Table 3.
Selected peptidomic studies in whole hypothalamus and by hypothalamic sub-region*
| Study | Animal | Extraction | Target(s) a priori? | Screen [S],Validation [V] | Map or Schematic | Major findings |
|---|---|---|---|---|---|---|
| Whole hypothalamus | ||||||
| Bures et al. 2001 | Ms | dissection | N | LC-MS [S]; LC-MS/MS [S] | N | Identified 27 peptides derived from known neuropeptides as well as 25 additional peptides not known to be in the neuropeptide processing pathway; all up-regulated in carboxypeptidase E mutant mice |
| Svensson et al. 2003 | Rt, Ms | dissection | N | nanoLC-ESI-Q-TOF-MS | N | Detected 550 endogenous peptides |
| Che et al. 2005 | Ms | dissection | N | LC-MS/MS | N | Knockdown of carboxypeptidase E activity in two paradigms for decreasing body mass show different peptide profiles |
| Décaillot et al. 2006 | Ms | dissection | N | Isotopic labeling & Nano-LC MS/MS | N | Detection 27 distinct peptides from hypothalamus and striatum in Cpefat/fat mice, with some showing changes in levels in mice chronically treated with morphine |
| Pan et al. 2006 | Ms | dissection | N | Isotopic labeling & LC-ESI-MS | N | Approx. one-third of the peptides found in wild-type mice were not found in prohormone convertase KO mice |
| Che et al. 2007 | Ms | dissection | N | Nano-LC MS/MS | N | Identified 95 peptides from samples, 64 of which were neuropeptides or other peptides derived from proteins in the secretory pathway; found OT to be preferentially abundant in hot-acid extracts over hot-water extracts |
| Sköld et al. 2007 | Ms | dissection | N | Nano-LC MS [S]; Q-TOF LTQ MS/MS [V] | N | Identified 23 neuropeptides, hormones and potentially biologically active peptides; all were primarily up-regulated in control mouse brain relative to brains processed with longer post mortem times |
| Mihailova et al. 2008 | Rt | dissection | N | Capillary 2-D LC/MS | N | Identified 107 peptides, 26 of which displayed differences in concentration under hypoxic stress conditions |
| Cai et al. 2011 | Pg | dissection | N | MSPD & Nano-LC MS/MS | N | 14 potential endogenous peptides were identified using MSPD extracts versus to peptides using acid extracts |
| Colgrave et al. 2011 | Cw | dissection | N | LC-MS/MS | N | Used thermal stabilization methods to refine the yield of neuropeptides isolated from hypothalamus |
| Nilsson et al. 2012 | Ms | dissection | N | nano-LC-ESI-LTQ MS/MS or nano-LC-ESI-LTQ-FTICR-MS/MS | N | 14 peptides were significantly regulated by imipramine treatment |
| X. Zhang et al. 2012 | Ms | dissection | N | LC-FT-MS/MS | N | Identified 367 peptides from neuropeptide precursors from hypothalamic samples. |
| Fouillen et al. 2013 | Sw | dissection | N | LC-FT-MS/MS, SIEVE™ software-based analysis, | N | 12 hypothalamic peptides were up-regulated following prolonged general anesthesia |
| Frese et al. 2013 | Rt | dissection | N | HCD and ETD-based MS/MS [S]; LC-MS [V] | N | Identified 1,292 unique peptides from hypothalamus in rats fed on a regular diet, HFHS diet, restricted chow diet, or chocolate diet. HFHS diet produced the greatest increases in peptides as determined by label-free quantification. |
| Y. Gao et al. 2013 | Rt | dissection | N | 2D-GE, MALDI-TOF MS [S]; qRT-PCR, WB [V] | N | Identified 17 hypothalamic proteins with twofold or greater expression after electroacupuncture intervention of sciatic pain |
| Nakazawa et al. 2013 | Rt | dissection | N | RP HPLC; Nano-LC-MS/MS [S]; WB [V] | N | Found hundreds of peptides in relaxin- and saline-treated rats; two of which exhibited signatures both in microarray experiments and peptidomic experiments: OT and CART; with OT markedly up-regulated after relaxin exposure |
| Schmidlin et al. 2015 | Rt | dissection | N | LC-MS/MS [S]; SRM/Triple-Quad MS [V] | N | Demonstrated the feasibility of using SRM to evaluate a priori selected transitions of key neuropeptide fragments from the hypothalamus |
| Secher et al. 2016 | Rt | dissection | N | LC-MS/MS [S] | N | Identified 14,416 peptides in 786 protein families; sorted these by LPVs to isolate 2,835 peptides derived from 356 prohormone precursors; of these, 105 LPVs were not previously described |
| Yang et al. 2017 | Rt | dissection | N | nanoESI; nanoLC-MS/MS; MRM | N | Evaluated the efficacy of a rapid conductive sample heating system in stabilizing proteins from whole hypothalamic extracts |
| DeAtley et al. 2018 | Cw | dissection | N | LC-MS/MS; MRM | N | Observed 143 peptides in hypothalamus of pre- and post-pubertal heifers that were assigned neuropeptide status; three of which differed between the conditions |
| SCH: Suprachiasmatic hypothalamic nucleus | ||||||
| Hatcher et al. 2008 | Rt | acute tissue slice prep; μ-punch | N | HPLC, LC, SPE beads [S]; MALDI-TOF MS/MS ; LTQ FTMS [V] | N | Identified peptides released from acute slice preparations containing SCH, including after electrical stimulation of the retinohypothalamic input to the SCH; found peptide content in releasates to be stimulation-specific |
| J. H. Lee et al. 2010 | Rt | μ-punch | N | LC-FTMS/MS | N | list of 102 endogenous peptides, including 33 that were previously unidentified; also identified novel post-translational modifications |
| J. E. Lee et al. 2013 | Rt | μ-punch | N | LC-FTMS/MS, SIEVE™ software-based analysis | N | list of 190 endogenous peptides from 310 identified |
| Chiang et al. 2014 | Ms | dissection | N | fractionation, LC MS/MS [S]; RT-PCR, WB, IHC [V] | N | quantified 2,112 proteins, 20% of which exhibited a time-of-day-dependent profile; found 48 proteins exhibiting circadian rhythms of expression from this time-of-day proteome |
| Southey et al. 2014 | Rt | μ-punch | N | Spectral count, spectra index, SIEVE™ software-based analysis | N | differential peptide abundances between day and night conditions |
| Yang et al. 2017 | Rt | dissection | N | nanoESI; nanoLC-MS/MS; MRM | N | Evaluated the efficacy of a rapid conductive sample heating system in stabilizing proteins from SCH extracts |
| SO: Supraoptic hypothalamic nucleus | ||||||
|
Bora et al. 2008 [also see: Perkel 2008] |
Rt | μ-punch | Y | LC/MS & tandem mass spectrometry | N | 20 unique peptides identified |
*
Abbreviations: 2D-GE, two-dimensional gel electrophoresis; μ-punch, micropunch; CART, cocaine- and amphetamine-related transcript; Cw, cow; ESI, Electrospray Ionization; Fs, fish; FT, Fourier transformation; FTICR, Fourier-transform Ion Cyclotron Resonance; HCD and ETD-based MS/MS, High-energy Collisional Dissociation and Electron-transfer Dissociation-based tandem mass spectrometry; HFHS, high fat and high sucrose; Hu, human; KO, knockout; LC, liquid chromatography; LPVs, longest peptide variants; LTQ, Linear Trap Quadrupole; MALDI-TOF, Matrix-Assisted Laser Desorption/Ionization-Time of Flight; MRM, multiple reaction monitoring; Ms, mouse; MS/MS, tandem mass spectrometry; MSPD, Matrix Solid-Phase Dispersion; nanoESI, nanoscale electrospray ionization; nanoLC-MS/MS, nanoscale liquid chromatography coupled to tandem mass spectrometry; OT, oxytocin; Pg, pig; qRT-PCR, quantitative real-time polymerase chain reaction; Q-TOF, quadrupole time of flight; SRM, Selected Reaction Monitoring; Triple Quad MS, triple quadrupole mass spectrometry; Rt, rat; SPE, solid-phase extraction; Sw, shrew