. And then we revealed that GADD45α overexpression rescued DNA damage and kidney injury caused by tacrolimus or TFEB knockdown in vitro, and vise versa. The protective effect of GADD45α against TICN and DNA damage was further demonstrated by overexpressing it in mice. In conclusion, the persistent inhibition of TFEB-GADD45α pathway by tacrolimus contributes to TICN. This study identifies a specific target for intervention of TICN.
Authors
Ping Gao, Xinwei Cheng, Maochang Liu, Hui Peng, Guodong Li, Tianze Shang, Jianqiao Wang, Qianyan Gao, Chenglong Zhu, Zhenpeng Qiu, Chengliang Zhang
Abstract
The proof-of-principle of the therapeutic potential of heat shock protein 47 (HSP47) for diseases characterized by defects in the collagen I synthesis is here proved in osteogenesis imperfecta (OI), a prototype of collagen disorders. Most of the OI mutations delay collagen I chains folding, increasing their exposure to post translational modifications that affect collagen secretion and impact extracellular matrix fibrils assembly. As model, we used primary fibroblasts from OI individuals with defect in the collagen prolyl-3-hydroxylation complex, since are characterized by the synthesis of homogeneously overmodified collagen molecules. We demonstrated that the exogenous recombinant HSP47 (rHSP47) is uptaken by the cells and localizes at the ER exit sites and ER Golgi intermediate compartment. rHSP47 treatment increased collagen secretion, reduced collagen post translational modifications and intracellular collagen retention and ameliorated the general ER proteostasis, leading to improved cellular homeostasis and vitality. These positive changes were also mirrored by an increased collagen content in the OI matrix. A mutation dependent effect was found in fibroblasts from three probands with collagen I mutations, for which rHSP47 was effective only in cells with the most N-term defect. A beneficial effect on bone mineralization was proved in vivo in the zebrafish p3h1-/- OI model.
Authors
Roberta Besio, Nadia Garibaldi, Alessandra Sala, Francesca Tonelli, Carla Aresi, Elisa Maffioli, Claudio Casali, Camilla Torriani, Marco Biggiogera, Simona Villani, Antonio Rossi, Gabriella Tedeschi, Antonella Forlino
Abstract
Induction of podoplanin (PDPN) expression is a critical response of macrophages to LPS stimulation or bacterial infection in sepsis, but how this key process of TLR4-stimulated PDPN upregulation is regulated and the impact of PDPN expression on macrophage function remain elusive. Here, we determined how this process is regulated in vitro and in vivo. PDPN failed to be upregulated in TLR4 stimulated macrophages deficient in adhesion and degranulation-promoting adapter protein (ADAP), which could be rescued by the reconstitution of ADAP. A distinct PDPNhi peritoneal macrophage (PM) subset, which exhibited an M2-like phenotype and enhanced phagocytic activity, was generated in WT but not in ADAP-deficient septic mice. The blockade of PDPNhi PMs mimicked the effect of ADAP deficiency, which exacerbated sepsis. Mechanistically, BTK-mediated ADAP Y571 phosphorylation worked together with mTOR to converge on STAT3 activation for the transactivation of the PDPN promoter. Moreover, agonist activation of STAT3 profoundly potentiated the PDPNhi PM subset generation and alleviated sepsis severity in mice. Together, our findings reveal a mechanism whereby ADAP resets macrophage function by controlling the TLR4-induced upregulation of PDPN as a host innate immune defense during sepsis.
Authors
Pengchao Zhang, Xinning Wang, Xiaodong Yang, Hebin Liu
Abstract
Despite combination antiretroviral therapy (ART), HIV causes persistent gut barrier dysfunction, immune depletion, and dysbiosis. Further, ART interruption results in reservoir reactivation and rebound viremia. Both IL-21 and anti-α4β7 improve gut barrier functions, and we hypothesized combining them would synergize as a dual therapy to improve immunological outcomes in SIV-infected rhesus macaques (RMs). We found no significant differences in CD4+ T-cell reservoir size by intact proviral DNA assay. SIV rebounded in both dual-treated and control RMs following analytical therapy interruption (ATI), with time to rebound and initial rebound viremia comparable between groups; however, dual-treated RMs showed slightly better control of viral replication at the latest time points post-ATI. Additionally, following post-ATI, dual-treated RMs showed immunological benefits, including T-cell preservation and lower PD-1+ central memory T-cell (TCM) frequency. Notably, PD-1+ TCMs were associated with reservoir size, which predicted viral loads (VLs) post-ATI. Finally, 16S rRNA sequencing revealed better recovery from dysbiosis in treated animals, and the butyrate-producing Firmicute Roseburia predicted PD-1-expressing TCMs and VLs after ATI. PD-1+ TCMs and gut dysbiosis represent mechanisms of HIV persistence and pathogenesis, respectively. Therefore, combining IL-21 and anti-α4β7 may be an effective therapeutic strategy to improve immunological outcomes for people with HIV.
Authors
Samuel D. Johnson, Maria Pino, Arpan Acharya, Julien A. Clain, Deepanwita Bose, Kevin Nguyen, Justin Harper, Francois Villinger, Mirko Paiardini, Siddappa N. Byrareddy
Abstract
Lymphangioleiomyomatosis (LAM) is a progressive lung disease with limited treatments, largely due to an incomplete understanding of its pathogenesis. Lymphatic endothelial cells (LECs) invade LAM cell clusters, which include HMB-45-positive epithelioid cells and smooth muscle α-actin-expressing LAM-associated fibroblasts (LAMFs). Recent evidence shows that LAMFs resemble cancer-associated fibroblasts, with LAMF-LEC interactions contributing to disease progression. To explore these mechanisms, we used spatial transcriptomics on LAM lung tissues and identified a gene cluster enriched in kinase signaling pathways linked to myofibroblasts and co-expressed with LEC markers. Kinase arrays revealed elevated PDGFR and FGFR in LAMFs. Using a 3D co-culture spheroid model of primary LAMFs and LECs, we observed increased invasion in LAMF-LEC spheroids compared to non-LAM fibroblasts. Treatment with sorafenib, a multikinase inhibitor, significantly reduced invasion, outperforming Rapamycin. We also confirmed TSC2-deficient renal angiomyolipoma cells (TSC2-null AML) as key VEGF-A secretors, which was suppressed by sorafenib in both TSC2-null AML cells and LAMFs. These findings highlight VEGF-A and bFGF as potential therapeutic targets and suggest multikinase inhibition as a promising strategy for LAM.
Authors
Sinem Koc-Gunel, Emily C. Liu, Lalit K. Gautam, Ben A. Calvert, Shubha Murthy, Noa C. Harriott, Janna C. Nawroth, Beiyun Zhou, Vera P. Krymskaya, Amy L. Ryan
Abstract
The standard-of-care treatment of locally advanced cervical cancer includes pelvic radiation therapy with concurrent cisplatin-based chemotherapy and is associated with a 30-50% failure rate. New prognostic and therapeutic targets are needed to improve clinical outcomes. The vaginal microbiome has been linked to the pathogenesis of cervical cancer, but little is known about the vaginal microbiome in locally advanced cervical cancer as it relates to chemoradiation. In this pilot study we utilized 16S rRNA gene community profiling to characterize the vaginal microbiomes of 26 postmenopausal women with locally advanced cervical cancer receiving chemoradiation. Our analysis revealed diverse anaerobe-dominated communities whose taxonomic composition, diversity or bacterial abundance did not change with treatment. We hypothesized that characteristics of the microbiome might correlate with treatment response. Pretreatment microbial diversity and bacterial abundance were not associated with disease recurrence. We observed a greater relative abundance of Fusobacterium in patients that later had cancer recurrence, suggesting that Fusobacterium could play a role in modifying treatment response. Taken together, this hypothesis generating pilot study provides insight into the composition and dynamics of the vaginal microbiome, offering proof-of-concept for future study of the microbiome and its relationship with treatment outcomes in locally advanced cervical cancer.
Authors
Brett A. Tortelli, Jessika Contreras, Stephanie Markovina, Li Ding, Kristine M. Wylie, Julie K. Schwarz
Abstract
The mechanisms utilized by differentiating B cells to withstand highly damaging conditions generated during severe infections, like the massive hemolysis that accompanies malaria, are poorly understood. Here we demonstrate that ROCK1 regulates B cells differentiation in hostile environments replete with PAMPs (pathogen-associated molecular patterns) and high levels of heme by controlling two key heme-regulated molecules, BACH2 and Heme-regulated eIF2a kinase (HRI). ROCK1 phosphorylates BACH2 and protects it from heme-driven degradation. As B cells differentiate, furthermore, ROCK1 restrains their proinflammatory potential and helps them handle the heightened stress imparted by the presence of PAMPs and heme by controlling HRI, a key regulator of the integrated stress response and cytosolic proteotoxicity. ROCK1 controls the interplay of HRI with HSP90 and limits the recruitment of HRI and HSP90 to unique p62/SQSTM1 complexes that also contain critical kinases like mTORC1 and TBK1, and proteins involved in RNA metabolism, oxidative damage, and proteostasis like TDP-43. Thus, ROCK1 helps B cells cope with intense pathogen-driven destruction by coordinating the activity of key controllers of B cell differentiation and stress responses. These ROCK1-dependent mechanisms may be widely employed by cells to handle severe environmental stresses, and these findings may be relevant for immune-mediated and age-related neurodegenerative disorders.
Authors
Juan Rivera-Correa, Sanjay Gupta, Edd Ricker, Danny Flores-Castro, Daniel Jenkins, Stephen Vulcano, Swati P. Phalke, Tania Pannellini, Matthew M. Miele, Zhuoning Li, Nahuel Zamponi, Young-Bum Kim, Yurii Chinenov, Eugenia Giannopoulou, Leandro Cerchietti, Alessandra B. Pernis
Abstract
Renal osteodystrophy is commonly seen in patients with chronic kidney disease (CKD) due to disrupted mineral homeostasis. Given the impaired renal function in these patients, common anti-resorptive agents, including bisphosphonates, must be used with caution or even contraindicated. Therefore, an alternative therapy without renal burden to combat renal osteodystrophy is urgently needed. Here, we report that clinically relevant aerobic exercise significantly prevents high-turnover renal osteodystrophy in CKD mouse and patients without compromising renal function. Mechanistically, 4-week aerobic exercise in CKD mice increased expression of skeletal muscle PPARγ coactivator-1α (PGC-1α) and circulating irisin. Both exercise and irisin administration significantly activated osteoblasts, but not osteoclasts, via integrin αvβ5, thereby conferring bone quality benefits. Removal of irisin-influenced thermogenic adipose tissues or genetic ablation of uncoupling protein 1 did not alter the irisin-conferred anti-osteodystrophy effect. Importantly, in a pilot clinical study, 12-week aerobic exercise in patients with high-grade CKD significantly increased circulating irisin and prevented osteodystrophy progression, without detectable renal burden. The combination of irisin and current anti-resorptive agents effectively rescued renal osteodystrophy in mice. Our work provides mechanistic insights into the role of exercise and irisin in renal osteodystrophy, and highlights a clinically relevant, low-cost, kidney-friendly therapy for patients with this devastating disease.
Authors
Meng Wu, Huilan Li, Xiaoting Sun, Rongrong Zhong, Linli Cai, Ruibo Chen, Madiya Madeniyet, Kana Ren, Zhen Peng, Yujie Yang, Weiqin Chen, Yanling Tu, Miaoxin Lai, Jinxiu Deng, Yuting Wu, Shumin Zhao, Qingyan Ruan, Mei Rao, Sisi Xie, Ying Ye, Jianxin Wan
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