Multitarget ligands that comprise opioid/nonopioid pharmacophores for pain management: Current state of the science.

Chronic pain, which affects more than one-third of the world's population, represents one of the greatest medical challenges of the 21st century, yet its effective management remains sub-optimal. The 'gold standard' for the treatment of moderate to severe pain consists of opioid ligands, such as morphine and fentanyl, that target the µ-opioid receptor (MOP). Paradoxically, these opioids also cause serious side effects, including constipation, respiratory depression, tolerance, and addiction.

Plasma endocannabinoids are independently associated with the metabolic function of white adipose tissue.

Context: Little is known about the link between the endocannabinoid system and the in vivo metabolic function of white adipose tissue (WAT).

Objective: We aimed to evaluate whether endocannabinoids (EC) are linked to postprandial fatty acid metabolism and WAT metabolic function.

Design: Men and women, with (IGT, n=20) or without impaired glucose tolerance (NGT, n=20) underwent meal testing with oral and intravenous stable isotope palmitate tracers and positron emission tomography with intravenous [11C]-palmitate and oral [18F]-fluoro-thia-heptadecanoic acid to determine systemic and organ-specific dietary fatty acid (DFA) and non-esterified fatty acid (NEFA) metabolism and partitioning.

Design, Synthesis, and Characterization of Proteolytically-Stable Opioid-Neurotensin Hybrid Peptidomimetics.

Linking an opioid to a nonopioid pharmacophore represents a promising approach for reducing opioid-induced side effects during pain management. Herein, we describe the optimization of the previously reported opioid-neurotensin hybrids (OPNT-hybrids), & , containing the μ-/δ-opioid agonist H-Dmt-d-Arg-Aba-β-Ala-NH and NT(8-13) analogs optimized for NTS2 affinity. In the present work, the constrained dipeptide Aba-β-Ala was modified to investigate the optimal linker length between the two pharmacophores, as well as the effect of expanding the aromatic moiety within constrained dipeptide analogs, via the inclusion of a naphthyl moiety.

Development of Macrocyclic Neurotensin Receptor Type 2 (NTS2) Opioid-Free Analgesics.

The opioid crisis has highlighted the urgent need to develop non-opioid alternatives for managing pain, with an effective, safe, and non-addictive pharmacotherapeutic profile. Using an extensive structure-activity relationship approach, here we have identified a new series of highly selective neurotensin receptor type 2 (NTS2) macrocyclic compounds that exert potent, opioid-independent analgesia in various experimental pain models. To our knowledge, the constrained macrocycle in which the Ile residue of NT(7-12) was substituted by cyclopentylalanine, Pro and Pro were replaced by allyl-glycine followed by side-chain to side-chain cyclization is the most selective analog targeting NTS2 identified to date (K 2.

Rational Design of Selective TMPRSS6 Peptidomimetic Inhibitors via Exploitation of the S2 Subpocket.

TMPRSS6 is a potential therapeutic target for the treatment of iron overload due to its role in regulating levels of hepcidin. Although potent TMPRSS6 inhibitors have been previously developed, their lack of specificity requires optimization to avoid potential side effects before pursuing preclinical development with models. Here, using computer-aided drug design based on a TMPRSS6 homology model, we reveal that the S2 position of TMPRSS6 offers a potential avenue to achieve selectivity against other members of the TTSP family.