Modulation of the Innate Immune Response by Targeting Toll-like Receptors: A Perspective on Their Agonists and Antagonists

Toll-like receptors (TLRs) are a class of proteins that recognize pathogen-associated molecular patterns (PAMPs) and damaged-associated molecular patterns (DAMPs), and they are involved in the regulation of innate immune system. These transmembrane receptors, localized at the cellular or endosomal membrane, trigger inflammatory processes through either myeloid differentiation primary response 88 (MyD88) or TIR-domain-containing adapter-inducing interferon-β (TRIF) signaling pathways. In the last decades, extensive research has been performed on TLR modulators and their therapeutic implication under several pathological conditions, spanning from infections to cancer, from metabolic disorders to neurodegeneration and autoimmune diseases. This Perspective will highlight the recent discoveries in this field, emphasizing the role of TLRs in different diseases and the therapeutic effect of their natural and synthetic modulators, and it will discuss insights for the future exploitation of TLR modulators in human health.

Central Neuropathic Pain and Profiles of Quantitative Electroencephalography in Multiple Sclerosis Patients

Pain has a significant impact on the quality of life of patients with multiple sclerosis (MS). However, the neurophysiological mechanisms of central neuropathic pain in a MS course are not known. We hypothesized that changes in power spectral density (PSD) that take place in the electroencephalography (EEG) of MS patients with and without the central neuropathic pain (CNP) would differ. The study aimed to assess the features of quantitative EEG using the PSD indicator along with peak frequencies in the standard frequency bands in MS patients with and without CNP. We have analyzed the quantitative spectral content of the EEG at a resting state in 12 MS patients with CNP, 12 MS patients without CNP, and 12 gender- and age-matched healthy controls using fast Fourier transformation. Based on the ANOVA, at the group level, the theta band absolute and relative PSD showed an increase, whereas alpha band relative PSD showed a decrease in MS patients both with and without CNP. However, only in MS with CNP group, the absolute and relative PSD in the beta1 and beta2 bands increased and exceeded that in patients without pain. Only MS patients with CNP demonstrated the significantly increased absolute PSD for the theta, beta1, and beta2 frequency bands in most regions of interest. In the theta band, MS patients with CNP displayed the increase in absolute spectral power for the mid-temporal derivation of the right hemisphere and the increase in relative spectral power for the prefrontal derivation of this hemisphere. In the beta1 band, the increase in absolute spectral power was observed for the three temporal derivations of the right hemisphere, whereas in the beta2 band, for the occipital, parietal, and temporal lobes of both hemispheres. In the alpha band, only a relative spectral power decrease was revealed for the occipital lobes of both hemispheres and parietal lobe of the right hemisphere. In MS patients with CNP, the frequencies of the dominant spectral power (peak frequencies) in the high-frequency beta band were higher than in the healthy control in posterior areas of the left hemisphere. Data could represent central nervous system alterations related to central neuropathic pain in MS patients that lead to the disturbances in cortical communication.

How do Australians living with MS experience oral health and accessing dental care? A focus group study

OBJECTIVES

The symptoms of multiple sclerosis (MS) can affect oral care and access to dental services, but there is limited literature describing the oral health and perceived oral healthcare needs of people with MS. This study aimed to explore the oral health experiences, oral health behaviours and barriers to accessing dental care perceived by people living with MS in Australia.

METHODS

Six focus groups were held across two metropolitan areas (Brisbane, Queensland and Melbourne, Victoria) and one regional area (Toowoomba, Queensland). Focus group data were analysed using thematic analysis.

RESULTS

Living with MS was a highly individual experience due to the range of symptoms that may be experienced. In addition to having different symptom experiences to others with MS, individual symptoms also differed on a daily basis as the disease relapsed and remitted. The physical expressions of MS directly and indirectly affected the oral health of participants. Additionally, oral health was affected by the side effects of medications and orofacial pain symptoms. Depending on the symptoms experienced by the individual, personal oral hygiene was affected and professional dental appointments were difficult. Participants also experienced structural barriers to accessing professional dental care including difficulty accessing transport to-and-from dental appointments, space limitations in the dental surgery and financial barriers to care.

DISCUSSION

Dental care was perceived to be inflexible and was not tailored to individual experiences of MS, which contributed to perceptions of poor quality and appropriateness of care. It is important for dental professionals to offer tailored and individualized dental care when treating people with MS. Our findings suggest that there needs to be greater interprofessional communication and referral to manage atypical dental pain symptoms. Oral health education for people with MS should include altered strategies to performing daily oral hygiene, the management of xerostomia and advice regarding low cariogenic diets suitable for dysphagia. Additionally, policy and strategies to improve the oral health of people with MS should focus on enhancing access through transport, reducing the cost of dental services to the individual and providing domiciliary oral health care.