Charge density waves (CDWs) involved with electronic and phononic subsystems simultaneously are a common quantum state in solid-state physics, especially in low-dimensional materials. However, CDW phase dynamics in various dimensions are yet to be studied, and their phase transition mechanism is currently moot. Here we show that using the distinct temperature evolution of orientation-dependent ultrafast electron and phonon dynamics, different dimensional CDW phases are verified in CuTe.
View Article and Find Full Text PDFBiochim Biophys Acta Gen Subj
December 2021
The discovery of mitochondrial derive peptides (MDPs) has spotlighted mitochondria as central hubs in control and regulation of cell viability and metabolism in the testis in response to intracellular and extracellular stresses. MDPs (Humanin, MOTS-c and SHLP-2) are present in testes. Humanin, the first MDP, is predominantly expressed in Leydig cells, and moderately in germ cells and seminal plasma.
View Article and Find Full Text PDFHumanin (HN) is a mitochondrial-derived peptide that protects many cells/tissues from damage. We previously demonstrated that HN reduces stress-induced male germ cell apoptosis in rodents. HN action in neuronal cells is mediated through its binding to a trimeric cell membrane receptor composed of glycoprotein 130 (gp130), IL-27 receptor subunit (IL-27R, also known as WSX-1/TCCR), and ciliary neurotrophic factor receptor subunit (CNTFR).
View Article and Find Full Text PDFSubfertility is a major concern of long-term cancer survivors at the reproductive age. We have previously demonstrated that a potent humanin analogue, HNG, protected chemotherapy-induced apoptosis in germ cells but not cancer cells in a metastatic melanoma allograft model. In this study, we utilized severe combined immuno-deficiency (SCID) mice bearing human medulloblastoma to study the effect of HNG in Temozolomide (TMZ) induced male germ cell apoptosis and white blood cell (WBC) suppression.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
September 2018
The chemotherapeutic effect of doxorubicin (Dox) is limited by cumulative dose-dependent cardiotoxicity in cancer survivors. Dexrazoxane (DRZ) is approved to prevent Dox-induced cardiotoxicity. Humanin and its synthetic analog HNG have a cytoprotective effect on the heart.
View Article and Find Full Text PDFWe previously showed that testosterone (T) deficiency enhanced high-fat/low-carbohydrate diet (HFD)-induced hepatic steatosis in rats independent of insulin resistance and that T replacement reduced hepatic macrovesicular fat accumulation and inflammation. The present report explores the mechanism of T's protective effects on HFD-induced steatohepatitis. Adult male rats were randomized into four treatment groups for 15 wk: intact rats on regular chow diet or HFD, and castrated rats on HFD with or without T replacement.
View Article and Find Full Text PDFBackground: The kidney is a specialized low-regenerative organ with several different types of cellular lineages. The BrdU label-retaining cell (LRCs) approach has been used as part of a strategy to identify tissue-specific stem cells in the kidney; however, because the complementary base pairing in double-stranded DNA blocks the access of the anti-BrdU antibody to BrdU subunits, the stem cell marker expression in BrdU-labeled cells are often difficult to detect. In this study, we introduced a new cell labeling and detection method in which BrdU was replaced with 5-ethynyl-2-deoxyuridine (EdU) and examined the time-dependent dynamic changes of EdU-labeled cells and potential stem/progenitor markers in the development of kidney.
View Article and Find Full Text PDFHumanin is a peptide that is cytoprotective against stresses in many cell types. We investigated whether a potent humanin analogue S14G-humanin (HNG) would protect against chemotherapy-induced damage to normal cells without interfering with the chemotherapy-induced suppression of cancer cells. Young adult male mice were inoculated iv with murine melanoma cells.
View Article and Find Full Text PDFHumanin (HN) has cytoprotective action on male germ cells after testicular stress induced by heat and hormonal deprivation. To examine whether HN has protective effects on chemotherapy-induced male germ cell apoptosis, we treated four groups of adult rats with (i) vehicle (control), (ii) HN, (iii) cyclophosphamide (CP); or (iv) HN+CP. To investigate whether the protective effects of HN on germ cells require the presence of Leydig cells, another four groups of rats were pre-treated with ethane dimethanesulfonate (EDS), a Leydig cell toxicant, to eliminate Leydig cells.
View Article and Find Full Text PDFHuman (HN) prevents stress-induced apoptosis in many cells/tissues. In this study we showed that HN ameliorated chemotherapy [cyclophosphamide (CP) and Doxorubicin (DOX)]-induced male germ cell apoptosis both ex vivo in seminiferous tubule cultures and in vivo in the testis. HN acts by several putative mechanisms via binding to: an IL-12 like trimeric membrane receptor; BAX; or insulin-like growth factor binding protein-3 (IGFBP-3, a proapoptotic factor).
View Article and Find Full Text PDFNonalcoholic fatty liver disease is common in developed countries and is associated with obesity, metabolic syndrome, and type 2 diabetes. T deficiency is a risk factor for developing these metabolic deficiencies, but its role in hepatic steatosis has not been well studied. We investigated the effects of T on the pathogenesis of hepatic steatosis in rats fed a high-fat diet (HFD).
View Article and Find Full Text PDFHumanin (HN) is a novel 24-amino acid mitochondrial-derived peptide that has demonstrated diverse cytoprotective effects, including an emerging role in diabetes. The purpose of this study was to examine the pharmacokinetics of humanin analogues, which show great potential as therapeutic agents (HNG and the non-IGFBP-3 binding, HNGF6A). 11-week-old male IGFBP-3(-/-) and wild type (WT) mice were divided into 3 groups: WT mice treated with HNG, WT mice treated with HNGF6A, and IGFBP-3(-/-) mice treated with HNG.
View Article and Find Full Text PDFWe have previously demonstrated that the mitochondria-derived cytoprotective peptide humanin (HN), when administered intratesticularly to rats, rescues germ cells from apoptosis secondary to testicular stress of hormonal deprivation induced by gonadotropin-releasing hormone antagonist (GnRH-A). To decipher the cellular mechanisms of HN action in the amelioration of GnRH-A-induced germ cell apoptosis, adult male rats received the following treatments for 5 days: (i) daily intratesticular (IT) injections with saline (control); (ii) a single subcutaneous injection of GnRH-A on Day 1 and daily IT injection of saline; (iii) daily IT injection of synthetic HN; and (iv) GnRH-A injection on Day 1 and daily IT injection of HN (GnRH-A+HN). HN alone had no effect on germ cell apoptosis.
View Article and Find Full Text PDFStudy Question: Do exogenous male hormonal contraceptives that suppress intratesticular testosterone and spermatogenesis interfere with the blood-testis barrier integrity in men?
Summary Answer: When spermatogenesis was suppressed by testosterone alone or combined with levonorgestrel (LNG) treatment in men, the structural appearance of Sertoli cell tight junctions remained intact in the human testis.
What Is Already Known: Testosterone promotes the integrity of the blood-testis barrier. Intratesticular androgen deprivation induced by exogenous testosterone plus a progestin to suppress spermatogenesis in a contraceptive regimen may disturb the structural and functional integrity of the blood-testis barrier.
Mild testicular heating safely and reversibly suppresses spermatogenesis. In this study, we attempted to clarify the underlying molecular mechanism(s) involved in heat-induced spermatogenesis suppression in human testis. We conducted global proteomic analyses of human testicular biopsies before, and at 2 and 9 wk after heat treatment.
View Article and Find Full Text PDFKlinefelter syndrome is the most common chromosomal aneuploidy in men (XXY karyotype, 1 in 600 live births) and results in testicular (infertility and androgen deficiency) and nontesticular (cognitive impairment and osteoporosis) deficits. The extent to which skeletal changes are due to testosterone deficiency or arise directly from gene overdosage cannot be determined easily in humans. To answer this, we generated XXY mice through a four-generation breeding scheme.
View Article and Find Full Text PDFModulating germ cell death and survival have significant therapeutic potential for male infertility and contraception. We have shown previously that IGF binding protein 3 (IGFBP3) gene expression is up-regulated in human testis when germ cell apoptosis is induced by intratesticular hormonal deprivation created by testosterone administration. Humanin (HN) is a binding partner of IGFBP3, and both are expressed in rat testes.
View Article and Find Full Text PDFGerm cell apoptosis is crucial for spermatogenesis and can be triggered by various stimuli, including intratesticular hormone deprivation. This study proposes a role for insulin-like growth factor binding protein-3 (IGFBP-3) in male germ cell apoptosis. Groups of adult Sprague-Dawley male rats received one of the following treatments for 5 days: (i) daily intratesticular (IT) injections with saline (control); (ii) a single subcutaneous injection of the gonadotropin-releasing hormone antagonist (GnRH-A), acyline, on day 1 and a daily IT injection of saline; (iii) daily IT injection of IGFBP-3; and (iv) a GnRH-A injection on day 1 and a daily IT injection of IGFBP-3.
View Article and Find Full Text PDFProgrammed germ cell death is critical for functional spermatogenesis. Increased germ cell apoptosis can be triggered by various regulatory stimuli, including testicular hyperthermia or deprivation of gonadotropins and intratesticular testosterone. We have previously shown the involvement of the mitogen-activated protein kinase (MAPK) 14 in apoptotic signaling of male germ cells across species after hormone deprivation.
View Article and Find Full Text PDFThis study investigates the possible involvement of nitric oxide synthase (NOS) in activating germ cell death in monkeys after mild testicular hyperthermia and/or hormonal deprivation. Groups of 8 adult male monkeys received 1 of the following treatments for 12 weeks: 1) 2 empty Silastic implants, 2) 2 testosterone (T) implants, 3) daily exposure of testes to heat (43 degrees C for 30 minutes) for 2 consecutive days, or 4) 2 T implants plus testicular heat exposure. Testicular biopsies were performed before and on days 3, 8, 28, and 84 of the treatment.
View Article and Find Full Text PDFTreatment with injectable testosterone undecanoate (TU) alone or in combination with oral levonorgestrel (LNG) resulted in marked decreases in sperm concentrations. In this study, we used proteomic analyses to examine the cellular/molecular events occurring in the human testis after TU or TU + LNG treatment. We conducted a global proteomic analysis of the human testicular biopsies before and at 2 weeks after TU alone or TU + LNG treatment.
View Article and Find Full Text PDFThis study investigates the role of caspase 2 in apoptotic signaling of nonhuman primate male germ cells triggered by mild testicular hyperthermia, testosterone (T(e)) implants, or by combined interventions. Mean incidence of germ cell apoptosis increased significantly by Day 3 in the heat (H(e)) alone group and by Day 8 in the Te alone group but peaked at Day 3 in H(e) + T(e) group. We found activation of caspase 2 in both germ cells and Sertoli cells after induction of apoptosis.
View Article and Find Full Text PDFContext: In rodents and monkeys, a combination of hormonal and physical agents accelerates germ cell death.
Objective: A "proof of concept" study was performed to investigate whether addition of heat exposure or a progestin to an androgen induces germ cell death and more complete and rapid spermatogenesis suppression.
Design And Settings: A randomized clinical trial was performed at academic medical centers.
Male contraception has focused, to a great extent, on approaches that induce azoospermia or severe oligospermia through accelerated germ cell apoptosis. Understanding the specific steps in the germ cell apoptotic pathways that are affected by male contraceptives will allow more specific targeting in future contraceptive development. In this study, we have used a nonhuman primate model to characterize the key apoptotic pathway(s) in germ cell death after mild testicular hyperthermia, hormonal deprivation, or combined interventions.
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