Human umbilical cord mesenchymal stromal cells as an adjunct therapy with therapeutic hypothermia in a piglet model of perinatal asphyxia

Abstract

Background: With therapeutic hypothermia (HT) for neonatal encephalopathy, disability rates are reduced, but not all babies benefit. Pre-clinical rodent studies suggest mesenchymal stromal cells (MSCs) augment HT protection. Aims: The authors studied the efficacy of intravenous (IV) or intranasal (IN) human umbilical cordderived MSCs (huMSCs) as adjunct therapy to HT in a piglet model. Methods: A total of 17 newborn piglets underwent transient cerebral hypoxia-ischemia (HI) and were then randomized to (i) HT at 33.5°C 1À13 h after HI (n = 7), (ii) HT+IV huMSCs (30 £ 10 6 cells) at 24 h and 48 h after HI (n = 5) or (iii) HT+IN huMSCs (30 £ 10 6 cells) at 24 h and 48 h after HI (n = 5). Phosphorus-31 and hydrogen-1 magnetic resonance spectroscopy (MRS) was performed at 30 h and 72 h and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)positive cells and oligodendrocytes quantified. In two further piglets, 30 £ 10 6 IN PKH-labeled huMSCs were administered. Results: HI severity was similar between groups. Amplitude-integrated electroencephalogram (aEEG) recovery was more rapid for HT+IN huMSCs compared with HT from 25 h to 42 h and 49 h to 54 h (P 0.05). MRS phosphocreatine/inorganic phosphate was higher on day 2 in HT+IN huMSCs than HT (P = 0.035). Comparing HT+IN huMSCs with HT and HT+IV huMSCs, there were increased OLIG2 counts in hippocampus (P = 0.011 and 0.018, respectively), internal capsule (P = 0.013 and 0.037, respectively) and periventricular white matter (P = 0.15 for IN versus IV huMSCs). Reduced TUNEL-positive cells were seen in internal capsule with HT+IN huMSCs versus HT (P = 0.05). PKH-labeled huMSCs were detected in the brain 12 h after IN administration. Conclusions: After global HI, compared with HT alone, the authors saw beneficial effects of HT+IN huMSCs administered at 24 h and 48 h (30 £ 10 6 cells/kg total dose) based on more rapid aEEG recovery, improved 31 P MRS brain energy metabolism and increased oligodendrocyte survival at 72 h.

Melatonin for Neonatal Encephalopathy: From Bench to Bedside

“…Only partial protection was observed with the higher dose of 15 mg/kg; localised reduction in TUNEL positive cells in the sensorimotor cortex was reported but HT + melatonin did not confer improvement in aEEG background activity or cerebral energy metabolism compared to HT alone. Whilst the absence of ethanol, shown to be partially protective in Robertson et al (2020) [100], may have contributed to the lack of treatment benefit observed. Importantly, achievement of the Cmax (16.8 mg/L) was delayed until~8 h after HI (Figure 3).…”

“…The safety profile of melatonin doses of up to 30 mg/kg in ethanol [ 98 , 115 ] and ethanol-free formulations [ 99 , 101 ] (Chiesi Int. pat.…”

“…Given the narrow therapeutic window of melatonin, the intravenous route is the preferred route, as it provides the most predictable levels required for neuroprotection, bypassing the gastro-intestinal effects post HI and first passes metabolism in the liver. Neuroprotective agents given via the intranasal route has also received some interest [ 115 ] as it provides a more direct and rapid pathway to the brain, via the olfactory nerve and cribriform plate. Whilst this may reduce the melatonin dosing requirements and, therefore, exposure to the neurotoxic excipients, Van den Berg and colleagues [ 163 ] showed melatonin uptake in the CSF were similar between the intranasal and intravenous route.…”

Enhancement strategies for mesenchymal stem cells and related therapies

“…In essence, there are several different receptors and transporters expressed by MSCs which could be examined for drug loading and delivery strategies. Naïve MSCs as an adjunct therapy is an exciting avenue of research that is ongoing in several research areas [31][32][33] with the potential for drug loaded MSCs to further the prospects of the development of a highly effective therapy.…”

Optimizing neonatal outcomes with melatonin - Huge promise but slow progress

“…Whilst there is compelling pre-clinical data of melatonin's neuroprotective efficacy, clinical studies significantly lag behind. Other promising neuroprotective therapies for NE, such as erythropoietin (4) and mesenchymal stem cells (5) are moving along the translational pipeline; new concepts which may optimise protection include staggering therapy according to phase of injury and pre-treatment with melatonin (6) . Researchers, pharmaceutical companies, funding bodies, and clinicians need to combine efforts so that high risk babies can benefit from melatonin's healing powers.…”