Niveles plasmáticos de midkina en pacientes con trastorno por uso de cocaína en abstinencia / Plasma midkine levels in patients with cocaine use disorder during abstinence

Diversos estudios preclínicos han sugerido que la midkina endógenapodría jugar un papel modulador clave sobre los efectos neurotóxicosy adictivos de distintas drogas, incluidos los psicoestimulantes. Estahipótesis no ha sido aún explorada en humanos. Como primer pasoen esta dirección, en el presente trabajo hemos medido los nivelesplasmáticos de midkina en 75 pacientes con trastorno por uso decocaína en abstinencia y 26 controles apareados con los anteriorespor sexo, edad e índice de masa corporal. Los pacientes fueronademás divididos en un grupo de abstinencia temprana (menos deun mes, n = 30) y otro de abstinencia tardía (más de un mes, n =45). Se cuantificaron los niveles plasmáticos de midkina de todoslos participantes mediante un ensayo por inmunoabsorción ligadoa enzimas. Los pacientes en abstinencia temprana mostraron unincremento del 60% en su concentración plasmática de midkina conrespecto a los controles que tendió a desaparecer en los pacientes conperiodos de abstinencia más prolongados. Los resultados demuestranque los niveles periféricos de midkina están estrechamenterelacionados con el uso de cocaína y apoyan la idea de que dichacitoquina podría jugar un papel protector limitando la actividadbiológica de los psicoestimulantes. (AU)

Preclinical evidence suggests that endogenous midkine couldplay a key modulatory role on the neurotoxic and addictive effectsof different kinds of drugs of abuse, including psychostimulants.However, this hypothesis has not yet been explored in humans. As afirst approach to progress in this knowledge, we have comparativelystudied plasma midkine levels in 75 patients with cocaine use disorderunder abstinence and 26 control subjects matched for sex, ageand body mass index. Patients were further segmented into earlyabstinent (up to one month of abstinence, n = 30) and late-abstinent(more than one month of abstinence, n = 45). Midkine levels werequantified in plasma samples of all the participants by enzyme-linkedimmunosorbent assays. Early-abstinent patients exhibited a 60%increase of midkine plasma concentration in comparison with thecontrols. This elevation tended to normalize upon the progressionof abstinence. The results obtained demonstrate that peripheralmidkine levels are closely related to cocaine use and are consistentwith the idea that this cytokine could play a protective role by limitingthe biological activity of psychostimulants. (AU)

Pharmacokinetics of midkine with different N-terminal structures in rats.

Midkine (MK) is a heparin-binding growth factor that functions in multiple physiological processes, making it a promising drug target for treating various diseases including osteoarthritis (OA). However, the lack of pharmacokinetic studies on MK limits further clinical research. As the N-domain of MK protein appears to be more important for its stability, this study aimed to investigate the pharmacokinetic profiles of recombinant human (rh)MK with different structures at the N-terminus via different administration routes in rats and guinea pigs. A single intramuscular (IM) injection of 1 mg/kg rhMK with or without extended sequences at the N-terminus expressed by E. coli or Pichia was administered to six male SD rats. rhMK concentrations in sequential tail blood samples were measured by ELISA. rhMK without extended N-terminal sequences expressed by Pichia had a greater area under the curve (AUC), slower clearance, and longer half-life in rats following a single IM injection than those of the other rhMK proteins. The AUC values for rhMK after IM and intra-articular (IA) administration were 1523.3 ± 35.2 h × ng/mL and 872.0 ± 36.1 h × ng/mL, whereas the apparent volumes of distribution (Vd/f) were 0.184 ± 0.067 L/kg and 11.6 ± 0.8 L/kg, respectively, suggesting that rhMK was distributed more locally after IA injection than after IM injection as Vd/f magnitude gives a general idea of extent distribution in the body and higher Vd/f represents more locally distribution. rhMK concentration in the articular cartilage was markedly higher than that in serum and reached the highest level at 3 days after a single IA injection in Hartley guinea pigs. As the dose increased from 10 to 50 mg/kg, the AUC increased in a greater-than-dose-proportional manner, suggesting that rhMK exhibits non-linear pharmacokinetics in rats after a single IM injection in this dose range. These results indicated that the N-terminal structure and administration route have substantial effects on the pharmacokinetics of rhMK in rats. Furthermore, rhMK was maintained in articular cartilage with minimal diffusion into the blood following IA injection in Hartley guinea pigs, providing a foundation for clinical research on the use of rhMK for OA treatment via IA delivery.

Toxicologic evaluation of repetitive 4-week intravenous injections of midkine antisense oligonucleotide nanoliposomes in rats.

Midkine antisense oligonucleotide (MK-ASODN) nanoliposomes have previously been shown to have inhibitory activity against hepatocellular carcinoma growth. Herein we report the 4-week sub-chronic toxicity of MK-ASODN nanoliposomes in SD rats. The adverse effects included loss of body weight gain and food consumption, peri-rhinal bleeding, piloerection, peri-anal filth, and kidney, liver, spleen, thymus, lung, and injection site lesions at high doses. Macroscopic changes were observed in the kidneys of the high-dose group, accompanied by a variation in urine protein and white blood cells, blood urea nitrogen, and serum creatinine. The increased spleen and liver coefficient, and the variation in circulating white blood cells, lymphocytes, and eosinophils in the high-dose group demonstrated that inflammation was caused by MK-ASODN nanoliposomes and was consistent with the macroscopic changes in the spleen and liver. The main necropsy findings of the animals that died were macroscopic changes in the lung. No severe toxic effects or mortalities occurred in the low- and medium-dose groups. However, a No Adverse Effect Level (NOAEL) was not identified since there were changes in organs deemed to be adverse at all dose levels. Thus, the maximum tolerated dose of MK-ASODN nanoliposomes for rats was considered to be 6 mg/kg/day.