Latrophilin-2 is a novel receptor of LRG1 that rescues vascular and neurological abnormalities and restores diabetic erectile function

Yin Guo Nan,Kim Do-Kyun,Kang Ji In,Im Yebin,Lee Dong Sun,Han Ah-reum,옥지연,Choi Min-Ji,Kwon Mi-Hye,Limanjaya Anita,Jung Saet-Byel,Yang Jimin,Min Kwang Wook,Yun Jeongwon,Koh Yongjun,Park Jong-Eun,Hwang D 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by inappropriate hyperglycemia, which causes endothelial dysfunction and peripheral neuropathy, ultimately leading to multiple complications. One prevalent complication is diabetic erectile dysfunction (ED), which is more severe and more resistant to treatment than nondiabetic ED. The serum glycoprotein leucine-rich ɑ-2-glycoprotein 1 (LRG1) is a modulator of TGF-β-mediated angiogenesis and has been proposed as a biomarker for a variety of diseases, including DM. Here, we found that the adhesion GPCR latrophilin-2 (LPHN2) is a TGF-β-independent receptor of LRG1. By interacting with LPHN2, LRG1 promotes both angiogenic and neurotrophic processes in mouse tissue explants under hyperglycemic conditions. Preclinical studies in a diabetic ED mouse model showed that LRG1 administration into the penile tissue, which exhibits significantly increased LPHN2 expression, fully restores erectile function by rescuing vascular and neurological abnormalities. Further investigations revealed that PI3K, AKT, and NF-κB p65 constitute the key intracellular signaling pathway of the LRG1/LPHN2 axis, providing important mechanistic insights into LRG1-mediated angiogenesis and nerve regeneration in DM. Our findings suggest that LRG1 can be a potential new therapeutic option for treating aberrant peripheral blood vessels and neuropathy associated with diabetic complications, such as diabetic ED.

Pericyte-Derived Dickkopf2 Regenerates Damaged Penile Neurovasculature Through an Angiopoietin-1-Tie2 Pathway

Yin, Guo Nan,Jin, Hai-Rong,Choi, Min-Ji,Limanjaya, Anita,Ghatak, Kalyan,Minh, Nguyen Nhat,Ock, Jiyeon,Kwon, Mi-Hye,Song, Kang-Moon,Park, Heon Joo,Kim, Ho Min,Kwon, Young-Guen,Ryu, Ji-Kan,Suh, Jun-Kyu American Diabetes Association 2018 Diabetes Vol.67 No.6

<P>Penile erection requires well-coordinated interactions between vascular and nervous systems. Penile neurovascular dysfunction is amajor cause of erectile dysfunction (ED) in patients with diabetes, which causes poor response to oral phosphodiesterase-5 inhibitors. Dickkopf2 (DKK2), a Wnt antagonist, is known to promote angiogenesis. Here, using DKK2-Tg mice or DKK2 protein administration, we demonstrate that the overexpression of DKK2 in diabetic mice enhances penile angiogenesis and neural regeneration and restores erectile function. Transcriptome analysis revealed that angiopoietin-1 and angiopoietin-2 are target genes for DKK2. Using an endothelial cell-pericyte co-culture system and ex vivo neurite sprouting assay, we found that DKK2-mediated juxtacrine signaling in pericyte-endothelial cell interactions promotes angiogenesis and neural regeneration through an angiopoietin-1-Tie2 pathway, rescuing erectile function in diabetic mice. The dual angiogenic and neurotrophic effects of DKK2, especially as a therapeutic protein, will open new avenues to treating diabetic ED.</P>

Nerve injury-induced protein 1 (Ninjurin-1) is a novel therapeutic target for cavernous nerve injury-induced erectile dysfunction in mice.

Yin, Guo Nan,Kim, Woo Jean,Jin, Hai-Rong,Kwon, Mi-Hye,Song, Kang-Moon,Choi, Min Ji,Park, Jin-Mi,Das, Nando Dulal,Kwon, Ki-Dong,Batbold, Dulguun,Kim, Kyu-Won,Ryu, Ji-Kan,Suh, Jun-Kyu Blackwell Pub 2013 The journal of sexual medicine Vol.10 No.6

<P>Radical prostatectomy for prostate cancer can not only induce cavernous nerve injury (CNI) but also result in structural changes in the cavernous tissues. Nerve injury-induced protein 1, Ninjurin-1 (Ninj1), is known to be involved in neuroinflammatory processes and to be related to vascular regression during the embryonic period.</P>

Matrigel‐Based Sprouting Endothelial Cell Culture System from Mouse Corpus Cavernosum Is Potentially Useful for the Study of Endothelial and Erectile Dysfunction Related to High‐Glucose Exposure

Yin, Guo Nan,Ryu, Ji‐,Kan,Kwon, Mi‐,Hye,Shin, Sun Hwa,Jin, Hai‐,Rong,Song, Kang‐,Moon,Choi, Min Ji,Kang, Dong‐,Yeon,Kim, Woo Jean,Suh, Jun‐,Kyu John Wiley Sons Ltd 2012 JOURNAL OF SEXUAL MEDICINE Vol.9 No.7

Role of soluble CD14 in cerebrospinal fluid as a regulator of glial functions

Yin, Guo Nan,Jeon, Hyejin,Lee, Shinrye,Lee, Ho Won,Cho, Je-Yoel,Suk, Kyoungho Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of neuroscience research Vol.87 No.11

<P>Proteomic analysis of cerebrospinal fluid (CSF) samples derived from patients with Alzheimer's disease (AD) or Parkinson's disease (PD) was performed. On the basis of liquid chromatography–tandem mass spectrometry, two-dimensional gel electrophoresis analysis, and Western blot validation, it was found that the level of soluble form of monocyte differentiation antigen CD14 precursor was elevated in CSF from AD or PD patients compared with normal subjects. The soluble CD14 protein and mRNA expression was detected in microglia cells, indicating that microglia may be a cellular source of soluble CD14 in CSF. Next, the role of soluble CD14 in the regulation of glial functions was investigated. Soluble CD14 inhibited lipopolysaccharide (LPS)- or LPS/interferon-gamma-induced nitric oxide production and cell death of microglia and astrocytes. Soluble CD14 suppressed glial neurotoxicity in a coculture of glia/neuroblastoma. In addition, soluble CD14 moderately enhanced phagocytic activity of microglia. These results suggest that microglia-derived soluble CD14 is a candidate CSF biomarker for AD and PD, and the soluble CD14 may inhibit glial activation by interfering with LPS effects. © 2009 Wiley-Liss, Inc.</P>

Genomic and Transcriptomic Characterization Revealed the High Sensitivity of Targeted Therapy and Immunotherapy in a Subset of Endometrial Stromal Sarcoma

Nan Kang,Yinli Zhang,Shichao Guo,Ran Chen,Fangzhou Kong,Shuchun Wang,Mingming Yuan,Rongrong Chen,Danhua Shen,Jianliu Wang 대한암학회 2023 Cancer Research and Treatment Vol.55 No.3

Purpose The unique chromosomal rearrangements of endometrial stromal sarcoma (ESS) make it possible to distinguish high-grade ESS (HGESS) and low-grade ESS (LGESS) from the molecular perspective. Analysis of ESS at the genomic and transcriptomic levels can help us achieve accurate diagnosis of ESS and provide potential therapy options for ESS patients.Materials and Methods A total of 36 ESS patients who conducted DNA- and/or RNA-based next-generation sequencing were retrospectively enrolled in this study. The molecular characteristics of ESS at genomic and transcriptomic levels, including mutational spectrum, fusion profiles, gene expression and pathway enrichment analysis and features about immune microenvironment were comprehensively explored.Results <i>TP53</i> and <i>DNMT3A</i> mutations were the most frequent mutations. The classical fusions frequently found in <i>HGESS</i> (<i>ZC3H7B-BCOR</i> and <i>NUTM2B-YWHAE</i>) and LGESS (<i>JAZF1-SUZ12</i>) were detected in our cohort. <i>CCND1</i> was significantly up-regulated in HGESS, while the expression of <i>GPER1</i> and <i>PGR</i> encoding estrogen receptor (ER) and progesterone receptor (PR) did not differ significantly between HGESS and LGESS. Actionable mutations enriched in homologous recombination repair, cell cycle, and phosphoinositide 3-kinase/AKT/mammalian target of rapamycin pathways were detected in 60% of HGESS patients. Genes with up-regulated expression in HGESS were significantly enriched in five immune-related pathways. Most HGESS patients (85.7%) had positive predictors of immunotherapy efficacy. Moreover, immune microenvironment analysis showed that HGESS had relatively high immune infiltration. The degree of immune infiltration in HGESS patients with <i>ZC3H7B-BCOR</i> fusion was relatively higher than that of those with <i>NUTM2B-YWHAE</i> fusion.Conclusion This study investigated the molecular characteristics of ESS patients at the genomic and transcriptomic levels and revealed the potentially high sensitivity of targeted therapy and immunotherapy in a subset of HGESS with specific molecular features, providing a basis for guiding decision-making of treatment and the design of future clinical trials on precision therapy.

Differential Expression of Nerve Injury-Induced Protein 1 (Ninjurin 1) in In Vivo and In Vitro Models for Diabetic Erectile Dysfunction

김도경,Guo Nan Yin,류지간,서준규 대한비뇨의학회 2012 Investigative and Clinical Urology Vol.53 No.9

Purpose: Endothelial dysfunction and peripheral neuropathy are important mechanisms responsible for diabetes-induced erectile dysfunction (ED). Nerve injury-induced protein 1 (Ninjurin 1) is known to be related to neuroinflammatory processes and is also reported to induce vascular regression during the developmental period. In the present study, we determined the differential expression of Ninjurin 1 in penile tissue of streptozotocin (STZ)-induced diabetic mice with ED. Materials and Methods: Diabetes was induced in 8-week-old C57BL/6J mice by intraperitoneal injections of STZ (50 mg/kg for 5 days). Eight weeks later, erectile function was measured by electrical stimulation of the cavernous nerve (n=6 per group). The penis was then harvested for immunohistochemical analysis and Western blot analysis for Ninjurin 1 (n=4 per group). We also determined Ninjurin 1 expression in primary cultured mouse cavernous endothelial cells (MCECs) incubated under the following conditions: normal glucose condition (5 mM), high-glucose condition (30 mM), and high-glucose condition (30 mM)+insulin (1 nM). Results: The expression of Ninjurin 1 protein was significantly higher in both cavernous endothelial cells and the dorsal nerve bundle of diabetic mice than in those of controls. In the in vitro study in MCECs, Ninjurin 1 expression was also significantly increased by the high-glucose condition and was returned to baseline levels by treatment with insulin. Conclusions: Regarding the role of Ninjurin 1 in neuropathy and vascular regression, it would be interesting to examine the effects of inhibition of Ninjurin 1 on erectile function in animal models of ED with a vascular or neurogenic cause. Purpose: Endothelial dysfunction and peripheral neuropathy are important mechanisms responsible for diabetes-induced erectile dysfunction (ED). Nerve injury-induced protein 1 (Ninjurin 1) is known to be related to neuroinflammatory processes and is also reported to induce vascular regression during the developmental period. In the present study, we determined the differential expression of Ninjurin 1 in penile tissue of streptozotocin (STZ)-induced diabetic mice with ED. Materials and Methods: Diabetes was induced in 8-week-old C57BL/6J mice by intraperitoneal injections of STZ (50 mg/kg for 5 days). Eight weeks later, erectile function was measured by electrical stimulation of the cavernous nerve (n=6 per group). The penis was then harvested for immunohistochemical analysis and Western blot analysis for Ninjurin 1 (n=4 per group). We also determined Ninjurin 1 expression in primary cultured mouse cavernous endothelial cells (MCECs) incubated under the following conditions: normal glucose condition (5 mM), high-glucose condition (30 mM), and high-glucose condition (30 mM)+insulin (1 nM). Results: The expression of Ninjurin 1 protein was significantly higher in both cavernous endothelial cells and the dorsal nerve bundle of diabetic mice than in those of controls. In the in vitro study in MCECs, Ninjurin 1 expression was also significantly increased by the high-glucose condition and was returned to baseline levels by treatment with insulin. Conclusions: Regarding the role of Ninjurin 1 in neuropathy and vascular regression, it would be interesting to examine the effects of inhibition of Ninjurin 1 on erectile function in animal models of ED with a vascular or neurogenic cause.

Heat Shock Protein 70 in Penile Neurovascular Regeneration Requires Cystathionine Gamma-Lyase

Ghatak Kalyan,Yin Guo Nan,Hong Soon-Sun,Kang Ju-Hee,Suh Jun-Kyu,Ryu Ji-Kan 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.4

Purpose: Diabetes mellitus, one of the major causes of erectile dysfunction, leads to a poor response to phosphodiesterase-5 inhibitors. Heat shock protein 70 (Hsp70), a ubiquitous molecular chaperone, is known to play a role in cell survival and neuroprotection. Here, we aimed to assess whether and how Hsp70 improves erectile function in diabetic mice. Materials and Methods: Eight-week-old male C57BL/6 mice and Hsp70-Tg mice were used in this study. We injected Hsp70 protein into the penis of streptozotocin (STZ)-induced diabetic mice. Detailed mechanisms were evaluated in WT or Hsp70- Tg mice under normal and diabetic conditions. Primary MCECs, and MPG and DRG tissues were cultivated under normalglucose and high-glucose conditions. Results: Using Hsp70-Tg mice or Hsp70 protein administration, we demonstrate that elevated levels of Hsp70 restores erectile function in diabetic mice. We found that cystathionine gamma-lyase (Cse) is a novel target of Hsp70 in this process, showing that Hsp70-Cse acts through the SDF1/HO-1/PI3K/Akt/eNOS/NF-κB p65 pathway to exert its neurovascular regeneration- promoting effects. Coimmunoprecipitation and pull-down assays using mouse cavernous endothelial cells treated with Hsp70 demonstrated physical interactions between Hsp70 and Cse with a dissociation constant of 1.8 nmol/L. Conclusions: Our findings provide novel and solid evidence that Hsp70 acts through a Cse-dependent mechanism to mediate neurovascular regeneration and restoration of erectile function under diabetic conditions.

Crystal structure of LRG1 and the functional significance of LRG1 glycan for LPHN2 activation

Yang Jimin,Yin Guo Nan,Kim Do-Kyun,Han Ah-reum,Lee Dong Sun,Min Kwang Wook,Fu Yaoyao,Yun Jeongwon,Suh Jun-Kyu,Ryu Ji-Kan,Kim Ho Min 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

The serum glycoprotein leucine-rich ɑ-2-glycoprotein 1 (LRG1), primarily produced by hepatocytes and neutrophils, is a multifunctional protein that modulates various signaling cascades, mainly TGFβ signaling. Serum LRG1 and neutrophil-derived LRG1 have different molecular weights due to differences in glycosylation, but the impact of the differential glycan composition in LRG1 on its cellular function is largely unknown. We previously reported that LRG1 can promote both angiogenic and neurotrophic processes under hyperglycemic conditions by interacting with LPHN2. Here, we determined the crystal structure of LRG1, identifying the horseshoe-like solenoid structure of LRG1 and its four N-glycosylation sites. In addition, our biochemical and cell-biological analyses found that the deglycosylation of LRG1, particularly the removal of glycans on N325, is critical for the high-affinity binding of LRG1 to LPHN2 and thus promotes LRG1/LPHN2-mediated angiogenic and neurotrophic processes in mouse tissue explants, even under normal glucose conditions. Moreover, the intracavernous administration of deglycosylated LRG1 in a diabetic mouse model ameliorated vascular and neurological abnormalities and restored erectile function. Collectively, these data indicate a novel role of LRG1 glycans as molecular switches that can tune the range of LRG1’s cellular functions, particularly the LRG1/LPHN2 signaling axis.

Effects of preloads on joints on dynamic stiffness of a whole machine tool structure

Liang MI,Guo-fu YIN,Ming-nan SUN,Xiao-hu WANG 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.2

The machine tool joint is a very important factor in the overall machine tool dynamic analysis, and it has great effects on the machining performance of a machine tool. As a very important operation parameter, preload greatly influences the stiffness and the damping of a machine tool joint. This paper presents the effect of preload on the dynamic stiffness of the spindle nose of a horizontal machining center. By discussing types and distribution of machine tool joints, studies on the joints of ball screws, linear guides and bolts are carried out. The influence of preload on the axial stiffness of a ball screw is calculated based on Hertzian contact theory and the effect of pretightening moment on pressure of bolt joint is discussed, while the dynamic stiffness and the damping of a linear guide are identified by an optimum algorithm with the simulated and experimental results. A finite element model (FEM) of the whole machine tool structure considering the effects of different joints is created and verified against the test results, and then the influence of preloads on ball screws and linear guides is predicted. Results indicate that preloads on machine tool joints have significant effects on the dynamic stiffness of the spindle nose.