The optimal carfilzomib dosing is a matter of debate. We analyzed the inhibition profiles of proteolytic proteasome subunits β5, β2 and β1 after low-dose (20/27 mg/m2) versus high-dose (≥36 mg/m2)... Show moreThe optimal carfilzomib dosing is a matter of debate. We analyzed the inhibition profiles of proteolytic proteasome subunits β5, β2 and β1 after low-dose (20/27 mg/m2) versus high-dose (≥36 mg/m2) carfilzomib in 103 pairs of peripheral blood mononuclear cells from patients with relapsed/refractory (RR) multiple myeloma (MM). β5 activity was inhibited (median inhibition >50%) in vivo by 20 mg/m2, whereas β2 and β1 were co-inhibited only by 36 and 56 mg/m2, respectively. Co-inhibition of β2 (P=0.0001) and β1 activity (P=0.0005) differed significantly between high-dose and low-dose carfilzomib. Subsequently, high-dose carfilzomib showed significantly more effective proteasome inhibition than low-dose drug in vivo (P=0.0003). We investigated the clinical data of 114 patients treated with carfilzomib combinations. High-dose carfilzomib demonstrated a higher overall response rate (P=0.03) and longer progression-free survival (PFS) (P=0.007) than low-dose carfilzomib. Therefore, we escalated the carfilzomib dose to ≥ 36 mg/m2 in 16 patients who progressed during low-dose carfilzomib-containing therapies. High-dose carfilzomib recaptured response (≥ partial remission) in 9 (56%) patients with a median PFS of 4.4 months. Altogether, we provide the first in vivo evidence in RRMM patients that the molecular activity of high-dose carfilzomib differs from that of low-dose carfilzomib by co-inhibition of β2 and β1 proteasome subunits and, consequently, high-dose carfilzomib achieves a superior anti-MM effect than low-dose and recaptures response in RRMM being resistant to low-dose carfilzomib. The optimal carfilzomib dose should be ≥ 36 mg/m2 to reach a sufficient anti-tumor activity, while the balance between efficacy and tolerability should be considered in each patient. Show less
Electrochemical CO2 reduction (CO2R) is an attractive option for storing renewable electricity and for the sustainable production of valuable chemicals and fuels. In this roadmap, we review recent... Show moreElectrochemical CO2 reduction (CO2R) is an attractive option for storing renewable electricity and for the sustainable production of valuable chemicals and fuels. In this roadmap, we review recent progress in fundamental understanding, catalyst development, and in engineering and scale-up. We discuss the outstanding challenges towards commercialization of electrochemical CO2R technology: energy efficiencies, selectivities, low current densities, and stability. We highlight the opportunities in establishing rigorous standards for benchmarking performance, advances in in operando characterization, the discovery of new materials towards high value products, the investigation of phenomena across multiple-length scales and the application of data science towards doing so. We hope that this collective perspective sparks new research activities that ultimately bring us a step closer towards establishing a low- or zero-emission carbon cycle. Show less
Zhou, P.; Zhang, G.-Y.; Zhou, X.; Arias de Saaverda Benitez, M.; Koo, B.C.; Vink, J.; ... ; Lee, Y.H. 2022
Context: The X-linked immunoglobulin superfamily, member 1 (IGSF1), gene is highly expressed in the hypothalamus and in pituitary cells of the POU1F1 lineage. Human loss-of-function mutations in... Show moreContext: The X-linked immunoglobulin superfamily, member 1 (IGSF1), gene is highly expressed in the hypothalamus and in pituitary cells of the POU1F1 lineage. Human loss-of-function mutations in IGSF1 cause central hypothyroidism, hypoprolactinemia, and macroorchidism. Additionally, most affected adults exhibit higher than average IGF-1 levels and anecdotal reports describe acromegaloid features in older subjects. However, somatotrope function has not yet been formally evaluated in this condition.Objective: We aimed to evaluate the role of IGSF1 in human and murine somatotrope function.Patients, Design, and Setting: We evaluated 21 adult males harboring hemizygous IGSF1 loss-of-function mutations for features of GH excess, in an academic clinical setting.Main Outcome Measures: We compared biochemical and tissue markers of GH excess in patients and controls, including 24-hour GH profile studies in 7 patients. Parallel studies were undertaken in male Igsf1-deficient mice and wild-type littermates.Results: IGSF1-deficient adult male patients demonstrated acromegaloid facial features with increased head circumference as well as increased finger soft-tissue thickness. Median serum IGF-1 concentrations were elevated, and 24-hour GH profile studies confirmed 2- to 3-fold increased median basal, pulsatile, and total GH secretion. Male Igsf1-deficient mice also demonstrated features of GH excess with increased lean mass, organ size, and skeletal dimensions and elevated mean circulating IGF-1 and pituitary GH levels.Conclusions: We demonstrate somatotrope neurosecretory hyperfunction in IGSF1-deficient humans and mice. These observations define a hitherto uncharacterized role for IGSF1 in somatotropes and indicate that patients with IGSF1 mutations should be evaluated for long-term consequences of increased GH exposure. Show less
The progesterone receptor (PR, encoded by Pgr) plays essential roles in reproduction. Female mice lacking the PR are infertile, due to the loss of the protein's functions in the brain, ovary, and... Show moreThe progesterone receptor (PR, encoded by Pgr) plays essential roles in reproduction. Female mice lacking the PR are infertile, due to the loss of the protein's functions in the brain, ovary, and uterus. PR is also expressed in pituitary gonadotrope cells, but its specific role therein has not been assessed in vivo. We therefore generated gonadotrope-specific Pgr conditional knockout mice (cKO) using the Cre-LoxP system. Overall, both female and male cKO mice appeared phenotypically normal. cKO females displayed regular estrous cycles (vaginal cytology) and normal fertility (litter size and frequency). Reproductive organ weights were comparable between wild-type and cKO mice of both sexes, as were production and secretion of the gonadotropins, LH and FSH, with one exception. On the afternoon of proestrus, the amplitude of the LH surge was blunted in cKO females relative to controls. Contrary to predictions of earlier models, this did not appear to derive from impaired GnRH self-priming. Collectively, these data indicate that PR function in gonadotropes may be limited to regulation of LH surge amplitude in female mice via a currently unknown mechanism. Show less
Zhou, X.; Paushter, D.H.; Pagan, M.D.; Kim, D.; Nunez Santos, M.; Lieberman, R.L.; ... ; Hu, F. 2019
Mutation in the GRN gene, encoding the progranulin (PGRN) protein, shows a dose-dependent disease correlation, wherein haploinsufficiency results in frontotemporal lobar degeneration (FTLD) and... Show moreMutation in the GRN gene, encoding the progranulin (PGRN) protein, shows a dose-dependent disease correlation, wherein haploinsufficiency results in frontotemporal lobar degeneration (FTLD) and complete loss results in neuronal ceroid lipofuscinosis (NCL). Although the exact function of PGRN is unknown, it has been increasingly implicated in lysosomal physiology. Here we report that PGRN interacts with the lysosomal enzyme, glucocerebrosidase (GCase), and is essential for proper GCase activity. GCase activity is significantly reduced in tissue lysates from PGRN-deficient mice. This is further evidence that reduced lysosomal hydrolase activity may be a pathological mechanism in cases of GRN-related FTLD and NCL. Show less
In this study, Single walled carbon nanotube (SWNT)-streptavidin complexes were used to capture and purify biotinylated proteins, including bio-GFP and bio-DBS using a pull-down method. The... Show moreIn this study, Single walled carbon nanotube (SWNT)-streptavidin complexes were used to capture and purify biotinylated proteins, including bio-GFP and bio-DBS using a pull-down method. The purification conditions were systematically studied, including surface blocking of SWNT using chicken egg albumin (CEA), the ratio of SWNT-streptavidin complexes to the cell lysate, as well as the centrifugation speed. Optimization of the protein purification using SWNT-streptavidin complexes shows the possibility of carbon nanotubes as a promising candidate for protein purification applications. The SWNT-streptavidin could be used as a scaffold to analyze protein structure directly by cryo-transmission electron microscopy, which provides better understanding in protein-protein interactions and biological processes. Show less
Human and animal studies have converged to suggest that caffeine consumption prevents memory deficits in aging and Alzheimer’s disease through the antagonism of adenosine A2A receptors (A2ARs). To... Show moreHuman and animal studies have converged to suggest that caffeine consumption prevents memory deficits in aging and Alzheimer’s disease through the antagonism of adenosine A2A receptors (A2ARs). To test if A2AR activation in the hippocampus is actually sufficient to impair memory function and to begin elucidating the intracellular pathways operated by A2AR, we have developed a chimeric rhodopsin-A2AR protein (optoA2AR), which retains the extracellular and transmembrane domains of rhodopsin (conferring light responsiveness and eliminating adenosine-binding pockets) fused to the intracellular loop of A2AR to confer specific A2AR signaling. The specificity of the optoA2AR signaling was confirmed by light-induced selective enhancement of cAMP and phospho-mitogen-activated protein kinase (p-MAPK) (but not cGMP) levels in human embryonic kidney 293 (HEK293) cells, which was abolished by a point mutation at the C terminal of A2AR. Supporting its physiological relevance, optoA2AR activation and the A2AR agonist CGS21680 produced similar activation of cAMP and p-MAPK signaling in HEK293 cells, of p-MAPK in the nucleus accumbens and of c-Fos/phosphorylated-CREB (p-CREB) in the hippocampus, and similarly enhanced long-term potentiation in the hippocampus. Remarkably, optoA2AR activation triggered a preferential p-CREB signaling in the hippocampus and impaired spatial memory performance, while optoA2AR activation in the nucleus accumbens triggered MAPK signaling and modulated locomotor activity. This shows that the recruitment of intracellular A2AR signaling in the hippocampus is sufficient to trigger memory dysfunction. Furthermore, the demonstration that the biased A2AR signaling and functions depend on intracellular A2AR loops prompts the possibility of targeting the intracellular A2AR-interacting partners to selectively control different neuropsychiatric behaviors. Show less
